This antioxidant-rich polyphenol from Chardonnay grape seeds reduces blood sugar, triglycerides, insulin resistance and oxidative stress linked to obesity, according to a new study in hamsters.
Researchers from the University of Montpellier, France, report that animals fed a high-fat diet but supplemented with the Grape Seed Extract (GSE) had 61% higher Adiponectin levels than animals fed only the high fat diet.
Adiponectin is a protein hormone produced and secreted exclusively by adipocytes (fat cells) that regulates the metabolism of fats and sugars and reduces inflammation.
Adiponectin increases the body’s response to insulin. Low blood levels of Adiponectin are associated with Diabetes, Obesity and Heart Attacks.
“This is the first time that chronic consumption of grape phenolics is shown to reduce obesity development and related metabolic pathways including adipokine secretion and oxidative stress,” wrote the researchers, led by Jean-Max Rouanet, in the journal Molecular Nutrition and Food Research.
Dr Rouanet and his co-workers divided hamsters into three groups: One group received a standard diet, one group was fed a high-fat diet, and the third received the high-fat diet and the grape seed extract (provided by Partoeno, Bordeaux).
After 12 weeks on the diets, the researchers found that animals on the high-fat diet had increased abdominal fat, compared to the hamsters on the standard diet.
On the other hand, hamsters fed the high-fat diet that were supplemented with the grape seed extract did not have increased abdominal fat, they said.
Additionally, in the high-fat diet group, increases in blood sugar, triglycerides, insulin and insulin resistance were observed, but according to the researchers, supplementation with the grape seed extract prevented “in part these effects.”
In the GSE supplemented group, blood levels of insulin and leptin were reduced by 16.5 and 45% respectively.
Researchers also found that GSE lowered blood sugar levels and strongly reduced cardiac production of the oxygen free-radical superoxide by as much as 74%.
“These results suggest that grape seed extract acted by mechanisms operating-at least in part-inside an antioxidant effect and the possibility that adiponectin might modulate oxidative stress, leading to anti-obesity effects,” wrote the researchers.
“Thus, we provided insights into one mechanism, increased oxidant stress, that probably contributes to the pathological after-effects of obesity and that may have important public health implications, being a target for interventions to decrease the pathology,” they added.
Source: Molecular Nutrition and Food Research
Published Online ahead of print, doi: 10.1002/mnfr.200800165
“Chardonnay grape seed procyanidin extract supplementation prevents high-fat diet-induced obesity in hamsters by improving adipokine imbalance and oxidative stress markers”
Authors: K. Decorde, P.-L. Teissedre, T. Sutra, E. Ventura, J.-P. Cristol, J.-M. Rouanet