BOSTON – A new study has found that obese men have a much lower risk of suicide, a finding that scientists believe might be related to their higher production of insulin and other hormones that affect mood.
The study, being published today in the Archives of Internal Medicine, reported that the men were 42 percent less likely to commit suicide than those at the lower end of the normal weight range.
Lead author Kenneth Mukamal of Beth Israel Deaconess Medical Center said he wasn’t recommending that people overeat to stave off depression because obesity carries numerous health risks.
But the results could point to a new avenue for research into the role of hormones on mood, he said.
“I see this as a springboard for developing new and better ways to prevent suicide because, frankly, we don’t have great ones now,” Mukamal said.
He cautioned the study was not applicable to women in part because of hormone differences related to gender. In addition, he said, the stigma of obesity falls more heavily on women.
The study examined the relationship between suicide and body mass index, a ratio of weight to height. For example, a 6-foot man who weights 154 pounds has a BMI of 21.
Researchers looked at men with BMIs ranging from below 20, which is considered underweight, to those with a BMI above 30, which is considered obese.
The study found that underweight men with a BMI below 21 had a 39 percent greater risk of suicide than men in the low-normal range of 21 to 22.9.
The researchers surmised that higher amounts of insulin in the obese men increased their levels of serotonin, a key brain chemical that regulates mood. The theory fit with other evidence: For example, the mood of Type 2 diabetics improves after receiving insulin.
Mukamal added that obese men also produce larger amounts of leptin and sex hormones, which might serve to alleviate depression.