A new study suggests grapes may help fight heart disease and hypertension (high blood pressure) in those people that consume a diet high in salty foods.
Findings suggest that because of the high levels of naturally occurring antioxidants found in black, green and red grapes, the fruits may help lower blood pressure which can lead to heart failure.
Scientists believe flavonoids, a beneficial chemical found in grapes, may be the substance that provides beneficial effects found in a study of lab rats.
For the study, researchers gave rats a powered form of regular grapes – a blend of black, green and red - then analyzed the effects on rats that develop hypertension when fed a salty diet.
The rats were split in two groups – one group was given a diet containing a powered form of grapes and a high-salt diet. The other group of mice was fed grapes and a low-salt diet. The powder contained the same nutrients found in grapes which allowed researchers to closely measure the rats’ intake.
After 18 weeks, researchers found that the group of rats that consumed a grape-enriched diet had better heart function, lower blood pressure, reduced overall inflammation and less signs of heart muscle damage then the rats that consumed a salty diet but no grapes.
Rats on salty diets and hydralazine, a blood pressure medication, had lower blood pressure, but their hearts weren’t as protected from damage as the rats that were also fed grapes.
“The study findings support our belief that a chemical within the grapes can directly affect cardiovascular risk, beyond that of simple blood-pressure-lowering which we already known can be seen from a diet rich in fruits and vegetables,” says E. Mitchell Seymour, research associate University of Michigan’s Cardioprotection Research Laboratory.
“The inevitable progression of heart failure and hypertension was changed by adding grape powder to a high-salt diet,” said Dr. Steven Bolling, MD.
Researchers note that grapes and other fruits high in antioxidant phytochemicals have shown promise, as does the impact of red wine on heart health.
Overall, for people with elevated blood pressure, the best advice is to lower their intake of salty foods, Bolling says.
Researchers say that while the findings suggest that a grape-enriched diet can have broad effects on high blood pressure, more research is needed to determine if the beneficial effects will also prove helpful to humans.
The California Table Grape Commission provided financial support for the study which is published in the October issue of the Journal of Gerontology: Biological Sciences.
A previous study, published in the online Journal of the Public Library of Science, found that resveratrol slowed signs of aging in mice as effectively as a calorie-restricted diet, already proven to slow the decline in heart function associated with aging. #