Choosing the Right Diet for Your Brain: Mediterranean, MIND, and Keto Explained

When it comes to brain health, choosing the right diet can be confusing. With so much information available, it’s hard to know which dietary approach is best for supporting cognitive function and reducing the risk of cognitive decline. According to Preventive Medicine physician, Dr. Dan Angerbauer, there’s no one-size-fits-all diet, but a few well-researched options stand out. Here, we’ll explore the Mediterranean, MIND, and ketogenic diets, highlighting their potential benefits and limitations for brain health.

The Mediterranean Diet

The Mediterranean diet is often recommended for overall health, and Dr. Angerbauer agrees that it’s hard to go wrong with this approach. “If you just Google right now, that question, ‘what is the best diet to prevent or treat cognitive decline?’ It will come up and say Mediterranean diet,” he explains. This diet emphasizes fruits, vegetables, nuts, seeds, legumes, and whole grains, along with moderate amounts of lean protein like chicken and fish. Olive oil serves as the primary fat source, and moderate red wine intake is also included.

Dr. Angerbauer points out that the evidence supporting the Mediterranean diet is robust: “If you also go through PubMed and all the research studies, whether it’s observational or randomized clinical trials…it does have the most evidence for preventing and potentially even treating cognitive decline.” Omega-3s from fish—recommended three times per week on this diet—are another key component that may benefit brain health, offering anti-inflammatory and neuroprotective effects.

The MIND Diet

The MIND diet combines elements of the Mediterranean diet with specific recommendations from the DASH diet, focusing on foods thought to support cognitive function. Dr. Angerbauer describes the MIND diet as “pretty much a Mediterranean diet that is a little more specific on a few things that may have specific brain health benefits.” For example, where the Mediterranean diet encourages fruit consumption broadly, the MIND diet specifically recommends “one serving of berries every day,” which have been linked to improved cognitive function.

Similarly, the MIND diet emphasizes green leafy vegetables with a recommendation for “one cup of green leafy veggies a day,” which Dr. Angerbauer notes can offer additional protective benefits. The MIND diet also suggests minimizing intake of certain foods, including sugar, fried foods, butter, and cheese. However, while promising, research on the MIND diet’s impact on brain health is still evolving. Dr. Angerbauer cites Barnes et al. (2023), a large randomized controlled trial published in the New England Journal of Medicine, that showed no statistically significant difference in cognitive outcomes between groups on the MIND diet and a control diet with mild caloric restriction, though he suggests that weight loss among participants in both groups may have been a confounding factor.

The Ketogenic Diet

While initially developed as a treatment for epilepsy in the 1920s, the low-carb keto diet later attracted widespread attention as a quick and effective way to slim down. More recently, studies have explored the ketogenic diet and its potential to support brain health by shifting the body’s primary fuel source from glucose to ketones.

In Alzheimer’s disease and other forms of cognitive decline, the brain can struggle to utilize glucose efficiently—a concept Dr. Angerbauer refers to as the “energy crisis theory.” He explains that by adopting a ketogenic diet and achieving nutritional ketosis—a metabolic state in which the body, deprived of sufficient carbohydrates, shifts to burning fat and producing ketones—these ketones may then serve as an alternative fuel source for the brain, potentially compensating for the reduced glucose utilization.

However, Dr. Angerbauer is clear that “for prevention, there’s virtually no data.” He explains that while ketogenic diets might be helpful for those already experiencing cognitive impairment or early Alzheimer’s, evidence for preventive benefits remains limited.

“If you’re 45 years old and you had a parent or a grandparent or someone that had Alzheimer’s or some other form of dementia, and you're saying "what should I do to prevent this?" - keto is not the answer. We just have no data for that.”

For individuals with early cognitive impairment, Dr. Angerbauer points to a meta-analysis by Ron et al. (2024), of ten randomized clinical trials that showed positive results for ketogenic diets in short-term improvements in cognitive tests like the Mini-Mental State Exam. However, he warns that the ketogenic diet can increase LDL and triglyceride levels, which might be concerning for some individuals. Additionally, people carrying the APOE4 gene variant—associated with a higher risk of Alzheimer’s—may not benefit as much from a ketogenic diet. Dr. Angerbauer explains that Norwitz et al. (2021) explored precision nutrition for Alzheimer’s prevention in APOE4 carriers and found that, “in those that had no copies of E4, there's probably some benefit there to the ketogenic diet. To those that do have a copy, one or two, of E4, it seems like there is not, or at best, the effect is diminished compared to those that do.” These differences could potentially be explained by impaired mitochondrial function in E4 carriers.

Key Takeaways for Choosing the Right Diet

1. Mediterranean Diet: This diet has the strongest evidence for preventing cognitive decline and is widely recommended for general health. Dr. Angerbauer believes that it’s “probably hard to go wrong” with this approach.
2. MIND Diet: Building on the Mediterranean diet, the MIND diet includes more targeted recommendations for brain health, such as specific servings of berries and green leafy vegetables. While early studies are promising, more research is needed for conclusive results.
3. Ketogenic Diet: This diet may offer benefits for individuals with mild cognitive impairment or early Alzheimer’s, but it’s not recommended as a preventive measure for cognitive decline, especially for those with an APOE4 allele.

Dr. Angerbauer encourages people to find a sustainable approach to diet that meets their needs. He explains, “Find a diet that helps you maintain an optimal body composition … that’s, I think, a first order thing.” For general cognitive health, he advises focusing on whole foods and avoiding excessive processed foods or sugars, which can contribute to metabolic issues and may accelerate cognitive decline.

When it comes to choosing the right diet for brain health, there is no perfect answer. However, by understanding the strengths and limitations of each dietary approach, you can make an informed choice based on your health goals and needs. Dr. Angerbauer recommends a “Mediterranean-ish” diet as a well-supported, balanced choice that can promote both brain and overall health. While the ketogenic diet may have therapeutic potential, especially in individuals with cognitive decline, the Mediterranean and MIND diets currently have more robust research supporting their general benefits for cognitive health.

To learn more about the “best diet” for brain health, watch our conversation with Dr. Dan Angerbauer in the video above.

By Alicia J. Barber, PhD