It’s relatively rare to see a man sporting a reddish beard, especially if his head hair is not red. This phenomenon often catches attention, leading many to wonder why some men have red beards while their scalp hair remains dark, blonde, or even graying. According to Nina Jablonski, a professor of anthropology at Penn State University, this curious condition has roots in the biology of hair color and pigmentation.
The Role of the MC1R Gene in Hair Color
The underlying cause of red beards can be traced to the MC1R gene, a key factor in the production of melanin, the pigment responsible for the color of hair. Red hair occurs in individuals who have a mutation in the MC1R gene, which leads to an abundance of pheomelanin (the red pigment) in their hair. In people with red hair, the MC1R gene mutation causes the hair to be predominantly red because of the lack of conversion of red pigment into dark pigment, a process typically regulated by the MC1R gene.
However, Jablonski notes that having a red beard without red head hair suggests a more complex situation. She explains, “This will almost certainly be due to the differential expression of MC1R in the follicles of beard hair versus scalp hair,” leading to a different mixture of pigments between the two. In such cases, the individual likely carries only a single mutation of the MC1R gene, meaning they are not a full “redhead,” but rather a carrier of the redhead gene.
How the MC1R Gene Works Differently in Beard Hair
Interestingly, the MC1R gene behaves differently in the follicles of the beard compared to scalp hair. Jablonski explains that this leads to the production of a distinct mix of dark brown eumelanin and yellow-red pheomelanin in the beard hair. This difference results in the reddish hue of the beard, even if the person’s head hair remains dark or blonde. In other words, the same gene, which controls hair color, can have differential effects depending on the body part it is acting on.
The Impact of Aging on Red Beards
It’s not only the younger generations who experience this phenomenon. Aging can also influence hair pigmentation. As men grow older, typically after their 40th birthday, their hair follicles may age at different rates. The pigment-producing cells in beard hair and scalp hair can deteriorate differently, which can cause red beards to appear even if the man’s scalp hair is dark or graying. According to Jablonski, this is due to the “aging at different rates” of the pigment-producing cells in each area of the face and head.
Where Red Hair is Most Common
Globally, red hair is a rare trait, with only about 1% to 2% of humans possessing natural red hair. The highest concentration of redheads can be found in Celtic countries like Scotland, Ireland, and Wales. The mutation in the MC1R gene that causes red hair can also result in other variations of hair color, leading to different expressions of pigment in various body parts.
This makes the study of red hair and the genetics behind it a fascinating topic for researchers like Jablonski, as it reveals how complex genetic traits can manifest in different ways across the body.
