05 December 2008

Drink enough water, but don't overdo it or you could die

You gotta have water, but don't drink so much so quickly and be sure you're getting enough electrolytes.

Proper hydration and intake of electrolytes are necessary for maintenance of homeostasis. And severe water and electrolyte loss can occur due to excessive sweating, vomiting or diarrhea. If water is replaced by plain water without electrolytes, then body fluids can become even more dilute. For this reason, oral rehydration therapy solutions include a small amount of table salt to avoid body fluid dilution.

Water intoxication occurs when a person consumes water steadily and faster than the kidneys can excrete the water or when renal function is poor. The water accumulates in the body, the excess causes cells to swell, which may produce convulsions, coma and death.

No scientific consensus has been reached on how much water should be consumed daily. The safest recommendation is half your body weight in ounces (e.g. 100 lbs = 50 oz). Drink a little more if you're losing more water daily due to exercise or if it's bloody hot, like in Arizona.

Reference

Tortora GJ, Derrickson B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons; p1041.

04 December 2008

Olestra, Frankenstein fat substitute

Who knew that when Procter and Gamble accidentally created Olestra by attaching up to eight fatty acids to regular table sugar, they had also created a monster? While the molecule tastes and looks like fat to the human eye, in the body its freakishly spiderlike structure can't be broken down at all, thus, the intestine cannot absorb it for caloric energy.

After a fatty meal, the body doesn't even really start digesting the triglycerides until they reach the small intestine (although there is a bit done by saliva and stomach fluid) [1].

As fats reach the duodenum, they form into large globules that stimulate secretion of bile from the liver that emulsifies them into tiny globules or droplets [1p716]. A protein called colipase binds to the droplets, which allows various enzymes called lipases secreted by the pancreas to access them more easily [1p779]. Lipases hydrolyze triglycerides freeing a couple of the fatty acids from their glycerol backbone so that both the monoglyceride and fatty acids can be transported by intestinal cells [1p716].

It's not a perfect system. The hydrolysis is absolutely necessary for absorption, but then those fatty acids and monoglycerides are just made into triglycerides again [1p716]. But in the bloodstream they can be hydrolyzed again to be degraded by beta-oxidation into acetyl CoA for production of ATP or, as witnessed by my love handles, can be stored in adipose tissue [1].

Unlike triglycerides, Olestra would never be broken down or absorbed at all because it is unrecognizable to colipase and lipases. The colipases are particular in binding to droplets, and lipases, like all enzymes, are specific in the way of binding to substrates [1p639].

The "fake fat", thus, is pooped out as slimy diarrhea and, along with it, fat-soluble nutrients.  Yes, it's true, those P&G snacks are fortified with extra vitamin A and D to cancel out the leaching. 

But, because they're not vitamins, fortification does not include carotenoids such as lycopene, which is hugely beneficial to prostate and heart health. According to FDA, eating Olestra products can significantly reduce carotenoids in the body.[3]   

References

1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
2. Cutting edge. "Fat Blockers". Interactive Concepts of Biochemistry. Available at http://www.wiley.com/legacy/college/boyer/0470003790/cutting_edge/fat_blockers/fat_blockers.htm. Accessed on October 4, 2008.
3. Olestra and the FDA. NEJM. Volume 335:668-670.

30 November 2008

Give Thanks to Your Mitochondria This Holiday Season

Once you've finished gorging yourself on turkey and pie and have decided to burn off that extra "fuel" by shopping non-stop (as an aerobic workout) on Black Friday morning, remember that you have your cells' mitochondria to thank [1].

The mitochondria house the enzymes and conditions necessary for aerobic respiration via the citric acid cycle [1p761-2]. Just a couple of turns of the cycle and the food you eat can give you double the energy than what the cell can produce under anaerobic conditions of glycolysis and the pyruvate dehydrogenase complex [1p761-2].

But the citric acid cycle also does so much more. In the same oxygen-requiring breath of turns, the citric acid cycle makes up molecular precursors or "building blocks" needed by the body [2]. Like glycolysis this role gives the citric acid cycle amphibolic status that includues both catabolism of food and anabolism, or biosynthesis [1p770].

In fact, we owe the citric acid cycle thanks for biosynthesizing non-essential amino acids [1p770]. When the body runs low on one of these, the cell uses the carbon skeletons of citric acid cycle intermediates to produce them again [1p770]. Two intermediates used are:

- Oxaloacetate, in conjunction with glutamate, for the production of aspartate via a transamination reaction—where an enzyme catalyzes the transfer of an alpha-amino group to an alpha-ketoic acid [1p770].

- Alpha-ketoglutarate, in conjunction with ammonium and reduced by NADPH, produces glutamate, which is used to produce glutamine, proline and arginine [1p770].

These amino acids are then used for production of various essential proteins including enzymes and for building body tissues [1p596-7]. Other anabolic building blocks of the citric acid cycle include citrate for creating fatty acids and cholesterol, succinyl-CoA for heme, malate for producing pyruvate, and oxaloacetate for producing glucose [2].

Although the citric acid cycle is also found in bacteria [2], the mitochondria's efficient amphibolic role made its inclusion as part of eukaryotic cells an essential step in the evolution of multi-celled organisms [1p746]. Because mitochondria have their own mtDNA and grow and multiply like bacteria, they are thought to have descended of bacteria captured in eukaryotic cells millions of years ago [1p746].

Genetic research reveals the capture happened only once because all mitochondria can be traced back to one alpha-proteobacterial ancestor [3] and humans one Mitochondrial Eve [4]. As more is learned about that day of capture of our Mitochondrial Eve, we might also find it to be a true day for celebration and to express gratitude.

References

1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.

2. Wiley. The citric acid cycle [animation]. Available at http://www.wiley.com/college/pratt/0471393878/student/animations/citric_acid_cycle/index.html. Accessed November 28, 2008.

3. Gray MW, Burger G, Lang BF. The origin and early evolution of mitochondria. Genome Biol. 2001; 2(6): reviews1018.1–reviews1018.5. Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=138944. Accessed on November 28, 2008.

4. Cann RL, Stoneking M, Wilson AC. Nature. 1987 January;325:31-36. Available at http://www.nature.com/nature/ancestor/pdf/325031.pdf. Accessed on November 28, 2008.

26 November 2008

Incredible, edible egg but so high in cholesterol

If it wasn't for its high content of cholesterol, egg yolks would be regarded more strongly as one of nature's health powerhouses [1]. And, if regularly eaten, the egg would go a long way of ensuring against different nutritional deficiencies [1].

Hope has come for a more incredible, edible egg...

If soluble fiber and red yeast rice works on humans to lower cholesterol, why not chickens? They do. Soluble fiber has been shown to significantly impact the amount of total cholesterol in eggs [2]. And a study in China revealed that chickens fed red yeast rice produced egg yolks with significantly less triglycerides and LDL cholesterol [3].

In addition, eggs fortified with omega-3 oils are now a popular marketplace novelty and a welcome approach. Although omega-3 fortification won't change egg cholesterol content, it may help improve its profile for heart health [4].

Contrary to popular opinion, switching to quail eggs would not be beneficial since their cholesterol content is similar to that of chicken eggs [5].

1. Nutrition Data. Available at: http://www.nutritiondata.com/facts/dairy-and-egg-products/113/2. Accessed on November 26, 2008.

2. McNaughton JL. Effect of Dietary Fiber on Egg Yolk, Liver, and Plasma Cholesterol Concentrations of the Laying Hen. J Nutr. Available at: http://jn.nutrition.org/cgi/content/abstract/108/11/1842. Accessed on November 26, 2008.

3. Wang J, Pan T. Effect of red mold rice supplements on serum and egg yolk cholesterol levels of laying hens. Available at: http://cat.inist.fr/?aModele=afficheN&cpsidt=150059352. Accessed on November 26, 2008.

4. Manitoba Agriculture and Rural Initiatives. Increasing Omega-3 Fatty Acids in Eggs from Small Chicken Flocks. Avaialable at: http://www.gov.mb.ca/agriculture/livestock/poultry/bba01s04.html. Accessed on November 26, 2008.

5. Bragagnolo N, Rodriguez-Amaya DB. Comparison of the cholesterol content of Brazilian chicken and quail eggs. J Food Comp Anal. Available at: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJH-48B5K4K-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=beb35c37292ad81fe9a7e2e94bc9b859. Accessed on November 25, 2008.

When cholesterol starts creeping up past 200

When total cholesterol begins to creep up past 200 mg/dL, it's time to change diet [1]. If it reaches 240 mg/dL or higher, then the body is at high risk of coronary artery disease and cardiac death [1]. The risk is only accentuated if LDL cholesterol is higher than 160 mg/dL and HDL cholesterol is lower than 40 mg/dL (50 for women) [1].

So, what can be done? Takng cholestyramine and colestipol will help promote excretion of bile [2]. The "statins" atorvastatin, lovastatin and simvastatin can block key enzymes that synthesize cholesterol [2]. Even niacin in the form of nicotinic acid can help through its effects on widening blood vessels [3]. But the benefits of these drugs and the vitamin are extremely limited, because if treatment is stopped, cholesterol can and probably will go back up again unless there is a change of diet [4]. The drugs can also have possible side effects such as liver damage, muscle pain and break down, and kidney problems [4].

A change in diet and lifestyle is most important. Regular exercise, particularly aerobic exercise, increases HDL cholesterol, which in turn helps to lower total cholesterol and LDL cholesterol [5]. In addition, according to Mayo Clinic, the top five foods for lowering cholesterol are oat bran (soluble fiber), nuts, fish oil, olive oil, and plant sterols [6]. Soluble fiber included with meals may reduce absorption of cholesterol, nuts like walntus and almonds can replace high-saturated fat and high-cholesterol foods because their lipid profile includes PUFAs, fish helps to lower TGs through its content of omega-3 oils, olive oil PUFAs and antioxidants help (avoid lite olive oil), and plant sterols block absorption of cholesterol [6].

References

1. Mayo Clinic. Cholesterol levels: What numbers should you aim for? Available at: http://www.mayoclinic.com/health/cholesterol-levels/CL00001. Accessed on November 25, 2008.

2. Tortora GJ, Derrickson B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.

3. Grundy SM, Mok HY, Zech L, Berman M. Influence of nicotinic acid on metabolism of cholesterol and triglycerides. Available at: http://www.jlr.org/cgi/content/abstract/22/1/24. Accessed on November 25, 2008.

4. Mayo Clinic.Statins: Are these cholesterol-lowering drugs right for you? Available at: http://www.mayoclinic.com/health/statins/CL00010. Accessed on November 25, 2008.

5. Stein RA, Michielli DW, Glantz MD, Sardy H, Cohen A, Goldberg N, Brown CD. Effects of different exercise training intensities on lipoprotein cholesterol fractions in healthy middle-aged men. Am Heart J.1990 Feb; 119(2 Pt 1): 277-83. Available at: http://grande.nal.usda.gov/ibids/index.php?mode2=detail&origin=ibids_references&therow=282138. Accessed on November 25, 2008.

