Healthy lifestyle can help prevent depression

A healthy lifestyle that involves moderate alcohol consumption, a healthy diet, regular physical activity, healthy sleep and frequent social connection, while avoiding smoking and too much sedentary behaviour, reduces the risk of depression, new research has found.

In research published in Nature Mental Health, an international team of researchers investigated how a combined range of lifestyle factors, including alcohol consumption, diet, physical activity, sleep, smoking, sedentary behaviour and social connection contribute to depression, and examine the underlying neurobiological mechanisms.

The researchers used data from the UK Biobank, a biomedical database and research resource containing anonymised genetic, lifestyle and health information. By examining data from almost 290,000 people – of whom 13,000 had depression – followed over a nine-year period, the team was able to identify seven healthy lifestyle factors linked with a lower risk of depression.

Having a good night’s sleep – between seven and nine hours a night – made the biggest difference, reducing the risk of depression, including single depressive episodes and treatment-resistant depression, by 22%. Frequent social connection, which in general reduced the risk of depression by 18%, was the most protective against recurrent depressive disorder. Moderate alcohol consumption decreased the risk of depression by 11%, healthy diet by 6%, regular physical activity by 14%, never smoking by 20%, and low-to-moderate sedentary behaviour by 13%.

Based on the number of healthy lifestyle factors an individual adhered to, they were assigned to one of three groups: unfavourable, intermediate, and favourable lifestyle. Individuals in the intermediate group were around 41% less likely to develop depression compared to those in the unfavourable lifestyle, while those in the favourable lifestyle group were 57% less likely.

The team then examined the DNA of the participants, assigning each a genetic risk score. This score was based on the number of genetic variants an individual carried that have a known link to risk of depression. Those with the lowest genetic risk score were 25% less likely to develop depression when compared to those with the highest score – a much smaller impact than lifestyle.

In people at high, medium, and low genetic risk for depression, the team further found that a healthy lifestyle can cut the risk of depression. This research underlines the importance of living a healthy lifestyle for preventing depression, regardless of a person’s genetic risk.

To understand why a healthy lifestyle might reduce the risk of depression, the team studied a number of other factors.

Firstly, they examined MRI brain scans from just under 33,000 participants and found a number of regions of the brain where a larger volume – more neurons and connections – was linked to a healthy lifestyle. These included the pallidum, thalamus, amygdala and hippocampus.

The team then looked for markers in the blood that indicated problems with the immune system or metabolism. Among those markers found to be linked to lifestyle were the C-reactive protein, a molecule produced in the body in response to stress, and triglycerides, one of the primary forms of fat that the body uses to store energy for later. The pathway from lifestyle to immune and metabolic functions was the most significant, meaning that a poorer lifestyle impacts the immune system and metabolism, which in turn increases the risk of depression.

Dr Christelle Langley, also from the Department of Psychiatry at the University of Cambridge, said: “We’re used to thinking of a healthy lifestyle as being important to our physical health, but it’s just as important for our mental health. It’s good for our brain health and cognition, but also indirectly by promoting a healthier immune system and better metabolism.”

Professor Jianfeng Feng, from Fudan University in China and Warwick University, added: “We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools.”

Source: Zhao, Y & Yang, L et al. The brain structure, immunometabolic and genetic mechanisms underlying the association between lifestyle and depression. Nature Mental Health; 11 Sept 2023;