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Researchers studied 10,000 years of DNA to explore the genetics behind red hair and fair skin
Redheads may have immunity to HIV, resistance to leprosy and lower risks of arthritis or male-pattern baldness
The same genetics linked to red hair may increase risks of Crohn’s disease and celiac disease due to gluten sensitivity
Redheads may carry certain genetic advantages — as well as some distinct disadvantages — in their DNA, new research says.
The genetics behind red hair and fair skin was studied by researchers from Harvard Medical School, who examined 10,000 years’ worth of DNA samples from nearly 16,000 humans. They found that redheads benefited from natural selection over thousands of years — and the very same genetics that cause red hair and fair skin come with other traits, in results published by Nature on Wednesday, April 15, 2026.
Stock image of a redheaded woman brushing her hair
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According to the study, more than 60% of the DNA examined had immunity to HIV infection, resistance to leprosy, a lower risk of arthritis or alcoholism and increased resistance to bacterial or viral infections. They also had a lower chance of male-pattern baldness.
A previous study, first published in June 2020, uncovered that those with red hair were more efficient at making vitamin D — an advantage in less sunny climates.
“Perhaps having red hair was beneficial 4,000 years ago, or perhaps it came along for the ride with a more important trait,” the Harvard Medical School explained in a press release shared on Wednesday.
However, redheads were at a higher risk of Crohn’s disease and celiac disease — possibly because the selection sample dovetails with the advent of wheat farming, as those disorders are characterized by the immune system reacting to gluten, a protein in wheat.
Stock image of a redheaded woman in the sun
Credit: Getty
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“This paper shows how complex selection can be and provides an opportunity to consider the richness of variation in human populations,” Harvard geneticist David Reich said in the release.
“With these new techniques and large amount of ancient genomic data, we can now watch how selection shaped biology in real time,” said Harvard University’s Dr. Ali Akbari, the first author of the study.
Read the original article on People