Diet and brain health: What does science tell us?

When it comes to brain health, diet plays a significant role, but how much can it really do? Can our food choices truly support cognition and protect against neurodegenerative diseases? While there are no (magic) foods to prevent conditions like Alzheimer’s or Parkinson’s disease, emerging research suggests diet and dietary habits may support cognitive function and overall brain health.

As a registered dietitian with a background in neuroscience, I am here to share some insights into what we currently know (and still need to learn) about diet and brain health, along with practical dietary tips to support a healthy brain. Beware! This post is not exhaustive but rather a way to engage in constructive dialogue.

The brain-nourishing power of nutrients

Some nutrients and food compounds have attracted significant research attention due to their potential to support cognitive function. Below are some of the key players.

Omega-3 fatty acids

Omega-3s, especially docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids (and, in a minor way, ALA, alpha-linolenic acid), are known for their potential neuroprotective effects. DHA and EPA may be found in oily fish like salmon, mackerel, sardines, and algal oil. These fatty acids are essential components of brain cell membranes and display anti-inflammatory properties. ALA is mainly found in flaxseed, chia seeds, and walnuts and also has anti-inflammatory properties.

Research has linked omega-3 intake with improved cognitive function (foe example, memory and verbal fluency) and reduced cognitive decline in ageing populations (Schaefer et al., 2006; Sydenham et al., 2012; Alex et al., 2020; Ogawa et al., 2023). Including oily fish in our diet (a couple of times a week) or opting for algal oil (DHA and EPA) and other food sources like flaxseed and chia (ALA) may be a practical way to ensure we get these essential fats.

Choline

Choline is found in foods like eggs, liver, shitake mushrooms, and soybeans and is needed for acetylcholine production. Acetylcholine is a key neurotransmitter for memory and mood regulation. Studies suggest choline intake may support cognitive function, and researchers are exploring whether choline could play a role in reducing cognitive decline as we age (Poly et al., 2011). Given its critical role, including choline-rich foods in our diet may offer potential brain benefits.

Polyphenols

Polyphenols, found in foods like fruits, vegetables, cocoa and green tea, are compounds with antioxidant properties. Polyphenols may help counter oxidative stress, which is associated with neurodegeneration (Joseph et al., 2009; Vauzour et al., 2008). Some studies have linked polyphenol-rich diets with improved memory and cognitive performance, but more research is needed (Godos et al., 2024). For now, incorporating a variety of colourful fruits and vegetables, alongside occasional dark chocolate, green tea, or coffee, may help provide those extra polyphenols.

The MIND diet

Developed as a combination of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets, the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet emphasises whole grains, green leafy vegetables, nuts, pulses, berries, fish, poultry, and olive oil. People following the MIND diet may have a reduced risk of developing cognitive decline, as suggested by some studies (Morris et al., 2015; Berendsen et al., 2017; Sawyer et al., 2024). Interestingly, recent evidence highlights potential gender differences related to the potential protective effects of the MIND diet on cognitive decline (Sawyer et al., 2024).

Beyond nutrients: A life-course perspective on brain health

Brain health goes beyond what we eat today. It is a story that starts from the very beginning of life and continues through every stage. From prenatal development throughout our later years, our brains need different nutrients to stay sharp, healthy, and resilient.

  • Prenatal life: Brain health actually begins before we are even born. During pregnancy, nutrients like folate, omega-3s, iron, and choline are critical in helping a baby’s brain form and grow (yes, mums-to-be, what you eat may make a difference). For example, folate helps prevent neural tube defects early in pregnancy, while omega-3s play a crucial role in building the structure of brain cells. Research suggests that when these nutrients are plentiful during pregnancy, children might go on to experience better cognitive and emotional health (Georgieff, 2007).
  • Childhood and adolescence: During childhood and teenage years, our brains are still developing at lightning speed, making balanced nutrition even more important. For example, B vitamins, iron and zinc (the list goes further) may be essential for memory, learning, and emotional balance (Prado & Dewey, 2014). This is also an exceptional time to establish healthy eating habits that can benefit brain (and overall) health for life.
  • Adulthood: Our brains are fully developed as adults but continue to be plastic, enabling us to learn and adapt. Ever heard about myelination? (Lillard & Erisir, 2011; Zatorre et al., 2012). Nutrients like omega-3s and compounds like antioxidants and polyphenols may help keep our brains clear, focused, and resilient to stress.
  • Older age: Later in life, our brains may need a little extra support to stay on track. Vitamins like B12 and D and antioxidants may be particularly important as our bodies may become less efficient at absorbing nutrients as we age (Russell, 1992). Eating nutrient-rich foods may help keep cognitive function sharp and maintain memory as we age (Smith & Refsum, 2016). Supplements may be considered, but ideally only after nutrient deficiencies have been identified and food-first strategies are not working.

