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By Timothy Gower

A Plant-Based Diet May Protect Against Stroke

Mediterranean salad

If you have had a stroke or want to lower your risk for one, the case for eating more fruits, vegetables, and other healthy plant foods—and cutting back on meat and other animal products—gets stronger every year. A recent study published in Neurology adds to the evidence that a plant-based diet can reduce the odds of a stroke and preserve overall brain health. The study also indicates that the types of plant-based foods consumed may make a difference.

Earlier studies have looked at the benefits of plant-based diets, but this one focused on the quality of those diets, says Kathryn M. Rexrode, MD, senior author of the study and a family physician at Brigham and Women's Hospital in Boston. “Not all plant-based diets are healthy,” she notes. “After all, you can be a vegetarian and eat pasta and cake all day.”

Dr. Rexrode and colleagues at the Harvard T.H. Chan School of Public Health in Boston studied the diets of 209,508 men and women over a roughly 25-year period and found that people who ate mostly fruit, vegetables, whole grains, legumes (such as beans), and nuts reduced their overall risk for stroke by 10 percent. By contrast, they found no benefit against stroke among people who ate six daily servings of refined grains (such as white pasta and rice), potatoes (which convert to sugar rapidly in the body), fruit juice and sugar-sweetened beverages, and sugary desserts.

“If everyone in the United States followed healthy plant-based diets, we could see a reduction of about 80,000 strokes per year,” says Dr. Rexrode. “As someone who has seen the devastating impact of stroke on individuals and families, that sounds like a pretty substantial impact, and a reason to focus on diet.” Every year nearly 800,000 Americans experience a stroke, and survivors stand a one in four chance of having a second one.

A healthy diet can also help lower blood pressure and cholesterol, says Eliza Miller, MD, MS, assistant professor of neurology at Columbia University's Irving Medical Center in New York City. While medication is typically prescribed for people with high blood pressure or high cholesterol, a diet that includes plenty of plant foods and limits red meat addresses those cardiovascular risk factors too. A plant-based diet could guard against cognitive impairment and dementia as well, says Dr. Miller.

Avoiding red meat and egg yolks may help prevent strokes and heart attacks for yet another reason, says J. David Spence, MD, professor of neurology and clinical pharmacology at the University of Western Ontario in Canada. His research and that of others show that these foods interact with naturally occurring bacteria in the intestines of some people to produce trimethylamine N-oxide (TMAO), a gut metabolite that clogs arteries and can trigger strokes and heart attacks.

Dr. Spence cites a “defining” study from 2013 in the New England Journal of Medicine that found that among subjects who produced the highest levels of TMAO, risk for a stroke or heart attack was two and a half times higher than for those with the lowest levels. How much TMAO is produced in response to eating red meat and eggs depends on the strains of bacteria in the intestines (known as the gut microbiome), which differ from one person to another. Now researchers, including Dr. Spence, are trying to identify which microbes are the culprits, with the goal of developing a therapy to replace bad bacteria with healthier bacteria.

Shifting from a traditional American diet—high in unhealthy fats and sugar, low in produce and whole grains—to one emphasizing healthy plant-based foods can start with simple changes. Here are some strategies to adopt.

Keep it lean. Dr. Spence recommends limiting consumption of meat—sticking mainly to chicken and fish—to no more than about four ounces (a palm-size serving) every other day. Eat red meat even more sparingly. You can reduce your meat intake with some culinary sleight of hand. For example, when you make meatballs or burgers, replace one-third to one-half of the ground meat with finely diced mushrooms or eggplant. “You'll be hard-pressed to tell the difference,” says Molly Kimball, RD, CSSD, a sports and lifestyle dietitian who manages the nutrition program at Ochsner Fitness Center in New Orleans. Also consider nonmeat substitutes such as the Impossible Burger, which is made with soy and potato protein instead of beef. “It tastes surprisingly similar to meat,” says Kimball, who ran a blind taste test in which the Impossible Burger beat out all-beef burgers.