6. Mayo Clinic. Cholesterol: The top 5 foods to lower your numbers. Available at: http://www.mayoclinic.com/health/cholesterol/CL00002. Accessed on November 25, 2008.

22 November 2008

When you're full of dirty, hot air.

You could be a politician or you could have emphysema. The disorder usually is due to years of irritation from cigarette smoke, but anyone could get emphysema if exposed to years of air pollution or exposure to industrial dust [1p887].

The long-term irritation and resulting inflammation damages or destroys the walls of air sacs in the lungs [2]. The loss of elasticity causes bronchioles to collapse and air becomes trapped in the air sacs, over-stretching them and not allowing full ability to exhale [2]. The air sacs can rupture and the lung is left with abnormally large air spaces that stay filled with air [2].

Oxygen diffusion across the respiratory membrane is also reduced due to less surface area for gas exchange [1p887]. This limits the amount of oxygen in the blood and can result in leaving a person breathless even during mild exercise [1p887]. Symptoms are coughing, loss of appetite as well as fatigue [2].

Excessive mucus and inactivity of cilia–eventually allow irritants to damage the alveolar tissue, which can end up allowing squamous cancer cells to spread into the lower respiratory tract [3].

It's worth noting that oxygen therapy is one of the few therapies actually proven to keep those with emphysema living longer and with a better quality of life [4]. If you know anyone with emphysema, let them know. Oxygen therapy at night can be especially beneficial [4]. And if the patient doesn't exercise, all the more reason.

Three out of four adults with alpha-1 antitrypsin deficiency (AAT), a genetic disorder, will also get emphysema. Since the liver makes the protein and releases it into the blood stream it only takes a blood test to find out if you have AAT deficiency.

References

1. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Mayo Foundation for Medical Education and Research. Emphysema and Smoking. Available at http://emphysema.org/.
3. http://www.pul.unimaas.nl/respir.htm
4. http://www.nslij.com/body.cfm?id=5987
5. http://www.nlm.nih.gov/medlineplus/alpha1antitrypsindeficiency.html

Bad case of heartburn

After a large meal and red wine some of the stomach acid produced can flow back into the esophagus due to a relaxed or weakened sphincter [1]. Lying down on the couch is a bad idea since it probably would make the acid backup worse [2].

The resulting heartburn causes the primary symptoms, which is a burning pain in the chest under the breastbone [2]. Heartburn can happen occasionally to almost anyone, but if the symptoms become frequent, then the heartburn may be related to gastroesophageal reflux disease [2].

You can drink some baking soda mixed with cream of tartar and water as a temporary measure, then think about changing your diet to smaller meals and losing some fat [2].

Home remedies might help. Digestive enzymes help to get the digestive process moving more quickly. Increasing fiber absorbs acid and gas. Tea soothes the stomach and gets things going. You can also try ginger.

1. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Mayo Clinic. Heartburn. Available at: http://www.mayoclinic.com/health/heartburn-gerd/DS00095. Accessed on November 22, 2008.

I'll have a tall glass of fresh-squeezed fructose

Orange juice delivers a potent dose of what is roughly half glucose and half fructose [1].

Glucose, we know, is the simple sugar that serves as the primary source of fuel to the blood, brain and muscle [2p735]. Its intake stimulates the release of insulin, goes through glycolysis to create energy, and is used to synthesize of glycogen for storage [2p735].

Fructose does not stimulate the release of insulin, nor does it enter glycolysis in the same way as glucose [3]. In fact it enters glycolysis a few steps later after going through its own metabolism. After being transported to the liver, fructose is phosphorylated by fructokinase to form fructose 1-phosphate, then by aldolase B to dihydroxyacetone phosphate and glyceraldehyde [3p58]. Glyceraldehyde is phosphorylated to glyceraldehydde 3-phosphate, and this molecule along with dihydroxyacetone enter glycolysis [3p58]. In the muscle, fructose is phosphorylated by hexokinase to fructose 6-phosphate, which is then used for glycogenesis or glycolysis [3p358].

Apart from being famous for being sweeter than glucose and the disaccharide sucrose (of which fructose is half part of), would the low-glycemic "fruit sugar" be better for the body since it create less of an insulin response? Science says "probably not."

In fact, high consumption of fructose is now being blamed for type 2 diabetes. The influx of fructose to the liver from soda with high-fructose corn syrup is found to interfere with glucose metabolism through metabolic dyslipidemia, a disturbance that may induce insulin resistance [4]. You get extra lipogenesis from fructose. Fructose by-passes the conversion of glucose 6-phosphate to fructose 1,6-phosphate. This is glycolysis's main regulatory step. Fructose, then, is "unregulated" and able to "uncontrollably" over-produce triglycerides. Evidence is now showing that the diabetes and obesity, which have become modern-day epidemics, could be prevented through significant reduction of fructose in the diet [4].

Research is also showing fructose may be more detrimental than glucose in high amounts. A study at the University of California on overweight or obese adults who were given beverages sweetened with fructose or glucose showed that those drinking the beverage with fructose gained pounds and had higher triglycerides and higher serum LDL cholesterol levels [5].

References

1. Ghanim H, Mohanty P, Pathak R, Chaudhuri A, Sia CL, Dandona P. Orange juice or fructose intake does not induce oxidative and inflammatory response. Available at:
http://care.diabetesjournals.org/cgi/content/abstract/30/6/1406. Accessed on November 20, 2008.
2. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
3. Salway JG. Medical biochemistry at a glance, 2nd ed. 2006; Malden, Mass: Blackwell Publishing. (excellent book!!)
4. Basciano H, Federico L, Khosrow A. Fructose, insulin resistance and metabolic dyslipidemia. Nutrition & Metabolism. Available at: http://www.nutritionandmetabolism.com/content/2/1/5. Accessed on November 22, 2008.
5. DeNoon DJ. Study: Fructose increases heart risk factors and weight. WebMD Health News. Available at: http://www.medicinenet.com/script/main/art.asp?articlekey=82117. Accessed on November 20, 2008.

21 November 2008

When you can't degrade glycogen

Your brain, blood and muscles depend almost entirely on dietary glucose as a fuel source so your body must store the sugar for continual supply [1p733]. If you go without eating for a while or jog a mile or two you’ll find yourself relying on glycogen for energy [1p733]. The long-branched glucose polymer acts as a store of glucose molecules, ready for the moment’s need [1p733]. But imagine having inherited a defective gene that resulted in not allowing your body to degrade glycogen stores.

If it wasn’t for Mendelian genetics, von Gierke’s disease may never have been completely understood [2]. Also called type 1 glycogen storage disease, the inherited disorder was found in 1952 using Mendel’s principles to result from a defective gene that causes the lack of glucose-6-phosphate [2 & 1p740]. The enzyme is necessary for catalyzing the final step in gluconeogenesis and glycogenolysis, which is needed for synthesis of glucose from noncarbohydrates precursors and removal of glucose from glycogen when blood glucose levels are low [1p740].

Without an ability to degrade glycogen, those with the disease suffer from low blood sugar between meals that can reach dangerous levels, and excessive accumulation of glycogen in the liver, muscle and in the tubules of the kidneys that can create further health complications [1p740 & 3]. Symptoms include an enlarged liver; puffy cheeks and limbs; a swollen belly; constant hunger; stunted growth; delayed or underdeveloped puberty, gout, easy bruising and nosebleeds, fatigue, and irritability [3].

Living with von Gierke’s disease requires avoiding low blood sugar through frequent meals that include carbohydrates and feeding tubes used at night [3]. Because lactose and fructose can’t be broken down properly, milk and fruits are usually avoided [3].

References

1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
2. Lorentz CP, Wieben ED, Tefferi A, Whiteman D, Dewald G. Primer on medical genomics part I: History of genetics and sequencing of the human genome. Mayo Clin Proc. 2002;77:773-782. Available at: http://www.mayoclinicproceedings.com/inside.asp?AID=165&UID=. Accessed on November 19, 2008.
2. MedlinePlus. Von Gierke disease. Medical Encyclopedia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000338.htm. November 19, 2008.

16 November 2008

A little history on breast cancer

It was good to learn a bit about breast cancer, especially considering that I walked for breast cancer just recently and was among many breast cancer survivors. Now I know a little more about what their lives are like.

A little history lesson summarized (see source below):

Breast cancer dates back to 1600 BC (as far as we know) in ancient Egypt. The Egyptians used to cauterize the tumors. The first surgeries removing lymph nodes didn't occur until the early 1800s. In 1882 the first mastectomies occurred, particularly the radical mastectomy. The procedure was popular up until the 1970s and is still common. One in 12-13 women will suffer from breast cancer. Research continues to find a cure.

Source: http://www.syl.com/articles/thehistoryofbreastcancerfightingthemostcommoncancerinwomen.html

David

Preventing spread of breast cancer

We may soon see drugs that can help prevent the spread of breast cancer. Last year in April it was found that breast cancers produce an overabundance of the protein Akt, which plays a key role in metastasis.(1)

Akt's role was tested by researchers who bred mice with a missing gene for Akt.(1) Mice with no copies of the gene for Akt rarely developed tumors, those with only one copy of the gene for Akt developed some tumors, while mice with two copies of the gene developed cancer rapidly.1

The research could potentially lead to drugs that target this protein in humans.(1)

Reference

1. Thomas Jefferson University (2007, April 11). Scientists Identify Protein Key To Breast Cancer Spread, Potential New Drug Target. ScienceDaily. Retrieved November 16, 2008, from http://www.sciencedaily.com­ /releases/2007/04/070409181641.htm

Radical Mastectomy and Arm Swelling

Due to the presence of breast cancer, Mrs. Franco had a right radical mastectomy in which her right breast and underlying muscle, right axillary lymph nodes and vessels were removed. Now she is experiencing swelling in her right arm Why did the surgeon remove lymph tissue as well as the breast? Why is Mrs. Franco's right arm swollen?

Radical mastectomy is now rarely performed and only used in cases of extensive tumors or cancer cells that have invaded the chest wall (1). In this case, the cancer may have moved into lymph nodes under the arm and in the chest muscle.(2) The spread of the cancer would have occurred via metastasis, cells traveling through the lymph or blood and establishing new tumors wherever they lodge (3p811).

The right arm is swollen due to lymphedema, which is an accumulation of lymph in lymphatic vessels (3p841). If the swelling comes with tenderness and redness and she is feeling a fever come on, it is possible that infection may have occurred.(4) She should seek treatment immediately to not see symptoms worsen.

