Can Diet Help Prevent Alzheimer’s Disease?

Source: Milad Fakurian/Unsplash + Brooke Lark/Unsplash

What’s going wrong in the brain in Alzheimer’s?

Alzheimer’s disease is the most common form of dementia worldwide, affecting tens of millions of people around the world. It’s characterized by memory issues, as well as issues with mood, behavior, and language. It’s thought that rates of Alzheimer’s disease are increasing around the world.

For decades, researchers have been trying to pin down the exact mechanisms of Alzheimer’s disease. A number of hypotheses have been posed. One of the most consistent relates to the buildup of a protein called amyloid.

In addition to amyloid buildup, alterations in another protein (called tau) are proposed to play a role in Alzheimer’s pathology.

Other potential major drivers of Alzheimer’s include brain inflammation, metabolic dysfunction vascular problems, and issues with the function of neurotransmitter systems like acetylcholine.

What does diet have to do with Alzheimer’s?

At a basic level, our brains are made up of building blocks that come from our diet. Additionally, diet influences the gut microbiome, the immune system, our metabolic health, and other key systems that impact the brain. It's notable that on review of all the pathways linked to problems in the brains of people with Alzheimer's disease, all are related in some way to diet. This doesn't mean, of course, that diet is the sole factor driving risk for disease, but rather that our dietary choices may act on multiple pieces of the larger puzzle of this complex disease.

When it comes to specific diets that may have a positive role in Alzheimer’s disease prevention, researchers have found that the Mediterranean and the MIND diets are at the top of the list. Specifically, these two diets may help prevent Alzheimer’s disease, as well as more generally enhancing brain health over the lifespan.

What does new research show?

In a study published in March of 2023, researchers examined the brains of about 600 people who died on average at age 91. These were all people who had completed dietary assessments in the years prior to their death. On reviewing the brains, the scientists looked for markers of Alzheimer’s disease, including tau protein tangles, amyloid plaques and associated changes. They then compared these findings to people’s reported diets when they were alive. The researchers concluded that people reporting adherence to a MIND or Mediterranean pattern of eating had less brain markers of Alzheimer’s disease, even after controlling for reported exercise and smoking.

What does this mean?

As of now, there’s no well-established effective treatment for Alzheimer’s disease. Though each year new drugs make waves for their potential to slow or reverse the disease, there’s been little to no real progress on making evidence-based pharmaceuticals available to the public for the reversal of this disease. There is some data that lifestyle interventions (mostly exercise) may have benefit in the early stages of the diseases, and some very limited data that certain dietary patterns (e.g., keto) may be valuable.

With all this in mind, and with the specter of Alzheimer’s increasingly spreading over an aging population, it’s more important than ever that we do everything we can to help prevent this disease. When it comes to diet, a Mediterranean or MIND pattern (low in ultra-processed foods, high in minimally processed foods, rich in polyphenols and omega-3 fats as well as vitamins and minerals like vitamin D, Vitamin C, and vitamin E) seems to be the best bet!