Hair color is associated with genetic differences that can influence the risk of developing certain diseases. Dark hair, for example, is associated with a lower risk of skin cancer.
Hair color is often associated with personality stereotypes, but scientists say it can also offer information about physical health. Determined by the type and amount of melanin in the body, natural hair pigmentation is shaped by genetics and there is research that suggests these differences may influence the risk of certain medical conditions.
Hair color depends mainly on two pigments: eumelaninamore abundant in dark hair, and black voicewhich gives red hair its characteristic hue. Blonde hair contains lower levels of both pigments.
Skin cancer risk
People with blonde or red hair are generally more sensitive to ultraviolet (UV) radiation. Darker hair is associated with higher levels of eumelanin, which helps protect the skinabsorbing harmful UV rays.
A 2024 published in Gene magazine found that individuals with red or blonde hair had a significantly higher risk of developing melanoma and keratinocyte skin cancer compared to those with brown or black hair. Redheads had the greatest increase in risk, reinforcing the long-standing medical recommendation that people with light hair use strong sun protection.
Parkinson’s disease
Research has also identified a possible link between lighter hair and Parkinson’s disease. A long-running study published in 2010 in the Annals of Neurology, involving more than 130,000 participants, found that individuals with red hair had approximately the same double the risk of developing Parkinson’s compared to those with black hair. Scientists believe the association may be linked to variations in the MC1R gene, which influences melanin production and is often found in redheads.
Pain sensitivity
Studies suggest that redheads may process pain differently. One published in the Journal of the American Dental Association in 2009 found that redheads were more likely to avoid dental work due to greater anxiety about pain. A 2004 study published in the journal Anesthesiology also reported that redheaded patients needed up to 19% more anesthesia during surgery, which may be related to the MC1R gene variant.
Oxidative stress and gray hair
While hair graying is a normal part of aging, early onset can signal an increase in oxidative stress — a biological imbalance between free radicals and antioxidants. A 2021 published in the open access journal Macedonian Journal of Medical Sciences linked early bleaching to higher levels of oxidative stresswhich are also linked to heart disease, cancer and neurodegenerative diseases.
Alopecia Areata
Data indicate that individuals with black or dark brown hair can be more prone to alopecia areataan autoimmune condition that causes hair loss. Blonde hair presented the lowest risk, although the reasons are still unclear.
prostate cancer
There is some positive news for redheaded men. A 2013 published in the British Journal of Cancer found that redheaded men had about half the probability of developing prostate cancer compared to men with light brown hair. The researchers suggest the finding may be related to genetic differences or vitamin D metabolism.
Although experts caution that hair color alone does not determine health outcomes, studies suggest that the genetics of pigmentation may play a greater biological role than previously thought.
