Salads: A stroke of luck.

Each year, some 480,000 people in the United States suffer an ischemic stroke. It's the most common type, caused by a blood clot in arteries of the brain. A new study suggests that one way to ward off the threat of this debilitating type of cardiovascular disease is to dine on a green salad.

Want to jazz up the meal? Toss in some orange slices or grapefruit, because citrus fruits also appear to be protective.

Kaumudi J. Joshipura and his colleagues at the Harvard School of Public Health in Boston collected data on 570 men and women who had developed ischemic stroke. The researchers compared the diets of these people and the eating habits described in surveys of almost 115,000 others. All were participants in either of two long-running Harvard programs: the female Nurses' Health Study or the male Health Professionals' Follow-up Study.

Consumption of fruits and vegetables appeared to be protective even after the scientists accounted for other standard cardiovascular risks, such as smoking, alcohol consumption, weight, activity level, and blood pressure. Each serving eaten on average per day reduced stroke risk by 3 percent in women and 5 percent in men, the team reports in the Oct. 6 JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION.

Sifting through the dietary data, Joshipura's group found that several families of foods accounted for most of that protection. These included crucifers, such as broccoli, cabbage, and cauliflower; green leafy vegetables; and vitamin C-rich foods, such as citrus fruits and juices. Though the scientists don't know the mechanism for these foods' benefit against strokes, they speculate that part of the protection may trace to folate, potassium, or antioxidants, such as vitamin C and flavonoid pigments.

"Our results provide further support for the recommendation to consume at least five servings of fruits and vegetables a day," Josphipura's team concludes. Currently, U.S. consumption of these foods averages 4.4 servings per day.