Supplements containing grape seed extracts may help reduce blood pressure in people at risk of hypertension, and improve cholesterol levels in people with metabolic syndrome, according to two new studies.
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.”
Functional Foods in Health and Disease
Volume 2, Issue 12,
“Effect of grape seed extract on postprandial oxidative status and metabolic responses in men and women with the metabolic syndrome - randomized, cross-over, placebo-controlled study”
Authors: I. Edirisinghe, J. Randolph, M. Cheema, R. Tadapaneni, E. Park, B. Burton-Freeman, T. Kappagoda
Journal of Pharmacy and Nutrition Sciences
Volume 2, Pages 155-159, doi: 10.6000/1927-5951.2012.02.02.6
“Effect of Grape Seed Extract on Blood Pressure in Subjects with Pre-Hypertension”
Authors: M. Robinson, B. Lu, I. Edirisinghe and C.T. Kappagoda