Can You Prevent Alzheimer’s With a Vegan Diet?

Eating capsicum and other plant-based foods could help lower your risk of dementia, according to vegan physician and nutrition expert Dr. Michael Greger.

Dr. Greger advocates for the healing potential of diet and lifestyle. He’s the author of “How Not to Die,” that analyzes the top fifteen causes of premature death in America, and how lifestyle changes can help prevent and reverse these diseases.

In an article for the Daily Mail, Dr. Greger wrote about the power of food and “what to eat to beat dementia.” Specifically, how a plant-based diet could help prevent Alzheimer’s disease, the most common form of dementia that affects millions of people around the world.

What Is Dementia?


Dementia is not a specific disease but the overarching label that includes various conditions, like Alzheimer’s and vascular dementia.

Sufferers of dementia often experience memory loss, problems with communication, disorientation, difficulty completing tasks, and mood and personality changes. Alzheimer’s, which accounts for 60 to 80 percent of dementia cases, is one of the most physically and emotionally burdensome diseases, both for the sufferers and for the people who care for them,” Dr. Greger wrote.

Alzheimer’s occurs when brain proteins dysfunction. This interferes with the work of neurons and triggers a series of “toxic events,” according to Mayo Clinic.

Scientists are still trying to understand why Alzheimer’s develops, however, most believe the disease is caused by a combination of genetic, lifestyle, and environmental factors that influence the brain over time, Mayo Clinic explained.

Whilst some risk factors can make people more prone to developing the disease, such as genetics and past head trauma, lifestyle factors play a significant role in Alzheimer’s and other forms of dementia.

How Diet Affects Dementia

There is mounting evidence that a healthy diet offers protection from Alzheimer’s disease.

“Numerous studies have shown Alzheimer’s is more a disease of lifestyle than genetics, and there is an emerging consensus that the same foods that clog our arteries can also clog our brains,” Dr. Greger explained.

The Alzheimer’s Association, that describes itself as the leading voluntary health organization in the disease’s research, also identifies the food we eat as having the “greatest impact on brain health through its effect on heart health.” 

Meat’s Impact on the Mind

A growing amount of research has linked meat consumption with heart disease, liver disease, diabetes, and cancer. Experts say animal-based meat could also impact the brain.

One study of more than 18,000 people found links between a diet high in fried foods and processed meat and low scores in learning and memory. Other research, which studied more than 5,000 people, found that a diet rich in red meat, processed meat, and fried food was associated with a faster decline in reasoning.

Dr. Greger pinpoints the Western diet – typically rich in animal products like meat, dairy, and egg – as a point of concern for dementia.

“[T]he prevalence of Alzheimer’s has shot up over the past few decades, which is thought to be in part due to the shift from a traditional rice-and-vegetable-based diet to one featuring triple the dairy intake and six times the amount of meat,” Dr. Greger wrote.

He highlights that in the U.S., those following a meat-free diet can cut their risk of developing dementia in half. “And the longer meat is avoided, the lower the risk may fall,” he said. “For example, compared with those who eat meat more than four times a week, the dementia risk of people who have consumed vegetarian diets for 30 years or more is three times lower,” Dr. Greger wrote.

Even the 2014 Dietary and Lifestyle Guidelines for the Prevention of Alzheimer’s Disease recommended swapping out animal products in favor of plant-based alternatives. “Vegetables, legumes [beans, peas and lentils], fruits and whole grains should replace meats and dairy products as primary staples of the diet,” the guidelines said.

Concern has also been raised regarding a “surprising link” between Alzheimer’s and mad cow disease, National Public Radio (NPR) reported. The discovery could help scientists figure out how the components of plaque in the brains of Alzheimer’s sufferers damage brain cells.

In mad cow disease, and a similar condition called new variant Creutzfeldt-Jakob disease that affects humans, prion proteins fold into an abnormal shape and degrade the brain and spinal cord. Prion diseases can be passed on by eating the brain or spinal cord of a sick animal. Researchers found that these proteins also play a role in Alzheimer’s, NPR revealed.

