Nevermind body fat; put focus on muscle with age

With all the attention given to body fat, a result of the high prevalence of obesity and type 2 diabetes, skeletal muscle is often given the back seat. Yet holding on to lean muscle mass alone, in itself, may be the most important factor in avoiding health problems above. What's often forgotten is that skeletal muscle is a metabolically active tissue that plays a critical role in consuming energy and determining metabolic rate, it's the large site for fat burning, and it's a primary site for blood glucose disposal. It's time to give muscle its due.

When you reach age 60 or older, it gets harder to keep, let alone build, muscle. The reasons are a combination of lack of energy, exercise, dietary protein, and hormones. One more is a blunted protein synthesis response that is described as anabolic resistance in aging. Left to run their course, these factors eventually bring on a decrease of muscle mass over time, or sarcopenia. The loss is also often accompanied with an increase in fat mass, or sarcopenic obesity. Sarcopenic obesity brings along with it the lack of both mobility and physical function, with compounding effects, that eventually lead to increased risk of chronic disease.

Depression and telomeres

Reference: Wolkowitz et al. 2011 March.

People who suffer from major depression have a higher risk of age-related illness and earlier mortality (1 &2). Researchers from University of California, San Francisco (UCSF), investigated (1) telomere length in depressed individuals versus matched controls and assessed other biological factors associated with telomere shortening.

Led by Nobel laureate Elizabeth Blackburn, Ph.D., the team of researchers published their findings in the March issue of PLos One. Their hypothesis was that not all depressed subjects would show shortened telomeres equally because of a large variance in depressive episodes over a lifetime. However, they predicted that those who suffered from depression for long durations would have shorter telomeres due to longer exposure to oxidative stress and inflammation induced by psychological stress.

The scientists recruited 18 subjects diagnosed with Major Depressive Disorder (MDD), excluding those with psychosis or bipolar histories, as well as those with Post-Traumatic Stress Disorder to eliminate confounding variables due to interferences with stress hormone regulation. Results from depressed individuals were compared to those of the matched control group.

Safe weight loss for seniors through diet and exercise

In the United States, the number of obese older adults has reached disturbing heights—now affecting approximately 20 percent of those ages 65 and older—and is only expected to rise as more Baby Boomers become senior citizens.

Weight loss through calories reduction or exercise are generally good for most people as an intervention in obesity, although the appropriateness of these methods has historically been a matter of controversy in older, obese adults.

A major concern with weight loss is the accompanying loss of lean tissue, which can accelerate existing sarcopenia (age-related loss of muscle and strength), and result in reduction of bone mineral density that could worsen frailty. This could lead to greater risk of bone fractures and broken hips. Studies have yet to provide sufficient evidence, one way or another, as to whether or not weight loss provides a true enhancement to quality of life.

Is there a link between telomeres and dietary fiber?

New evidence published in Archives of Internal Medicine has it that eating more dietary fiber, particularly from whole grains, could lead to a longer life. The large study found a high-fiber diet reduced risk of heart disease and cancer, as well as infectious and respiratory illnesses.

This is great news for those eating diets high in fiber. What’s also interesting is that another reason why dietary fiber is protective to health is because of its influence on telomeres. Telomeres are the protective caps at the end of chromosomes, and their length is considered the closest way to measure lifespan in humans.

As reported in a prospective cohort study published in the March 2010 issue of American Journal of Clinical Nutrition (AJCN), telomere length is positively associated with higher fiber intake in women. Dietary fiber from whole grains appears to provide the strongest benefit.

In addition, in the AJCN study, the researchers found telomere length was negatively associated with increased waist circumference and higher intake of omega-6 fatty acids in the diet.

Because the study was only observational, the authors reported that further investigation is necessary to further illuminate the link between dietary fiber and telomere length.

Whole grains examples are rolled oats, buckwheat, whole wheat, and wild rice. The grains contain the entire grain kernel, which include the bran, germ and endosperm. Less than 5 percent of Americans consume the minimum recommended amount of whole grains, which is about 3 ounce-equivalents per day, according to U.S. Department of Agriculture.

Americans barely receive half the amounts of dietary fiber recommended daily. How much dietary fiber is enough? The recommended amounts are 25 grams of fiber for women and 38 grams of fiber for men.

The AJCN study was among the first to document the relationship between diet and telomere length. The authors of the study concluded that the results provided more support that an improved diet and lifestyle would indeed help to slow the aging process.

"Telomere shortening is accelerated by oxidative stress and inflammation, and diet affects both of these processes," the authors report.

Studies have also found that the following changes in diet and lifestyle are all positively associated with telomere length:

•  not smoking
• exercising regularly
• maintaining a normal body weight
• healthy management of stress
• consuming sufficient long-chain omega-3 fatty acids from fish weekly
• maintaining a healthy vitamin D status
• consuming a quality multivitamin daily
• consuming antioxidants such as CoQ10 and green tea

Sources:

Park Y, Subar AF, Hollenbeck A, Schatzkin A. Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study. Arch Intern Med 2011.
Cassidy A, De V, I, Liu Y et al. Associations between diet, lifestyle factors, and telomere length in women. Am J Clin Nutr 2010;91:1273-80.

