A HEALTHY-BRAIN DIET
The most frightening thing about stroke is how suddenly it can strike. People who have had a stroke say there’s often no discernible warning, no sign—just a split-second sense that something has suddenly gone wrong.
But even though the stroke itself comes out of the blue, the problems that cause it can be years in the making. Stroke occurs when blood, and the oxygen and nutrients it contains, stop reaching parts of the brain—thanks usually to a blood clot blocking a tiny artery in your brain or, less often, when an artery ruptures and blood is lost.
High blood pressure, high cholesterol, diabetes, and a dangerous prediabetic condition called metabolic syndrome all raise your risk—and they’re all factors that can be reduced significantly by choosing the right foods. “Your diet plays a critical role in preventing stroke,” says Thomas A. Pearson, MD, PhD, professor of epidemiology and chairman of the department of community and preventive medicine at the University of Rochester in New York.
In a study of more than 87,000 nurses, for example, researchers at the Harvard School of Public Health found that women who ate the most fruits and vegetables were 40 percent less likely to have a stroke than those who ate the least. In another study, this one conducted at the University of California, San Diego, researchers discovered that people who ate a single serving of potassium-rich fruits or vegetables a day were also able to cut their risk of stroke by 40 percent.
These six eating strategies offer powerful protection:
Calm high blood pressure with dairy and potassium. High blood pressure (135/85 or higher) doubles your risk for a stroke. Here’s why. Pummeled by high-speed bloodflow, arteries in the brain thicken and can ultimately squeeze shut. Under pressure, small arteries may rupture. High blood pressure also ups the risk for developing clot-producing plaque in artery walls. If everyone with high blood pressure in the United States brought it under control, more than 300,000 strokes annually could be prevented.
Your food plan? Include low-fat dairy products and plenty of potassium-rich foods in your diet. Not only does potassium fight high blood pressure (something 50 million of us suffer from), it also appears to make blood less likely to clot, which can reduce the risk of stroke even more. Not sure what foods are good sources of potassium? Fat-free and 1% milk, low-fat yogurt, vegetable juice cocktail, baby limas, kidney beans, and lentils are all rich in potassium. So are baked potatoes, prune juice, dried peaches, and Swiss chard.
Milk is another beverage that appears to play a role in reducing the risk of stroke. In one large study, researchers from the Honolulu Heart Program found that men who did not drink milk were twice as likely to have a stroke as those who drank at least 16 ounces daily. When reaching for the carton, however, be sure that it contains low-fat or fat-free milk, since the saturated fat in whole milk may offset its benefits.
Reverse metabolic syndrome with smart meal combos. Metabolic syndrome is a combination of prediabetic conditions including insulin resistance—which occurs when your cells stop responding quickly to insulin’s command to absorb blood sugar—plus slightly high blood pressure, blood sugar, and triglycerides, plus low levels of good high-density lipoprotein (HDL) cholesterol. Nearly everyone with this condition—and there are at least 40 million Americans at risk for metabolic syndrome—is overweight. Having metabolic syndrome doubles stroke risk.
What fights it? Eating high-fiber, low-sugar foods, lean protein, good fats such as nuts, oily cold-water fish (or fish oil capsules), and flaxseed. Eating fruits, vegetables, and grain products low on the glycemic index (a ranking system based on how foods affect your blood sugar levels) also keeps blood sugar and insulin levels lower. This can cut cravings and help you lose weight and can almost instantly make cells throughout your body more sensitive to insulin’s signals. Foods to avoid: doughnuts, sugary soft drinks, and white bread, which send sugar levels soaring, fast. Foods to embrace: most whole grains, beans, fruits, and vegetables, which digest more slowly and so release sugar into the bloodstream at a leisurely rate. You can also slow the rise in blood sugar after a meal by combining a high-fiber or high-protein food with a refined carbohydrate—for example, have some navy beans with instant rice.
Lose weight. Not only what you eat but how much you eat can play a role in controlling stroke. Overweight raises a woman’s stroke risk by 75 percent. Obesity raises it by 100 percent. The stroke connection: When Harvard University researchers compared body weight and stroke risk in 116,759 nurses, they found that overweight women were two to four times more likely to have high blood pressure, diabetes, and high cholesterol.
