Grape seed extract lowered the blood pressure
of patients who participated in a UC Davis study
of the benefits of the supplement on people with
high blood pressure.
Conducted by UC Davis cardiovascular researchers,
the study was the first human clinical trial to
assess the effect of grape seed extract on people
with metabolic syndrome, a combination of risk factors
that increase the risk for heart disease, including
high blood pressure, excess abdominal body weight,
high blood cholesterol fats and high blood sugar.
The researchers will present the results at the
American Chemical Society Meeting and Exposition
on March 26 in Atlanta, and at the Federation of
American Societies for Experimental Biology's 2006
meeting in San Francisco April 2.
It is estimated that 40 percent of American adults,
or 50 million people, have metabolic syndrome.
The one-month study involved 24 male and female
patients diagnosed with metabolic syndrome. The
patients were divided into three groups of eight.
The first group received a placebo, while the second
and third groups received 150 milligrams and 300
milligrams, respectively, of a new grape seed extract.
All participants' blood pressure was automatically
measured and recorded for 12 hours after ingestion.
"Participants in the two groups receiving grape
seed extract experienced an equal degree of reduced
blood pressure. The average drop in systolic pressure
was 12 millimeters. The average drop in diastolic
pressure was 8 millimeters," said the study's lead
researcher, C. Tissa Kappagoda, professor of cardiovascular
medicine and director of the Preventive Cardiology
Program at UC Davis.
Kappagoda adds that the group taking 300 milligrams
of grape seed extract also had reduced serum oxidized
LDL cholesterol levels.
"Generally, the higher their initial oxidized LDL
level was, the greater the drop by the end of the
study," he said. The extract has received the GRAS
(generally recognized as safe) certification from
the FDA and has no known side effects.
The UC Davis research team recently has recently
embarked on a second placebo-controlled human clinical
study of grape seed extract, looking at its benefits
for pre-hypertension patients with systolic pressure
of 120-139 mmHg, and diastolic blood pressure of
80-89 mmHg. Three previous studies in animal models
by this team have indicated that grape seed extract
may also prevent atherosclerosis.