A recent study in the Journal of Gerontology has found that consuming a “handful of grapes” a day can counteract high blood pressure. The direct mechanisms causing this benefit is not clear, but grapes and other fruits could potentially limit anti-oxidative damage on the heart, allowing the heart to function more efficiently and thus improving blood pressure.
Other theories suggest that compounds found in grapes called phenolic phytochemicals may improve the heart’s function on a genetic level by causing favorable gene expression. Grapes have also been shown to limit TNF-alpha and IL-6, two different inflammatory compounds that when present in the heart, are correlated to advancing heart failure.
Whatever the mechanism, including a “handful of grapes” a day has been shown to reduce hypertension (high blood pressure) in individuals with high blood pressure. If you already have healthy blood pressure, you can still eat grapes and obtain the phytochemical benefits without any unsafe drop in blood pressure as the grapes were only found to lower blood pressure in individuals with hypertension.
Seymour, E.M. et al. (2008) Chronic Intake of a Phytochemical-Enriched Diet Reduces Cardiac Fibrosis and Diastolic Dysfunction Caused by Prolonged Salt-Sensitive Hypertension. Journal of Gerontology. 63A, 1034-1042.