Researchers from Belgium have also recently found that grape seed extract could disable the Norovirus which causes more than half of all food-born illnesses in the United States, and is the second greatest source of reported food borne illness outbreaks in the European Union.
New research show that the consumption of supplements containing grape seed and skin extract (GSSE) may be a valuabletherapeutic and preventative measure to fight obesity-induced kidney damage, according to new research data presented in the journal Applied Physiology, Nutrition, and Metabolism.
The new insights, from researchers in Tunisia, is the first to make a link between grape extract and an effect on kidney problems induced by a high-fat-diet.
In the study, rats were fed a high-fat diet that induced a low-grade kidney damage associated with high-fat diet, however, they found that almost all fat and kidney disturbances were reversed in rats that were given GSSE --which is known to contain powerful antioxidants.
"In our research, obesity-induced leaky kidney and proteinuria are shown to be prevented by GSSE, which suggests the use of GSSE as a preventive nutriceutical for high-risk patients," said study co-author Kamel Charradi, from the Center of Biotechnology of Borj-Cedria (CBBC) in Tunisia.
The researchers found that a high-fat-diet increased deposits of triglycerides (TG) in rats, raised signs of oxidative stress, and depleted copper levels in the kidneys.
However, when the animals received GSSE along with the high-fat diet there was a partial reversal of the TG deposition as well as repair of the damage caused. Furthermore the GSSE prevented the oxidative stress and copper depletion, the authors said.
Charradi and his team suggested that powerful polyphenols - including resveratrol - are likely the components in GSSE responsible for the positive effects.
Reducing Blood Pressure
A previous UC Davis study found that the benefits of grape seed extract on people with high blood pressure was effective in decreasing systolic values.
According to two new studies Grape seed extracts may also help reduce blood pressure in people at risk of hypertension, and improve cholesterol levels in people with metabolic syndrome, .
Using that Polyphenolics' MegaNatural-BP ingredient, researchers from the University of California, Davis, report that the grape seed extract was associated with significant reductions in systolic and diastolic blood pressure of pre-hypertensives, while no such improvements were observed in the placebo group.
A daily dose of 300 milligrams of the grape seed extract was associated with reductions in systolic and diastolic blood pressure of 8 and 5 mmHg after eight weeks, wrote the researchers in the Journal of Pharmacy and Nutrition Sciences.
This small, randomized, double-blind, placebo-controlled study "attempts to prove the concept that polyphenolic compounds present in grape seed are prototypes of biologically active compounds commonly found in fruits and vegetable which could form the non-pharmaceutical basis for managing pre-hypertension.
"It is recognized that larger placebo controlled long-term trials (conducted extending over several years) are required to determine whether these compounds reduce the number of people transitioning from prehypertension to overt hypertension."
In another trial with 12 people with metabolic syndrome taking Polyphenolics' MegaNatural-Gold grape seed extract, researchers from the Illinois Institute of Technology and the University of California Davis found that the a single dose of grape seed extract before a high-fat, high-carb breakfast was associated with improvements in antioxidant status and reduced glycemic response to a meal.
Metabolic syndrome refers to a cluster of conditions including high blood pressure, raised blood sugar level, excess body fat around the waist or low HDL (the good cholesterol) and increased blood triglycerides --all of which are known to significantly increase the risk for heart disease, stroke and diabetes.
MetS is also known to be associated with impaired glucose tolerance and poor glycemic control, explained the researchers. "Consumption of a meal high in readily available carbohydrates and fat causes postprandial increases in glycemia and lipidemia and markers of oxidative stress, inflammation and insulin resistance," they added.
"Administration of grape seed extract one hour before breakfast enhanced antioxidant status of people with MetS and was associated with decreased postprandial glycemia, suggesting enhanced insulin economy," they wrote in Functional Foods in Health and Disease .
"The clinical implications of our findings require additional research; however, these findings support a growing body of research that suggests consuming polyphenol rich foods/extracts with or within an hour of a meal can minimize the unfavorable perturbations in postprandial redox balance and metabolism induced by modern day eating and lifestyle patterns."
Natasha Longo has a master's degree in nutrition and is a certified fitness and nutritional counselor. She has consulted on public health policy and procurement in Canada, Australia, Spain, Ireland, England and Germany.