23 May 2019
A prudent and healthy diet includes plenty of fresh vegetables, fruit, salad, and grilled fish. Photo: Reuters
A prudent and healthy diet includes plenty of fresh vegetables, fruit, salad, and grilled fish. Photo: Reuters

The brain diet: Eating for maximum brainpower

Want a keener mind and a more balanced mood in older age? A healthy diet may hold the key. Although it’s a small organ, the brain is metabolically the most active organ of the body and it requires continuous nourishment for optimal functioning.

“Diet has a very important effect on brain function and cognition, and mounting evidence suggests that enhancing your diet by paying more attention to the range of foods you eat and the quality of those foods can help improve your chances of staying sharp and mentally healthy,” says Uma Naidoo, MD, a psychiatrist at Massachusetts General Hospital (MGH), an Instructor of Psychiatry at Harvard Medical School, and an expert on the effects of food on neurochemistry.

Direct pathway

An important indication of the brain/diet connection is recent research that for the first time conclusively links dietary patterns to specific changes in the size and functioning of the hippocampus, a brain region critical to learning, memory, and mental health, in older adults.

The study, published Sept. 8, 2015 in the journal BMC Medicine, compared participants who ate a “prudent/healthy” diet that included plenty of fresh vegetables, fruit, salad, and grilled fish with others who ate a “Western/unhealthy diet” that included large amounts of foods such as sausages, roast meats, hamburgers, steaks, fries, potato chips and sodas.

Researchers found that over four years, the participants who ate the healthy diet showed an increase in the volume of the left hippocampus on brain scans, while those who ate the unhealthy diet showed a decrease. Diet accounted for 62 percent of the decline in left hippocampal volume, independent of other factors, such as health and socioeconomic status.

Choice of options

Studies such as this one suggest that if you wish to protect your aging brain, eating foods that help reduce the risk for cardiovascular disease, obesity, inflammation, and other health problems that can damage the brain is essential. The following three diets have been associated with lower risk for cognitive decline and/or dementia.

The DASH Diet

The Dietary Approaches to Stop Hypertension (DASH) diet is recommended by the American Heart Association and other health organizations to help lower blood pressure, keep your cardiovascular system in good condition and ensure that your brain receives a vigorous flow of blood that keeps it well-nourished and oxygenated. The DASH diet also provides antioxidants that protect tissues from damage.


Small portions (3.oz.) of lean meats, poultry, fish, and low-fat dairy. Get plenty of fruits, vegetables, whole grains and nuts, which supply fibre, essential nutrients, and antioxidants that facilitate brain function and combat the body’s formation of toxic free radicals.


Unhealthy saturated fats (e.g., fats found in high-fat dairy products such as whole milk, cream and high-fat cheese, animal products such as lard, fatty meats, and some fried foods) and trans fats (found in many processed foods and margarines).


Refined products and processed foods, which are often loaded with salt, unhealthy fats, sugar and preservatives, and avoid excessive sweets. Too many sweets can lead to metabolic syndrome and diabetes, which have been associated with greater risk for high blood pressure, cardiovascular disease, and cognitive problems.

The Mediterranean Diet

Regular consumption of the diet typical of Mediterranean regions has been linked to slower cognitive decline and reduced risk for mild cognitive impairment (MCI), as well as a decrease in the likelihood of developing dementia.


Plenty of fish, fresh fruits and vegetables, legumes, nuts, and whole grains. Use olive oil in place of other fats, and enjoy an occasional glass of red wine, if you wish.


Red meats, dairy products including cheese, saturated fats and trans fats, processed foods, and sweets.

The MIND Diet

A combination of the DASH and Mediterranean diets, the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet is associated with a significant reduction in risk for cognitive decline and dementia. Better still, the MIND diet has been found to slow cognitive decline and provide significant protection against Alzheimer’s disease even in individuals who adhere only partially to their diet.


Vegetables, including leafy greens, whole grains, legumes, nuts, berries, poultry, fish, olive oil, and a daily glass of red wine, if you wish.


Fried or fast foods, red meats, butter and stick margarine, cheese, and pastries and sweets.
“You needn’t change your diet all at once,” Dr Naidoo counsels. “Make sensible, small changes in the direction of good health. Start with the ingredients, such as substituting fresh foods and whole grains for processed foods. Choose healthy snacks, such as fruit or nuts, and make sure you are getting at least three meals a day that supply the simple building blocks of a nutritious diet. Finally, remember to exercise portion control to help manage your weight.”

Dietary essentials for a healthy brain

To stay sharp, see to it that your brain cells get what they need. Besides oxygen and water (six to eight glasses a day) the following essential dietary elements ensure a healthy brain:


This brain fuel, which must be constantly supplied from the bloodstream, is essential for repairing cells, manufacturing enzymes and neurotransmitters, sending signals throughout the neuronal network, and performing activities such as learning, remembering and concentrating. Glucose is a form of sugar derived from the carbohydrates you consume in your diet. These starches and sugars are best eaten in complex forms that come largely from fruit, whole grains, vegetables and legumes

Fatty acids

About two-thirds of brain tissue is composed of fats, which enhance communication among brain cells and stabilize and promote the elasticity of brain-cell membranes, among other functions. Important fats for brain health are oleic acid, found in olive and peanut oils, almonds and avocados; omega-3 fatty acids, found in cold-water fish, nuts and dark leafy greens; and omega-6 fatty acids, found in vegetable oils. A ratio of three omega-6 fatty acids to one omega-3 fatty acid is best, since excessive amounts of omega-6 are unhealthy.

Amino acids

Derived from proteins in the diet, amino acids are the building blocks of neurotransmitters, the chemical messengers that allow brain cells to communicate with one another. Good sources of amino acids are lean meat, fish, eggs, poultry, and low-fat dairy products. Grains, legumes, nuts and seeds also provide important amino acids.


In addition to playing an important role in regulating chemical reactions and processes within the brain, micronutrients such as vitamins, minerals and phytochemicals (plant compounds that are thought to have antioxidant and other health-promoting qualities) are vital to your brain’s defense system. Among their most important effects is the control of highly reactive forms of oxygen called free radicals. A byproduct of normal cell metabolism, free radicals can damage brain cells through chemical reactions that destabilize cellular mitochondria (the cell’s energy producers), DNA, membrane fatty acids and other cell components.

– Contact us at [email protected]



More health and well-being tips from MassGeneral Hospital experts:

Food allergies should not stop you from enjoying holidays

Improve your balance, improve your brain

How time with loved ones improves your health

How to give your baby a healthy start

How to help your teen form and keep healthy relationships

Get plenty of fruits and vegetables if you want to follow the Dietary Approaches to Stop Hypertension (DASH) regimen. Photo: Reuters

The original and largest teaching hospital of Harvard Medical School and a biomedical research facility in Boston, Massachusetts

EJI Weekly Newsletter

Please click here to unsubscribe