While no specific diet can prevent or treat Alzheimer’s, experts encourage people to eat a balanced and nutritious diet. This means including fruits, vegetables, and whole grains ⁠while avoiding foods high in saturated fat, sugar, and salt.

Research indicates that the Mediterranean and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets have links to lower rates of Alzheimer’s.

Additionally, study findings suggest the ketogenic diet may be beneficial for increasing daily function and quality of life in people with Alzheimer’s disease. However, unlike the Mediterranean and MIND diets, experts have concerns about the keto diet’s long-term side effects.

Many diets and supplements claim to be miracle cures for Alzheimer’s. People should know that although some studies have shown a relationship between cognitive function and certain diets or nutrients, there is no evidence that any particular one can prevent or treat the disease.

Read more about how diet can affect Alzheimer’s, which diets a person can try, and more.

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In 2020, approximately 5.8 million people in the United States had Alzheimer’s. It is a progressive condition affecting the parts of the brain that control language, memory, and thought.

Because Alzheimer’s medications only slightly delay the condition’s progression, a doctor may also recommend additional non-drug interventions. This can include diet and nutrition.

According to the National Institute on Aging (NIA), many studies suggest a link between food and cognitive function.

In particular, some research suggests that the Mediterranean and MIND diets may benefit people with Alzheimer’s. Although some studies support the use of the keto diet, it can cause potentially harmful side effects.

People with neurodegenerative diseases, such as Alzheimer’s, are less likely to eat nutritious diets and more likely to be malnourished. Symptoms of the disease can make them lose their appetite, have trouble swallowing, and forget to eat.

Because the keto diet can reduce a person’s appetite, it may cause a person with these symptoms to become even more malnourished.

It is important to note that in addition to diet, other lifestyle changes can benefit people with Alzheimer’s.

Studies show that exercise, blood pressure control, and cognitive training are important for brain health. Cognitive training refers to activities, such as crossword puzzles and sudoku that can improve the brain’s intellectual functions.

Learn more about diet and dementia risk here.

The Mediterranean diet focuses on fruits, vegetables, fish, whole grains, legumes, and healthy fats, including nuts and olive oil. It also includes limited amounts of meat and poultry. Additionally, the diet limits red meat consumption and encourages people to use herbs for flavor rather than salt.

Some studies indicate the diet may benefit people with or at risk of the disease.

A 2021 study investigated the link between the Mediterranean diet and Alzheimer’s. It compared how well people stuck to the eating plan, and it involved a range of participants with symptoms ranging from no cognitive impairment to mild cognitive impairment.

The study results indicated that closer adherence to the diet had links to better memory, less plaque accumulation in the brain, and some protection against brain atrophy. While some of these results may indicate that the diet helps brain function, they also show that people with a better memory are more able to stick to the diet.

Learn more about the Mediterranean diet here.

The MIND diet is a mixture of the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet. Although experts designed the DASH diet for people with high blood pressure, some research has also shown its potential benefits for people with Alzheimer’s.

Studies have shown that following the MIND diet may reduce the risk of developing Alzheimer’s. For example, a 2015 study of 923 participants ages 58–98 found that those who adhered to MIND-type diets had lower rates of Alzheimer’s.

The diet emphasizes plant foods and limits high saturated fat foods and animal foods. In particular, it focuses on berries and green leafy vegetables.

Learn more about the MIND diet here.

The ketogenic diet is high in fat and low in carbohydrates.

Although approaches to the diet vary, most protocols aim to keep carbs under 10% of a person’s daily calorie intake. This makes the body shift from using glucose for energy to using fat.

Experts supporting the use of the keto diet for Alzheimer’s say that it may reduce an accumulation of plaque in the brain. This accumulation is one of the signs of Alzheimer’s.

Additionally, the diet reduces inflammation, one of the essential factors in Alzheimer’s pathology, which is the abnormal physiology underlying a condition.

Despite these potential benefits, the keto diet has some downsides.

Unlike nutritious, balanced eating plans, such as the Mediterranean and MIND diets, keto’s long-term safety is questionable.

Possible adverse effects include hardening of the arteries, impaired liver function, reduced bone density, and kidney stones, along with vitamin and mineral deficiencies.

Additionally, it can reduce a person’s appetite, which may be particularly harmful in people with Alzheimer’s, as they are less likely to eat a less nutritious diet.

Learn more about the ketogenic diet.

The Alzheimer’s Association recommends a balanced diet, including:

  • fruits
  • vegetables
  • whole grains
  • sources of lean protein, such as beans, fish, and poultry
  • dairy products

The Alzheimer’s Association advises avoiding or limiting:

  • foods high in saturated fat and cholesterol, such as butter and red meat
  • foods high in sugar
  • foods high in salt

Multiple studies have examined the value of dietary supplements for Alzheimer’s. The NIA reports that despite early indications of a possible benefit, no vitamin or supplement has proven effective in preventing the condition.

Researchers have not studied many products on the market extensively enough to know their:

Several supplements show potential benefits, but the research supporting their use is limited. They include DHA, curcumin, and others.

Docosahexaenoic acid

Some research supports taking docosahexaenoic acid (DHA), an omega-3 fatty acid, in supplement form.

However, a 2018 systematic review found that although omega-3 fatty acids may be beneficial for people with very mild Alzheimer’s, there is currently not enough evidence to support omega-3 fatty supplementation in treating the disease.

Curcumin

The authors of a 2018 study found that curcumin, a polyphenol in the spice turmeric, may have value in preventing and treating Alzheimer’s.

The results indicated that curcumin maintains the structure and function of blood vessels in the brain, which may protect cognitive function. It also has antioxidant and anti-inflammatory properties.

Curcumin supplements are safe and well-tolerated, but absorption is poor. To address this problem, researchers are currently studying new curcumin supplement formulations.

Learn more about vitamins, minerals, and supplements in our dedicated hub.

Changes in the brain happen years before the first symptoms of Alzheimer’s appear. This suggests that there is a time frame in which lifestyle practices may help delay or prevent the condition.

People with concerns about their risk of developing Alzheimer’s may want to consult a doctor. They can evaluate a person’s risk factors and make any relevant dietary recommendations.

Learn the difference between a nutritionist and a dietitian here.

Research suggests that while no diet can prevent or treat Alzheimer’s, the Mediterranean and MIND diets may benefit people with the condition.

Both diets emphasize plant foods, such as fruits, vegetables, and whole grains, and have other health benefits without long-term health risks.

Conversely, some findings suggest that while the keto diet may offer advantages for Alzheimer’s, it has some long-term adverse effects.

Other lifestyle factors, including exercise, blood pressure control, and cognitive training, may also help a person’s brain function.