Eating a bunch of grapes a day could help fight high blood pressure related to a salty diet calm other factors that are also related to heart disease, such as heart failure, according to researchers at the University of Michigan in the US.

The new study gives clues to the potential of grapes in reducing heart disease risk. The effect is thought to be due to the high level of phytochemicals – naturally occurring antioxidants – that grapes contain.

The researchers studied the effect of regular table grapes (a blend of green, red, and black grapes) by feeding them to rats, as part of either a high- or low-salt diet – the high-salt diet raised their blood pressure.

They found that the rats that ate 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 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.

’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,’ said researcher Mitchell Seymour.

The rats in the study were in a similar situation to millions of people, who have high blood pressure related to diet, and who develop heart failure over time because of prolonged high blood pressure. And the healthy antioxidant flavanoids found in grapes could offer protection, said researcher Dr Steven Bolling. But he added that it’s equally important to cut down on salt.

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

’But in general we say stay away from excess salt.’