References

1. http://www.oncologychannel.com/mastectomy/index.shtml
2. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
3. http://som.medselfed.com/asp/prodDisplay.asp?prodId=407&partnerId=som&id=&cachedate=
4. http://www.breastcancer.org/tips/lymphedema/avoid.jsp

Scuba Diving Hypoxia

Just reading and writing about blood loss has made me feel a little lightheaded, and then I realized where I'd seen the term hypoxia.

Hypoxia can occur at high altitudes, especially if scuba diving at high altitudes, because the air has less pressure than at sea level and you inhale less oxygen.(1)

To prevent hypoxia while scuba diving at high altitudes (which could kill you), you should take a few days to acclimatize yourself to thinner air, make sure you don't over-exert yourself underwater, catch your breath regularly, and rise to the survace slowly.(1)

Reference

1. http://www.ehow.com/how_2238064_prevent-hypoxia-scuba-diving.html

Gunshot hypovolemic shock

A gunshot wound and bleeding is sure to cause hypovolemic shock due to blood loss, external and internal (1p756). The body is generating the response as part of a negative feedback system that is attempting to correct the problem (1p756):

- Low systolic blood pressure is due to reduced amount of blood.

- Rapid heart rate is caused by sympathetic increase of blood levels of epinephrine and norepinephrine.

- Weak, rapid pulse is due to reduced amount of blood and cardiac output.

- Reduced blood flow to kidneys causes secretion of antidiuretic hormone that increases water reabsorption and causes blood vessel constriction by secreting renin.

- The thirst is due to loss of extracellular liquid.

- Cool, pale, and clammy skin is due to the sympathetic constriction of blood vessels and stimulation of sweating.

- The confused and disoriented mental state is because of reduced oxygen supply to the brian.

An emergency room will need to stop the bleeding right away and replace loss of blood and fluids.(2) This is in addition to helping whatever other situation the bullet might have caused.

Reference

1. Tortora GJ, Derrickson B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons, p756-758.
2. MedlinePlus. Hypovolemic shock. Medical Encyclopedia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000167.htm.

Why Vitamin B is My Co-pilot

B vitamins play a major role in producing energy in the cells, but they certainly aren't top gun. They are converted in the body to act as coenzymes.

As coenzymes they have almost no independent catalytic power because they must rely on being temporarily bound as organic prosthetic groups to an apoenzyme, then called a holoenzyme (1p643).

In a very complex reaction of three enzymes and five coenzymes, four B vitamin-derivative coenzymes act in synergy with yet another coenzyme (lipoamide) to produce pyruvate dehydrogenase complex (1p750).

Thus, any deficiency of the four B vitamins—thiamine, riboflavin, niacin, and pantothenic acid—could severely impact cellular respiration.(1p750)

You could think of pyruvate dehydrogenase complex as a fighter jet equipped with B vitamin wingmen. The pilot is its substrate pyruvate, which later develops into that maverick of a central charcter in the citric acid cycle, acetyl CoA (1p751).

Reference

1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.

15 November 2008

Power-Saving Tips From Biochemistry

Need to lower the electric bill? You could learn a thing or two about conservation from your body's own cells.

Each one possesses a highly evolved system of energy efficiency that consists of regulatory enzymes (1). These catalysts can be activated and deactivated depending on conditions in the cell (1p649-651).

When strategically located as a first step or near-first step of a metabolic pathway, a regulatory enzyme acts as biochemical light switch.(2) The enzyme switches "on" and "off" effectively speeding up or slowing down pathway production and preventing any drain of effort.(2)

An example of three regulatory enzymes in action can be found in glycolysis, the 10-reaction pathway used to produce energy from carbohydrates(1p726):

1. Hexokinase catalyzes the first reaction of the pathway and is inhibited by high concentration of its own product.

2. Phosphofructokinase, the key regulatory enzyme, catalyzes the third reaction and is allosterically inhibited by glycolysis product, ATP, and intermediate, citric acid. This is an example of feedback inhibition.

3. Pyruvate kinase catalyzes the last reaction. Because it is activated by activation of phosphofructokinase through feedforward activation, it is allosterically inhibited by inhibition of phosphofructokinase.

In other words, the last enzyme in the pathway is saying, "First and third one out, don't forget to turn off the lights."

Reference

1. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007

2. Stavrianeas, S. Teaching glycolysis regulation to undergraduates using an electrical power generation analogy. Adv Physiol Educ. 2005;29:128-130. Available at: http://advan.physiology.org/cgi/content/full/29/2/128-a. Accessed on Nov. 15, 2008.

14 November 2008

Deeply Flawed

Our bodies are not perfect. Far from it. In fact, they have serious flaws. Most importantly, its greatest flaw is that one day it will die. Over time evolution decided it preferred that humans die so those younger, stronger kids can take over eating, mating, etc.

You and I may not be OK with dying. If we pour effort or money into anything, it should be in trying to keep ourselves living longer. Live long and forever, if at all possible. Gosh, I think I'll have to dedicate my life to learning about longevity.

Most of all, longevity of the brain. The way I se it, if my brain goes, I pretty much am done too. Gotta study longevity, brain health, etc.

08 November 2008

Choline for adrenaline

Ciara is driving home from school, listening to her favorite music, when a dog darts into the street in front of her car. She manages to swerve to avoid hitting the dog. As she continues on her way she notices her heart is racing, she has "goose-bumps" and her hands are sweaty.

When the dog darted in front of Clara's car, her body went through a sympathetic "fight-or-flight" response, which is an inborn, automatic effect that can occur under conditions of acute stress.(1&2) The effects may have also included pupils dilating, airways to her lungs dilating, blood vessels to her kidneys and gastrointestinal tract constricting, blood vessels involved in exercise to fight off danger dilating, release of glucose by the liver, liver cells performing glycogenolysis.(1p537)

The effect is triggered by acetylcholine released from sympathetic nerves, which can activate many tissues simultaneously.(1p537 & 2) A release of adrenaline and norepinephrin from the medulla of the adrenals facilitate the intense physical effects.(2) We share this response with many other animals.(2)

Gives you a new reason to make sure you get the choline you need daily for synthesis of acetylcholine.

References

1. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Psychologist World. Stress: The fight or flight response. Available at: http://www.psychologistworld.com/stress/ fightflight.php. Accessed on Oct. 25, 2008.

I am 99% bacteria, 1% human

Sounds really creepy, but it's true. And we count on all our little friends to keep us healthy, keeping our gastrointestinal tract functioning and absorbing minerals well, and producing the critical vitamin K that is so important to our lives. Vitamin K, made by the large intestine flora, is vital for synthesis of clotting factors that make up normal blood clotting. It also helps inhibit osteoporosis by keeping calcium out of your arteries and in your bones.

So next time you need to get rid of an infection and are on antibiotics, be sure to repopulate and grow your gut flora with probiotics and prebiotics to keep yourself healthy long-term.

07 November 2008

A Tale of Two Bacterial Strains

It was the hottest of times, it was the coldest of times, and it was billions of years before the French revolution when one bacterial strain became two and possibly a few more.1p630 One of these strains would thrive in what we now know to be the Arctic Cold.1p627 Another would survive in the vents of a volcano.1p627 Not so coincidentally, both strains depend on vital functions of hexokinase.1p627 Normally hexokinase would become denatured while exposed to hot, molten rock.1p627

How does the volcano strain survive? The answer lies in significantly more R group interactions of amino acids found in holding its tertiary structure together.1p630 These noncovalent interactions play their role of stability via hydrogen bonding, ionic bonding and van der Waals forces.1p614 The extra support keeps hexokinase's globular protein alpha-helix and beta-pleated sheets from unfolding.1p609

Although perhaps not nearly complex as R group interactions, the bacterial strains would require another variation: maintaining membrane fluidity.1p582 The two bacterial strain's membrane lipids differ in their ratios of saturated and unsatured fats.1p582 While North Pole bacteria require a greater percentage of unsaturated fat double-bond "kinks" for their membranes to stay fluid, the membranes of bacteria in a firy environment are usually made up of a higher percentage of saturated fats.1p582

What does this information mean for humankind? The mystery of the beginning of life may partially lie in how both bacterial strains developed. Animals and plants both contain hexokinase, which plays roles in glycolysis and possibly sugar signal transduction pathways.1p726 & 2 Additionally all cells contain membrane lipids.1p557 Thus, the more we learn about these bacteria, the more we may learn about ourselves and our own humble origins.

References

1. Denniston, KJ, Topping, JJ, Caret, RL. General, Organic, and Biochemistry, 5th ed. New York: McGraw Hill; 2007.

2. Sheen, J, Jang, J. The role of hexokinase in plant sugar signal transduction and growth and development. Plant Molec Biol. 2000;44:451–461. Available at: http://genetics.mgh.harvard.edu/sheenweb/reprints/sugarPMB00.pdf. Accessed on November 5, 2008.

02 November 2008

Lecithin - good for your brain and liver

Lecithin provides choline, which is a precursor for the neurotransmitter acetylcholine in the brain.(1) Choline is also necessary to remove fat from the liver.(2) Thus, supplementation could be extremely beneficial for alcoholics to prevent against cirrhosis.(2)

References

1. http://www.jacn.org/cgi/content/abstract/11/5/473
2. http://www.medschool.northwestern.edu/newsworthy/past-years/2002/2002H-May/choline.htm

Ampipathic lecithin

Lecithin's talent comes from its amphipathic nature.(1) The compound's hydrophilic polar head dissolves in water while its hydrophobic polar tail dissolves in the triglycerides, thus, acting in a way of suspending triglycerides in water.(1p568)

As an emulsifier in ice cream, lecithin keeps ice cream smooth with fat globules evenly distributed throughout the solution.(2) It serves to bring fat and ice crystals together, which normally don't mix. Before commercial lecithin was available, egg yolks were used.(2)

Another useful application:

Want to know how to make your own salt air foam to a homemade margarita? The secret is soy lecithin. You can buy it at any health food store and mix about a teaspoon with water, salt and lime juice.

Reference

1. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007, p568.

2. Halford, B. Ice cream: The finer points of physical chemistry and flavor release make this favorite treat so sweet. Science & Technology. 2004;82(45):51. Available at: http://pubs.acs.org/cen/whatstuff/stuff/8245icecream.html. Accessed on November 1, 2008.

Why does low cholesterol cause aggression?

There might be a Darwinian explanation. According to Meninger clinic researchers, lower blood LDL cholesterol may be a signal for famine, which led to an adaptation of a response of more aggressive behavior.(1) Of course I think this is a pretty far-reaching hypothesis, but it's interesting.

Reference

Erickson, MT. Lowered serum cholesterol, famine and aggression : a Darwinian hypothesis. Available at: http://cat.inist.fr/?aModele=afficheN&cpsidt=2872688. Accessed on November 2, 2008.

What's the new rage? Omega-3 Index

Blood omega-3 oils could be just as or more important than blood LDL cholesterol levels.

