Functional Foods for Mental and Cognitive Health

February 21, 2025

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The “nutritional psychiatry"is an emerging field that investigates the relationship between nutrition, brain health, and the development of mental disorders. The concept of functional foods stands out in this field of study. Based on scientific evidence, this article will address the potential effects of these foods on brain function, emotional balance, and mental health.

What are functional foods?

According to Brazilian legislation, foods or ingredients with functional properties are those that can generate metabolic and physiological effects, in addition to contributing to health, aiding in the growth, development, and proper functioning of the body. Several macronutrients and bioactive compounds act synergistically to regulate the production and balance of neurotransmitters and hormones in the brain. Among the most studied by science are some dietary fibers with proven prebiotic properties: omega-3 fatty acids and tryptophan.

Dietary fiber

Dietary fiber is a nutrient that plays an essential role in intestinal health, and its benefits can go far beyond improving bowel functionDepending on the type of fiber and the amount consumed, they can provide various benefits, such as controlling blood sugar and cholesterol, increasing satiety, and improving bone health. More recently, prebiotic fibers have been studied for their benefits, including mood regulation.

Adequate intake of fibers such as inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS) can promote the production of beneficial substances in the intestine, such as short-chain fatty acids, which have anti-inflammatory effects and may help reduce anxiety and increase cognitive ability. This occurs through the so-called gut-brain axis, a two-way communication between the intestine and its microbiota and the brain, and which suggests that the intestinal microbiota (microorganisms present in the intestine) directly influences our brain, affecting our mood, stress and even our cognition. The functional activity of the gut-brain axis is bidirectional via the vagus nerve, endocrine system and blood.

A recent study conducted by Jackson et al. (2023) investigated the effects of supplementing a fructooligosaccharide called oligofructose (OF) from chicory, alone and in combination with a human milk oligosaccharide, 2'-fucosyllactose (2'FL). In addition to observing its effect on gut microbial composition, its impact on the mood state of healthy adults with mild to moderate symptoms of anxiety and depression was also studied. This randomized, double-blind, placebo-controlled clinical trial involved 92 participants who received the interventions for four weeks. The results demonstrated that both oligofructose alone and the combination of 2'FL/2'FL promoted significant increases in intestinal Bifidobacterium counts, compared to the control group. Furthermore, improvements in mood parameters, including reductions in depression and anxiety scores, were observed in the groups receiving OF and OF/2'FL. These findings suggest that oligofructose supplementation, alone or combined with 2'-fucosyllactose, may benefit mental health through modulation of the intestinal microbiota.

Omega 3

Omega-3 is a type of essential fat found primarily in fatty fish such as salmon, sardines, and tuna, as well as walnuts and chia seeds. Because our bodies can't produce it, it is necessary to obtain it through food and/or supplementationOmega-3 fatty acids play fundamental roles in brain development, function, and aging, as they are involved in processes such as neurogenesis, neurotransmission, and neuroinflammation control. High-quality clinical trials are already evaluating the efficacy of omega-3s in risk reduction and treatment of mental and neurodegenerative disorders, including anxiety, depression, Parkinson's and Alzheimer's.

Docosahexaenoic acid (DHA) constitutes more than 90% of the omega-3 polyunsaturated fatty acids in the brain, being especially concentrated in the gray matter. Its presence is associated with improvement of neurological and cognitive function, benefiting individuals with attention deficit disorder and elderly people in the process of brain aging.

Tryptophan

Tryptophan is an essential amino acid found in foods such as turkey, eggs, milk, cheese, nuts, and seeds. It plays a crucial role in the brain, as it is the precursor of serotonin, a neurotransmitter responsible for regulating mood, sleep and appetite.

THE deficiency of serotonin is associated with disorders such as depression and anxiety, making adequate tryptophan consumption essential for mental health. Foods rich in this amino acid help increase serotonin production, promoting a positive impact on mood and emotional well-being. Furthermore, serotonin contributes to sleep quality, an essential aspect for cognitive health. Studies indicate that a tryptophan-rich diet (25 mg/kg of body weight per day for 12 weeks) can increase tryptophan metabolism and improve scores on mental health assessment tests in elderly individuals with mood disorders.

Food as an ally in the mind

While functional foods are important for mental and cognitive health, it is essential to maintain a balanced diet rich in a variety of nutrients. There is no single food or supplement that can solve all mental health challenges.. The real benefit is in the combination of different foods, which together provide comprehensive support for the body. Furthermore, a proper diet should be combined with healthy habits, such as regular physical activity, stress management, and good quality sleep. These factors are equally essential for maintaining mental and cognitive well-being.

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About the author:
Leila Hashimoto is a nutritionist and holds a PhD in Nutrition Science from the University of São Paulo. She coordinates the postgraduate program in clinical nutrition applied to gastroenterology at the LG Institute/PUC-Goiás. She teaches classes and lectures and works in a nutritional practice.