Alzheimer's disease: can Mediterranean and MIND diets help reduce plaques in the brain?

 Alzheimer's disease: can Mediterranean and MIND diets help reduce plaques in the brain?

A study showed that people who follow the MIND diet or the Mediterranean diet have fewer plaques and Alzheimer's disease plaques and tangles. Signature/Stocksy Study.

• More than 55 million people worldwide suffer from dementia, including Alzheimer's disease.
• One of the main features of Alzheimer's disease is plaques and tangles that form in the brain.
• Researchers at RUSH University found that there is a link between adherence to the MIND or Mediterranean diet and less plaque and cluster formation in Alzheimer's disease.

More than 55 million people worldwide suffer from dementia and an estimated 10 million new cases occur each year. Alzheimer's disease is a type of dementia.

Although scientists do not yet know exactly what causes Alzheimer's disease, one of the main features of the disease is plaques and tangles in the brain.

Now, researchers at RUSH University have discovered a link between adherence to the MIND or Mediterranean diet and the reduction of plaques and tangles in Alzheimer's disease.
The study was recently published in Neurology, the medical journal of the American Academy of Neurology.

What are plaques and bundles in Alzheimer's disease? 

Research to date has shown that Alzheimer's disease severely affects two specific types of proteins in the brain.

The first of these is called beta amyloid. In Alzheimer's disease, the naturally occurring amyloid beta protein changes and becomes "sticky". This causes clumps known as plaques to form in the brain. These plaques stick between neurons and prevent communication between them.

Another protein adversely affected by Alzheimer's disease is tau. Tau is naturally present in neurons and helps them stand upright. When a person develops Alzheimer's disease, abnormal amounts of tau protein can accumulate in neurons and form tangles. These tangles block the neurons' transport system and prevent communication between neurons.

Comparison between MIND and the Mediterranean diet

The Mediterranean diet focuses on the consumption of foods common among the inhabitants of the Mediterranean region. These include:

• legumes
• Hazelnut
• Olive oil
• fruits and vegetables
• a moderate amount of red wine
• whole grains
• moderate amounts of poultry and seafood

People who follow the Mediterranean diet consume very little dairy products and red meat. They also avoid highly processed foods, hydrogenated oils, sugary drinks and sweets.

The MIND diet is a combination of the Mediterranean diet and the DASH diet, which aims to reduce hypertension. The MIND diet aims to improve brain health.

People following the MIND diet focus on the following foods:

• vegetables, especially leafy greens
• nuts
• fish and poultry
• no more than one glass of red or white wine per day
• legumes
• olive oil
• whole grains
• a reliable source

People following the MIND diet are advised to avoid butter and margarine, cheese, red meat, sweets and fried foods.

Nutrition and Alzheimer's disease

According to Dr. Puja Agarwal, Assistant Professor in the Department of Internal Medicine, Nutritional Epidemiologist at the Rush Alzheimer's Disease Center at Rush University and lead author of this study, she and her team decided to investigate the potential impact of the MIND and Mediterranean diets on people with Alzheimer's disease, as the latter is the most common neurodegenerative disease, the Reliable Source reports, affecting our growing elderly population.

"Because treatment options to reverse memory loss or dementia are limited, understanding the role of modifiable risk factors such as diet could have an impact on public health," she told Medical News Today. In this observational study, we followed the elderly from the time they joined the study until their death. We learned about what they ate during the follow-up and then analyzed Alzheimer's pathology (amyloid and tangles) in the brains of those who donated their brains at the time of their death to see how what they ate was related to plaques and tangles in the brain."

Dr. Agarwal said the study included people with and without Alzheimer's disease. Thirty-nine percent of the participants had been diagnosed with dementia shortly before death. When examined after death, 66 percent met the criteria for Alzheimer's disease.

Analyzing the data, the research team found a link between adherence to the MIND or Mediterranean diet and fewer Alzheimer's plaques and tangles.

"These results are not surprising, but encouraging because improving diet in one aspect, such as eating more than six servings of green leafy vegetables per week or avoiding fried foods, was associated with less amyloid plaque in the brain, similar to about four years of rejuvenation," Dr. Agarwal said.

"These results are interesting because they show that a healthy diet, such as the MIND diet or the Mediterranean diet, can reduce the risk of Alzheimer's," he continued. "In light of these results, doctors may recommend this healthy diet to seniors at risk of Alzheimer's."

Next steps of the research

Regarding the next steps in this research, Dr. Agarwal said that other potential mechanisms by which diet may have a protective effect on the brain are planned to be investigated by examining its association with cerebral vascular and other pathologies, detailed neuroimaging and newly established neurodegenerative and metabolic plasma biomarkers.

"We also plan to investigate various person-specific factors and use novel in vivo biomarkers and human brain tissue when available, especially in a heterogeneous sample including more participants of different races and ethnicities," he added.

Diet changes for brain health

Medical News Today spoke with Molly Rapozo, RDN, registered dietitian-nutritionist and senior educator in diet and health at the Pacific Neuroscience Institute in Santa Monica, California, about this study. Rapozo was not involved in the study.

"I am an advocate of both diets, but I prefer MIND as a newer blend of Mediterranean and DASH with modifications based on nutrition and brain research," she says. "I appreciate the emphasis on foods that contain nutrients important for the brain. For example, the MIND diet is normalized for green leafy vegetables, which were found to be protective in this new study." By talking about specific foods to include in the MIND diet, consumers can learn more about nutrient density, such as the antioxidant value of strawberries."

For those who want to make quick changes to their diet to improve brain health, Rapozo recommends adding more whole plant foods to the diet.

"If leafy green vegetables are not already a staple food, this can be a good place to start," he adds. "There are many ways to incorporate green leafy vegetables."

Some of Rapozo's ideas are:

• Start breakfast with eggs and sautéed green vegetables or add a handful of spinach to your morning smoothie.
• Have a salad for lunch.
• Enjoy a side salad at dinner.
• Add vegetables already washed and ready to eat to sandwiches, wraps, tacos, etc.
• Leafy greens, such as kale, keep longer in the refrigerator and can be included in combination dishes such as soups, stews, and casseroles.
• Try a new green leafy vegetable or combine vegetables in a new way, such as cooking escargot with salmon on a plate.