Post originally written to be posted here.

Living longer with an ideal BMI

Maintaining a healthy body mass index, or BMI, is one of the most important ways to help you live longer, according to a new study published in the December issue of New England Journal of Medicine.

BMI is not a perfect measure, but it is one of the simplest for estimating body weight. It is calculated by weight in pounds divided by height in inches squared and multiplying the number by 703, or by weight in kilograms divided by height in inches squared. What’s your BMI? Find out using this free calculator provided by the National Heart Lung and Blood Institute, of the National Institutes of Health.

The study’s findings support an optimal BMI in the “normal weight” range of 20 to 24.9, which is generally associated with the lowest risk of death from all causes including chronic diseases such as cardiovascular disease and cancer. The association was strongest among participants who were younger than 50 years old.

A BMI of 25 or more was associated with the highest mortality risks. The higher the BMI, the higher the likelihood of dying from cardiovascular disease.

“The results of our analysis are most relevant to whites living in affluent countries,” write the authors who pooled and analyzed data from 19 prospective studies encompassing 1.4 million white adults ages 19 to 80.

In the United States, among non-Hispanic whites, there was an estimated 11 percent of men and 17 percent of women with a BMI of 35 or higher in 2008.

The authors restricted the study to non-Hispanic whites based on self-reported ethnic group and controlled for pre-existing conditions, alcohol consumption, barbital status, education, and physical activity. They also excluded those with a BMI of less than 15 or higher than 50.

Smokers made up 25 percent of the study participants in the lowest BMI category of 15 to 18.4 and 8 percent of those in the highest BMI category.

Source: Berrington de Gonzalez A, Hartge P, Cerhan JR et al. Body-Mass Index and Mortality among 1.46 Million White Adults. NEJM 2010;363:2211-9.

Thoughts:

BMI is easy for anyone to measure, so this study gives us some back-up for using it as a way to speak to clients about real implications of obesity causing a shortened lifespan because of increased risk of cardiovascular disease and cancer.

It's important, however, to realize that while BMI may be easy it's possible for someone to be at a "normal weight" and still be "obese" -- dubbed normal weight obesity. This is still hazardous to your health, so you can't completely rely on BMI. Opt instead for body fat percentage measurement.

Aubrey de Grey Response to Rose and Coles

Aubrey de Grey

Next up at H+ @Caltech this afternoon was the famous and fast-talking Aubrey de Grey, who provided a response to previous talks by Michael Rose and Stephen Coles.

This is my take as how I understood the arguments. It was, admittedly, a bit hard to follow.

What we heard from Rose and Coles, explained de Grey, was that we have an exponential rise in deaths and then, we have what de Grey called, a "weird leveling off."

So, he said that as we get older, the data point to the fact that we eventually do reach a plateau in old age when mortality rates decline (passing the "aging phase" into a "biological immortality phase"), an argument of which Coles vehemently disagrees with.

He also said that it would probably not be a plateau like the type that Rose discussed in his talk, and as he showed in fruitflies.

Basically the data are sparse in these older populations, so there's no way we can really know what to expect.

"We definitely need more data," de Grey summarized.

And everyone else appeared to agree with that.

He also re-hashed his SENS approach for ridding the "accumulation of damage" that he says eventually causes the end of an individual's life.

De Grey pointed to the Gompertz Curve to support his arguments and the fact that because there are so few old people, there's too few data to make any kind of sense of whether there's an immortality phase or not.

Previously, about de Grey:
- Anti-Aging with Aubrey de Grey
- How to Prevent an Aging Crisis 

Building Methuselahs

Michael Rose, evolutionary biologist

Michael Rose is an evolutionary biologist, of University of California at Irvine, who knows how to sum up the complexity of aging.

He told us at H+ @ Caltech that aging is just a normal process of natural selection. It's obviously a "big picture" view versus a cellular or molecular view.

But to prove his point, he decided to trick natural selection and produce fruitflies that live five times longer than the average.

The trick? Take the fruitflies that can reproduce in old age, which still have most of their physiological function, and repeat.

Pretty simple. Eventually, you get longer-living fruitflies selected for late-life reproduction. And he shared data on how this all worked.

From the fruitfly data, Rose then explained, we can learn a bit about why humans age in the way they do, with pressures of reproduction playing in as a major factor. Also, we can make use of data on the flies and other animals that suggests that species enter a "biological immortality" phase once reaching an older age.

Then, he gave a two-part strategy into how humans can deter aging using "natural immortality technology." The strategy is easy and can be started tonight, he said.

What is natural for humans?
-It's not industrial lifestyle with cars, Twinkies, TV
-But is it the agricultural lifestyle or the hunter-gatherer lifestyle that is natural for us?

As an experimental evolutionist, Rose has research that shows that populations have adapted well to new environments in just 30 to 60 generations, so Eurasian populations are better adapted to the agricultural lifestyle.

How this happens? History in the environment, smaller effective population sizes, and lots of early accidental mortality leading to earlier plateaus.