Last week I attended a conference in Las Vegas where I heard a cardiologist say bluntly that doctors need to be retrained to stop limiting their focus to blood LDL cholesterol for preventing heart disease and start using the novel Omega-3 Index.

What's that?

According to a 2004 article in Preventative Medicine, the index serves as a "novel, physiologically relevant, easily modified, independent, and graded risk factor for death from CHD that could have significant clinical utility."(1)

The Omega-3 Index is used as a biomarker to measure the percentage of EPA and DHA omega-3 fatty acids in the blood cell membranes.(2) The omega-3 oils replace other fatty acids.(2)

A high value of omega-3 oils is linked to reduced risk of cardiovascular disease as well as other benefits.(2) A value of 8 percent or above in omega-3 oils can mean a 90 percent reduced risk of sudden cardiac death.(2)

References

1. Harris, WS, Von Schacky, C. The Omega-3 Index: a new risk factor for death from coronary heart disease. Available at: http://www.ncbi.nlm.nih.gov/pubmed/15208005. Accessed on November 1, 2008.

2. Daniells, S. Omega-3 index could be goalpoasts for max heart health. Available at: http://www.nutraingredients.com/Research/Omega-3-index-could-be-goalposts-for-max-heart-health. Accessed on November 1, 2008.

01 November 2008

Promoters say cholesterol is a nutrient - not true

I am a bit stunned by argument for consuming cholesterol by cholesterol-promoterscholesterol-and-health.com because the body makes all the cholesterol it needs (about a gram a day)and a dietary amount is unnecessary.(1) For this reason, I'm not sure I can bring myself to call the lipid a nutrient.

While it is true that cholesterol-rich foods such as eggs may be considered good for the body and could even reduce risk heart disease, these benefits are not attributed to their cholesterol amounts, but to other nutrients that come with the cholesterol.(2)

From what I can gather, the only real reason for seeking out dietary cholesterol is if a person has a genetic disorder that would interfere with the body's own cholesterol production.(3)

References

1. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on November 1, 2008.

2. Harvard's School of Public Health. Nutrition Source: Eggs and heart disease. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/eggs/index.html. Accessed on November 1, 2008.

3. University of Utah Genetic Science Learning Center. Smith-Lemli-Opitz Syndrome. Available at: http://learn.genetics.utah.edu/content/disorders/whataregd/slos/. Accessed on November 1, 2008.

3 reasons to still avoid cholesterol (even though it's not bad for you)

More than 50 years have gone by since it was first discovered that too much LDL cholesterol in the blood is linked to heart disease, and, in response, healthcare professionals of all kinds have provided a simple message: "cholesterol is bad".(1)

More recent research, however, tells a different story -- that eggs, liver, shrimp and lobster are not the demons they were once thought to be.(1) Most people who eat these cholesterol-rich foods will find they have little or no impact on blood cholesterol levels.(1) This is good news for the average man who eats 337 milligrams and average woman who eats 217 milligrams daily.(2)

Why then do the American Heart Association and many informed healthcare professionals still recommend intake of cholesterol be no more than 300 milligrams?(2)

Reason 1: Dietary cholesterol comes from animal foods usually along with saturated fat.(2) Both saturated fat and trans fat have a significant impact on higher amounts of LDL cholesterol in the blood.(2)

Reason 2: The body produces about a gram of cholesterol a day, all it needs.(2) Extra cholesterol from the diet is unnecessary and must be removed from the body via the liver.(2)

Reason 3: Cholesterol intake can have an impact on blood LDL cholesterol levels in certain individuals.(2) Thus, those with high blood cholesterol should be conscious of this fact.(2)

References
1. Harvard School of Public Health. The bottom line: Choose healthy fats, limit saturated fat, and avoid trans fat. Nutrition Source: Fats and Cholesterol [online]. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-full-story/index.html. Accessed on Nov. 1, 2008.
2. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on Nov. 1, 2008.

Don't drive long-distances with grandpa if he has diabetes

The ultra-frequent pit stops will drive you nuts (even if he's your beloved grandpa). Buy grandpa a plane ticket!

Excessive thirst and urination signals uncontrolled diabetes mellitus, diabetic ketoacidosis or diabetes insipidus.(1) Urinalysis and blood testing are meant to detect the first two conditions.(2&3) When blood testing shows normal glucose levels and there is no presence of ketones in the urine, then diabetes insipidus is diagnosed.(1&2)

Diabetes insipidus is a condition that occurs when the kidneys cannot conserve water properly.(3) The cause is a defect in antidiuretec hormone receptors or an inability to secrete antidiuretic hormone.(4p659) The hormone, produced by the hypothalamus and stored and released by the pituitary gland, cause the kidneys to return more water to the blood.(4p631-3) Without the hormone working properly, urination increases substantially.(4p633)

References

1. MedlinePlus. Urination - excessive volume. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/003146.htm. Accessed on Nov. 1, 2008.
2. MedlinePlus. Ketones - urine. Available at: http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/003585.htm. Accessed on Nov. 1, 2008.
3. MedlinePlus. Diabetes insipidus. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000377.htm. Accessed on Nov. 1, 2008.
4. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons, p.659.

Get an opthalmoscopic exam

A non-invasive, five- to 10-minute opthalmoscopic examination can reveal:

Hypertension - Detected by swelling of the optic nerve and visual center of the retina can, hypertension is caused from narrowing arteries and amount of blood pumped by the heart.(2&3) If hypertension is not controlled it can lead to permanent damage to the optic nerve or macula. Decreasing salt intake, eating healthy, physical activity and even supplementation with omega-3 oils or coenzyme Q10 can improve conditions.(3)

Diabetes mellitus and diabetic retinopathy - Diabetes is a condition whereby the body is resistant to insulin or cannot produce sufficient insulin.(4) It can lead to spots floating in vision, blurred vision, dark streaks or a red film blocking vision, poor night vision and diabetic retinopathy. The latter is detected using a dye to spot bleeding from blood vessels in the center of they eye.(5)

Cataracts - Detected by examining abnormalities in the cornea, iris, lens, and the space between the iris and cornea, cataracts cause clouding of the lens of the eye.(6) The impaired vision can develop slowly and reach a point when surgery may be needed.(6) Cataracts can be prevented through early detection, not smoking, eating well, protection from the son, and treating other problems such as diabetes.(6)

Age-related macular disease - Detected when abnormal blood vessels behind the retina start to grow and leak fluid damaging the macula rapidly, age-related macular disease (degeneration) gradually destroys sharp, central vision.(7) The disease causes no pain so its onset can be a surprise.(7) The disease appears to affect white women more than other populations.(7) Prevention involves not smoking, eating healthy, maintaining normal blood pressure, maintaining a healthy weight and exercising regularly.(7)

References

1. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. MedlinePlus. Hypertensive retinopathy. Medical Encyclopedia [online]. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000999.htm. Accessed on Nov. 1, 2008.
3. Mayo Clinic. High blood pressure (hypertension). Available at: http://www.mayoclinic.com/health/high-blood-pressure/DS00100. Accessed on Nov. 1, 2008.
4. Mayo Clinic. Type 2 diabetes. Available at: http://www.mayoclinic.com/health/type-2-diabetes/DS00585. Accessed on Nov. 1, 2008.
5. Mayo Clinic. Diabetic retinopathy. Available at: http://www.mayoclinic.com/health/diabetic-retinopathy/DS00447. Accessed on Nov. 1, 2008.
6. Mayo Clinic. Cataracts. Available at: http://www.mayoclinic.com/health/cataracts/DS00050. Accessed on Nov. 1, 2008.
7. National Eye Institute. Age-related macular degeneration. Available at: http://www.nei.nih.gov/health/maculardegen/armd_facts.asp. Accessed on Nov. 1, 2008.

25 October 2008

Vitamin E

Alpha tocopherol is a type of vitamin E that exists naturally as d-alpha tocopherol, but supplement manufacturers also market synthetic "mirror image" l-alpha tocopherol as well as a mixture of d- and l-alpha tocopherol.

The synthetic kind and the mix are cheaper, but l-alpha tocopherol has little or no actual vitamin E activity in the body. It may interfere with d-alpha tocopherol activity and there's no long-term safety data.

When buying vitamin E supplements, be sure to choose d-alpha tocopherol along with other natural tocopherols such as beta-, gamma- and delta-.

Reference

1. Gaby, A. Does high-dose vitamin E kill people? Townsend Letter for Doctors and Patients. Available at: http://findarticles.com/p/articles/mi_m0ISW/is_259-260/ai_n10299312/pg_2. Accessed on Oct. 25, 2008.

18 October 2008

Walk for your memory

You may or may not remember last year's landmark four-year study related to Alzheimer's disease sponsored by the Italians. The study appeared in December's issue of Neurology. I found a link to an article about it below.

In summary it showed that elderly people (over 65) who regularly walk significantly lower risk of vascular dementia.(1) Thus there is a lot of talk about physical activity, like walking, as having a potential effect for reducing risk of Alzheimer's disease.(1) Because walking and other activity increases oxygen in the brain, it may be directly improve memory.(1)

Suggestion: Walk a mile or two before taking Anatomy and Physiology tests!

Reference

1. American Academy of Neurology. Walking and moderate exercise help prevent dementia. ScienceDaily. Available at: http://www.sciencedaily.com/releases/2007/12/071219202948.htm. Accessed on Oct. 18, 2008.

"It's not a tumor"

Many of us will remember the scene in Kindergarten Cop when detective John Kimble (Arnold Schwarznegger) said he had a headache.

"It might be a tumor," said Lowell, one of the kids.

"It's not a tumor!" said John.

Actually it may have been a tumor, or more correctly a brain tumor, since one of the symptoms is a headache.(1) Other symptoms would be poor balance and coordination, dizziness, double vision, slurred speech (still Arnold?), nausea and vomiting, fever, abnormal pulse, breathing rates, personality changes, numbness and weakness of the limbs (definitely not Arnold), and seizures.(1p518)

What is a brain tumor?

A brain tumor is an abnormal growth of tissue in the brain that could be malignant or benign, which are both equally serious because the tumor compresses adjacent tissues and causes a build-up of pressure in the skull.(1p518)

Treatment

Treatment for brain turmors, which can include surgery, radiation therapy and/or chemotherapy, can vary depending on size, location and type of the brain tumor.(1p518)

Reference

1. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.

ADHD and omega-3

According to an article in the Scandinavian Journal of Nutrition (Scandinavia being where much of our purified fish oil supplements comes from), there is "mounting evidence" showing that fish oil DHA/EPA omega-3 fatty acids can be used in clinical treatment of ADHD.(1)

Several studies have reported that supplementation with fish oil at high dosages (16g per day - that's really high) was shown to provide significant results in behavioral patterns.(2)

References

1. Richardson, A.J. The importance of omega-3 fatty acids for behaviour, cognition and mood. Available at: http://www.ingentaconnect.com/content/tandf/ssnu/2003/00000047/00000002/art00008. Accessed on Oct. 18, 2008.

