5 Things to Know About a Plant-Based Diet and Brain Health

There are pros and cons to consider before making the switch

Christine Richmond

Updated April 24, 2025

A close up of Asian green curry with coconut milk in a pan

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Have you cut back on how much meat you eat? Are you considering a more plant-based diet?

There are many reasons for rethinking a meat-centric diet, including environmental and animal welfare concerns, and better health. Eating a plant-based diet was associated with a lower risk of heart disease, cancer and mortality in a study published in JAMA Network Open in 2023. Studies have shown that the Mediterranean diet, which emphasizes plant foods and fish, with only a small amount of meat, can help lower blood sugar, cholesterol and blood pressure while offering protection against cognitive impairment later in life. That’s why AARP’s Global Council on Brain Health, in its report “Brain Food,” recommends plant-based diets like the Mediterranean diet, noting that “a healthy diet is crucial to optimal brain health.”

Here are five things to keep in mind when deciding whether a plant-based diet is right for you.

1. A plant-based diet can support your memory.

Older adults who ate a plant-based diet performed better on tests of long-term memory and executive function in a study of 3,039 adults with a mean age of 70 published in Nutritional Neuroscience in 2022. The researchers speculated that, because they tend to be high in fiber and unsaturated fats, plant-based diets can help fight inflammation in the brain, which, in turn, supports cognitive function.

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2. Getting enough protein may be challenging.

A growing number of researchers think that the current recommended dietary allowance (RDA) for protein — 0.8 grams of protein per kilogram (2.2 pounds) of body weight — is inadequate for older adults. They argue that getting closer to 1 to 1.2 grams of protein per kilogram of body weight daily is necessary to prevent age-related muscle loss. Yet, in a study published in The Journal of Nutrition, Health and Aging in 2024 that analyzed data from 607 adults age 65 and older, switching from a diet heavy in animal protein to a plant-based diet resulted in a 5 percent decline in protein intake. People eating vegan (meaning no animal products, including meat, fish, dairy or eggs) had the most difficulty getting enough protein.

If you choose to eat less meat — and if you also decide to cut out other animal products — you’ll need to make up for it by eating plenty of vegetarian sources of protein, such as lentils, beans, nuts and tofu.

3. The quality of your diet matters.

Just because you’re eating less meat doesn’t mean you’re eating healthily: It’s easy to load up on highly processed foods, like chips and snack cakes, that are low in fiber and other key nutrients and high in sugar and sodium. This helps explain the results of a 2022 study that found that a healthy plant-based diet, rich in whole grains, fruits, vegetables, nuts, beans, vegetable oils and tea/coffee was associated with a lower risk of frailty. An unhealthy plant-based diet, based on sweetened beverages, refined grains, potatoes and sweets/desserts actually increased the risk of frailty. Published in the Journal of Cachexia, Sarcopenia and Muscle, the study followed 82,234 women age 60 and older.

4. The jury’s still out on bone health.

Some research has suggested that eating a plant-based diet could put you at a higher risk for bone fractures because you may get less protein, calcium, vitamin D and vitamin B12 than people who regularly eat meat. In a study of 16,085 adults, about 29 percent of whom were over age 65, published in Nutrients in 2023, researchers found an association between a plant-based diet and reduced bone mineral density, which may increase the risk of bone loss. But another study that followed 70,285 women with a mean age of 55 for up to 30 years found no evidence that long-term adherence to a plant-based diet increased the risk of hip fractures. In fact, the study, published in JAMA Network Open in 2024, found that people who most closely adhered to a healthy plant-based diet had a 21 percent lower risk of hip fractures compared with people who didn’t follow a plant-based diet as closely.

Bone is a complex structure that requires a balance of nutrients to remain strong, especially as people age, says nutritional epidemiologist Katherine Tucker, director emeritus and founder of the Center for Population Health at the University of Massachusetts Lowell. And our bodies absorb the calcium in dairy products, like cheese and yogurt, more easily than the calcium in green leafy vegetables, which is partially blocked by two naturally occurring compounds called oxalate and phytate. Therefore, strict vegans who don't eat dairy products may need to make an extra effort to eat a wide variety of vegetables and other foods, such as tofu and soy milk, that offer key nutrients like calcium and protein.

5. You don’t have to go all in.

Completely overhauling your diet can be difficult — and isn’t always advisable. Be sure to talk to your doctor before making any drastic changes to how you eat. If you’d like to switch to more plant-based eating, a gradual approach can include going meatless one night per week. Consider having a plant-based burger on a multigrain bun or our Butternut Squash & Black Bean Tostadas. You may also have success shifting to a Mediterranean diet; it allows for a small amount of red meat, and may be easier to follow.