The human brain, despite representing only 2% of body weight, consumes nearly 20% of the energy we ingest each day. This high energy expenditure makes it an organ particularly sensitive to what reaches it through the bloodstream: nutrients, structural fats, vitamins, and also excesses that can damage small blood vessels. Diet doesn't guarantee a perfect memory, but it does play a role in the environment in which attention and recall operate. In recent years, science has accumulated solid evidence linking certain dietary patterns to brain health, and several of the most relevant studies have been conducted in Europe, with the participation of Spanish research centers.
Recent research, such as that led by University College London and the Barcelona Institute for Global Health (ISGlobal), has observed that greater adherence to the Mediterranean diet is associated with greater psychological well-being in people over 50. The study, published in BMJ Open, analyzed data from more than 3.200 participants in the England Longitudinal Study of Ageing (ELSA) and found that those who more closely followed this dietary pattern had higher scores in autonomy, enjoyment of life, and sense of purpose, even after adjusting for socioeconomic factors and depressive symptoms. Furthermore, during the COVID-19 pandemic, emotional distress was less pronounced among those who maintained a Mediterranean diet, suggesting a possible protective effect.
The Mediterranean diet, a pattern that takes care of the brain
The Mediterranean diet, based on fruits, vegetables, legumes , fish, extra virgin olive oil, and nuts, has been the subject of numerous studies for its cardiovascular benefits. Now, research is focusing on its impact on the brain. The PREDIMED-Plus project, one of Europe's largest clinical trials on diet and lifestyle, has provided key data. A team from the Rovira i Virgili University (URV), the CatSud Biomedical Research Institute (IRBCatSud), and CIBEROBN evaluated more than 6.600 participants aged 55 to 75 with overweight or obesity and metabolic syndrome over a two-year period. The results, published in The American Journal of Clinical Nutrition, show that a higher intake of choline and betaine is associated with more favorable development in cognitive functions such as attention, language, and executive function. Choline, found in eggs, fish, lean meats, and dairy products, is essential for the formation of cell membranes and the production of acetylcholine, a key neurotransmitter for memory and learning. Betaine, abundant in whole grains, spinach, beets, and shellfish, is involved in metabolic processes and cell protection.
Choline and betaine: two nutrients that make a difference
Researchers at the URV highlight that individuals with the highest choline intake showed improved attention and language skills over two years, while betaine was associated with significant preservation of executive function and language. These findings reinforce the idea that nutrients present in commonly consumed foods can contribute to preserving certain cognitive abilities during aging. Jordi Salas-Salvadó, Professor of Nutrition at the URV and principal investigator of PREDIMED-Plus, emphasizes that "we have increasing evidence that diet also influences brain health." However, the authors stress that longer-term follow-up studies are needed to confirm these benefits and determine their potential role in preventing cognitive decline and dementia.
Nuts, a snack that promotes memory
Within the Mediterranean diet, nuts hold a prominent place due to their high nutritional density. A study published in 2023 observed that, in older adults at risk of cognitive decline, more frequent nut consumption was associated with more favorable changes in overall cognitive performance over two years. Walnuts, almonds , pistachios, and hazelnuts provide vitamin E, magnesium, unsaturated fats, and polyphenols, compounds that protect nerve cells from oxidative stress and improve cerebral blood flow. The recommended serving is around 25 to 30 grams per day, preferably raw or roasted without added salt or sugar. Including them in breakfast, as a snack, or in salads is a simple way to support long-term memory and concentration.
The MIND pattern and other complementary strategies
Beyond the classic Mediterranean diet, the MIND pattern (a combination of the Mediterranean and DASH diets) has shown promising results. A study from the Rush Center in Chicago, published in Alzheimer's and Dementia in 2015, followed 923 people between the ages of 58 and 98 for almost five years and found that those who followed this pattern most consistently had 53% fewer cases of Alzheimer's disease. Even moderate adherence was associated with a 35% reduction. The foods that stand out most in this pattern are leafy green vegetables, berries, extra virgin olive oil, oily fish, nuts, and legumes, while processed meats, pastries, and fried foods are limited. Although a subsequent trial found no significant differences in cognitive tests, experts point out that the diet acts slowly and in combination with other habits such as sleep, exercise, and blood pressure control.
Taken together, current evidence suggests that a diet rich in plant-based foods, fish, olive oil, and nuts, along with moderate consumption of eggs and dairy products, can help maintain brain health during aging. Studies conducted in Spain and other European countries reinforce the idea that the Mediterranean diet, rather than any specific food, offers protection. As researchers point out, preventing cognitive decline should be approached holistically, combining a healthy diet with physical activity, adequate rest, and management of vascular risk factors.
