Don't Have a Stroke: Eat Your Veggies
At the time the study began, the use of vitamin C supplements was rare in Japan, so these results are based on vitamin C derived from foods in the diet. "Since we were not studying vitamin C pills, we do not know whether vitamin C pills prevent stroke or not," Yokoyama says.
"One interesting fact from this study is that eating vegetables was very strongly correlated with stroke reduction," Melvyn Rubenfire, MD, tells WebMD. "That increases the chance these results may not be due to vitamin C alone. For example, vegetables are loaded with pyridoxine [a type of vitamin B6] and folic acid, and we know that folic acid may reduce homocysteine levels." Homocysteine is a substance in the body that is highly correlated with the incidence of stroke. Rubenfire is director of preventive cardiology and a professor of internal medicine at the University of Michigan School of Medicine, in Ann Arbor. He was not involved in the Japanese study.
"Some stories in the lay press will look at this research and say vitamin C is terrific, and we should all be taking vitamin C supplements," he says. "However, that's not what this research says. The people in this study didn't take vitamin pills; they got vitamin C from food they ate, together with many other micronutrients. The key is frequent consumption of fruits and vegetables; that is what's associated with low rates of stroke."
The basic message of this study is that you should eat a diet rich in fruits and vegetables on a daily basis, Rubenfire says. "We strongly believe that vitamin supplements are taken too often in place of a good diet. There is evidence suggesting you may even block the absorption of important nutrients if you take lots of vitamin pills, because they only supply limited forms of these nutrients."
The American Heart Association and other organizations have established that eating a healthy diet can help reduce the risk of stroke, Sacco points out.
"You really need to do something now to reduce the risk of stroke later," he says. "And just because you're eating a good diet, that doesn't mean you can smoke, drink a lot, or stop exercising. You can't look at any one of these choices in a vacuum; they all fit together."