Wednesday, October 29, 2008

The WHAM of Grapes: Possible High Blood Pressure Aid?

A new University of Michigan study suggests that eating grapes can help fight high blood pressure related to a salty diet, as well as calm some of those other factors related to heart diseases.

The new study, published in the October issue of the Journal of Gerontology: Biological Sciences, gives clues to the potential of grapes in reducing cardiovascular risk. The effect is thought to be due to the high level of phytochemicals – naturally occurring antioxidants – that grapes contain. (As you know, grapes have shown other cardio benefits when they are used in the production of wine, as well.)

The researchers noted that while these study results are extremely encouraging, more research needs to be done in humans, as this work was with animals.

The researchers studied the effect of regular table grapes (a blend of green, red, and black grapes) that were mixed into the test animals' diet in a powdered form, as part of either a high or low-salt diet. They performed many comparisons between the rats consuming the test diet and the control rats receiving no grapes — including some that received a mild dose of a common blood-pressure drug. All the rats were from a research breed that develops high blood pressure when fed a salty diet.

In all, after 18 weeks, the rats that received the grape-enriched diet had lower blood pressure, better heart function, reduced inflammation throughout their bodies, and fewer signs of heart muscle damage than the rats that ate the same salty diet but didn’t receive grapes. The rats that received the blood-pressure medicine, hydrazine, along with a salty diet also had lower blood pressure, but their hearts were not protected from damage as they were in the grape-fed group.

U-M heart surgeon Steven Bolling, M.D., a professor of cardiac surgery at the U-M Medical School, notes that the animals in the study were in a similar situation to millions of Americans, who have high blood pressure related to diet, and who develop heart failure over time because of prolonged hypertension.

“The inevitable downhill sequence to hypertension and heart failure was changed by the addition of grapes to a high-salt diet,” he says.

“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." Bolling explained that all of these ingredients were in the rats' diet.

I don't know about you, but I am going to start placing "table grapes" on my table more often!


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