Diet influences many aspects of health, including mental health. Anxiety and depression are among the most common mental health problems in the world. According to the World Health Organization (WHO), depression could be one of the main health problems in the world in 2030.
Nutritional psychiatry: a new field of research
Not surprisingly, researchers continue to search for new ways to reduce the impact of mental health problems. Instead of relying solely on current therapies and medications. Nutritional psychiatry is an emerging area of research. Specifically studies the role of nutrition in the development and treatment of mental health problems.
The two main questions that arise in relation to the role of nutrition in mental health are:
Does diet help prevent mental health disorders?
Are nutrition interventions useful for the treatment of these disorders?
When does the diet prevent, reduce or promote depression?
Several observational studies have shown a relationship between the overall quality of eating and the risk of depression. For example, a review of 21 studies conducted in 10 countries found that a healthy diet was associated with a lower risk of depression. A healthy diet includes: high intake of fruits, vegetables, whole grains, olive oil, fish, low-fat dairy products, and antioxidants. There is also a low consumption of foods of animal origin.
By contrast, a Western-style diet was associated with a significantly increased risk of depression. That is, a diet that implies: a high consumption of red and processed meats, refined cereals, sweets, dairy products with a high fat content, butter and potatoes, as well as a low consumption of fruits and vegetables.
A previous study found similar results. High adherence to the Mediterranean diet was associated with a 32% reduction in the risk of depression.
More recently, a study of adults over the age of 50 linked higher levels of anxiety to diets high in saturated fat and added sugars.
Also in children and adolescents
Researchers have found similar results in children and adolescents. For example, a 2019 review of 56 studies found an association between high consumption of healthy foods such as olive oil, fish, nuts, legumes, dairy products, fruits and vegetables and reduced the risk of depression during adolescence.
Treatment of mental health problems through food
Research on whether dietary interventions can help treat mental health problems is relatively new and still quite limited. The SMILES trial was one of the first randomized controlled trials to examine the role of diet in the treatment of depression.
For 12 weeks, 67 people suffering from moderate or severe depression received dietary advice. The dietary intervention was similar to a Mediterranean diet. He focused on vegetables, fruits, whole grains, fatty fish, extra-virgin olive oil, legumes, and raw nuts. It also allowed the consumption of moderate amounts of red meat and dairy products.
At the end of the study, people who followed this diet saw their symptoms of depression improve significantly. These improvements remained significant even when the scientists accounted for confounding variables. These included body mass index (BMI), physical activity, and smoking. Also, only 8% of people in the control group achieved remission, compared to 32% of people in the diet group.
Although these results look promising, the SMILES study was a small, short-term study. Therefore, larger and longer-term studies are needed to apply their results to a larger population.
Therefore, it is difficult to draw firm conclusions from the body of existing research. This is particularly true because the type of dietary intervention studied varied considerably from study to study. In general, further research is needed on specific eating habits and the treatment of mental disorders. In particular, a more standardized definition of a healthy diet is needed. As well as larger and long-term studies.
The role of food supplements?
In addition to eating habits, scientists are interested in the possible effects that individual nutrients in the form of dietary supplements could have on mental health.Scientists have found links between low levels of certain nutrients such as folate, magnesium, iron, zinc, and vitamins B6, B12, and D, and impaired mood, feelings of anxiety, and risk of depression.
Omega-3 fatty acids are essential fats that play a key role in brain development and cell signaling. An article published in Frontiers in Physiology explains how they reduce inflammation levels. Due to their anti-inflammatory effects and their importance for brain health, scientists have studied the possible effects of omega-3s on mental health.
In 2018 and 2019, reviews of randomized controlled trials showed that omega-3 supplements were effective in treating anxiety and depression in adults. Experts recommend acquiring most of these nutrients through a healthy and varied diet. Anyone who is concerned that they cannot meet their nutrient needs through diet alone should consult a doctor to see if supplements may be helpful.
The 3 main hypotheses of the link between diet and mental health
In general, observational studies suggest that there is a link between what people eat and their mental health. But it is not yet known why food can have this effect. There are several theories about how diet may influence mood or risk of conditions such as depression and anxiety.
Some scientists believe that the inflammatory effects of certain diets may help explain the relationship between diet and mental health. Several mental health problems appear to be linked to increased levels of inflammation. The authors of the articles published in the journals Frontiers in Immunology and Current Neuropharmacology discuss this relationship. For example, diets associated with mental health benefits tend to be high in fruits, vegetables, whole grains, and healthy fats. These are all foods rich in anti-inflammatory compounds. Diets rich in antioxidants and anti-inflammatory foods are associated with a reduced risk of depression.
Another possible explanation is that diet may affect the bacteria in the gut, known as the gut microbiome. Ongoing research has found a strong link between gut health and brain function. For example, healthy gut bacteria produce about 90% of the neurotransmitter serotonin, which affects mood. Additionally, early research shows a possible link between a healthy gut microbiome and lower rates of depression.
Since diet plays an important role in the health and diversity of the gut microbiome, this theory is a promising explanation for how what we eat can affect our mental well-being.
Finally, it is possible that diet plays a more indirect role in mental health. People who eat a healthy diet may be more likely to engage in behaviors that are also linked to a lower risk of mental health disorders. These include regular physical activity, good sleep habits, and not smoking.
The complexity of mental health
It is important to note that many factors can influence both eating habits and mental health.
Factors that can contribute to mental health problems include biological factors, such as genetics, life experiences, and family history. Socioeconomic status can also influence mental health, as well as access to food and the general quality of the diet.
Mental health can, in turn, influence eating habits. For example, it’s not uncommon to turn to less healthy foods, like sweets or highly processed snacks, when you’re feeling angry or upset. Similarly, many antidepressants and anti-anxiety medications can increase appetite and cravings. In both situations, struggling with mental health can make adherence to a healthy diet more difficult.
In general, while diet can be an important factor in mental health, it’s important to remember that many other aspects of life can also contribute to mood.
Although more research is needed, current studies suggest that we can influence our mental health through our food choices.
You may also be interested in reading: Loosestrife and its great health benefits