If high cholesterol and triglycerides have you feeling sour, red grapefruit's antioxidant punch could help you lower cholesterol by 15 percent and triglycerides by as much as 17 percent, says a new Israeli study published in the Journal of Agricultural and Food Chemistry (2006, vol. 54, no. 4). Study participants who ate a red grapefruit every day for a month saw a greater decrease in their cholesterol and triglycerides, compared with those who ate white grapefruit or no grapefruit at all. Although the researchers aren't sure why red grapefruit is such a powerful heart helper, the study is further evidence that a vegetable and fruit–rich diet that's high in antioxidants is crucial to reducing the risk of coronary heart disease.