A drink based on a flower called Indian sorrel can prevent high blood pressure and maintain a healthy heart, according to a new study.

Also known as Florida cranberry, the hibiscus sabdariffa flower drink contains powerful antioxidants that can help to mop up chemicals in the body known as free radicals, which are linked to cancer and heart disease.

The American Heart Association conducted the study and found just two cups a day of hibiscus juice provides the best natural remedy yet for high blood pressure sufferers.

"Hibiscus is now the most promising herb for treating blood pressure,"

"Studies have found that people who drank two cups of hibiscus daily for four weeks lowered their diastolic blood pressure by 12 per cent - results similar to those for common blood pressure medication,"

During the study, researchers found that hibiscus contains naturally occurring antioxidants called anthocyanins, which help improve capillary function and strengthen collagen.

For the study, researchers looked at 65 people aged between 30 and 70 and split them into two groups.

The first group drank hibiscus three times a day for six weeks and the second group were given a placebo.

Their diet, activity and blood pressure were monitored daily. After the six weeks, the hibiscus group showed a drop of 7.2 per cent in blood pressure; with those suffering the most showing a 13.2 per cent drop.

The placebo group recorded a 1.3 per cent drop.

Will Irving, owner of Ibis Organics, which makes a hibiscus-based drink called Simply Hibi in the UK, said: "The results of the study by the American Heart Association show very clearly that drinking hibiscus can provide a step in the right direction for sufferers."