Increased exercise levels can significantly reduce the chances of developing depression, even among people who are genetically predisposed to the condition.
That is the key finding of a study published in the journal Depression and Anxiety
, which showed that individuals who engaged in regular exercise each week were less likely to be diagnosed with a new episode of depression, even in the face of high genetic risk for the disorder.
Drawing on genomic and electronic health record data from nearly 8,000 participants in the Partners Healthcare Biobank, researchers at Massachusetts General Hospital (MGH) followed patients who filled out a survey about their lifestyle habits (including physical activity) when they enrolled in the Biobank.
The team mined millions of electronic health record data points over two years and identified people who received diagnoses related to depression.
They also calculated genetic risk scores for each participant, combining information across the entire genome into a single score that reflects a person's inherited risk for depression.
The team concluded that people with higher genetic risk were, as expected, more likely to be diagnosed with depression over the next two years.
Significantly, though, people who were more physically active at baseline were less likely to develop depression, even after accounting for genetic risk.
In addition, higher levels of physical activity were protective for people even with the highest genetic risk scores for depression.
Both high-intensity forms of activity and lower-intensity forms – including yoga and stretching – were linked to decreased odds of depression.
Overall, individuals could see a 17 percent reduction in odds of a new episode of depression for each added four-hour block of activity per week.
It is believed to be the first study to show how physical activity can influence depression despite genetic risk.
"Our findings strongly suggest that, when it comes to depression, genes are not destiny and that being physically active has the potential to neutralize the added risk of future episodes in individuals who are genetically vulnerable," said Karmel Choi, lead author of the study.
"On average, about 35 additional minutes of physical activity each day may help people to reduce their risk and protect against future depression episodes."
To read more about the study, click here.