Skip egg yolks. Egg whites or egg-white-based substitutes can be purchased by the carton at most grocers. “You can make amazingly good egg salad sandwiches with egg substitutes,” says Dr. Spence. Egg-white frittatas and omelets are good meatless options too.

Join club Med. Traditional diets of people in the Mediterranean region tend to focus on fruits, vegetables, whole grains, legumes, nuts, and olive or canola oil; they include few servings of meat, dairy products, and processed foods. In a study published in the New England Journal of Medicine in 2018, the Mediterranean diet reduced the risk of strokes and heart attacks by about 30 percent versus a low-fat diet over a five-year period.

Go natural. Choose fresh foods whenever you can and eliminate as many processed products as possible. “With that change, you can reduce the amount of salt, sugar, refined carbohydrates, and unhealthy fats you consume,” says neurologist Ayesha Sherzai, MD, of Loma Linda University Health in Loma Linda, CA. Eat fruit instead of drinking juice, and opt for fruit over pastries or other prepared desserts. An apple, for example, provides nutrients and fiber but not the 5 grams of artery-clogging saturated fat and additional 175 or so calories in a slice of store-bought apple pie. If fresh or frozen foods are hard to come by where you live, look for canned vegetables, says Dr. Sherzai. “They're not ideal, but they're better than potato chips.”

Avoid refined carbohydrates. When people eat less meat, they may load up on pasta instead. But the standard types made from refined wheat convert to sugar rapidly during digestion, which can promote hyperglycemia—a risk factor for severe strokes. Look for whole-grain pasta or varieties made from nonwheat sources, such as zucchini and hearts of palm, says Kimball. Similarly, when buying bread, select whole-grain rather than white bread.

Beware of salt. “Sodium is sneaky,” says Dr. Miller, since you may not realize how high the sodium content is in certain foods, such as canned soup, deli meats, pizza, and even packaged bread. Too much sodium contributes to high blood pressure, a risk factor for stroke. Read food labels and find products you enjoy that have lower sodium levels, suggests Dr. Miller. Nutritionists encourage people to consume less than 20 percent of the daily value (the amount not to exceed each day) for sodium, which is 2,300 milligrams. A first step in reducing sodium intake could be eliminating crackers and potato chips as snacks; possible replacements include unsalted popcorn with a pinch of Parmesan; apple slices with unsalted peanut butter; or home-baked pita chips flavored with olive oil, paprika, and unsalted garlic powder. Dr. Miller also suggests making your own bread, which allows you to limit how much salt goes in “and can be a fun activity for families.”

Skip sodas. Sugary drinks like colas can spike blood sugar, says Dr. Sherzai. Diet sodas are no better, as artificially sweetened beverages are associated with a higher risk of stroke and dementia, according to a 2017 study in Stroke. If you don't like water, try iced or hot tea sweetened with agave or honey.

Dine at home. “A lot of people are afraid of cooking,” says Dr. Sherzai, but learning just a few simple, healthy recipes gives you greater control over what you eat and avoids the unhealthy ingredients in processed meals and restaurant fare. “Cooking [a healthy diet at home] can save lives,” says Dr. Sherzai.

How to Choose Healthy Options When Dining Out

Following a plant-based diet may help reduce your risk of stroke. Here’s how to stick to healthy eating even when you’re at a restaurant or fast-food place.

Be assertive. Speak up about healthy choices, says Molly Kimball, RD, CSSD, a sports and lifestyle dietitian in New Orleans. “Don’t be afraid to ask for broccoli instead of rice pilaf, for example,” she says. Switching a side dish is usually easy for the kitchen staff.

Adapt your orders. Most restaurants have healthier options, says neurologist Ayesha Sherzai, MD, of Loma Linda University Health in Loma Linda, CA. She counseled a patient who gets many meals at a Mexican drive-through to order beans and guacamole on her tortilla instead of meat and cheese, with salsa on the side.

Decide beforehand. If you’re heading to a fast-food or chain restaurant, look up the menu online and pick out the healthiest options that appeal to you, suggests Kimball. “If you know what you want in advance, you won’t be as tempted to order something on the menu that’s not as nutritious.”