The role of nutrition on psichiatry
Research indicates a strong link between nutrition and mental health. It is believed that an appropriate diet can play both a preventive role – protecting against diseases – and a supportive role in the treatment of various mental disorders, such as depression, schizophrenia, or anxiety disorders (Grajek et al., 2022).
Diet and mental illnesses
Mental illnesses are a serious health issue, affecting the daily lives of millions of people around the world. The most common conditions include depression, schizophrenia, bipolar disorder, and anxiety disorders. Their treatment is primarily based on pharmacotherapy and psychotherapy; however, researchers are increasingly highlighting the importance of diet as a supportive element in therapy. The following section will provide a general overview of these disorders. If you wish to explore detailed descriptions and the diagnostic criteria used by clinicians, it is recommended to consult the ICD-11 (International Classification of Diseases) or the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders).
Mental illnesses are disorders that affect the way a person thinks, feels, and behaves. They can hinder everyday functioning – such as studying, working, or maintaining relationships. Individuals struggling with these issues may feel down, anxious, have trouble concentrating or sleeping, and sometimes find it difficult to distinguish reality from imagination. These disorders are not a sign of “weakness” – they are real health conditions that can and should be treated. The sooner they are recognised, the greater the chances of effective support and improved quality of life.
Depression
Depression is one of the most common mental disorders, characterised by a prolonged low mood, lack of energy, and a loss of interest in everyday activities. People with depression may also experience sleep disturbances, concentration difficulties, and changes in appetite
Researchers are increasingly studying the impact of diet on depressive symptoms, highlighting the importance of nutrients that support brain function. Omega-3 fatty acids, B vitamins, and antioxidants are of particular interest, as they may support neurotransmitter function and reduce inflammation in the body. In some studies, the Mediterranean and ketogenic diets have shown beneficial effects in alleviating symptoms of depression, although further research is needed in this area. These nutrients and diets will be discussed in more detail later in this module.
Schizofrenia
Schizophrenia is a serious mental disorder that affects thinking, emotions, and the perception of reality. Its symptoms include hallucinations (e.g. hearing voices), delusions, concentration problems, and difficulties with social functioning.
In recent years, researchers have begun to explore the role of diet in the treatment of schizophrenia, particularly in relation to glucose metabolism and mitochondrial function in the brain – that is, how brain cells produce energy. The ketogenic diet causes the body to derive energy mainly from fat instead of sugar (carbohydrates). This results in the production of so-called ketone bodies, which replace glucose as fuel for the brain. In this way, the diet may support the stabilisation of brain function and help reduce certain symptoms of schizophrenia. Additionally, following a diet rich in antioxidants may help protect nerve cells from damage. The role of this diet will be discussed in more detail later in the module.
Bipolar disorder (BD) pression
Bipolar disorder is characterised by alternating episodes of depression and mania (excessive excitement, hyperactivity, and often impulsive decision-making). This condition significantly affects daily functioning and requires long-term pharmacological treatment.
Researchers have observed that individuals with BD often experience metabolic disturbances and difficulties in maintaining stable blood glucose levels. As a result, hypotheses have emerged suggesting that a ketogenic or low-carbohydrate diet may support mood stabilisation by improving mitochondrial function and regulating neurotransmitter levels. Although research in this area is still in its early stages, findings suggest that a well-balanced diet may be a helpful element in supporting therapy.
Anxiety disorders
Anxiety disorders include various conditions such as chronic anxiety, panic attacks, and phobias. People suffering from these disorders often experience persistent worry, muscle tension, and sleep disturbances.
In the context of anxiety disorders, researchers are increasingly focusing on the role of gut microbiota and its influence on brain function (the gut–brain axis, which refers to the connection between the gut and the brain, meaning that what we eat can affect how we feel). A diet rich in probiotics (e.g. natural yoghurt) and in nutrients that support serotonin production (e.g. foods high in tryptophan) may have a beneficial effect on reducing anxiety. An increasing number of studies suggest that a healthy diet can support emotional stability, although it should not be considered a replacement for pharmacological treatment.
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The impact of diet on mental health
As previously mentioned, there is a connection between diet and mental health. For example, excessive body weight and poor dietary quality – such as ultra-processed, high-calorie food that is low in essential nutrients – are considered significant factors influencing mental well-being (Grajek et al., 2022).
Source: Grajek et al. (2022)
Modern dietary habits contribute to weight gain, often accompanied by nutrient deficiencies. Despite the increasing intake of kilocalories, the consumption of key micro- and macronutrients – such as B vitamins and magnesium, which are essential for proper nervous system function – remains insufficient. In addition, a decline in the consumption of vegetables and fibre-rich grain products has been observed. These negative effects are further intensified by factors such as smoking, low physical activity, and excessive alcohol consumption, all of which increase the risk of mental disorders, including depression (Grajek et al., 2022).
