What is a brain-healthy diet?

A heart-healthy diet is also a brain-healthy diet

Cardiovascular diseases are one the most common causes of death in Finland. Their risk factors include high blood pressure and cholesterol, elevated blood sugar levels, and abdominal obesity, especially in middle age. A study based on data from fifteen thousand people found that cardiovascular risk factors such as high blood pressure, elevated fasting blood sugar, and obesity, particularly in early adulthood, were linked to earlier decline in cognitive abilities (study 1). Treating these risk factors by following a diet in line with nutritional guidelines also promotes brain health.

The brain likes healthy fats

Dietary fats, especially omega-3 fatty acids, are important for brain function. A deficiency in omega-3 fatty acids has been linked to various neurological disorders, such as mental health issues, ADHD, and dementia (study 2). Essential fatty acids are compounds that our bodies cannot produce on their own. They are needed for the functioning of the nervous system and immunity, for example. These include linoleic acid (LA), a precursor of omega-6 fatty acids, and alpha-linolenic acid (ALA), a precursor of the omega-3 fatty acids EPA and DHA. Since the body's ability to convert ALA into EPA and DHA is limited, it's important to include sources of them in the diet. Good sources of healthy fats include fatty fish, vegetable oils, margarine, nuts and seeds, and avocados.

On the other hand, saturated fats and trans fats negatively affect brain function (study 2). According to nutritional recommendations, the intake of saturated fats should be less than ten percent of total energy intake, and the intake of trans fats should be as low as possible. According to the FinDiet 2017 study, only about 5% of Finns meet the recommendation for saturated fat intake (study 3). The main sources of saturated fats in the Finnish diet are high fat dairy products and meat-based foods. Tropical vegetable oils, such as coconut oil and palm oil, are also high in saturated fats.

Less salt, more fiber

Excess salt intake raises blood pressure and increases the risk of atherosclerosis in the brain. In contrast, fiber intake supports brain health. A nearly 20-year follow-up study examining the connection between fiber intake and the incidence of dementia in almost 4,000 adults found that the more fiber, especially soluble fiber, was consumed, the lower the risk of dementia (study 4). Only less than a third get the recommended amount of fiber (25–35 g/day) and nearly all Finns consume too much salt salt (< 5 g/day). Good sources of fiber include whole grains, legumes, and plant-based foods.

Micronutrients also play a role

Sufficient intake of vitamins B6, B12, C, D, and E has been linked to slower cognitive decline or better cognitive performance (study 2). In addition to vitamins, folate (vitamin B9) is important for brain function, and its deficiency has been linked to cognitive impairments. Furthermore, nutrients such as choline, calcium, zinc, selenium, copper, and flavonols have been shown to be related to brain function. Foods rich in antioxidants also promote brain health, as the brain is particularly sensitive to oxidative stress. Antioxidants protect cells from the harmful effects of free radicals. Although dietary supplements are not currently recommended for maintaining brain health, there is evidence that a daily multivitamin may improve memory in older adults (study 5).

Certain foods have been linked to brain health, including berries due to their high flavonol and antioxidant content, green leafy vegetables for their high nutrient density, fatty fish and nuts (especially walnuts) for their beneficial fatty acids, as well as tea and coffee. Caffeine appears to have positive effects on cognitive performance and memory. Among herbs, turmeric in particular seems to reduce brain degeneration, at least in animal models. Brain health is best supported by a plant-focused diet rich in fiber, micronutrients, and healthy fats.

Brain health is more than food

In addition to diet, physical activity is especially important for the brain, as it helps to prevent cardiovascular risk factors, improves mood, and may enhance brain performance. Social interaction and mentally engaging activities, such as doing crossword puzzles, also support brain function. Taking care of brain health is not just for the elderly; it is a lifelong process.

Summary:

• Treating risk factors for cardiovascular disease also promotes brain health.
• A brain-healthy diet consists of plant-based foods and sources of healthy fats, especially berries, dark green vegetables, nuts, and fatty fish
• Sources of saturated fats, such as high fat dairy products and meat-based foods, as well as high salt foods, should be limited.
• In addition to diet, physical activity, social connections, and mentally engaging activities support brain function.

Main Text:
Emma Järvensivu
Student of Nutritional Science at the University of Helsinki
Intern at the Mind Nutrition project

References

Study 1: Yaffe, K., Vittinghoff, E., Hoang, T., Matthews, K., Golden, S. H., & Zeki Al Hazzouri, A. (2021). Cardiovascular Risk Factors Across the Life Course and Cognitive Decline: A Pooled Cohort Study. Neurology, 96(17), e2212–e2219. https://doi.org/10.1212/WNL.0000000000011747

Study 2: Gómez-Pinilla F. (2008). Brain foods: the effects of nutrients on brain function. Nature reviews. Neuroscience, 9(7), 568–578. https://doi.org/10.1038/nrn2421

Study 3: Liisa Valsta, Niina Kaartinen, Heli Tapanainen, Satu Männistö, Katri Sääksjärvi (toim.) Ravitsemus Suomessa - FinRavinto 2017 -tutkimus. Terveyden ja hyvinvoinnin laitos (THL), Raportti 12/2018.

Study 4: Yamagishi, K., Maruyama, K., Ikeda, A., Nagao, M., Noda, H., Umesawa, M., Hayama-Terada, M., Muraki, I., Okada, C., Tanaka, M., Kishida, R., Kihara, T., Ohira, T., Imano, H., Brunner, E. J., Sankai, T., Okada, T., Tanigawa, T., Kitamura, A., Kiyama, M., … Iso, H. (2023). Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study. Nutritional neuroscience, 26(2), 148–155. https://doi.org/10.1080/1028415X.2022.2027592

Study 5: Yeung, L. K., Alschuler, D. M., Wall, M., Luttmann-Gibson, H., Copeland, T., Hale, C., Sloan, R. P., Sesso, H. D., Manson, J. E., & Brickman, A. M. (2023). Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial. The American journal of clinical nutrition, 118(1), 273–282. https://doi.org/10.1016/j.ajcnut.2023.05.011