A University of Gothenburg study of over one million Swedish men has found that fitness during adolescence appears to reduce the risk of suicide in later life.
“Being in poor physical shape at 18 years of age, measured as the test results on an exercise bike during their medical exam for compulsory military service, can be linked to a risk of suicidal behavior as an adult that is 1.8 times greater,” said psychologist and researcher Dr. Margda Waern.
The study, published in journal Psychological Medicine, includes evidence that an increased risk of suicide was evident even 42 years after the exam for military service.
It has previously been shown that physical exercise has a highly positive effect on brain function; for example, more nerve cells are developed with physical exercise.
“The teenage years are a critical period in terms of brain development since this is when social and emotional faculties are established. Therefore, it was important to do a larger study on the importance of physical fitness in terms of suicidal behavior in this age group,” said Maria Åberg, M.D., who led the study together with Waern.
In the study, researchers reviewed health information on all Swedish men born between 1950 and 1987 who completed the previously mandatory military exam. They then compared the results from physical tests during the military exam with the national registers of disease and death.
By carefully examining the roughly 340,000 brothers who took part in the study, researchers were able to study how hereditary factors and the home environment affect this relationship.
In a much discussed study published in 2012, the researcher group showed that good physical fitness as a teenager can also be linked to decreased risk of severe depression later in life.
“But even when we exclude individuals who suffer from severe depression in connection with suicide or attempted suicide, the link between poor physical shape and an increased risk of suicidal behavior remains,” Waern said.
While depression is a particularly strong predictor of suicidal behavior in later life, the picture among younger people is complex and many factors are involved.
“One theory is that the brain becomes more resistant to different types of stress if you are physically active,” said Åberg.
The researchers think that physical exercise should be considered in suicide prevention projects aimed at young people.
The new findings are supported by earlier cross-sectional studies where teenagers were interviewed about their physical fitness, connected with the risk for suicidal thoughts.
Source: University of Gothenburg