So, people of ages under 30, should take an Andrew Weil approach to diet (as opposed to a Paleo diet and lifestyle) with plenty of fruits and vegetables, whole grains, and dairy.

However, he adds that as we age, the physiology of people with Eurasian ancestry progressively reverts back to the hunter-gatherer lifestyle.

"You will lose that adaptation to the novel environment as you age," Rose said.

So, the recipe for natural immortality?

- adopt a hunter-gatherer lifestyle after 40 if Eurasian, earlier if ancestry is less Eurasian

- use best modern medicine

- use autologous tissue repair when it becomes available (5+ years)

- use next-generation pharmaceuticals with less side effects

Interestingly, Aubrey de Grey expressed outrage that his recipe of immortality did not include rejuvenation research. He'll be speaking soon.

UPDATE: I ended up writing a more in-depth take into Michael Rose's talk for KurzweilAI, which can be found here.

Is there a maximum human lifespan?

Stephen Coles

"Death is an imposition on the human race and can no longer be tolerated" - Alan Harrington

With Harrington's quote, Stephen Coles opened his talk on whether or not there is a maximum limit to human lifespan at H+ @ Caltech in Los Angeles.

As a biogerontologist, Coles studies old people, as well as old yeast, microscopic worms, flies and primates. Each of these species have lifespan limits, and, indeed, he answers, there is a maximum number of years that humans live.

However, he adds, the more we understand aging, and the diseases that kill us, it is possible to extend life's max limit.

"All bets are off if we can do something about it," Coles said.

Although, he explains that the entire process of aging is so complex that it is sort of like the blind men touching the elephant because, if your blind, it has a different shape depending on where you're touching.

Putting together the pieces that make up aging is the AMMG, which has met several times in the last couple of decades and has an accumulated "a whole lot of data."

Coles remains optimistic that Calment Limit of 120 will be surpassed, as he shows us data on the increase in the number of centenarians and supercentenarians in the world.

In addition, the average life expectancy has increased over these years. 

Average life expectancies historically:

100 KYA 18

5 KYA (Ancient Egypt) 25

1400 AD (middle ages) 30

... Anyone else know the rest?

Most of us now die in our 70s from cardiovascular disease and cancer.

There's seriously a revolution going on in the understanding of aging, partly because of Stephen Coles's research in supercentenarians, including analysis of there genomes, etc. He's also worked with autopsies of centenarians.

Coles also showed data on autopsies of supercentenarians that revealed that most of them succumb to TTR (transthyretin amyloidosis).

He argues that if real life extension is to come in the future because of new technologies, then "we need a bridge plan."

These bridges are outlined here . 

What can beetles tell us about slowing aging? Answers are in the mitochondria

Mitochondrial genes influence life expectancy in beetles, a new study reports.

Genetic research into aging and longevity revolves mainly around the nuclear genome, which encodes most of our multicellular bodies, but a new Monash University study performed on beetles suggests shifting focus to the mitochondrial genome.  

The mitochondria—kidney-shaped organelles often referred to as the cell's powerhouses—each contain their own set of DNA, passed on from mother to offspring, and according to the study, it's these strands that may hold key genes that determine one's life expectancy, at least in bugs.  

The study, published in the August issue of The American Naturalist, found evidence that particular combinations of genes (haplotypes) in the mitochondrial genome influenced lifespan in a species of seed beetles (Callosobruchus maculates).  

As a result, the research supports growing evidence that particular mitochondrial gene combinations could also play a major role in accelerating the aging process in humans because they could cause mitochondria to produce greater amounts of toxic molecules called free radicals causing oxidative damage to cells, cellular proteins and DNA.  

Evolutionary biologist Damian Dowling of Melbourne, who conducted the study, hopes his research will help medical scientists identify which gene combinations accelerate aging, as well as develop gene therapies that alter the combinations, or develop antioxidant therapies that neutralize free radicals and protect cells from oxidative damage. Do mothers show favoritism toward daughters?  

Although Dowling found his discovery interesting, he said it was not the original intent of his research; in fact, he was testing a debated theory that mitochondrial genes make an impact on the tug-of-war between the sexes in the beetles. Previous research in beetles and fruit flies has explored a ubiquitous phenomenon in insects commonly called the "cost of mating"—that is, that the simple act of sexual reproduction can take a toll on mothers, and sometimes fathers, by reducing their life expectancy.  

Dowling’s wanted to find out if mitochondria bestowed any reward to female beetles. He explained to me: "Because the mitochondrial genome is maternally inherited it has been hypothesized that it will take the female's best interests at heart." 

But, he adds, "Our study was the first experimental test of this idea, and we didn't support the controversial idea." However, what Dowling did find was something more exciting—that different mitochondrial gene combinations, sourced from different geographic locations from around the globe, produced large differences in life spans in the beetles.  

“Beetles that harbored certain mitochondrial DNA sequences could live up to 30 percent longer,” he told me. Thirty percent longer is about 20 more days for the life of a beetle, which is nothing short of a leap for the crawling critters—when scaled up to human years, it amounts to adding about 23 more years.