Oct. 5, 1999 (Cleveland) -- An apple a day -- plus a couple of oranges, a serving of cauliflower, and a heaping plate of spinach -- may keep strokes away, according to a new study from the Harvard School of Public Health.
Harvard experts tracking over 100,000 nurses and other health professionals (including physicians, dentists, and veterinarians) over several years found that those health workers who said they ate five or six servings of fruit or vegetables every day reduced their risk of ischemic stroke by 30%. An ischemic stroke occurs due to a blockage in a blood vessel that supplies blood, oxygen, and nutrients to the brain.
Currently stroke is the third leading cause of death in the United States, and the risk of stroke doubles with each decade after age 35. About 5% of people older than 65 have had at least one stroke.
Nutritionists currently recommend that a well-balanced diet contain at least five servings of fruit and vegetables daily. A serving is considered one piece of fruit, a half-cup of fruit juice, or a half-cup of vegetables.
The new study, based on data collected in the Health Professionals Follow-up Study and the Nurses' Health Study, is published in this week's Journal of the American Medical Association.
Study author Meir Stampfer, MD, tells WebMD that the researchers considered just dietary intake, not supplements or vitamins. Stampfer is a professor of epidemiology and nutrition at Harvard School of Public Health. The greatest benefit, he says, appears to be associated with green leafy vegetables, citrus products, and cruciferous vegetables such as cabbage, broccoli, brussels sprouts, and cauliflower.
Stampfer says that each serving of fruit or vegetables was associated with a 6% decrease in the risk of ischemic stroke but that the decrease "flattens out after about six servings."
The study has some experts sounding a note of caution. Alice Lichtenstein, DSc, tells WebMD that the study shouldn't be taken as an excuse to continue with an unhealthy lifestyle but with occasional stops at the juice bar to fill up on veggie supplements or extracts. She says the study is "just one piece of the puzzle. What is important here is to understand that those persons who consume more fruits and vegetables had a better diet in general and tend to live more heart-healthy lifestyles." Lichtenstein is a professor of nutrition at Tufts University in Medford, Mass., and spokesperson for the American Heart Association's Nutrition Committee.
Lichtenstein says that it may be that people eat more fruits and vegetables eat fewer pizzas and Big Macs. The fruits and vegetables may just be displacing "fats and animal proteins in a diet," says Lichtenstein. "The take-home message is that there is no easy answer. Physicians need to keep pushing lifestyle and saying the same boring, unsexy things about diet and exercise."
In a statement from the AHA Lichtenstein says, "It is important to remember that their study did not reveal any single 'magic' or 'super' food to lower the risk of ischemic stroke."
Stampfer also says that not all fruits are created equal. "When we say vegetables, we are not referring to potatoes. A potato is more like a sweet because metabolically it is converted to sugar very, very rapidly. When people think of vegetable servings they definitely should not count potatoes."
He says that the data also suggest that smokers may reap an even greater benefit from increased fruit and vegetable consumption than do nonsmokers. However, he says, "actually smokers appear to eat fewer fruits and vegetables. But smoking is the biggest risk factor for stroke, so eating more fruits and vegetables can't cancel out that risk. My advice to smokers is to eat more fruits and vegetables while they are quitting smoking."
The study was support by a grant form the National Institutes of Health and The State of Florida Department of Citrus.