There were suggestions from health professionals that men's overall health has somehow connected with their natural testosterone levels, but their relationship has yet been fully understood.
A study by the University of Cambridge School of Clinical Medicine in Britain found that higher naturally occurring levels of the male hormone testosterone apparently would protect men from fatal heart attacks or strokes and death from all causes.
The findings, which appeared on November 26, 2007 in the journal Circulation, showed strong benefits in men with higher natural levels of the hormone. However, the researchers cautioned men not to simply begin taking testosterone supplements just based on the results of this 10-year study because the benefits and risks are still unclear.
11,606 British men ages between 40 and 79, who had no known cancer or cardiovascular disease at the start of the study, were tracked. These participants joined the study from 1993 to 1997 and they were followed until 2003.
During the study period, 825 men died. Their testosterone levels were measured using frozen blood samples provided earlier, and were compared to a group of men still alive at the end of the study period.
The results of the study indicated that men in the upper 25 percent of natural testosterone levels had a 41 percent lower risk of dying from heart attack, stroke and other cardiovascular conditions, cancer and all other causes, comparing with those having the lowest levels.
The relationship between testosterone levels and cardiovascular disease mortality was found to be comparable in magnitude to risk factors such as high blood pressure and cholesterol levels. Thus, this would imply that men who might not have other known risk factors but have low testosterone levels could be at elevated risk for cardiovascular death.
Although the findings did indicate men with low levels of testosterone might cut their risk of death if they take testosterone supplementation, the researchers would not recommend doing this without further research supporting these results.
This is because the study looked only at naturally occurring levels of the hormone but not supplementation. Moreover, research had shown that high testosterone might be a risk factor for prostate cancer.