Grape Seed Extract for Blood Pressure?
Study: Grape Seed Extract May Help Tame Prehypertension
March 27, 2006 -- Grape seed extract might help control blood pressure, a
new study shows.
The news comes from scientists at the University of California at Davis.
They studied 24 adults with metabolic syndrome, a cluster of abnormalities that
raises the risk of diabetes and heart disease.
Most participants had prehypertension; the others had normal blood pressure.
Prehypertension falls between normal and high blood pressure.
Participants were split into three groups. One group got a fake (placebo)
treatment. Another group took 150 milligrams per day of grape seed extract. The
third group took 300 milligrams daily of the same grape seed extract.
Four weeks later, blood pressure had dropped for those taking grape seed
extract. Blood pressure didn't change in the placebo group.
The findings were presented in Atlanta at the American Chemical Society's
National Meeting & Exposition.
Blood Pressure Effects
The two extract doses were "equally efficient in lowering the blood
pressure," researcher C. Tissa Kappagoda, MD, PhD, tells WebMD. Kappagoda
specializes in cardiovascular medicine at the University of California at
Systolic blood pressure (the top number in a blood pressure reading) dropped
12 points, on average. Diastolic blood pressure (the bottom number in a blood
pressure reading) dropped an average of 8 points, Kappagoda says.
The blood pressure changes were seen "across the board," not just in
people with prehypertension, says Kappagoda. He notes that his team had already
done preliminary work on people with normal blood pressure and found no
dangerous drop in blood pressure with grape seed extract.
Kappagoda and colleagues had previously found that grape seed extract might
help dilate blood vessels. "Because of that, we thought it had potential as
a blood-pressure-lowering agent," Kappagoda says.
In Kappagoda's latest study, LDL "bad" cholesterol levels also fell
in people taking the higher extract dose, but not in those taking the lower
Talk to Doctor First
Grape seed extract isn't marketed with any health claims, Kappagoda points
He says people who are thinking about taking grape seed extract should
consult their doctors. Kappagoda also says he "wouldn't want to
recommend" that anyone stop taking medicine for high blood pressure in
favor of grape seed extract.
"But on the other hand, if their physicians have said, 'You know, you're
kind of borderline,' and so on, then there may be some place for this after
consulting their physician," Kappagoda says, pointing out that doctors
usually recommend lifestyle change -- not prescription drugs -- to treat
The study was funded by the extract's maker, Polyphenolics Inc.