A Diet Low in Meat and Dairy and High in Plants Keeps a Brain Healthy

Think you can’t prevent Alzheimer’s? Think again. You actually have more control over your risk of dementia, Alzheimer’s included, than you might suspect, doctors now tell us. In fact, many experts say that most Alzheimer’s cases, at least 90 percent, can be prevented or at least delayed through a healthy lifestyle. That’s good news, considering that more than five million Americans aged 65 and over have been diagnosed with Alzheimer’s, a population that’s expected to grow to 13.8 million by 2050, according to the Alzheimer’s Association.

While healthy lifestyle habits like exercising regularly and getting quality sleep are also key to the prevention of mental decline, a diet focused on plants also plays a significant role, studies now say.  “Evidence suggests that diet can play a decisive role in whether a person gets Alzheimer’s,” says Neal Barnard, M.D., president of the Physicians Committee for Responsible Medicine (PCRM) and author of Your Body in Balance and Power Foods for the Brain.

Researchers from Loma Linda University in California suggest that eating a whole-food, plant-only diet can lower their risk by 53 percent. “The myth has long been that Alzheimer’s cannot be prevented, treated or even slowed down,”  says Dr. Dean Sherzai, neurologist and co-director of Loma Linda's Brain Health and Alzheimer’s Prevention Program. “The truth is it can be prevented, treated, and slowed over time.”

So even if you have a genetic predisposition to Alzheimer’s, or someone close to you in your family has suffered from dementia, eating a mostly or fully plant-based diet can lower your risk, these doctors say. Here’s what you need to know to make it happen.

It’s no secret that the meat-heavy diet most Americans follow is bad for the heart, leading to high blood pressure, high cholesterol, and coronary blockages, all part of heart disease. But what’s good for the heart is good for the brain, and the opposite is also true, as the standard American diet has deleterious effects on the brain, as is evidenced by numerous studies.

Take, for instance, just one study published in the Journal of the American College of Nutrition, which found that meat consumption was the highest dietary risk factor for Alzheimer’s. Also detrimental were eggs and high-fat dairy which raised risk of Alzheimer's--though not as much as meat did. Meanwhile, plant-based foods like grains, vegetables and fruits were found to be protective against Alzheimer’s.

Interestingly, the study also found that eating grains, fruits, vegetables, and fish are associated with reduced risk of Alzheimer's, but do not counter the effects of meat, eggs, and high-fat dairy. So it's not enough to add plants; you have to cut out animal products for the full benefit. Higher vitamin D intake is also associated with a reduced risk of Alzheimer's.

So what is it about animal foods that seem to drive Alzheimer’s? Numerous factors are undoubtedly at play, but one of the most obvious ones may be saturated fat in animal foods. “Saturated fat raises cholesterol, which affects the brain in the same way it does the heart, and that could be the main mechanism,” Barnard says. And while saturated fat and cholesterol are directly linked with Alzheimer’s, they also increase risk factors for Alzheimer’s like high blood pressure, high cholesterol, and greater inflammation in the body.

Here’s the surprise, though: Changes in the brain as a result of an unhealthy lifestyle start early, perhaps even earlier than you might imagine. Dr. Barnard points to one study that tracked cholesterol levels in almost 10,000 participants starting at age 40, and found that the risk of Alzheimer’s increased as cholesterol levels went up, linking the incidents of damaged arteries to more frequent occurrences of brain disease. Other studies have shown a decline in arterial health in kids as young as 12, meaning that changes in your brain could also begin to take hold in teenagers who have unhealthy diets.

If you want to improve your brain health and lower your risk of Alzheimer’s, the message is clear: Eat mostly or all plants, starting now.

By cutting the animal foods from your diet, you’ll eliminate the brain-damaging saturated fat and cholesterol these foods are high in. Not to mention that plants give your brain all the healthy nutrients and phytochemicals it needs. “A whole-food, plant-based diet provides the necessary macro and micronutrients for your brain to grow, thrive and connect,” says Dr. Ayesha Sherzai, neurologist, and co-director of the Alzheimer’s Prevention Program at Loma Linda,  and co-author of The Alzheimer’s Solution.

Of course, you’ll be best protected if you eliminate all animal foods from your diet. “Even when people eliminate some animal foods but keep others in their diet, whether eggs, dairy, fish, chicken or meat, the saturated fat and cholesterol in those foods are more than enough to have noticeable effects on their cholesterol levels, body weight and other physical measures that affect brain health,” Dr. Barnard says.

Yet that’s not to say that even small changes can't make a difference. In one of Dr. Sherzai’s studies, every incremental step, such as eating a salad instead of a deli sandwich for lunch or adding a couple of servings of fruits to your daily menu, made a monumental difference in study subjects’ risk of stroke, which also applies to the risk of developing Alzheimer’s as well.

While the plant kingdom is loaded with brain-healthy food, there are stand-outs, such as leafy greens, which top Dr. Sherzai's list of "go-to" brain foods. “Greens have some of the highest nutrient contents, including polyphenols, antioxidants, vitamins, and minerals that provide the brick and mortar for creating connection and infrastructure in the brain, while working as a garbage disposal for getting rid of toxic byproduct,” she says.

Second behind greens are beans. They’re not only high in antioxidants, plant protein, and other brain-healthy nutrients, they also have fiber, which can help lower cholesterol, Sherzai says. What’s more, they have a “second meal effect” that helps regulate your body’s glucose for 24 hours, which becomes even more critical if you’ve eaten something sugary. “Sugar is one of the major promoters of inflammation in the body, which damages the brain,” she says. Your body can handle a small amount of sugar but not in the excessive amounts Americans eat, and every time you eat a cookie or cupcake, even if it’s vegan, you’re putting that brain at risk, more so if you eat excess sugar regularly.

Other brain-healthy foods include cruciferous vegetables like broccoli and Brussels sprouts; vitamin E-rich foods like walnuts and sesame and sunflower seeds; and brightly colored fruits like grapes and blueberries, Barnard adds. For more brain-healthy foods, check out the top 20 brain health foods from Team Sherzai.