Low-dose supplementation of resveratrol daily may reduce oxidative stress and improve the body's sensitivity to insulin, a study from University of Pecs in Hungary suggests.
In a double-blind, placebo-controlled study published in the British Journal of Nutrition, Hungarian researchers report observations that people with type 2 diabetes who take 5 milligrams of resveratrol twice daily improved their sensitivity to insulin after only our weeks.
"The present study shows for the first time that resveratrol improves insulin sensitivity, which might be due to a resveratrol-induced decrease in oxidative stress that leads to more efficient insulin signaling via the Akt pathway," the authors concluded.
The Akt pathway is a pathway involved in cellular uptake of glucose in response to insulin—it induces glucose transport, particularly into muscle cells. When working properly, insulin stimulates cells to take in glucose from the blood stream, thereby lowering circulating glucose levels and providing carbohydrate for the cells for energy production.
In this study, the researchers randomized 19 Caucasian male participants with type II diabetes into two groups. The intervention group received 5 milligrams of resveratrol, twice daily for four weeks. The control group received a placebo twice daily.
By the fourth week, the intervention group showed significantly reduced oxidative stress and increased levels of phosphroylated Akt, indicating improved insulin sensitivity. Similar studies also documented a glucose-lowering effect of resveratrol in diabetic rodents.
Resveratrol, a naturally occurring compound found in grapes and other foods, is also famed because of evidence as an anti-aging bioactive and an aid in weight management.
Reference
Brasnyo P, Molnar GA, Mohas M et al. Resveratrol improves insulin sensitivity, reduces oxidative stress and activates the Akt pathway in type 2 diabetic patients. Br J Nutr 2011;1-7.
Showing posts with label resveratrol. Show all posts
Showing posts with label resveratrol. Show all posts
12 November 2010
Resveratrol influences belly fat behavior
Fat can not only be unsightly, but if it’s sitting on your belly, may also contribute to overproduction of signaling hormones called adipokines, which are linked to metabolic changes that can worsen health.
New research from Aarhus University has found that abdominal adipose tissue extracted from overweight adults, and then exposed to resveratrol, exhibited reduced adipokine production. According to these authors, "small interfering molecules such as resveratrol are, in this matter, hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity."
The scientists obtained the abdominal adipose tissue via liposuction from seven women and one man, ages 43-55, who had body mass indexes categorized as overweight. All subjects were Caucasian, healthy and not on any medication that could confound the results.
Because previous studies in rodents have shown that calorie restriction reduces production of adipokines by activating an enzyme called Sirtuin 1, the scientists had hypothesized that resveratrol may act similarly. Resveratrol is well-known as a potent Sirtuin 1 activator.
This most recent in vitro study, published in International Journal of Obesity, suggests that regular dietary intake of resveratrol may guard against the metabolic changes that occur when there is excess fat on the body – as it has with rodents and monkeys.
Resveratrol is a phytoalexin (a plant-produced antimicrobial substance) found in small amounts, most notably, in red wine, as well as in other common foods such as grapes, peanuts, and chocolate. The most concentrated natural source is the Japanese Knotweed (Polyganum cuspidatum).
Resveratrol gained scientific interest after it demonstrated effects similar to calorie restriction in slowing the rate of aging and increasing the lifespan in a number of species including nematode worms, mice, and rhesus monkeys. In addition, resveratrol protects overfed mice from weight gain and lemurs from seasonal weight gain.
Source: Olholm J, Paulsen SK, Cullberg KB, Richelsen B, Pedersen SB. Int J Obes (Lond) 2010;34:1546-53.
New research from Aarhus University has found that abdominal adipose tissue extracted from overweight adults, and then exposed to resveratrol, exhibited reduced adipokine production. According to these authors, "small interfering molecules such as resveratrol are, in this matter, hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity."
The scientists obtained the abdominal adipose tissue via liposuction from seven women and one man, ages 43-55, who had body mass indexes categorized as overweight. All subjects were Caucasian, healthy and not on any medication that could confound the results.
