Doctors who treat soldiers who have experienced defeat in combat are aware of a condition termed "defeated army" syndrome. The syndrome is characterized by a significant lowering of serum testosterone levels. Now research suggests that much less dramatic lifestyle changes can have a significant effect on male testosterone levels as well.

A study published in the Journal of Clinical Endocrinology followed 1,600 men in the Boston area for more than 17 years. Over time, the authors observed events and behaviors that appeared to speed up the expected loss of testosterone that comes as men get older.

Some testosterone-lowering events, like the death of a spouse, were beyond the control of the study subjects. However, the researchers observed that even small increases in body mass index (BMI) were associated with a drop in testosterone levels that was equivalent to 10 years of aging! Such changes in testosterone levels put men at substantially higher risk for diabetes, loss of muscle and bone mass, and if severe enough, sexual dysfunction.

The authors concluded that preventable factors, such as a sedentary lifestyle, weight gain, excessive alcohol use, and other behaviors can result in rapid declines in serum testosterone equivalent to a much more rapid aging process. This process can be prevented, however, by making appropriate lifestyle choices.