It is well know that a diet rich in fruits and vegetables is good for your overall health and also for the health of your heart. However, new research suggests that the phytochemicals found in fruits such as grapes may play an especially important role in maintaining healthy blood pressure levels and preventing damage to the heart.
The study examined the effects of various dietary combinations in Dahl Salt Senstive (Dahl-SS) rats to determine the cumulative cardiac effects of supplementation with grape phytochemicals. Grapes contain high quantities of phytochemicals called flavonoids, including anthocyanins, proanthocyanins, catechins and flavonols. Dahl-SS rats are an excellent model because when fed a high salt diet they develop hypertension and cardiac dysfunction similar to that seen in humans with salt-sensitive hypertension. The rats included in the study were fed one of five diets – low salt, low salt + grape powder, high salt, high salt + grape powder or high salt + the vasodilator hydralazine, for a period of 18 weeks.
At the end of the study rats fed a high salt diet supplemented with grape powder demonstrated significantly lower blood pressure, improved cardiac function, less indicators of inflammation, reduced cardiac hypertrophy, less oxidative damage to the heart and increased cardiac glutathione levels compared to those fed a high salt diet alone. Furthermore, while the high salt + hydralazine diet reduced blood pressure, it did not reduce cardiac pathogenesis.
It is likely that the grape-compounds exert beneficial cardiovascular effects through a number of mechanisms. Firstly, grape phytochemicals act to reduce blood pressure – possibly by causing vasodilation via increased nitric oxide levels. The phytochemicals in grapes also have powerful antioxidant properties, and can help protect the heart from oxidative damage. Polyphenols in grapes also act to increase glutathione levels – further preventing oxidative stress in the heart.
Seymour EM, Singer AAM, Bennink MR, Parikh RV, Kirakosyan A, Kaufman PB, Bolling SF. Chronic intake of a phytochemical-enriched diet reduces cardiac fibrosis and diastolic dysfunction caused by prolonged salt-sensitive hypertension. Journal of Gerontology. 2008; 63A(10): 1034-1042.
For more information see Pronogenol-2
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