So are baldness and height related?
When one considers the category of bald men, are there more Dwayne Johnsons, Steve Ballmers and Samuel L. Jacksons out there ... or would we find the majority of hairless men to be like Jason Alexander, Andre Agassi and Danny Devito?
German researchers from the University of Bonn are now giving us the answer – or more appropriately, shall we say ... the low down.
After studying the genetic material of more than 22,500 adult males from seven countries, they determined that "short men have an increased risk of becoming bald prematurely," according to a statement announcing today's publication of the study in Nature Communications. Citing from the study, in describing their work the authors called it "the largest ... meta-analysis of MPB [male-pattern baldness] to date."
Drawing from "eight independent genome-wide association studies early-onset MPB samples," the research team analyzed data from 10,846 subjects with premature baldness and another 11,672 men with no evidence of hair loss. Not only did researchers establish the association between premature hair loss and lack of height, they also linked male-pattern baldness, or androgenic alopecia, to other physical characteristics.
"We were thus able to identify 63 alterations in the human genome that increase the risk of premature hair loss," said Dr. Stefanie Heilmann-Heimbach, a human geneticist and one of the study's lead authors, who was quoted in the statement. "Some of these alterations were also found in connection with other characteristics and illnesses, such as reduced body size, earlier occurrence of puberty and various cancers," an increased risk of prostate cancer being one that has been previously identified as a possibility.
Regarding that connection, testosterone, which influences and contributes to physical growth, can convert into "another androgen, dihydrotestosterone," or DHT, explains the Harvard Medical School. But "DHT also stimulates the growth of prostate cells, producing normal growth in adolescence but contributing to benign prostatic hyperplasia (BHP) in many older men," otherwise known as enlargement of the prostate gland.
"Our data provide molecular evidence that rather than being an isolated trait, MPB shares a substantial biological basis with numerous other human phenotypes," the authors wrote, adding that "these novel insights into the genetic basis of MPB and its association with other traits may help to elucidate the evolutionary forces responsible for the relatively high prevalence of MPB in the European population," which they cite as "a lifetime prevalence of ∼80% in European men."
But for men lacking in height – who don't have the verticality of someone like the actor Dwayne Johnson (pictured) – there are some health benefits.
"We have also found links to light skin color and increased bone density," says the study's co-author Prof. Markus Nöthen. "These could indicate that men with hair loss are better able to use sunlight to synthesize vitamin D. They could also explain why white men in particular lose their hair prematurely."