2. Sorgi, P.J., Hallowell, E.M., Hutchins, H.L, & Sears, B. "Effects of an open-label pilot study with high-dose EPA/DHA concentrates on plasma phospholipids and behavior in children with attention deficit hyperactivity disorder." Journal of Developmental & Behavioural Pediatrics; 2007, 28:82-91.

Take Tylenol not Aspirin (unless you have osteoporosis, in which take fish oil and glucosamine)

Aspirin (acetylsalicylic acid) is a carboxylic acid derivative while Tylenol (acetaminophen) is an amide derivative.(1p478, 506) Both act as analgesics for relieving pain and reducing fever.

By inhibiting the enzyme cyclooxygenase in prostaglandin synthesis, aspirin reduces inflammation making it a nonsteroidal anti-inflammatory drug.(1p478) In the stomach environment, the carboxylic acid derivative reacts directly with the stomach lining and can potentially cause bleeding.(2 & 3)

Tylenol acts on nerve endings to suppress pain, but is not a nonsteroidal anti-inflammatory drug.(3 & 1p506) In the stomach environment, because of its structure as an amide derivative, it doesn't react with the stomach lining and causes no bleeding.(2)

References

1. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
2. Kleiner, K. Fatty molecules make aspirin easier to stomach. Available at: http://www.newscientist.com/article/mg14519652.700-fatty-molecules-make-aspirin-easier-to-stomach.html. Accessed on Oct. 18, 2008.
3. Papazian, R. OTC options: Pain pain go away. FDA Consumer. Available at: http://www.fda.gov/bbs/topics/CONSUMER/CON00296a.html. Accessed on Oct. 18, 2008.

Why do pregnant women need iron?

Pregnant women need additional iron intake, but if the body controls absorption and uptake, then why is diet not enough? While it may be true that the diet doesn't provide enough, it may also include other factors beyond iron intake that may also affect women pre- and post-pregnancy.

There are many dietary factors that can inhibit iron absorption.(1) Among these factors are:

- polyphenols of gallic acid that are found in coffee and tea,
- oxalic acid of spinach, chard, berries, chocolate and tea,
- phytates found in legumes,
- preservatives like EDTA,
- phosvitin found in egg yolks;
- and other minerals such as calcium, calcium phosphate salts, zinc, manganese, and nickel.(1p422)

In addition, there are factors that enhance iron absorption. These include:

- acids like ascorbic, citric, lactic and tartaric acid
- sugars
- meat, poultry and fish
- and mucin.(1p422)

When iron deficiency is a problem, thus, wisdom would suggest considering what is inhibiting absorption and what could be added to the diet to enhance absorption.

Reference

1. Gropper, S.S., Smith, J.L. & Groff, J.L. Advanced Nutrition and Human Metabolism, 4th ed; 2005. Belmont, CA: Thomson Wadsworth.

Sodium supplements or salt shakers?

I couldn't imagine why anyone would supplement with sodium. We do so much "supplementation" already with our salt shakers. All that shaking is linked to hypertension, but overall, when food is salted lightly, the salting may not be all bad.

When you eat salt, it guards you against sodium deficiency. The deficiency is not as likely now, but in earlier days it may have been an issue and continues to be a problem with anorexia.(1) The deficiency's symptoms include nausea, muscle atrophy, poor growth and weight loss.(1p380)

Plus, if the salt is iodized, then it helps guard against iodine deficiency. Iodine is extremely variable in foods so having it as part of salt is beneficial.(1p468) The thyroid collects the iodine, in its ionic form iodide, and uses it for genesis of hormones.(1p418)

Reference

1. Gropper, S.S., Smith, J.L. & Groff, J.L. Advanced Nutrition and Human Metabolism, 4th ed; 2005. Belmont, CA: Thomson Wadsworth.

10 October 2008

Vitamin Supplementation Debate

Vitamin supplementation may have its place in clinical nutrition, but confusion of how or when to supplement can ultimately harm the consumer.(1) The confusion arises from "extreme" views of healthcare practitioners who say supplementation is not necessary at all and those who push for too much supplementation.(1p119) Non-credentialed experts and vitamins manufacturers interested in making profits may also lead consumers in the wrong paths.(1p119)

Pros of Supplementation

As a person ages or changes his or her diet or environment, vitamin needs can change resulting in a potential need for help from vitamin supplementation.(1p119)

Supplementation can remove the guesswork out of making sure enough of a certain vitamin is in the diet. A woman, for example, who has a need for additional folic acid during times of pregnancy may choose supplementation rather than attempting to make significant changes to diet.(1p119) A child or adolescent can also be given supplements to be sure of healthy growth despite a reluctance to eat a balanced diet.(1p119)

Supplementation can be used to prevent clinical issues.(1p119) An example includes infants given vitamin K and D and trace minerals iron and fluoride.(p119)

Impaired nutrient absorption, storage and usage can be helped by supplementation.(1p119) An example includes elderly who may may need vitamin C, thiamin, riboflavin, pyridoxine and cobalamin.(1p119)

Lifestyle choices may influence need of supplementation.(1p120) Use of oral contraceptives, restricted diets, exercise programs, smoking, alcohol and caffeine can all generate situations of vitamin deficiency due to insufficient dietary intake and/or interference with absorption of vitamins.(1p120)

Certain diseases may create a situation where a person could benefit from supplementation.(1p120) Especially in cases of long-term illness, supplementation can be used to meet increased vitamin needs to support the body.(1p120)

Cons of Supplementation

While there are many "pros" to vitamin supplementation, the "cons" can be equal in detriment. A large amount of a certain vitamin can be toxic such as the case of retinol, which has potential of causing liver or brain damage.(1p120)

Megadoses of vitamins can also lead to a deficiency of another vitamin due to how they work together in the body.(1p120) An "artificially induced" deficiency can result when a person suddenly stops taking a large amount of a certain vitamin, such as infants who develop scurvy because their mothers took megadoses of vitamin C during pregnancy.(1p121)

A non-credentialed "expert" or vitamin manufacturer may miss these points as he or she recommends or markets certain vitamins to unsuspecting customers.

Conclusion

Proper vitamin supplementation should be done with wisdom and care. Supplementation principles include reading labels carefully, understanding that large doses can be harmful, that supplement use is governed by individual needs, that all nutrients work together, and that food remains the best source of nutrients.(1p121) Lastly, sound knowledge and evidence should guide reasons for supplementation.(1p121)

Reference

1. Nix, S. Williams' Basic Nutrition &Diet Therapy, 12th ed, Elsvier Mosby, 2001; 119-121.

04 October 2008

Health Starts in The Gut

Going in with the gut, I'm led to deduce that health begins exactly there.

The gut and other parts of the gastrointestinal system make up the basic conduit of nutrition.(1) Food eaten is broken down by the system into simpler substances, nutrients are absorbed and transported to cells, and then are metabolized for creation of new body substances or for energy. (1p58)

Clinical Applications of Digestion, Metabolism and Absorption

Clinical application begins with the knowledge of how the process of digestion works. A nutritionist can then begin applying solutions.(1p67) To help a patient limit burping, a nutritionist can suggest he or she avoid nervously gulping down carbonated beverages through a straw.(1p67) To limit flatulence in a patient, the nutritionist can recommend he or she limit fiber and slowly reintroduce it in the diet or take a lactase supplement before consuming milk.(1p67)

Nutritionists can use diet therapy to also encourage absorption and metabolism of nutrients. An example is inclusion of non-digestible oligosaccharides to the diet. Understanding how these nutrients affect growth of intestinal flora helps a nutritionist encourage proper mineral absorption such as calcium in a patient.(2, 3, 4)

Clinical Applications of Energy Balance

Energy balance is a chief factor when nutritionists consider diet therapy. The food the body digests is partly converted to energy through cell metabolism.(1p74) Nutritionists should know how foods affect energy via each kilocalorie present.(1p75) For proper health, the body must have a sufficient amount of kilocalories from food for fuel and function, but not so much daily that would lead to gain of too much weight.(1p75, 81)

The amount of kilocalories for proper energy balance requires evaluation of daily energy requirements. Nutritionists would consider the body’s uses of energy, namely resting metabolic rate, physical activity and thermic effect of food.(1p81) A calculation of total energy output can then determine how many calories a patient should receive.(1p81)

Basing clinical diet therapy on energy balance as well as digestion, absorption and metabolism, the patient is adequately served and sure to receive best results.

References

1. Nix, Staci, Williams' Basic Nutrition &Diet Therapy, 12th edition, Elsvier Mosby, 2001; 57-86.

2. Kolida, S & Gibson. Prebiotic capacity of inulin-type fructans. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

3. Scholz-Ahrens, KE & Schrezenmeir, J. Inulin and oligofructose and mineral metabolism: The evidence from animal trials. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

4. Abrams, SA, Griffin, J, and Hawthorne, KM. Young adolescents who respond to an inulin-type fructan substantially increase total absorbed calcium and daily calcium accretion to the skeleton. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

Women and Asians can't hold their alcohol as well as European men

If you thought it interesting that women have less of aldehyde dehydrogenase, then you'll no doubt be interested to know that many Asians have a deficiency.(1) This is why Chinese, Japanese and Koreans can be much more sensitive to alcohol than Europeans and Americans of European ancestry.(1) You'll notice that Asians with this deficiency are susceptible to alcohol-induced flushing.(1)

The adaptation that those of European ancestry have to be able to handle alcohol may be due differences of water intake in the continents, according to Sharon Moalem, Ph.D.(2) To reduce disease by avoiding pathogens in the water, early Asians boiled water for drinking tea.(2) Early Europeans, however, may have used fermentation so the alcohol would kill the pathogens.(2)

1. Wall, TL, Peterson, CM, Peterson, KP, Johnson, ML, Thomasson, HR, et al. Alcohol Metabolism in Asian-American Men with Genetic Polymorphisms of Aldehyde Dehydrogenase. Annals of Internal Medicine; September 2007:127(5)376-379. Available at http://www.annals.org/cgi/content/full/127/5/376. Accessed on October 4, 2008.

2. Moalem, S. Survival of the Sickest: The Surprising Connections Between Disease and Longevity; 2006. New York: HarperCollins.

Want a reason to get drunk?

