New research is shedding light on how the choices we make every day – what we eat, how much we move, our sleep patterns, and even our social interactions – play a role in our mental health outcomes.
According to the World Health Organization, one in 20 adults experiences depression. This condition poses a significant burden on public health worldwide.
An international coalition of scientists from institutions including the University of Cambridge and Fudan University set out to investigate the relationship between lifestyle habits and depression risk.
The researchers explored many factors that may influence this link, including lifestyle, genetics, brain structure and our immune and metabolic systems.
The experts analyzed data from the UK Biobank, a biomedical database containing genetic, lifestyle and health information. They focused their analysis on 290,000 people – of whom 13,000 had depression – over a nine-year period.
The team ultimately identified a combination of positive lifestyle habits that can act as a protective shield against depression.
In particular, seven healthy lifestyle factors were linked with a lower risk of depression:
Surprisingly, of these, optimal sleep stood out as the biggest protective factor, reducing the risk of depression by 22%.
Frequent social connection, which diminished the risk of depression by 18%, was found to be 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 behavior reduced the risk by 13%.
The researchers looked at participants’ DNA to establish a genetic risk score based on the presence of depression-linked genetic variants. They found that lifestyle choices have a much greater influence on depression risk compared to genetics.
“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 important,” said Professor Barbara Sahakian.
“Some of these lifestyle factors are things we have a degree 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.”
When the experts analyzed MRI brain scans from 33,000 participants, they discovered intriguing correlations between a wholesome lifestyle and larger volumes in brain regions such as the pallidum, thalamus, amygdala, and hippocampus.
The blood markers told another part of the story. Elevated levels of C-reactive protein, a stress-induced molecule, and triglycerides, a primary fat storage form, were tied to suboptimal lifestyles.
These links are supported by previous research. For example, stress can wreak havoc on our ability to regulate blood sugar, deteriorating immune functions and hastening cellular aging.
Meanwhile, inadequate sleep and physical inactivity compromise our resilience to stress. The repercussions of social isolation are equally dire, increasing infection risk and weakening immunity.
The team found that the pathway from lifestyle to immune and metabolic functions was the most significant. A poorer lifestyle impacts our immune system and metabolism, which in turn increases our risk of depression.
“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,” said Dr. Christelle Langley.
“It’s good for our brain health and cognition, but also indirectly by promoting a healthier immune system and better metabolism.”
“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,” said Professor Jianfeng Feng.
The study is published in the journal Nature Mental Health.
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