1/03/2006. Researchers from the Hadassa Medical School , branch of the Hebrew University of Jerusalem, conducted both in vitro and human studies on the antioxidant effects of red and white grapefruits.

This study , which results were published in the Journal of Agricultural and Food Chemistry, showed that eating a red grapefruit a day reduces cholesterol by 15% and triglycerides by 17%, which protects against coronary and cerebrovascular accidents.

Grapefruits and other citrus fruits are known to have high concentrations of antioxidants like vitamin C and flavonoids. This new study claims to be the first to evaluate the different types of grapefruits and their influence on humans who suffer from high cholesterol and hardening of the arteries (atherosclerosis), conditions that play a major role in heart disease.

The in vitro studies measured antioxidant activity in terms of the capacity to capture free radicals and other parameters, favoring the results of the red grapefruit, although the levels of Vitamin C and flavonoids were similar for both types of grapefruits.

In the human study, 57 patients with high triglyceride level in the blood and who had undergone a surgery of the coronary arteries were evaluated.

"The results of the investigation in humans showed that the supplementation with red or white grapefruits lowered the total blood cholesterol level and the LDL cholesterol ("bad" cholesterol). However, only the red grapefruits significantly lowered the levels of triglycerides" said Sheila Gorinstein, leader researcher of the study.