Second UC Davis study concludes that a new unique grape seed extract may help lower blood pressure in pre-hypertensive patients

Grape seed extract may play a beneficial role in helping people diagnosed with pre-hypertension manage their condition, according to a study conducted by cardiovascular researchers at UC Davis School of Medicine and Medical Center. The findings, along with the mechanism of action, were presented at the Experimental Biology Conference in Washington, DC, on April 30, 2007. This is the second human clinical study conducted by UC Davis on the effects of grape seed extract on elevated blood pressure.

The most current study focused on adults suffering from pre-hypertension, or elevated blood pressure, which increases the risk of having a heart attack or stroke. Blood pressure decreases when the blood vessel walls are relaxed and the interior of the blood vessel (lumen) can dilate, or increase in size. This effect, called vasodilation, helps the body achieve positive physical gains beyond healthy blood pressure.

“Grape seed extract is rich in polyphenolic substances, which are known vasodilators. GSE works by acting on specific receptors within the endothelial cells,” said Dr. C. Tissa Kappagoda, M.B.B.S., Ph.D., Professor of Medicine, Division of Cardiovascular Medicine, University of California, Davis and Director of Preventive Cardiology Program, UCDMC. “This study indicated that the unique grape seed extract, supplied by Polyphenolics, does in fact help lower blood pressure in pre-hypertensive patients.”

In the study, pre-hypertensive subjects -- defined as having systolic blood pressure between 120 and 139 mmHG and/or a diastolic pressure between 80 and 89 mmHG – were randomly placed into a placebo group or an experimental group. The experimental group received 300 mg. of a unique grape seed extract called MegaNatural®_BP, developed and made by Polyphenolics, daily for eight weeks.

Those patients who were given the grape seed extract showed an 8 mm drop in systolic pressure versus zero for those in the placebo group; and a 5 mm drop in diastolic pressure versus an increase of 2 mm in the placebo group. “These statistically significant findings suggest that the unique grape seed extract, supplied by Polyphenolics, might be beneficial in people with pre-hypertension when used in conjunction with other lifestyle modifications including diet, exercise and weight management. The Joint National Committee (JNC7) does not recommend drug therapy at this time for these individuals.” said Dr. Kappagoda.

These results come on the heels of another human clinical study completed by UC Davis on the effects of this unique patent pending grape seed extract on the blood pressure of patients suffering from metabolic syndrome. In that study, participants receiving the MegaNatural®-BP grape seed extract experienced an average drop in systolic pressure of 12 mm, and an average drop in diastolic pressure of 8 mm.

Polyphenolics, a division of Constellation Wines U.S. and a leading manufacturer of ingredients for the nutritional and beverage industries, funded the research. Its extracts are produced in Constellation Wines U.S. wineries in California from unfermented grapes, using a patented, solvent-free, water extraction process. For more information, call 480-883-6716 or visit

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