Beetroot juice may help lower blood pressure

The team found that high nitrate levels in the vegetable were responsible for the blood pressure-lowering effects. Other vegetables that contain high nitrate levels include cabbage, spinach and sprouts.

Diets rich in fruits and vegetables are known to reduce the risk of heart disease, high blood pressure and other cardiovascular problems, explain lead researcher Professor Amrita Ahluwalia, from Queen Mary University in London, UK, and colleagues.

But they add that, until now, it was not known what caused the blood pressure lowering effects of a diet rich in fruit and vegetables, with many people believing that it was the high vitamin content of such foods.

For their study, the researchers enrolled 14 healthy people with similar blood pressure levels, who were asked to drink either 500 ml of beetroot juice or the same amount of water daily.

Tests revealed that, in participants who drank beetroot juice, blood pressure levels fell within just 1 hour of drinking the juice, with a peak drop occurring 3-4 hours after consumption. Some degree of blood pressure reduction continued up to 24 hours after drinking the juice. In contrast, so such effects occurred among participants who drank water.

Further tests in other volunteers revealed that it was the nitrate content of the beetroot juice that caused reductions in blood pressure. Indeed, blood nitrate measurements showed that the greatest reductions in blood pressure levels among the volunteers occurred at the same time as peaks in their nitrate levels.

Professor Ahluwalia concluded: "Our research suggests that drinking beetroot juice, or consuming other nitrate-rich vegetables, might be a simple way to maintain a healthy cardiovascular system, and might also be an additional approach that one could take in the modern day battle against rising blood pressure."

Commenting on the findings, Victoria Taylor, senior dietician at the British Heart Foundation, said: "This study begins to explore in more detail how vegetables offer protection against heart and circulatory disease and in doing so, confirms our existing knowledge about the health benefits of consuming a diet rich in fruit and vegetables."

The research is published in an advance online issue of the journal Hypertension.