An incredibly risky one? If you happen to drink methanol, then you'll end up in the emergency room with an IV intended to get you drunk as fast as possible.1 2 If the treatment isn't applied immediately you could end up blind or worse.1,2p426

Methanol may be good for certain racing cars, but it's toxic to human beings because the body's liver oxidizes it to produce formaldehyde.2p387,426 This particular aldehyde is highly reactive in the body, damaging cells and their vital proteins including DNA.2p426,4 Even the fumes of formaldehyde may be cancerous.1,3 Formaldehyde in the body will lead to loss of eyesight, respiratory failure, convulsions and death.2p426

To keep the liver from oxidizing methanol to formaldehyde, the ER personnel will use ethanol as a distraction.2p426 Ethanol, the by-product of yeast found in alcoholic drinks, is oxidized by the liver using the same enzyme that oxidizes methanol.2p387,426 In fact, it is preferred by the enzyme, which helps minimize production of formaldehyde through "competitive inhibition".2p426

The product of ethanol oxidation is acetaldehyde, which is less toxic.2p426 Acetaldehyde will give a person a hangover in the morning and too much over time can lead to fatty liver disease, but its effects are nowhere near those of formaldehyde.2p430 The liver detoxifies acetaldehyde to etanoic acid and then used as an caloric energy source.2p430

1. Antizol. Methanol poisoning overview. Available at: http://www.antizol.com/mpoisono.htm. Accessed on September 30, 2008.

2. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007:426.

3. National Cancer Institute. Formaldehyde and cancer: Questions and answers. Available at: http://www.cancer.gov/cancertopics/factsheet/risk/formaldehyde. Accessed on September 30, 2008.

4. Salariino, AJ, Wiley, JC, Lechner, JF, Grafstrom, RC, LaVeck, M & Harris, CC. Effects of Formaldehyde, Acetaldehyde, Benzoyl Peroxide, and Hydrogen Peroxide on Cultured Normal Human Bronchial Epithelial Cells. Cancer Research, vol 45; 1985 June. Available at: http://cancerres.aacrjournals.org/cgi/reprint/45/6/2522?ck=nck. Accessed on September 30,2008.

21 September 2008

Why we need fats

Nothing else can stimulate the taste buds quite like the smell of fat. The human body comes adapted with a special affinity for this resource, according to evolutionary nutrition researchers S. Boyd Eaton, MD, and Stanley B. Eaton III (a father-son duo) (1998). Dr. Eaton and Eaton suggest early hominids eventually ate a greater amount of nuts and seeds and later, around 2.5 million years ago, humans on a hunter-gatherer diet might have preferred animal fat, specifically supplied in the brain and marrow—an alteration of diet that may have been a factor in supporting a larger brain (1998). This history of fat in the diet helps shape understanding of how vital fat is for the diet.

The body needs fat for various functions as well as other fat-related substances in the family of lipids. Most lipids in the body are of a type called triglycerides—three fatty acids with a glycerol backbone—which act as concentrated sources of energy stored in greater amounts in adipose tissue cells (Tortora & Derrikson, 2006, p. 46). Triglycerides are used as a “back-up” fuel source, as insulation to help maintain body temperature, and as “protective padding for vital organs” (Nix, 2005, pp. 34 & 40). The major lipid that makes up cell membranes is the phospholipid—two fatty acids with a glycerol backbone—along with other fat-related substances cholesterol and lipoproteins (Tortora & Derrikson, 2006, p. 46). Multiple types of lipids also play a role as a protective covering for nerve cells called a myelin sheath, which is also important for increasing speed of nerve impulses (Tortora & Derrikson, 2006, p. 410). To maintain proper amount of lipids in the body, dietary fat is important.

Dietary fat, however, occurs in various ways. The “building blocks” of fats are fatty acids, which can consist of short-, medium- or long-chains of carbon atoms with a methyl group on one end and carboxyl group on the other (Nix, 2005, p. 31). The fatty acids can also be “saturated’ or “unsaturated” (including polyunsaturated) depending on their amount of hydrogen atoms (p. 31). The saturated are generally from animal origin and the unsaturated from plant origin, although there are plants that contain saturated fat and animals will have unsaturated fat (p. 31-33). Essential fatty acids are specifically types of polyunsaturated fats that are necessary for the body (p. 33). Trans fats occur when unsaturated fats are chemically “saturated” to make them more solid at room temperature (p.35). With the various types of fatty acids, confusion may lie in how to best utilize food with proper amounts of each in the diet.

Too much fat is harmful, but so is not enough. When the diet is high in fat over time, higher incidence of chronic diseases (Nix, 2006, p. 39). Heart disease is a good example being the leading killer of men and women in the U.S.A. According to the American Heart Association (AHA), great amounts of fat, especially of saturated fat and trans fat, contribute to obesity and heart disease (2008). A low-fat diet, then can help protect the heart. However, when the body does not take in sufficient fat, however, essential fatty acid deficiency can occur (Nix, 2006, p. 39). Essential fatty acid deficiency is rare, but signs include scaly dermatitis, alopecia, thrombocytopenia and growth retardation (Morley, 2007). The key to the health is a correct balance.

Fat intake in the right amounts as well as the right kinds leads to a healthy lifestyle. U.S. Dietary Guidelines recommend no more than 20% to 35% of total fat, no more than 10% calories from saturated fat, and no more than 300 mg/day of dietary cholesterol (Nix, 39, 2006). AHA adds that it is best to avoid saturated and trans fats, replacing them with mono- and polyunsaturated fats “while still limiting” total fat (2008). Of the polyunsaturated, it’s important to remember that two are essential—omega-6 and omega-3 fatty acids.

Omega-3 is the more important of the two. In 2002 AHA began recommending people without heart disease consume fish at least twice a week to help maintain a health heart as long as a close watch was instituted over intake of fish contaminants (e.g. mercury) (Kris-Etherton et al). Further, AHA recommends those with heart disease take at least 1 g per day of EPA/DHA omega-3 fatty acids in capsule form (to avoid contaminants of eating fish), and for 2 to 4 grams daily in capsule form for those who needed to lower triglycerides (Kris-Etherton et al). In addition, the U.S. Food and Drug Administration (FDA) put out a qualified claim about “reduced risk of coronary artery disease” for any whole food, packaged food or dietary supplement that contained both EPA/DHA omega-3 fatty acids (2004). The information suggests that a low-fat diet with an emphasis on polyunsaturated oils especially omega-3 fatty acids is best for health. Since the brain is made up of mostly omega-3 fats, that would explain why hunter-gatherers preferred the brain on the menu.

References

American Heart Association. (2008, Sept 21). Face the Fats. Retrieved Sept. 17, 2008 from http://www.americanheart.org/presenter.jhtml?identifier=3046074.

Department of Health and Human Services Centers for Disease Control and Prevention. (2008). Heart Disease. Retrieved Sept. 17, 2008 from http://www.cdc.gov/heartdisease/.

Eaton, S.B. & Eaton, S.B. III, (1998). Evolution, diet and health. [Scientific Session – International Congress of Anthropological and Ethnological Sciences in Williamsburg, VA]. Retrieved Sept. 17, 2008 from http://www.cast.uark.edu/local/icaes/conferences/wburg/posters/sboydeaton/eaton.htm.

Kris-Etherton, P.M., Harris, W.S., & Appel, L.J. (2002). Fish consumption, fish oil, omega-3 fatty acids and cardiovascular disease. Circulation: Journal of the American Heart Association, 106; 2747-2757. Retrieved Sept. 22 from http://circ.ahajournals.org/cgi/reprint/106/21/2747.

Morley, J.E. (2007, June). Essential Fatty Acid Deficiency. The Merck Manual for Healthcare Professionals. Retrieved Sept. 21 from http://www.merck.com/mmpe/sec01/ch002/ch002d.html.

Nix, S. (2005). Williams’ Basic Nutrition & Diet Therapy, 12th ed. St. Louis, MO: Elsevier Mosby.

Tortora, G.J., & Derrikson, B. (2006). Principles of Anatomy and Physiology, 11th ed. New York: John Wiley & Sons.

U.S. Food and Drug Association (2004). FDA announces qualified health claims for omega-3 fatty acids. Retrieved on Sept. 21, 2008 from http://www.fda.gov/bbs/topics/news/2004/NEW01115.html

Brittle Bones of a Jedi Master

After leading the fight against the Galactic Alliance, Luke Skywalker might have found himself with a developed case of osteoporosis and kidney stones. That's because space travel diminishes bone loss and a rise of calcium in the blood, according to NASA researchers (Hullander & Barry, 2001). The reason for the bone loss is weightlessness.

When the body is weightless (or immobile), bone cells act differently. The International Osteoporosis Foundation states that astronauts and bedridden patients share a state in which they "can lose up to 15% of mineral density within three months" (Sochaczewski, 2006). According to NASA, the weightlessness upsets the balance of bone-building to bone destroying (Hullander & Barry, 2001.) Thirty million people on Earth who suffer from osteoporosis in the U.S.A. happen to be going through the same demineralization of the bone, although slower (Tortora & Derrikson, 2006, p. 189). The key to prevent osteoporosis on land and in space appears to be continual weight-bearing exercise on the body.

Once safe on the forest moon Endor, Luke should perform plenty of squats or he might begin to look more like Yoda.

References

Hullander, D. & Barry, P.L. (2001). Space Bones. Science and Nasa [Web site]. http://science.nasa.gov/headlines/y2001/ast01oct_1.htm.

Sochaczewski, (2006, May 31). What's the link between astronauts and osteoporosis. International Osteoporosis Foundation: Bone research in space symposium, June 2, IOF World Congress on Osteoporosis. Retrieved Sept. 18, 2008 from http://www.iofbonehealth.org/wco/2006/downloads/pre_congress_whats_the_link_between.pdf.

Tortora, G.J., & Derrikson, B. (2006). Principles of Anatomy and Physiology, 11th ed. New York: John Wiley & Sons.

19 September 2008

Health Hazards From Use of Technology

In today’s modern world, technology plays a predominant role in the lives of people. The computer is used for work and play. For many people, more time is spent in front of the monitor than anywhere else as a place to conduct business, go shopping, go to school, answer e-mails, converse with friends, and play video games. In conjunction to computer use, other technologies frequently used are digital phones, TV, and MP3 players. While all these facets of technology are seemingly advantageous, they do come with a downside. The body can show resistance to conforming to a technology-centered lifestyle by exhibiting signs of poor health and fitness.

Depending on how technology is used daily, the body’s anatomy and/or internal organs are at risk of becoming distressed and the distress may eventually result in damage. These risks can come from lack of movement entirely due to little exercise or simple movements such as using a mouse or typing on a keyboard. Finally, distress may result simply from posture or how or how long a person views a computer screen. Fitness and health ultimately suffers after sitting and typing on a keyboard while staring at a screen for regular durations of eight hours or longer a day. Computer use, especially when prolonged, places our bodies in a position that has potential to increase risk of health hazards.

Learning about the different problems associated with using computers offers opportunity for the better. Many of the health hazards have simple preventive measures. The education of these measures can millions who use computers to avoid serious health problems such as those associated with prolonged computer use. The main preventive measures that should be learned by those using computers for long periods of time are those associated with the brain, vision, neck and spine, hands and weight management.