Furthermore, being overweight is perhaps the leading cause of high blood pressure, which vastly increases stroke risk. In fact, people with high blood pressure are five times more likely to have a stroke than those whose blood pressures are normal. In addition, being overweight makes you more likely to develop diabetes, which also increases the risk of stroke.
Get serious about treating diabetes with slow carbs. Having diabetes makes a woman’s risk for stroke two to four times higher than normal. An even more potent threat for women than men, diabetes seems to up women’s stroke odds by raising their blood pressure and boosting their odds for brain-threatening blood clots.
What’s the best food strategy? Keep diabetes under control by choosing “good,” “slow,” complex carbohydrates like fruits, vegetables, and whole grains. These keep blood sugar lower and steadier and also help control levels of insulin in your body. Experts suspect that surges of insulin after a meal heavy in refined carbs contribute to biochemical changes in the body that promote high blood pressure and blood clot formation—two big stroke risks.
Rebalance your cholesterol profile with better fats. High levels of bad low-density lipoprotein (LDL) cholesterol and low levels of good HDL cholesterol both raise stroke risk. A lack of good HDL leaves your body unable to haul away the bad-guy LDL, giving it free rein to lodge inside the lining of artery walls and start the process that leads to clogged arteries.
For lower LDL and higher HDL levels, eat less saturated fat and more good fats. Choosing olive and canola oil over other fats for cooking, and snacking on a small handful of walnuts can help maintain healthy HDL levels. (Add exercise to really give ’em a boost.)
At the same time, skip full-fat milk, cheese, sour cream, and ice cream … and turn down that fat-marbled prime rib. What you don’t eat can be just as important as what you do, adds Dr. Pearson. Research has shown, for example, that people getting the most fat in their diets—especially the saturated fat in meats and other animal foods—are much more likely to have a stroke than those eating more healthful foods. This is because a diet that’s high in saturated fat raises cholesterol levels. Cholesterol, which is notorious for clogging arteries in the heart, can also block blood vessels in and leading to the brain.
“Reducing saturated fat intake is the most powerful dietary maneuver you can make to lower cholesterol levels,” says John R. Crouse, MD, professor of medicine and public health sciences and currently associate director of the Wake Forest University School of Medicine General Clinical Research Center.
For most people, limiting meat servings to 3 or 4 ounces a day, using little (or no) butter, switching to low-fat dairy foods, and avoiding high-fat snacks is all it takes to keep cholesterol at healthy levels.
And choose lots of produce, too. When researchers from the well-known Framingham Heart Study group scrutinized the diets of more than 830 men, they found that for every three servings of fruits and vegetables people ate every day, their risk of stroke declined 22 percent.
Dropping just a few pounds can cut stroke risk. You don’t have to be model-thin to stay healthy, says Thomas A. Pearson, MD, PhD, of the University of Rochester. Losing 10 to 20 pounds is often enough to lower blood pressure and with it, the risk of having a stroke.
There are several reasons that fruits and vegetables are so beneficial for preventing stroke. For one thing, they’re high in fiber, which has been shown to lower cholesterol. And according to epidemiologist Michael Hertog, PhD, of the National Institute of Public Health and Environmental Protection in the Netherlands, these foods also contain powerful antioxidants, which help prevent the harmful LDL cholesterol from sticking to artery walls and blocking bloodflow to the brain. Foods especially high in antioxidants include garlic, onions, kale, carrots, Brussels sprouts, broccoli, blueberries, plums, cherries, oranges, and red grapes.
It doesn’t take a lot of antioxidant-rich foods to get the benefits. In the Nurses’ Health Study, for example, Harvard researchers found that women who got as little as 15 milligrams of beta-carotene daily, about the amount in one large carrot, reduced their risk of stroke.
Along with fruits and vegetables, tea (both the green and black varieties) is an excellent source of flavonoids. When Dr. Hertog studied more than 550 men ages 50 to 69, he found that those who got most of their flavonoids from tea were able to reduce their risk of stroke by 73 percent, compared with those who got the least of these healthful compounds. He found that those who drink at least 5 cups of tea daily can reduce their stroke risk by more than two-thirds, compared with those who drink less than 3 cups a day.