A daily glass of grapefruit juice keeps blood vessels healthy and could protect against heart disease, a new study shows. Just half a pint a day was enough to improve circulation.
Scientists have identified that health-boosting chemicals, called flavanones, that are naturally found in citrus fruits are responsible for the benefits.
The findings, published in the American Journal of Clinical Nutrition, suggest regular grapefruit juice consumption could play a vital part in warding off heart disease – Britain’s biggest killer.
Around 73,000 people a year in the UK die from heart-related illnesses. They kill one in six of all men and one in ten women. Eating a diet rich in fruit has long been known to have a protective effect. But there has been less research on precisely what it is in citrus fruits like grapefruit that helps to sustain a healthy heart.
Researchers at the French National Institute for Agricultural Research at Clermont-Ferrand, France, recruited 48 healthy women aged between 50 and 65 – one of the highest risk groups for heart disease.
Half the group was given a daily quota of 340 millilitres – roughly half a pint – of grapefruit juice packed with flavanones and the rest an identical-looking drink but with no flavanones. After a few months the two groups then swapped over. The results from the six-month trial showed that after regular consumption of flavanone-containing juice, there was a significant improvement in the health of the volunteers’ blood vessels. But there was little or no change when they drank the flavanone-free version.
Researchers measured this with a test called flow-mediated dilation, which is designed to show how ‘stretchy’ and flexible artery walls are. The more elastic they are the better as it allows blood to flow more freely to the heart.
In a report on their findings the researchers said: ‘Regular grapefruit juice consumption by middle-aged, healthy postmenopausal women is beneficial for arterial stiffness. This effect may be related to flavanones present in grapefruit.’
The study was part-funded by a grant from the Florida Department of Citrus.
However, patients with existing heart disease should be careful about drinking grapefruit juice as it can interfere with medication.
Levels of drugs used to treat raised cholesterol or high blood pressure can increase significantly after just one glass of the juice, exposing patients to a greater risk of side-effects.
