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Grapes Lower High Blood Pressure
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If you want to lower your blood pressure (BP) naturally,
start eating more grapes. According to new research from the Cardioprotection Research Laboratory
at the University of Michigan, grapes help lower blood pressure (BP) and improve heart function. At
least it works in rats. Reuters reports that researchers are hopeful the findings may help people
who have hypertension. "These findings support our theory that something within the grapes
themselves has a direct impact on cardiovascular risk, beyond the simple blood pressure
(BP)-lowering impact that we already know can come from a diet rich in fruits and vegetables," lead
study author Mitchell Seymour said in a statement. The findings, published in the Journal of
Gerontology: Biological Sciences, may help people with high blood pressure
Because black, green, and red grapes contain high levels of
naturally occurring antioxidants, the fruits may reduce hypertension
that can lead to heart failure, shows the study, published in the October issue of the Journal
of Gerontology: Biological Sciences.
Scientists including Mitchell Seymour, MS, report that
flavonoids -- found in abundance in the skin, flesh, and seeds of grapes -- may be the
substances that provide the beneficial effects they found in their study of laboratory
rats.
The researchers studied the effects of regular table grapes
-- a blend of green, red, and black fruits -- that were fed to rats in powdered form.
After 18 weeks, rats that ate the grape-enriched powder had
lower blood pressure (BP), better heart function, and reduced inflammation throughout their
bodies than comparable rodents that didn't receive the mixture. Rats on salty diets plus
hydralazine, a blood pressure (BP) medicine, had lower blood pressure (BP), but their hearts
weren't as protected from damage as the animals fed grapes.
"Although there are many natural compounds in the grape
powder itself that may have an effect, the things that we think are having an effect against the
hypertension may be the flavanoids – either by direct antioxidant effects, by indirect effects
on cell function, or both. These flavanoids are rich in all parts of the grape - skin, flesh and
seed, all of which were in our powder." Bolling explains.
You can get flavanoids from berries and cherries as well. The
amount of grapes used is equivalent to a human eating 9 servings of grapes per day
The researchers say the study suggests that a grape-enriched
diet can have broad effects on hypertension, but that more work is needed to see if the
beneficial effects will apply to humans.
Food producers are keen to show the health benefits of their
products. Studies sponsored by chocolate makers, almond and walnut producers have shown various
heart benefits, including reducing inflammation in blood vessels and lowering the risk of heart
attacks and stroke.
Grape powder comprised about three percent
of the rats' diet. For humans, that would be about nine servings of grapes a day. One serving is
about 15 grapes.
The California Table Grape Commission provided financial
support for the study and supplied the grape powder. Other sponsors included the National Heart,
Lung and Blood Institute, part of the National Institutes of Health.
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grape seed extracts have shown improvements in blood flow
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So far, most of the evidence on grape polyphenols comes from laboratory
experiments and animal studies. However, a few studies support the disease-preventing benefits of
grapes in humans. Studies in patients treated with grape seed extracts have shown improvements in
blood flow and cholesterol levels. In other studies, drinking Concord grape juice has improved
measures of blood flow in patients with coronary artery disease and lowered blood pressure (BP) in
patients with hypertension.
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