The impact of bioactive food components on mental health
A growing number of studies show that certain bioactive compounds present in food can influence brain function and overall well-being. Bioactive compounds are substances that are not essential for survival, but have beneficial effects on health – they may improve mood, reduce stress, and even support the treatment of conditions such as depression or schizophrenia. They work in various ways: by affecting neurotransmitters (chemicals in the brain that help us feel calm and well), reducing inflammation (a state that can impair brain function and worsen mood), and supporting gut function, which is connected to the brain. These compounds are found in natural food sources such as vegetables, fruits, nuts, and fish (Grajek et al., 2022).
The table below presents examples of bioactive compounds worth considering when planning the diet of a person with psychological difficulties
| Name of bioactive compound | Mechanism of action | Dietary sources |
|---|---|---|
| Omega-3 fatty acids | Improve brain function, support neurotransmitters, reduce inflammation | Fatty fish (salmon, mackerel, sardines), walnuts, flaxseeds |
| Polyphenols | Protect neurons from damage, improve blood flow to the brain, have anti-inflammatory effects | Dark chocolate, berries, grapes, green tea, cocoa |
| Tryptophan (amino acid) | Precursor to serotonin (“happiness hormone”), improves mood and aids sleep | Bananas, eggs, turkey, milk, nuts, pumpkin seeds |
| Magnesium (mineral) | Supports nervous system function, reduces stress | Nuts, pumpkin seeds, wholegrain products, cocoa, spinach |
| Probiotics | Support gut health, which influences brain function (gut–brain axis – the connection between the gut and the brain) | Kefir, natural yoghurt, fermented foods |
| B vitamins (B6, B9, B12) | Improve brain function, support neurotransmitter production | Meat, eggs, legumes, wholegrain products, green vegetables |
| Zinc (mineral) | Supports nervous system function, has anti-inflammatory effects | Beef, nuts, pumpkin seeds, legumes, oysters |
| Antioxidants (e.g. vitamins C, E, carotenoids) | Protect brain cells from oxidative stress, which can contribute to mental disorders | Peppers, citrus fruits, carrots, nuts, olive oil |
| S-adenosylmethionine (SAMe) | Helps brain cells function properly, supports mood | Meat, eggs, wholegrain products |
| N-acetylcysteine (NAC) | Anti-inflammatory, supports regeneration of nerve cell | Nuts, seeds, meat, eggs |
Source: Grajek et al. (2022)
The role of diet in working with individuals experiencing mental health problems is crucial, as nutrition directly influences brain function and overall mental well-being. Numerous studies confirm that poor dietary habits—particularly the consumption of ultra-processed foods—can increase the risk of depression, anxiety, and other disorders. In contrast, a well-balanced diet rich in essential nutrients can have a protective effect and support the treatment process.
Although pharmacotherapy and psychotherapy remain the foundations of mental health treatment, a growing body of research suggests that an appropriate diet can aid therapeutic progress and improve patients’ quality of life. To work effectively with individuals facing mental health challenges, it is important to understand how diet impacts mental health and to be familiar with specific nutritional strategies that support therapy.
It is essential to remember, however, that diet should never replace pharmacological treatment. Any dietary changes should be made under the supervision of a doctor and a dietitian to ensure safety and effectiveness.
In the following modules, we will explore detailed dietary interventions, common nutrient deficiencies, and frequent dietary mistakes made by patients. We encourage you to continue reading to expand your knowledge and better support individuals dealing with mental health disorders.
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| Bibliography |
| Grajek, M., Krupa-Kotara, K., Białek-Dratwa, A., Sobczyk, K., Grot, M., Kowalski, O., & Staśkiewicz, W. (2022). Nutrition and mental health: A review of current knowledge about the impact of diet on mental health. Frontiers in Nutrition, 9, 943998. https://doi.org/10.3389/fnut.2022.943998 Bhave, V. M., Oladele, C. R., Ament, Z., Kijpaisalratana, N., Jones, A. C., Couch, C. A., Patki, A., Garcia Guarniz, A. L., Bennett, A., Crowe, M., Irvin, M. R., & Kimberly, W. T. (2024). Associations between ultra-processed food consumption and adverse brain health outcomes. Neurology, 102(11), e209432. https://doi.org/10.1212/WNL.0000000000209432 Contreras-Rodriguez, O., Reales-Moreno, M., Fernández-Barrès, S., Cimpean, A., Arnoriaga-Rodríguez, M., Puig, J., Biarnés, C., Motger-Albertí, A., Cano, M., & Fernández-Real, J. M. (2023). Consumption of ultra-processed foods is associated with depression, mesocorticolimbic volume, and inflammation. Journal of Affective Disorders, 335, 340–348. https://doi.org/10.1016/j.jad.2023.05.009 |