Because previous studies in rodents have shown that calorie restriction reduces production of adipokines by activating an enzyme called Sirtuin 1, the scientists had hypothesized that resveratrol may act similarly. Resveratrol is well-known as a potent Sirtuin 1 activator.
This most recent in vitro study, published in International Journal of Obesity, suggests that regular dietary intake of resveratrol may guard against the metabolic changes that occur when there is excess fat on the body – as it has with rodents and monkeys.
Resveratrol is a phytoalexin (a plant-produced antimicrobial substance) found in small amounts, most notably, in red wine, as well as in other common foods such as grapes, peanuts, and chocolate. The most concentrated natural source is the Japanese Knotweed (Polyganum cuspidatum).
Resveratrol gained scientific interest after it demonstrated effects similar to calorie restriction in slowing the rate of aging and increasing the lifespan in a number of species including nematode worms, mice, and rhesus monkeys. In addition, resveratrol protects overfed mice from weight gain and lemurs from seasonal weight gain.
Source: Olholm J, Paulsen SK, Cullberg KB, Richelsen B, Pedersen SB. Int J Obes (Lond) 2010;34:1546-53.
11 August 2010
Resveratrol-Rich Plant Extract Stifles Inflammation in Humans
Resveratrol’s antioxidant and anti-inflammation actions shown previously only in vitro and in laboratory animals have now been observed in a small human study.
State University of Buffalo New York and Kaleida Health researchers found that supplementation with a plant extract containing resveratrol suppressed generation of free radicals called reactive oxygen species (ROS) and reduced expression of two major proinflammatory pathways.
Writing in their study, published in Journal of Clinical Endocrinology and Metabolism, the researchers state that they have demonstrated for the first time in humans “comprehensive effects on ROS generation and inflammation” and the “antiaging action of resveratrol.”
In the trial, two groups of 10 healthy adults were randomized to receive placebo or 200 milligrams of Japanese knotweed extract (Polygonum cuspidatum) supplying 40 milligrams of resveratrol daily. Fasting blood samples were collected before, during and after six weeks of supplementation. Subjects chosen were not on any antiinflammatory drugs.
The researchers’ data showed clear suppression of ROS generation and reduced expression of TNF-alpha and IL-6, which are regulated by NFkB, that led to falling levels of C-reactive protein, which are all involved with inflammatory response.
In parallel, the extract reduced expression of two major proinflammatory enzymes, JNK-1 and IKK-beta.
Resveratrol’s effects on reducing oxidative stress and inflammation are thought to take place because it activates production of SIRT1, one of a family of proteins that is positively associated with influencing fat metabolism, slowing aging, and extending lifespan in response to calorie restriction and fasting in yeast and animals.
Chronic oxidative stress and inflammation are implicated as factors that accelerate aging because of damage caused to cellular components including membranes, mitochondria and DNA.
Source: Ghanim H, Sia CL, Abuaysheh S, Korzeniewski K, Patnaik P, Marumganti A, Chaudhuri A, Dandona P. An Antiinflammatory and Reactive oxygen Species Suprressive Effects of an Extract of Polygonum Cuspidatum Containing Resveratrol. J Clin Endocrin Metab. 2010; 10:12.
State University of Buffalo New York and Kaleida Health researchers found that supplementation with a plant extract containing resveratrol suppressed generation of free radicals called reactive oxygen species (ROS) and reduced expression of two major proinflammatory pathways.
Writing in their study, published in Journal of Clinical Endocrinology and Metabolism, the researchers state that they have demonstrated for the first time in humans “comprehensive effects on ROS generation and inflammation” and the “antiaging action of resveratrol.”
In the trial, two groups of 10 healthy adults were randomized to receive placebo or 200 milligrams of Japanese knotweed extract (Polygonum cuspidatum) supplying 40 milligrams of resveratrol daily. Fasting blood samples were collected before, during and after six weeks of supplementation. Subjects chosen were not on any antiinflammatory drugs.
The researchers’ data showed clear suppression of ROS generation and reduced expression of TNF-alpha and IL-6, which are regulated by NFkB, that led to falling levels of C-reactive protein, which are all involved with inflammatory response.
In parallel, the extract reduced expression of two major proinflammatory enzymes, JNK-1 and IKK-beta.