Detrimental Impact of Technology on Health

Many parts of the body’s anatomy and internal organs are vulnerable to prolonged computer use. These include the brain, heart, eyes, neck, spine and hands. Becoming overweight and also obese is also a risk and can increase risk of other health problems such as diabetes. Many concerns are directly related to use of computers and others are indirectly related due to how the computer is used by the person. All these concerns could make a heavy impact on a person’s health.

Obesity

When media is used for long periods of time during much of the day, no longer is a person burning enough calories to prevent the disease of obesity. Thus, it has become an epidemic and it’s even affecting children. According to the USDA’s Children Research Center, preschool children who watch television or use computers have a higher risk of becoming overweight or obese (Mendoza, Zimmerman & Christakis, 2007). Unfortunately for these children, health concerns at such a young age can come with long-term consequences.

Brain

Technology offers plenty of opportunity for the brain to become engaged and exercised, but without regular movement of the body the brain can eventually be left lacking. Acclaimed neuroscientist John Medina, Ph.D., predicts that Homo sapiens evolved bipedalism to move across great distances—up to 12 miles daily—while conserving as much energy use as possible (Chap. 1, Locations 122-27, 2006). During these periods of exercise the brain benefited through improved circulation, which led to unique cognitive skills and exploratory skills. As people age, the lack of movement due to spending time in a desk in front of a computer can lead to decreased cognitive performance and risk of losing memory (Chap. 1, Locations 166-171). Loss of memory is the key symptom of age-related dementia.

Heart

When the computer is all it takes to bring home the daily bread and the television for entertainment, the cardiovascular system also suffers from lack of sufficient movement. Humans used to depend on physical activity to hunt and gather as well as for entertainment, but according to nutritionist Staci Nix, MS, RD, CD, inadequate cardiac output of today is now leading to progressively weakened heart muscles for many people (2005, p. 356). A diet of excessive carbohydrates and salt, which is a typical meal found in the nearby vending machine, offers little help and leads to hypertension (p. 356). Coronary artery disease has been named by the Centers for Disease Control and Prevention as the leading killer of men and women in the U.S.A. (2008). Ultimately it is linked partly to continuous lack of movement due to use of television and computers.

Eyes

Eyestrain, or aesthenopia, can occur due to prolonged computer use and altered vision may become a problem over time. Mayo Clinic warns extended computer is largely to blame eyes become sore, tired, burning or itching, watery and dry; vision can become blurred, the neck can become sore and the eyestrain may cause headache and increased sensitivity to light (2008). Continuous irritation of eyes can induce complications such as unpleasantness and inability to concentrate, but serious or long-term consequences are uknown (2008). Continuous eye problems over time, however, may affect quality of life greatly.

Neck

Neck pain can result from wear and tear of tissues as a result of bending of the neck for long durations of time to see a computer screen. According to the American Academy of Orthopaedic Surgeons, prolonged “wear and tear” of soft tissues of the neck, or cervical spine, can cause injury and cause neck pain (2007). The pain can ultimately lead to rheumatoid arthritis in the upper neck area, cervical disk degeneration, or make the head and neck more vulnerable to injury (2007). Long computer use can eventually cause serious neck injuries.

Neck and Shoulder

Neck and shoulder pain risk can increase due to mouse and keyboard use. Danish researchers found that use of mouse and keyboard could lead to pain in the neck and right shoulder due to rotator cuff syndrome and tension neck syndrome (Brandt et al, 2004). The risk of symptoms increased depending on how many hours per week the mouse and keyboard were used. Preventive measures for these serious problems should not be overlooked when using computer technology.

Lower Back

Lower back pain can be due to the office chair in front of the computer. According to Mayo Clinic, the “body can tolerate being in one position for about 20 minutes” before aches and pains begin to occur (2007). An awkward posture and a muscle tension added on can result in serious back pain. Pain and tightness can ultimately lead to injury.

Hands

Constantly at the keyboard are the digits of the hand. When the tendons of the digits beome inflamed causing a narrowing of the tunnel they pass through, a person experiences carpal tunnel syndrome (Tortora & Derrikson, 239). Carpal tunnel syndrome has plagued thousands of hands due to computer use and treatment is slow. Once affected, the hands develop extreme pain.

Possible Solutions to Health Hazards from Use of Technology

Many of the health problems that stem from computer use are solved easily with preventive measures. These can consist of easy-to-apply habits and, in some cases, changes of lifestyles. The education of these measures within the workplace and of children could affect their lives for the better.

Movement for Brain, Heart and Obesity

Out of the 1,440 minutes there are in a day, just 30 minutes could offer an enormous difference. According to John Medina, a half hour of daily aerobic exercise has been shown in the laboratory to offer the brain the benefit of cognitive performance enhancement (2006, Locations 181-186). This amount of exercise could be used to treat age-related dimentia and Alzheimer’s disease, but perhaps also depression and other neurological disorders. Just 20 minutes of aerobic exercise two times a week could improve cardiovascular health. That’s all it takes, according to John Medina to decrease chances of a stroke by 57 percent (2006, Locations 191-196). Plus, the exercise could seriously make an impact on obesity due to burning of calories. In the age of technology opportunities for change abound with solutions for this problem.
Exercising while using technology may be key. John Medina points out that a work environment and entertainment environment that consists of a treadmill with laptop attached or in front of the television will be enough to stimulate blood vessels and increase blood flow across tissues of the body (2006, Locations 271-276). The increased circulation provides greater ability to think and perform better. Across the world, many kind of similar efforts could be created to perform exercise while working.

Eye Health is a Blink Away

A few tips for reducing vision complications can go a long way. According to Mayo Clinic, many people blink less when using the computer, which causes dryness and, eventually, induces eyestrain (2008). The clinic encourages making a “conscious effort to blink more often” and taking frequent “eye breaks,” at least five minutes every hour to focus on something besides the computer screen (2008). Educating computer users of such an easy task can make life easier in the long run.

Simple Activities for Neck and Back

Avoiding problems of the neck and back can be simple. Posture is key. Michael Cohen, DAc, DC, states that poor posture—sitting at the front of the office chair hunched forward—is what puts “considerable strain on the back” and should be avoided to prevent neck and back pain (2006). To maintain an upright posture and avoid the “natural tendency” to hunch forward, Cohen suggests placing a tennis ball between the middle back and the office chair and holding it in place (2006). Frequent breaks should be taken and include stretching, relaxation and movement. According to Mayo Clinic, taking a walk, performing deep-breathing exercises and stretching can make a significant difference in preventing back pain (2007). Taught accordingly to computer users, these activities can be applied easily.

Simple Activities for Hand Health

The hands could also benefit from correct posture and breaks. Arthur Schoenstadt, M.D., who encourages prevention and early intervention for those at risk, suggests taking frequent breaks to allow the hand to rest and recover as well as using correct posture and wrist position (2007). Schoenstadt states that even a 10- to 15-minute break every hour makes a difference for prevention. When preventive techniques are this simple, only awareness and a conscious effort are main factors.

References

American Academy of Orthopaedic Surgeons. (2007, October). Neck pain. Retrieved on Sept. 19, 2008 from http://orthoinfo.aaos.org/topic.cfm?topic=A00231.

Brandt, L.P., Anderson, J.H., Lassen, C.F., Kryger, A., Overgaard, E., Vilstrup, I. & Mikkelsen, S. (2004). Neck and shoulder symptoms and disorders among Danish computer workers. Scandinavian Journal of Work, Environment & Health, 30:5, pp.399-409 [abstract]. Retrieved on Sept. 17 from http://cat.inist.fr/?aModele=afficheN&cpsidt=16198679.

Cohen, M. (2006, April 6). “Office chair advice.” Spine Health: Trusted Information for Pain Relief. Retrieved on Sept. 12 from http://www.spine-health.com/wellness/ergonomics/office-chair-advice
Department of Health and Human Services Centers for Disease Control and Prevention. (2008). Heart Disease. Retrieved on Sept. 17, 2008 from http://www.cdc.gov/heartdisease/.

Mayo Clinic. (2008, July 12). Eye. Retrieved on Sept. 17, 2008 from http://www.mayoclinic.com/health/eyestrain/DS01084

Mayo Clinic. (2007, Feb 7). Back pain at work: Preventing aches, pains and injuries. Retrieved on Sept. 17, 2008 from http://www.mayoclinic.com/print/back-pain/HQ00955/METHOD=print.
Medina, J. (2008). Brain Rules: 12 Principles for Surviving and Thriving at Work, Home and School. Seattle: Pear Press.

Mendoza, J.A., Zimmerman, F.J., & Christakis, D.A. (2007, Sept). Television viewing, computer use, obesity, and adiposity in US preschool children. International Journal of Behavioral Nutrition and Physical Activity, 4:44 doi:10.1186/1479-5868-4-44. Retrieved on Sept. 17, from http://www.ijbnpa.org/content/4/1/44.

Nix, S. (2006). Williams’ Basic Nutrition & Diet Therapy, 12th ed. St Louis, MO: Elsevier Mosby.

Schoenstadt, A. (2007, Oct 19). Carpal tunnel Prevention. eMedTV. Retrieved on Sept. 17, 2008 from http://carpal-tunnel.emedtv.com/carpal-tunnel-syndrome/carpal-tunnel-prevention-p2.html.

Tortora, G.J., & Derrikson, B. (2006). Principles of Anatomy and Physiology, 11th ed. New York: John Wiley & Sons.

15 September 2008

Even a Caveman Can Eat Low-Carb

With good reason carbohydrates (carbs) are the staple fuel source for most diets in the world. Not only are they plentiful and cheap to produce—created by plant photosynthesis—but also utilized easily by the body. The body’s process, in fact, according to Staci Nix, MS, RD, CD, is “far more efficient than any man-made machine (2005, p.16). There are different types of carbs: the simple, which are quickly absorbed by the body, and the complex, which are more slowly absorbed.

Simple carbs have one sugar molecule such as monosaccharides such as glucose, fructose and galactose, or disaccharides such as sucrose, lactose and maltose (Nix, 2005, pp. 16-17). The complex carbs (polysaccharides) include starches, glycogen, dietary fiber, cellulose, noncellulose polysaccharides and lignins. With the exception of dietary fiber and noncellulose polysaccharides, the body breaks down these carb types, turns them into glucose and distributes the glucose through blood circulation to all the cells that need it in the body.

The glucose—whether produced by simple or complex carbs—is not only important for energy, but for sparing the need to use stores of protein and fat, which can be used to sustain the body in other ways (Nix, 2005, p. 24). More important is glucose’s role in supplying adequate fuel to the nervous system including the brain (p. 24). Unlike carbs, protein and fat energy cannot supply a constant stream of glucose to the brain, giving carbohydrates a role that is vital for life.

