A study by University of Michigan indicates that grapes act as a shield against blood pressure. The study indicates that black, green and red grapes contain high levels of natural antioxidants that reduce hypertension. Flavonoids found in the skin, pulp and seeds of grapes help in lowering the blood pressure.

Experiments were conducted on two groups of rats. The researchers found that after 18 weeks, rats that ate the grape-enriched powder had lower blood pressure, better heart function, and reduced inflammation throughout their bodies. Whereas the second group which did not didn't get the mixture and was treated with hydrazine, a blood pressure medicine, showed less healthy hearts.

"Though it's true that your mom told you to eat all your fruits and your vegetables, and that we are learning a lot about what fruits, including grapes, can do ... we would not directly tell patients to throw all their pills away and just eat grapes," says Steven Bolling, MD, who heads the program.  

"These findings support our theory that something within the grapes themselves has a direct impact on cardiovascular risk, beyond the simple blood-pressure-lowering impact that we already know can come from a diet rich in fruits and vegetables," says Seymour, who manages the University of Michigan Cardioprotection Research Laboratory.