Eating Your Way To Risk? The Major Impact of Diet on Alzheimer’s Disease

Research shows plant-based diets reduce Alzheimer’sAlzheimer's disease is a disease that attacks the brain, causing a decline in mental ability that worsens over time. It is the most common form of dementia and accounts for 60 to 80 percent of dementia cases. There is no current cure for Alzheimer's disease, but there are medications that can help ease the symptoms.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>Alzheimer’s risk, contrasting with the harmful impact of Western diets rich in meats and processed foods. Rising U.S. obesity trends suggest a significant increase in Alzheimer’s rates by 2038.

In a detailed study, “Diet’s Role in Modifying Risk of Alzheimer’s Disease: History and Present Understanding” published in the Journal of Alzheimer’s Disease, we can finally see which diets are helpful in reducing the risk of developing Alzheimer’s disease. The role of diet in modifying the risk of Alzheimer’s disease is discussed in detail. Diets that are more plant-based, like the Mediterranean diet and traditional diets in China, Japan, and India, are shown to reduce risk, especially when compared to the Western diet.

Dietary Transitions and Alzheimer’s Risk

Alzheimer’s disease rates rise in these countries as they make the nutrition transition to the Western diet. This study identifies dementia risk factors including higher consumption of saturated fats, meat, especially red meat such as hamburgers and barbeque as well as processed meats such as hot dogs, and ultra-processed foods high in sugar and refined grains.

Understanding Food Impact on Alzheimer’s Risk

This review also lets us know why certain foods increase or reduce risk of Alzheimer’s disease. For example, meat raised risk of dementia the most by increasing risk factors such as inflammation, insulinInsulin is a hormone that regulates the level of glucose (sugar) in the blood. It is produced by the pancreas and released into the bloodstream when the level of glucose in the blood rises, such as after a meal. Insulin helps to transport glucose from the bloodstream into the cells, where it can be used for energy or stored for later use. Insulin also helps to regulate the metabolism of fat and protein. In individuals with diabetes, their body doesn't produce enough insulin or doesn't respond properly to insulin, leading to high blood sugar levels, which can lead to serious health problems if left untreated.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>insulin resistance, oxidative stress, saturated fat, advanced glycation end products, and trimethylamine N-oxide. This study also outlines several foods that are protective against Alzheimer’s disease, such as green leafy vegetables, colorful fruits and vegetables, legumes (like beans), nuts, omega-3 fatty acids, and whole grains.

Effects of specific dietary food groups and factors on risk of Alzheimer’s disease. Credit: Steve Blake 2023

Ultra-Processed Foods and Health Risks

Ultra-processed foods can increase the risk of obesity and diabetes, themselves risk factors for Alzheimer’s disease. Ultra-processed foods often lack the very ingredients found in whole plant foods that keep dementia away, such as anti-inflammatory components and antioxidants.

Socioeconomic Factors in Diet Choices

Poverty is an important driver of Alzheimer’s disease in the U.S. since ultra-processed foods and meat are cheaper sources of energy than fruits, vegetables, whole grains, and other more nutritious foods, thus promoting obesity.

Projected Increase in Alzheimer’s Rates

The paper also suggests that Alzheimer’s disease rates in the US are projected to increase by 50% from 2018 levels by 2038. This calculation is based on comparing trends of obesity in the US with Alzheimer’s disease trends. This comparison shows a 20-year lag between obesity rates and Alzheimer’s disease rates. This estimate is very close to the estimate published by the Alzheimer’s Association in 2018, an estimate of a 56% increase. Our estimate suggests that the rising trend of obesity, due to consumption of meat and ultra-processed foods, is the force driving dementia. Although our personal risk of Alzheimer’s disease can be reduced with diet, it is expected that those who continue to eat the Western diet will continue to have a higher risk.

Expert Opinions on Diet and Alzheimer’s

“Grant and Blake comprehensively review and synthesize the role of dietary factors in Alzheimer’s disease. Evidence from diverse perspectives support that a diet that emphasizes fruits, vegetables, legumes, nuts, whole grains, and…de-emphasizes meat, especially red meat, saturated fats, and ultra-processed foods is associated with lower risk of Alzheimer’s disease. Physical inactivity and obesity also contribute to higher risk. In addition, the dietary and lifestyle patterns associated with higher risk of Alzheimer’s disease are known to affect the constellation of mechanisms believed to increase risk, including inflammation, insulin resistance and oxidative stress, among others. Grant and Blake make a strong case that, while further research is needed to better understand the mechanisms, diet and lifestyle factors linked to diabetes, cardiovascular diseaseCardiovascular disease refers to a group of conditions that affect the heart and blood vessels, such as coronary artery disease, heart failure, arrhythmias, and stroke. It is caused by a variety of factors, including lifestyle choices (such as smoking and poor diet), genetics, and underlying medical conditions (such as high blood pressure and diabetes). Cardiovascular disease is a leading cause of death worldwide, but can often be prevented or managed through lifestyle changes, medications, and medical procedures such as bypass surgery and angioplasty.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>cardiovascular disease, and some cancers are likely to influence risk of Alzheimer’s disease.”

— Edward Giovannucci, MD, ScD, Professor of Nutrition and Epidemiology, Harvard University.

“Grant and Blake provide a comprehensive review on the dietary and other factors that affect the risk of Alzheimer’s disease (AD). Apart from the particular type of diet they demonstrate that the consumption of red meat, insulin resistance, obesity, reactive oxygen speciesA species is a group of living organisms that share a set of common characteristics and are able to breed and produce fertile offspring. The concept of a species is important in biology as it is used to classify and organize the diversity of life. There are different ways to define a species, but the most widely accepted one is the biological species concept, which defines a species as a group of organisms that can interbreed and produce viable offspring in nature. This definition is widely used in evolutionary biology and ecology to identify and classify living organisms.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>species, and oxidative stress, phytochemicals and homocysteine amongst other factors interact with neuroinflammation and play a major role in the aetiology of AD. This treatise provides an excellent overview of modifiable risk factors for AD.”

— Paul Marik, MD, Chairman and Co-Founder, FLCCC (Front Line COVID-19First identified in 2019 in Wuhan, China, COVID-19, or Coronavirus disease 2019, (which was originally called "2019 novel coronavirus" or 2019-nCoV) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has spread globally, resulting in the 2019–22 coronavirus pandemic.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>COVID-19 Critical Care Alliance).

Reference: “Diet’s Role in Modifying Risk of Alzheimer’s Disease: History and Present Understanding” by William B. Grant and Steven M. Blake, 28 October 2023, Journal of Alzheimer’s Disease.
DOI: 10.3233/JAD-230418