Not all medicines fit inside a syrup or a blister of pills. Science has shown that following a healthy lifestyle, such as a healthy diet, physical exercise, not smoking or sleeping well, can prevent cardiovascular diseases, cancer, obesity or diabetes, among other ailments. But there is also growing evidence that these healthy habits build a protective wall against mental disorders. A study by the Hospital del Mar Research Institute suggests, for example, that adherence to a healthy diet, such as the Mediterranean, reduces the risk of depression by 16%. Other studies have reported similar effects with physical exercise: those who did more exercise were up to 21% less likely to develop depression. “Physical exercise, a balanced diet, avoiding the consumption of toxic substances, having social support and respecting circadian rhythms are protective factors,” summarizes psychiatrist Víctor Pérez.
Like a kind of defensive wall, healthy habits help avoid the appearance of symptoms that can lead to complex mental disorders. “The best prevention is to choose the parents well because the genetic code and the zip code are given to us by them. But since we can’t do that, we then have all those healthy habits, which are protective. They are not preventive, we cannot say that someone who follows a balanced diet does not become depressed. But these factors, if added together, increase protection,” points out Pérez, who is head of Psychiatry at the Hospital del Mar in Barcelona.
The interactions of diet on mental health are not the most studied, but there are already a handful of studies that point in the same direction. A recent one is a meta-analysis by the Hospital del Mar Research Institute and published in the journal European Journal of Nutritionwhich evaluated the impact of four types of healthy diets (Mediterranean, one vegetarian, one recommended by the World Health Organization and another to prevent depression) on the risk of suffering from depression. The research concluded that adherence to any of these diets was a protective factor against depression and the Mediterranean diet obtained the highest score.
Gabriela Luján, author of this study, points out that there are several hypotheses that can explain this link. The first, the so-called gut-brain axis, a bidirectional communication path between the intestinal tract and the central nervous system that may be the basis of some pathologies. “What we eat influences our microbiome [el ecosistema de microbios que puebla el intestino y media en la salud y la enfermedad]. From there, nutrients, amino acids and other molecules are absorbed to generate proteins and neurotransmitters. If this microbiome-gut-brain axis is altered, that will influence the development of these pathologies,” explains Luján.
Another hypothesis, the researcher points out, is related to the role of inflammation. “There is a chain of stress that influences our body,” he says. Peréz, who has not participated in Luján’s research, elaborates on this phenomenon and remembers that depression, for example, is a pathology that is related to inflammatory processes. Unlike healthy diets, current Western eating habits, rich in carbohydrates, sugars and ultra-processed foods, favor this inflammatory state of the body. Along these lines, research published last February highlighted that the risk of depression skyrocketed when ultra-processed foods exceeded 30% of a person’s daily diet.
Experts also highlight that many pathologies closely linked to unhealthy eating habits are also closely linked to the development of mental health problems. And, like a cascade of events, both end up being communicating vessels. “Obesity and depression are connected in a bidirectional relationship and diet is a determining factor of body weight and, therefore, of the causal pathway,” exemplifies Luján in his study. In an article published in 2020, Joseph Firth, from the University of Manchester, also noted that “high glycemic index diets are a risk factor for diabetes, which is often a comorbid condition with depression.” And he added: “Although the main models of pathophysiology [origen] While diabetes and mental illness are separate, the common abnormalities in insulin resistance, brain volume, and neurocognitive performance in both conditions support the hypothesis that these conditions have overlapping pathophysiology.”
Joaquim Raduà, psychiatrist at the Hospital Clinic-IDIBAPS, has also participated in a study that sought to build solid recommendations to reduce anxiety and depressive symptoms. And after analyzing data from nearly a thousand people, they concluded that avoiding excessive exposure to stressful news and maintaining a healthy and balanced diet, followed by spending time outdoors and doing physical exercise, were the behaviors most associated with a reduction in anxiety-depressive symptoms. “We saw the clearest benefit in eating a healthy diet and not only did anxiety symptoms improve in the short term, but also in the long term. The effect is not miraculous, but it may be enough for people who have minor symptoms,” he explains.
The scientific community admits, however, that, despite the data that points to the protective role of a healthy diet, there is still a need to “improve understanding” of the ways in which diet and nutrition influence your brain. In their article, Firth and his colleagues recall that “the causes of mental illness are many and varied, and will often occur and persist regardless of nutrition and diet.”
Physical exercise and sleep quality
Another healthy habit with the potential to prevent mental disorders is physical exercise. A review of studies revealed that adults who engaged in the recommended amount of physical activity had a 25% lower risk of depression; And even those who did half the recommended exercise also had an 18% lower risk. Based on estimates with the cohorts studied in this research, the authors stated: “If the least active adults had achieved the current recommendations for physical activity, 11.5% of cases of depression could have been avoided.”
Sleep quality is another key aspect that affects mental health. “It seems that the hours you sleep are not so important, but the rhythms, that you get up and go to bed at the same time, for example,” Pérez points out. A meta-analysis that condensed 50 years of research on sleep deprivation revealed that all forms of sleep loss (total sleep deprivation, partial sleep loss, and sleep fragmentation) produce emotional changes the next day, with the most consistent effects being a reduction positive mood and increased anxiety levels.
A group of researchers from the University of Manchester also highlights that there is already “a significant body of evidence that poor sleep is another key modifiable lifestyle factor, with large-scale meta-analyses showing prospective links with several psychiatric disorders and “Supporting findings from MRI studies suggest a causal role in bipolar disorder.” And they add: “Sleep disorders have been found to significantly increase the risk of suicidal behavior in people living with mental illness.” In fact, research with 8,000 preteens found that having sleep disturbances at age 10 was associated with an increased risk of suicidal thoughts and behaviors in the following two years.
The puzzle of the neurobiological pathways that explain how and why various lifestyle factors impact health is not yet complete. But the phenomenon of inflammation and the role of the microbiome are two key points in the impact of healthy living patterns. “With healthy habits you can prevent some mental illnesses because stress and inflammation derived from that stress are part of the etiopathology.” [las causas] of many mental disorders. All healthy habits add up, but physical exercise, healthy interpersonal relationships, a healthy diet and good family support are essential,” concludes Marina Díaz Marsá, vice president of the Spanish Society of Psychiatry.
Raduà appeals to the Latin aphorism Healthy men in healthy corpore: “It is very important to look for new therapies for people who suffer from mental disorders. But, sometimes, we forget about prevention. It may be easier to follow a healthy diet and physical exercise, which are strategies without harmful effects and good for the body, and we could avoid many cases of mental disorders,” he says.