No man looks forward to the first signs of balding — especially early in life — but now there’s fresh evidence that losing your hair may be a harbinger of a more serious health concern and worth tracking for reasons other than vanity.
In a study involving 669 men, researchers led by Dr. Philippe Giraud at the Paris Descartes University in Paris found that men who showed signs of hair loss in their 20s were twice as likely to develop prostate cancer decades later compared with men who didn’t show evidence of balding until their 30s.
It’s not the first study to link hair loss and prostate cancer, but previous findings have been confusing, to say the least. Several trials found a similar positive relationship between early male pattern baldness and cancer incidence, while one found a decreased risk of prostate cancer among those with early hair loss. The current trial, which enrolled men with and without a history of prostate cancer, and then asked about whether and when they experienced any balding, found that the type of hair loss didn’t matter. That is, men with both receding hairlines as well as balding at the crown during their 20s had the same heightened risk of cancer. (More on TIME.com: You May Be Less Bald Than You Think)
How are balding and prostate cancer linked? While the exact mechanism isn’t know, experts suspect that the male hormones known as androgens may play a critical role in promoting both conditions. Androgens, which include testosterone, can inhibit hair growth while triggering abnormal expansion of prostate cells. One clue supporting this theory is that the drug finasteride, or Propecia — which blocks the effects of androgens — works to both retard hair loss and control growth of prostate tumors.
The results of the current study, says co-author Dr. Michael Yassa, a radiation cancer specialist at Maisonneuve-Rosemont Hospital and the University of Montreal, suggest that it may be possible to screen for prostate cancer before the tumors become problematic. Because prostate cancers typically grow slowly, and the disease develops gradually over a period of years, doctors are currently debating whether men should be screened for the condition, similar to the way women are evaluated for breast cancer. In some men, particularly those who are older, it may not make sense to screen and treat the disease when these patients are more likely to die of other causes. But if early baldness is a risk factor for prostate cancer, then it may make sense to advise men with early hair loss to undergo more regular screening for any signs of tumors. (More on TIME.com: In High-Risk Men, Drug May Help Prevent Prostate Cancer)
“Now, we talk about maybe screening those at high risk for prostate cancer,” says Yassa. “Family history of a risk factor, and we know African Americans tend to develop more prostate cancer. But that is pretty much it. Maybe balding is one, so we think this is an area where we should do further research to identify those who might benefit from screening.”
Yassa isn’t saying that every man who finds more hairs in the sink should be concerned about cancer. The study focused on early balding, and Yassa notes that more research is needed to understand whether different types of hair loss — receding hair lines as opposed to shedding at the crown — are more or less connected to cancer. His study, he says included only a few men who showed balding at the pate, so a larger trial may suggest a link between the pattern of hair loss and cancer risk.
Still, he says, men “should not be alarmed.” The results are primarily fodder at this point for the medical community as they continue to debate how useful screening for prostate cancer might be, and balding may ultimately become a tool for detecting and preventing cancer early.
More on TIME.com: