Dr Shela Gorinstein from the Hebrew University of Jerusalem says the fruit, a cross between a grapefruit and a pomelo, could help people prevent blocked arteries and heart attacks.
Other fruits being studied for their heart health effects include the kiwi, pomegranate, berries and grapes. Fruits could represent an easy dietary strategy for cholesterol-lowering, considered a major factor in heart disease.
Foods designed to help prevent heart disease are growing at an annual compound rate of 7.6 per cent, according to Datamonitor, predicted to reach sales of £145 million (€212m) in 2007 in the UK alone.
Dr Gorinstein and colleagues gave 72 patients with hypercholesterolemia, or elevated cholesterol levels, that had undergone coronary bypass surgery daily supplements of pomelit juice (known commercially in Israel as Jaffa Sweetie juice) for 30 days.
The patients, who ranged in age from 43 to 71, were divided into three groups. One group received a daily supplement of 100 milliliters of the juice; a second received 200 milliliters; and a third - the control group - received none.
The results showed definite lowering of LDL blood cholesterol and an increase in blood antioxidant activity in patients from the two groups who drank the juice as opposed to those who did not, write Dr Gorinstein and colleagues in the 11 August issue of the Journal of Agricultural and Food Chemistry 52(16):5215-22.
The patients who consumed the highest daily supplement of juice showed a significant increase in blood albumin and decrease in blood fibrinogen levels, which enhance anticoagulant activity and could prevent heart diseases.
Other research groups at various universities in Japan, South Korea, Germany, the Czech Republic and Poland did similar tests and all gained positive results.
"Addition of fresh Sweetie juice to generally accepted diets may be beneficial for hypercholesterolemic patients," conclude the reserachers.
The juice could also offer protection to those who have had no symptoms of arterial occlusion or heart problems but would like to benefit from the prophylactic benefits of the fruit, they add.