Resveratrol’s effects on reducing oxidative stress and inflammation are thought to take place because it activates production of SIRT1, one of a family of proteins that is positively associated with influencing fat metabolism, slowing aging, and extending lifespan in response to calorie restriction and fasting in yeast and animals.
Chronic oxidative stress and inflammation are implicated as factors that accelerate aging because of damage caused to cellular components including membranes, mitochondria and DNA.
Source: Ghanim H, Sia CL, Abuaysheh S, Korzeniewski K, Patnaik P, Marumganti A, Chaudhuri A, Dandona P. An Antiinflammatory and Reactive oxygen Species Suprressive Effects of an Extract of Polygonum Cuspidatum Containing Resveratrol. J Clin Endocrin Metab. 2010; 10:12.
29 July 2010
Resveratrol blocks weight gain in primate study
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| Gray mouse lemur |
The study was published in BMC Physiology by a team of researchers from the Centre Nationale de la Recherche Scientifique, Museum National d’Histoire Naturelle, of Paris, who wrote that they had “demonstrated for the first time the short-term effects of resveratrol on the metabolism of an heterothermic [with varying body temperatures] primate.”
Gray mouse lemurs are a species of prosimian primate that can double in weight (seasonal fattening) within a matter of weeks. This increase in energy reserves is induced by the arrival of shorter days and longer nights (shorter photoperiod), which serves as a means of adapting to the long dry winters in its natural environment in Madagascar.
When given four weeks of resveratrol supplementation at the time of pre-winter fattening (200 milligrams per kilogram per day), the gray mouse lemurs exhibited the following “significant effects on energy metabolism”:
Reduction in seasonal body-mass gain associated with an increase in resting metabolic rate of 29 percent while decreasing food calorie intake by 13 percent.
Strong reduction of daily heterothermia expression (changes of body temperature relating to season) with no change in the daily amount of locomotor activity.
An increased secretion of glucose-dependent insulinotropic polypeptide (a gut hormone known to induce insulin secretion) levels that may play an additive role in limiting body-mass gain.
The researchers concluded that, “resveratrol activates energy expenditure by inducing an increase in resting metabolic rate and a decrease in torpor [temporary hibernation] patterns that play key roles in energy saving in this primate. Moreover, resveratrol had a satiety effect in this primate that reduced their spontaneous food intake.”
Resveratrol’s effects are potentially due to stimulation of SIRT1, one of family of sirtuin enzymes, that has a direct role in fat metabolism. Calorie restriction and, recently, intermittent fasting have also been shown to activate SIRT1 activity.
Mouse Lemurs to Humans
In a prepared statement, Fabienne Aujard, a co-author of the study, wrote, “The physiological benefits of resveratrol are currently under intensive investigation, with recent work suggesting that it could be a good candidate for the development of obesity therapies.”
When asked through e-mail about how the study related to humans, Aujard replied that the main point of the study is that the gray mouse lemur is a non-human primate, “This species is genetically closer to human. The data obtained with this lemur should be more easily extrapolated to humans compared to rodent studies.”
Investigation conducted in humans have mainly studied bioavailability in lesser amounts, not in the high amounts given to the lemurs (equivalent of a human weighing 70 kilograms taking 14 grams of resveratrol). At present, the maximum single dose studied in humans has been 5 grams (70 milligrams per kilogram for a human of 70 kilograms).
“However, despite being a primate, the mouse lemur’s organism is certainly very different from that of a human because of its size and its seasonality,” writes Aujard. “The mouse lemur is a small animal and, like all small mammals, it has a very active metabolism, thus, a very important nutrient metabolism. Therefore, we believe that the doses to be ingested by human to reach the same long-term effects will certainly be lower than that given to lemurs.”
The general recommendation for humans is between 50 to 500 milligrams daily, which is safe as supported by human clinical studies. Although this study shows promising results, it is not yet known whether or not resveratrol will influence fat metabolism or body composition in humans.
Source: Dal-Pan A, Blanc S, Aujard F. Resveratrol suppresses body mass gain in a seasonal non-human primate model of obesity. BMC Physiol 2010;10:11.
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