Men who start going bald early on in life may face a greater risk of developing the disabling neurodegenerative disease amyotrophic lateral sclerosis (ALS), more commonly known as Lou Gehrig’s disease, a new study finds.
Researchers from Harvard University’s School of Public Health (HSPH) recently found significant evidence suggesting that men who begin losing their hair earlier in life were more likely to develop ALS, a debilitating disease that renders a person’s muscles immobile and cripples neck and spinal cord function. The findings have strong implications for better understanding the disease, researchers added, as ALS currently remains a mystery in many respects.
More than 50,000 men participated in the team’s meta-analysis of seven genome-wide association studies. The men ranged in age from 46 to 81. In 1992, the men were asked to report the degree to which their hairline was receding at age 45. Over the course of the next 16 years, follow-up surveys showed 42 of the men developed ALS. Of those, 13 reported no balding, 18 reported moderate balding, and 11 reported extensive balding. Due to the linear trend beginning at age 45 with each year of age, the team concluded that “men with early-onset alopecia seem to have a higher risk of ALS.”
"This doesn't mean that bald people should worry," said study author Elinor Fondell, researcher at HSPH, also noting the portion of men with ALS who never went bald, so the link may not hold true for everyone. Fondell and her team said the link deserves further testing, given its implications for learning about ALS.
What May Underlie The Risk
ALS is the most common of the five motor neuron diseases and affects a range of bodily functions. People with ALS often experience muscular atrophy and spasticity, difficulty speaking and swallowing, and difficulty breathing. In the U.S. the disease is often named after famed Yankees great Lou Gehrig; however, Professor Stephen Hawking and Chinese political leader Mao Zedong have also contracted the disease, which is known elsewhere as motor neuron disease.
While there is a known genetic component in ALS, the precise cause is unknown. HSPH researches are hoping the findings into early balding can help explain the disease based on hormones and gene location. Theories for the genetic component of the disease point to a genetic variation in early balding. The gene implicated in the variation neighbors another gene that has shown links with ALS. Scientists believe the two genes may affect each other in some way.
In 1980, researchers tested for a protein called the androgen receptor, which regulates the hormone testosterone, in ALS patients. The idea originated when researchers observed that the disease affected all motor neurons except those that lacked the androgen receptor, LiveScience reports.
"Everybody got so excited about this theory. So they tested it, but found that the androgen receptor does work,” Fondell said, noting that the findings halted the team’s study. “I think they dropped it too early."
Source: Fondell E, Fitzgerald K, Falcone G, O’Reilly E, Ascherio A. Early-Onset Alopecia and Amyotrophic Lateral Sclerosis: A Cohort Study. American Journal of Epidemiology. 2013.