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Is Your Brain Sad or Sluggish? Maybe It's Your Diet

Studies suggest how to eat (and not to eat) to beat mental decline.

Key points

  • Researchers are getting closer to finding out how specific foods affect brain structure and function.
  • Too much sugar and saturated fats in your diet can kill neurons and shrink grey matter in your brain.
  • A Mediterranean-style diet rich in specific nutrients can help keep your brain happier and healthier.
Alexandra Koch/Pixabay
Source: Alexandra Koch/Pixabay

If your life goals include more happiness and healthy, slower brain aging, you might want to take a closer look at your diet to identify changes you could make to help you reach those goals. Nutritional cognitive neuroscience is an up and coming field of study designed to help uncover those specific dietary patterns and nutrient profiles in food that lead to better brain health and help delay brain aging.

While the science is not set in stone, the results of several recently published studies have confirmed and added to the existing body of knowledge suggesting that dietary choices and nutrients in the diet may play a critical role in brain health and well-being. These studies focus on the effects of eating patterns and specific nutrients that have either a favorable or detrimental affect on physical brain health and cognition.

How Food Affects Your Brain

A nutritionally poor diet affects both specific neurotransmitters and grey matter in your brain. Dr. Piril Hepsomali, researcher at the University of Reading and coauthor of a recent study looking at the association between diet quality and brain structure, points out that a diet high in sugar and saturated fat may kill neurons (nerve cells), throw off the balance of neurotransmitters in the brain, and reduce the volume of grey matter. Neurons do not multiply, nor can damaged neurons be regenerated. That’s why medical conditions resulting from the loss of functional neurons can sometimes be managed but not reversed or cured.

Grey matter tissue, which is made up of a high concentration of brain cell bodies, plays an important role in all areas of human function; grey matter throughout your central nervous system affects memory, emotions, and movement. Changes in grey matter are associated with Alzheimer’s disease, Parkinson’s disease, and stroke as well as depression and anxiety.

While it’s unclear exactly how diet affects brain health, it is known that neurotransmitters in the frontal area of the brain are associated with our food choices, helping to determine what we eat and how we feel after we eat certain foods. Diets that are high in saturated fats and sugar are known to interfere with neurotransmitter production and the delivery of neurotransmitters to where they are needed. An unhealthy diet can result in an imbalance of the gut microbiome (the community of both healthful and unhealthful bacteria thriving in your gut), and of insulin and blood glucose levels, which in turn can also impact neurotransmitter production and health.

A Diet for Brain Health

Again and again, a Mediterranean-style diet—thought to be one of the healthiest, if not the healthiest diet in the world—has been found to help maintain both mental and physical health. At the same time, studies have also found that a diet high in ultra-processed foods can be quite detrimental to brain health. Ongoing research is helping to determine just how dietary patterns and specific nutrients in the diet affect cognitive function and the overall health of the brain.

A recent study from the American Academy of Neurology followed the diets of more than 30,000 adults age 45 and older. The researchers found that those participants who consumed a diet high in ultra processed foods, such as commercially prepared snacks and desserts, were at higher risk of stroke and cognitive impairment. Statistically, they linked a diet containing more unprocessed or minimally processed foods to a 12 percent lower risk of cognitive damage.

Yet another recent study from the University of Nebraska-Lincoln looked at the diet profile of 100 older men and women in good cognitive health and identified specific nutrients linked to higher scores on tests of cognition. The researchers noted two types of brain aging: more accelerated or slower than they expected. Between the two types, they noticed significant differences in brain structure, function, and metabolic processes.

The study participants whose brains appeared to be aging more slowly (as determined by blood marker tests and MRI scans) were found to have a similar combination of nutrients in their systems, consisting of specific fatty acids, antioxidants, and carotenoids, choline and two forms of Vitamin E. While these aren’t the only nutrients necessary for brain function, this is the same nutrient profile already established in the Mediterranean diet as being favorable to brain health and delayed brain aging. And they provide a clearer basis for further study into establishing the best dietary patterns and most important nutrients for optimal brain health.

Eat This, Not That

The best general dietary advice for brain heath, just as for physical health, is to choose more fresh, whole foods, including multiple daily servings of grains, nuts, legumes, and deeply (and naturally) colored fruits and vegetables. These are the foods that contribute antioxidants, carotenoids, vitamin E, and healthy fats. Lean meats, eggs, and dairy products, along with cruciferous vegetables and nuts, contribute choline to the diet. Nuts, seeds, avocado, fatty fish, and vegetable oils contribute Vitamin E and more healthful fatty acids.

At the the same time, your brain may benefit from choosing to avoid or consume fewer highly processed and ultra-processed or “junk” foods that are high in added sugar and/or fat and made from refined grains. Processed foods that are considered less healthy are those that have not only been changed from their original state but also contain added sugar, salt, fat, or other ingredients. Ultra-processed foods can be defined as highly processed foods to which manufactured ingredients, such as preservatives, texture conditioners, and artificial colors and flavors, have been added. These include commercially prepared salty snack foods, fast foods, soft drinks, frozen entrees, packaged candies, cakes and cookies, and also some potentially healthier foods to which less healthful ingredients like sugar, salt, fat, and artificial ingredients have been added.

While it’s not likely you’ll damage or destroy any brain cells from the occasional indulgence in an ultra-processed food, it’s becoming clearer and clearer that your routine dietary habits—how you eat on a regular basis—can positively or negatively affect your physical brain structure and overall mental health.


Piril Hepsomali, Adele Costabile, Marieke Schoemaker, Florencia Imakulata, Paul Allen. Adherence to unhealthy diets is associated with altered frontal gamma-aminobutyric acid and glutamate concentrations and grey matter volume: preliminary findings. Nutritional Neuroscience, 2024; 1

Zwilling, C.E., Wu, J. & Barbey, A.K. Investigating nutrient biomarkers of healthy brain aging: a multimodal brain imaging study. npj Aging 10, 27 (2024).

Bhave VM, Oladele CR, Ament Z, et al. Associations between ultra-processed food consumption and adverse brain health outcomes. Neurology. June 11, 2024 (24): 11

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