Other research explores the link between Creutzfeldt-Jakob disease, mad cow disease, and Alzheimer’s. Looking at meat’s relevance in the diseases – or as the researchers write, “losing your mind for the sake of a shake or burger” –  the study highlights that “there is three times the risk of developing Alzheimer’s in meat eaters as opposed to vegetarians,” 

Plant-Based Food and the Brain

While animal products could up the risk of developing dementia, plant-based foods could help prevent it. Various vegan food – including tomatoes, nuts, avocados, whole grains, beans, and banana – have been linked to bettered brain health, especially for memory, concentration, and problem solving.

Dr. Greger explained that whole plant foods, especially berries, contain a number of antioxidants that are able to traverse the blood to brain barrier, protecting the neurological system from “rusting” effects and eventual dementia. Capsicum has also proven to be effective at lowering the risk of Parkinson’s disease, according to researchers at the University of Washington. Red, orange, and yellow capsicum generally have more nutrients than green, Dr. Greger recommended.

Research presented at the Alzheimer’s Association International conference in London last year further proved the power of plant-based foods. It found that people who follow a Mediterranean or MIND diet largely composed of vegan and vegetarian food can lower their risk of dementia by a third, CNN reports.

“Eating a healthy plant-based diet is associated with better cognitive function and around 30% to 35% lower risk of cognitive impairment during aging,” said Claire McEvoy, of the University of California, San Francisco’s School of Medicine.

The study, which analzyed the eating habits of nearly 6,000 older Americans, found that those who maintained vegetable-heavy Mediterranean or MIND diets displayed enhanced cognitive function. People who followed the diet but not to its full extent still saw benefits, but less than if they adhered to it completely; these individuals were 18 percent less likely to show signs of cognitive impairment.

Rudolph Tanzi, director of the Genetics and Aging Research Unit at Massachusetts General Hospital and co-author of a “Super Genes,” that discusses genes and aging, spoke to CNN about the importance of diet for optimal health. “While 35% is a greater than expected decrease for a lifestyle choice, I am not surprised,” he said about the study. “The activity of our genes is highly dependent on four main factors: diet, exercise, sleep and stress management. Of these, perhaps diet is most important.”

What Are Mediterranean and MIND Diets?

The Mediterranean diet consists of “simple, plant-based cooking,” CNN explains, with most meals focused on fruits and vegetables, whole grains, beans, and seeds. “Meat can make a rare appearance, but usually only to flavor a dish,” the news website writes, although fish is included in the diet.

The MIND diet – which stands for Mediterranean-DASH Intervention for Neurodegenerative Delay, with DASH standing for Dietary Approaches to Stop Hypertension – was developed by Martha Clare Morris, a nutritional epidemiologist at Chicago’s Rush University Medical Center.

The diet was developed especially to help boost brain function and reduce dementia. It consists of 10 “brain-healthy” foods, NHS explains, including green leafy vegetables, berries, beans, and whole grains. Five unhealthy foods are pinpointed: red meat, butter and margarine, cheese, pastries and sweets, and fried or fast food. While it encourages a mostly plant-based diet, the MIND diet does still include meat, like seafood.

A 2015 study, conducted by Morris, included nearly 1,000 seniors and found that those who followed a MIND diet had a 53 percent lessened chance of developing Alzheimer’s. People who followed it moderately lowered their risk by 35 percent.

Vegan Food and Dementia

Whilst largely plant-powered diets are shown to be more efficient at combatting disease than meat-heavy ones, a diet that consists only of vegan food could be most effective. Animal-based food leads to inflammation, which is the primary cause of all chronic diseases, according to research by Market Watch. “The lower you go with animal protein, the better you do,” the publication writes. It notes that various chronic diseases including diabetes, arthritis, heart disease, and dementia could be prevented, or at least delayed, by adhering to a diet rich in vegan and vegetarian food from a young age. In contrast, the overconsumption of animal products could trigger chronic disease as early as middle age.

The publication recommends eschewing red and processed meats especially, which are classed as a Group 1 carcinogen by the World Health Organization. In their place, whole foods like sweet potato, broccoli, cannellini beans, quinoa, banana, and nuts should be consumed.

Whole food, plant-based diets are considered best not only for chronic disease prevention but overall health. Vegan diets have been linked to a decreased risk of diabetes and cardiovascular disease, among many other diagnoses, as well as optimal health and longevity.

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