The role of hydration in cognitive health

While often overlooked, hydration is critical to maintaining focus and cognitive performance. Dehydration has been associated with poorer performance on tasks requiring sustained attention (Rosinger et al., 2024). As we age, we tend to feel less thirsty. Staying hydrated throughout the day is particularly important in physically demanding jobs or warm environments, where fluid loss can increase, but also in everyday life.

For older adults (and everyone else), keeping a water bottle on hand, including water-rich foods such as fruit and vegetables, and setting reminders to drink can support overall cognitive function.

Practical dietary tips for brain (and overall) health

Here are a few simple ways to support brain (and overall) health through diet. You may want to look further into personalisation according to your lifestyle and needs:

  • Balance your plate: The Eatwell Guide is a good starting point advising how to aim for nutritional balance in each meal, including complex carbohydrates, lean proteins, and healthy fats. This may contribute to sustaining energy levels and supporting cognition.
  • Should we incorporate “brain-friendly” foods? Including omega-3-rich foods and polyphenol sources like fruits and vegetables will help provide essential nutrients. But rather than focusing only on specific foods, why not consider following a colourful and varied diet to support our bodies and minds?
  • Stay hydrated: Keep a water bottle handy and monitor your fluid intake throughout the day.

What science has yet to explore

While there is promising research on diet and brain health, no food or nutrients may prevent (so far) neurodegenerative diseases. Brain function is complex, and factors like genetics, lifestyle, and environment are all involved. Still, a balanced diet, physical activity, and mental engagement can support overall well-being and potentially lower the risk of cognitive decline.

Beyond nutrients: The social, sensory and timing aspects of eating and brain health

Nutrition goes beyond what we eat. It is also about how, when, and with whom we eat. Beyond the nutritional value of food, the sensory experience, social connections, and timing of meals can profoundly impact our brain health and emotional well-being.

Social interaction, for instance, is linked with improved mood and can contribute to long-term brain health. Regular engagement with others, including something as simple as sharing a meal, may stimulate cognitive functions, providing our brains with emotional and social “exercise” as we age. Apparently, people who maintain strong social ties may have a lower risk of developing cognitive decline (Fratiglioni et al., 2004).

The appearance, smell, and texture of our food also make a difference. How often do we stop and think about these aspects? How was this food prepared? The sensory experience around food may evoke positive memories and emotions and add an extra layer of enjoyment (and well-being). Why not invest time to prepare and slow down to savour our meals mindfully?

Lastly, could meal timing impact our health? This may be the case, according to chrononutrition. Research suggests that the time of the day we eat may influence our energy levels and metabolism (Zarrinpar et al., 2016; Longo & Panda, 2016). Could approaches like intermittent fasting or eating meals at consistent times support cognitive function by aligning with our body’s natural rhythms? Research will tell us. That said, balance is essential. As social connection is vital for brain health, finding ways to enjoy shared meals, even within a chosen eating schedule, may be worth trying. Combining meal timing with the social and sensory joys of eating could be an extra step toward a healthier brain and overall well-being.

As we explore ways to support our brain health, what we eat and how, when, and with whom we eat may make a difference.

References

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Berendsen, A. A. M., Kang, J. H., van de Rest, O., Feskens, E. J. M., de Groot, L. C. P. G. M., & Grodstein, F. (2017). The Dietary Approaches to Stop Hypertension Diet, Cognitive Function, and Cognitive Decline in American Older Women. Journal of the American Medical Directors Association, 18(5), 427–432. https://doi.org/10.1016/j.jamda.2016.11.026

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Luis Emiliano Pena Altamira, PhD RD