Scientists Find High-Fat Diet May Help Maintain Brain Health

ikehand.id@gmail.com December 20, 2025

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Scientists Find High-Fat Diet May Help Maintain Brain Health

For a long time, fat was considered harmful to a healthy diet. In the 1970s and 80s, fad diets like Scarsdale and grapefruit diets were all the rage. There was a new market for low fat (often sugar and carbohydrate) food products. Researchers later questioned the potential drawbacks of severely restricting all dietary fat. However, this craze has left people with negative opinions about cooking oil. So it may come as a shock to discover that recent research shows that a high-fat diet can help maintain good brain health.

The Connection Between Fat and Understanding

A diet full of fast food and processed fats can lead to poor mental processing. Image Credit: Shutterstock

First, it is important to be aware of the different types of oil. One type is beneficial for brain health, while the other may be harmful. Some small studies in mice have linked a high-fat, fast-food diet to brain inflammation and poor memory. The authors found that metabolic problems interfere with the functioning of the hippocampus, a part of the brain that is important for forming memories.

Fast foods, fried foods, and highly processed foods often contain large amounts of saturated fats and partially hydrogenated fats, such as trans fats. These ingredients can increase the risk of type 2 diabetes, heart disease, metabolic syndrome, and, according to this study, cognitive impairment. Metabolic syndrome has already been linked to poor memory, cognitive decline, and an increased risk of dementia.

“We’ve known for a long time about the link between metabolic syndrome, obesity, and how an unhealthy high-fat diet may be linked to dementia,” said Derek Cheng, DO, a neurologist at Stamford Health, to Medical News Today.” He commented on a recent study in which the team put mice on a high-fat diet for two days. “However, it is interesting in this study to see that, in just a few days, memory formation can have an impact on eating disorders.”

Meanwhile, a diet high in healthy fats from fish, nuts and other whole foods can improve cognitive function. The human brain is like that it is made up of about 60% fat (dry weight), and using omega-3 fatty acids helps support its function.. Despite accounting for only 2% of the body’s weight, the brain uses about 20% of its energy. This makes it sense what the digestive system breaks down for fuel. Not surprisingly, many people with digestive problems, such as IBS and gastroparesis, report brain fog and grogginess, as documented in a 2025 study.

Read more: 9 Daily Habits for Better Mental Health, According to Neurologists

Can You Prevent Alzheimer’s With a High-Fat Diet?

Studio shot of half a fresh avocado with a pit balanced on an open book against a purple background, representing healthy brain food for students. — *Early research shows that a diet high in healthy fats, such as avocados, can improve memory and overall brain health. Image Credit: Shutterstock*

Researchers at the University of Missouri have tested how a ketogenic diet can affect brain health. The diet is known to be high in fat and low in carbohydrates. Their research, published in the Journal of Neurochemistry, found that this method can slow or prevent cognitive decline in people prone to Alzheimer’s disease. However, more intensive research is needed to confirm and extend this, especially given that the research was conducted on mice. Researchers found that female mice with the APOE4 gene (highly associated with Alzheimer’s) showed improved brain health when they ate a diet high in healthy fats. This was not the case with rats fed a high-carbohydrate diet. (Interestingly, males did not show the same level of improvement.)

“When we eat carbohydrates, our brain converts glucose into fuel for our brain, but those with the APOE4 gene, especially women, struggle to convert glucose into energy for the brain, and this can lead to cognitive decline down the road. “ said doctoral student and co-author Kira Ivanich in a press release. “By switching to a keto diet, ketones are produced and used as an alternative source of fuel. This may reduce the risk of Alzheimer’s by preserving the health of brain cells.”

This study develops the concept of “precise food.” This approach is opposed to “one-size-fits-all diet” concept and create meal plans based on a person’s specific biology, genetics, lifestyle, etc. “Rather than expecting a single remedy to work for everyone, it may be better to consider a variety of factors, including a person’s genotype, gut microbiome, gender and age,” said Ai-Ling Lin, a professor at the University of Missouri School of Medicine. “Since the symptoms of Alzheimer’s, which are often irreversible when they start, usually appear after the age of 65, the time to think about preserving brain health is even earlier.

Creating High-Fat Diets Tailored for Brain Health

Selection of healthy oil sources in the wood background. — *Some nutritionists recommend the Mediterranean diet because it focuses on whole foods and healthy fats. Image Credit: Shutterstock*

On the topic of a precise diet, remember that the ketogenic diet is very restricted, it is not suitable for people with certain medical conditions, and it is certainly not the only way to eat healthy fats. Neurologist Dr. Bryan Neth, who has studied the effect of diet on Alzheimer’s, eats very similar to the Mediterranean diet. As a parent, it can be challenging to make healthy meals with young children, so Neth focuses on whole foods and fresh produce rather than highly processed foods. The Mediterranean diet often includes olive oil, fish, nuts, avocados, and seeds that are high in healthy fats. Some people have been taught to avoid these types of foods.

“...Good quality fats are important for brain health and cardiovascular health,” said Dr. Neth in an episode of the Mayo Clinic’s On Nutrition podcast. “…It is important to have good quality fats that make up the cell membranes in the brain for good brain health…” He also added that this healthy fatty food can contain micronutrients such as vitamin E and Omega-3s, which also contribute to good brain health.

Although a healthy diet has not yet been proven to prevent Alzheimer’s, it can help people feel better and think better in the short term. So here are some high-fat foods to include in your brain-healthy diet: