Recent research has shed light on the relationship between a healthy lifestyle and the prevention of depression. This study delves into the mechanisms that underlie this connection, providing valuable insights into the role of brain structure, immunometabolic factors, and genetic mechanisms.
New research in Nature Mental Health, involving scientists from the University of Cambridge and Fudan University, examined factors like lifestyle, genetics, brain structure, and our immune/metabolic systems to understand how they connect to depression. Depression affects many people (1 in 20 adults) and is a global health concern due to its complex causes involving biology and lifestyle.
To understand the connection between these factors and depression, researchers used the UK Biobank, an extensive database with genetic, lifestyle, and health data from nearly 290,000 people. They followed these individuals for nine years; among them, 13,000 had depression. They found seven healthy lifestyle factors that lowered the risk of depression:
- Moderate alcohol consumption
- Healthy diet
- Regular physical activity
- Healthy sleep (7-9 hours per night)
- Never smoking
- Low-to-moderate sedentary behavior
- Frequent social connection
Of all these factors, getting a good night’s sleep reduced the risk of depression, including single and treatment-resistant episodes, by 22%. Frequent social connection, reducing the risk by 18%, was especially protective against recurrent depressive disorder.
Frequent social connections were the best at reducing the risk of depression, especially the recurring kind, by 18%. Other healthy factors that helped were:
- Moderate alcohol consumption (11% decrease in risk)
- A healthy diet (6% decrease in risk)
- Regular physical activity (14% decrease in risk)
- Never smoking (20% decrease in risk)
- Low-to-moderate sitting time (13% decrease in risk)
People were grouped based on how many factors they followed: unfavorable, intermediate, and favorable. Those in the middle group were 41% less likely to get depression than those in the opposing group. The optimistic group was even better, with a 57% lower risk.
The researchers also looked at people’s genetics and scored them based on their depression risk genes. People with the lowest genetic risk were 25% less likely to get depression than those with the highest risk. However, a healthy lifestyle had a much more significant impact on reducing depression risk than genetics.
No matter if someone had a high, medium, or low genetic risk for depression, living healthily reduced the risk. This study shows that a healthy lifestyle is crucial for preventing depression, no matter your genetic risk.
Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge, said: “Although our DNA – the genetic hand we’ve been dealt – can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more critical.”
“Some of these lifestyle factors are things we have a degree of control over, so trying to find ways to improve them – making sure we have a good night’s sleep and getting out to see friends, for example – could make a real difference to people’s lives.”
To understand why a healthy lifestyle can reduce depression risk, the researchers looked at different factors.
First, they studied MRI brain scans from nearly 33,000 people. They found that a healthy lifestyle was linked to more significant brain volume in areas like the pallidum, thalamus, amygdala, and hippocampus, which are essential for mood and mental well-being.
Next, they looked at markers in the blood that show how well our immune system and metabolism (how our body processes food and energy) are working. They found that a healthy lifestyle was linked to better levels of markers like C-reactive protein (related to stress) and triglycerides (a type of fat used for energy storage).
These findings match what other studies have shown. Stress can affect how well we control blood sugar and weaken our immune system, making us more prone to illness. Lack of exercise and poor sleep also hurt our body’s response to stress. Loneliness and lack of social support can lead to more infections and weaken our immune system.
The study found that the pathway from lifestyle to immune and metabolic functions was the most important. This means that living healthily helps our immune system and metabolism work better, which reduces 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 and indirectly by promoting a healthier immune system and better metabolism.”
Professor Jianfeng Feng, from Fudan University 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.”
This study highlights the importance of a healthy lifestyle in preventing depression. It provides a deeper understanding of the mechanisms involved. By focusing on brain structure, immunometabolic factors, and genetic influences, it becomes clear that lifestyle choices can profoundly impact mental well-being. These findings emphasize the significance of promoting healthy living as a preventive measure against depression, offering hope and actionable insights for individuals seeking to protect their mental health.
Journal Reference:
- Zhao, Y., Yang, L., Sahakian, B.J. et al. The brain structure, immunometabolic, and genetic mechanisms underlying the association between lifestyle and depression. Nature Mental Health. DOI: 10.1038/s44220-023-00120-1.