The amount of carbohydrates needed in the diet, however, has been a hotly contested debate. Nix mentions that sugar is not “the villain,” but that too much of its use is problematic (2005, p.24). Harvard nutritionist and physician Walter Willet, Ph.D. Willet agrees that the USDA food pyramid should be modified to steer people away from refined carb foods. They provide little nutrients, he says, but more detrimentally, they spike blood glucose causing higher needs for insulin only to bring glucose “crashing down” (Discover, 2003, http://discovermagazine.com/2003/mar/breakdialogue). The scenario happening regularly adds to higher risk of Type II diabetes. His “Healthy Eating Pyramid” stresses more focus on whole grains and fruits and vegetables and not the refined carbs (President and Fellows at Harvard College, 2008, http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid/index.html).

Low-carb dieting for encouraging weight loss has been led partly by some who have developed theories surrounding the diet of early humans. According to Loren Cordain, Ph.D., (2002, Chapter 1 [digital version]) and Noel T. Boaz (2002, Location 2309, Table 7 [digital version]), both top-selling authors of books with collected research on human evolution and diet of Paleolithic populations, suggest that the body may be adapted to a diet of high-protein, high-fiber, and low-carbohydrates.

Significant health problems, however, can occur as a result of low-carb dieting and should not be overlooked. Without enough carbs the body has to use the body’s protein and fat supply for creating quick energy (p. 24). According to Nix, muscle may be catabolized for its protein, muscle maintenance prevented, and the break down of fat stores for fast fuel can result in “incomplete fat oxidation”, thus creating an excess of strongly acidic ketones (2005, p.24). The ketoacidosis that occurs can become toxic to the body.

Many may have found themselves with ketoacidosis when on an extremely low-carb diet. A report in The Lancet of a 40-year-old woman hospitalized while following the popular low-carb Atkins diet is just one of several reports (Groch, 2006,http://www.medpagetoday.com/PrimaryCare/DietNutrition/tb/2878.). She had eaten nothing but meat, cheese and salad for in the month before the event. Criticism along with the report included comments by Lyn Steffen, Ph.D., M.P.H. and Jennifer Nettleton, Ph.D., who said the ketoacidosis would lead to “constipation, halitosis, diarrhea, headache and fatigue,” and long-term ketoacidosis would create problems for the kidneys and bones. Note that the Atkins diet has since been revised, according to Atkins Nutritionals (2008, http://www.atkins.com).

Considered moderately low-carb, the Mediterranean diet, which includes plenty of fruits, vegetables, and monounsaturated oils may be a better choice. According to an Israeli study published in the New England Journal of Medicine on three typical diets—a typical low-fat diet, a pre-revised-Atkins diet and the Mediterranean diet (based on recommendations by Walter Willet)—all the diets were regarded as safe, both low-carbohydrate diets provided metabolism benefits, but only the Mediterranean diet showed significant improvement for glucose and insulin levels (Shai et al, 2008). When it comes to carbs, as Staci Nix points out, “moderation is once again is the key” (2005, p. 24).



References

Atkins Nutritionals Inc. (2008). “Thoughtful approach. Powerful science.” Retrieved on Sept. 12, 2008 from http://www.atkins.com.

Boaz, N.T. (2002). Evolving Health: The Origins of Illness and How the Modern World Is Making Us Sick [digital version]. New York: John Wiley & Sons.

Cordain, L. (2002). The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat [digital version].New York: John Wiley & Sons.

Discover [interview with Walter Willett]. (March, 2003). “Nutritionist and physician Walter Willett—a voice of reason on diet.” Retrieved on Sept. 12, 2008 from http://discovermagazine.com/2003/mar/breakdialogue.

Groch, J. (2006). Atkins dieter develops life-threatening complications. Medical News: Diet & Nutrition. Retrieved on Sept. 13, 2008 from http://www.medpagetoday.com/PrimaryCare/DietNutrition/tb/2878.

Nix, S. (2005). Williams' Basic Nutrition & Diet Therapy. Philadelphia: Mosby.

President and Fellows at Harvard College. (2008). “The nutrition source healthy eating pyramid.” Retrieved on Sept. 12, 2008 from http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid/index.html.

Shai, I., Schwarzfuchs, D., Yaakov, H., Sahar, D.R., Witkow, S., et al. (July, 2008). Weight loss with a low-carbohydrate, Mediterranean or low-fat diet. The New England Journal of Medicine, 359:229-241.

Yes, I live in Arizona so I have a higher risk of melanoma

Of the three types of skin cancer, melanoma is the most serious. It affects the melanocytes, which produce the pigment melanin that gives skin its color. The cancerous melanocytes do not die when they should (apoptosis) and form a cancerous mass.

Melanoma can show up in a mole or other pigmented tissues such as the eye or intestines. According to the U.S. National Cancer Institute, more than 53,600 people find out they have melanoma each year. It is a figure that grows annually. The estimated amount of deaths is 8,420.

Those at risk that have many moles, fair skin, personal history of skin cancer, family history of skin cancer, weakened immune system or have had at least one severe, blistering sunburn.

To help prevent melanoma people should avoid midday sun, wear long sleeves, long pants and a wide-brim hat when outside, protect themselves from UV rays that penetrate clothing, windshields and windows, as well as those that are reflected by sand, water, snow and ice. Skin lotions, cream and gel may help. The higher the SPF the better protection. Sunglasses help too by protecting eyes and skin around the eyes.

Reference

U.S. National Cancer Institute. (2008). "What you need to know about melanoma." Retrieved on Sept. 15, 2008 from http://www.cancer.gov/cancertopics/wyntk/melanoma

14 September 2008

Man can't live by bread and water alone

Imagine you have been on a "bread and water" diet for three weeks and have noticed that a cut on your shin won't heal and bleeds easily. Why?

The inability to heal would largely be due to lack of vitamin C. Proper maintenance and repair of tissue depends on this essential nutrient (Tortora & Derrikson, 2006).

Once confirming a deficiency of vitamin C, assume signs of scurvy. According to Medline, along with skin hemmorrhages, general weakness, anemia, and gum disease.

Just an orange a day is sufficient for preventing scurvy, according to researchers from University of Toronto (Weinstein, Babyn & Zlotkin, 2001). The vitamin C in the citrus fruit serve as the right treatment.

My body would also need protein to produce healing. Nutrition consultant James Collier says the amino acids, along with vitamin C and zinc, are essential for the production of collagen and even a short duration of lack of protein can significantly slow healing (n.d.). Collier also suggests B vitamins, vitamin K, carbohydrates and fats are important. A few of these nutrients may have been supplied by the bread. Lack of protein would also significantly slow healing because your body would hold onto it for other vital functions (Tortora & Derrikson, 2006).

References

Collier, J. (n.d.). "Nutrition and wound healing." Retrieved on Sept. 14, 2008 from http://www.dietetics.co.uk/article-nutrition-wound-healing.asp.

Medline Plus. (2008). "Medical Encyclopedia: Scurvy." Retrieved on Sept. 14, 2008 from http://www.nlm.nih.gov/medlineplus/ency/article/000355.htm.

Tortora, G.J. & Derrikson, B. (2006). Principles of Anatomy and Physiology. New York: John Wiley & Sons.

Weinstein, M., Babyn, P. & Zlotkin, S. (2001). An orange a day keeps the doctor away: Scurvy in the year 2000. Pediatrics, 108:3, p. e55. Retrieved on Sept. 14, 2008 from http://pediatrics.aappublications.org/cgi/content/abstract/108/3/e55.

13 September 2008

What fluids should I use before my marathon?

Marathon runners can become dehydrated due to the extreme physical activity. What types of fluids should they consume in order to rehydrate their cells?

When you’re dehydrated, water is the hypotonic solution of choice for speedily moving via osmosis from blood directly into body cells that need rehydration (Tortora & Derrickson, 2006). Marathon runners, however, may need a little more solutes in the solution.

The physical exertion of running can create need of other nutrients for these athletes. Regular sweating and using up of glycogen calls for needs of carbohydrates to maintain blood glucose and salts for proper balance of plasma osmalility (Chen & Zimmerman, 1978). Sports drinks can offer an answer for proper running, but too many solutes in a drink would stop its hydration ability.

A good sports drink should remaining effective as a hypotonic solution, but still provide steady electrolytes, carbohydrates and possibly even vitamins. The extra sodium, according to British researchers of Loughborough University, results in improved performance (Merson et al, 2008). Thus, marathon runners should apply this knowledge for best results.

References

Cohen, I. & Zimmerman, A.L. (1978). Changes in serum electrolyte levels during marathon running. South Africa Medical Journal, 25:53(12):449-53.

Merson, S.J., Maughan, R.J. & Shirreffs, S.M. (July, 2008). Rehydration with drinks differing in sodium concentration and recovery from moderate exercise-induced hypohydration in man. European Journal of Applied Physiology, 103(5):585-94.

Tortora, G.J. & Derrikson, B. (2006). Principles of Anatomy and Physiology. New York: John Wiley & Sons.

06 September 2008

Should I see a nutritionist or stick to dietary guidelines?

We may all be made of flesh and blood, but each one of us has a body with unique differences. These varying individual distinctions can call for custom measures when it comes to needs for health. For these reasons good clinicians can accept established dietary guidelines as a general route for a population to make sensible eating choices, but, when appropriate, offer a tailored alternative to provide best results for a patient.

A suitable deviance from normal recommendations, for example, may be to take milk and cheese off the menu for patients of Native American and African ancestry. Lactose intolerance has been found by Cambridge researchers to affect these populations indiscriminately, which should lead clinicians to diverge from the US Department of Agriculture’s guidelines of dairy intake when caring for such affected patients (Scrimshaw & Murray, 1988).

For others increasing dietary intake of dairy may be useful. An athletic patient seeking nutritional advice may find herself or himself encouraged to supplement with protein from dairy whey directly after exercise since Australian researchers have just found that this practice may speed recovery of muscle (Buckley et al., 2008).

Customization of diet should not be limited to genetic and other physical variations in patients. The clinician who discovers a four-year-old girl’s inclination to refuse vegetables may recommend her concerned parents try a more-likeable chewable vitamin in place.

The examples given suggest person-centered care may be better for all. A community has benefited, however, from a fixed norm developed by public policy. Guidelines should not be considered as strict, but should help the grocery store and restaurant offer options while sensitive to the health of customers as well as help the lay person make smart daily food choices.

Selected References

Buckley, J.D., Thomson, R.L., Coates, A.M., Howe, P.R., Denichilo, M.O., & Rowney, M.K. (Sept, 2008). “Supplementation with a whey protein hydrolysate enhances recovery of muscle force-generating capacity following eccentric exercise.” Journal of Science and Medicine in Sport. [Ahead of print]. Retrieved Sept. 5, 2008, from Pubmed online database.

Scrimshaw, N.S. and Murray, E.B. (Oct.1988). “The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance.” American Journal of Clinical Nutrition. 48(4 Suppl):1079-159.