Scientists have long believed that redheads, with their fair skin and hair, are more sensitive to sunlight than others. Last week, a team of researchers at Massachusetts General Hospital strengthened the case with new findings suggesting that they have an increased risk of developing melanoma even in the absence of UV radiation.
The study, published in the journal “Nature” and led by Harvard Medical School professor David E. Fisher, originally aimed to explore how moles develop into melanoma in the presence of UV radiation. The researchers examined this phenomenon in mice, breeding one group to express a pigment-producing gene that causes red hair and fair skin while the other group expressed a dark-colored pigment. The next step in their plans was to expose the mice to UV radiation in order to examine how the rate of melanoma development differed between the two groups.
However, the researchers noticed that the “redheaded” mice developed melanoma even before they were exposed to UV radiation.
“The real surprise in this is that we were anticipating to provide UV radiation because UV is so associated with melanoma risk...but what we observed is that the redheaded mice developed melanoma...at a high rate even before we could get to the point of delivering the UV,” said Fisher, who is also the Head of the MGH Department of Dermatology. “One of our initial responses was to get a meter and go into the animal room to make sure that the bulbs were not actually emitting UV radiation by mistake.
The authors concluded that the actual pigment responsible for red hair and fair skin is the root of the carcinogenic effects. “We know that UV is not the only important factor in redheads now and redheads may need to be more thorough in checking themselves and more cautious because it’s not just a question of sun exposure,” said Dunster House resident Annie M. Morgan ’13, a co-author of the paper. “We know it’s not just UV so then the question is: what is the whole spectrum of factors that add up to predispose people to melanoma?”
The researchers cautioned that this does not mean that people can expose themselves to UV radiation without concern.
According to Devarati Mitra, a lead researcher in this study and a Harvard MD/PhD student and Cabot House Resident Tutor, the role of UV radiation in melanoma development is still significant.
“You definitely still need to wear sunscreen and cover up and all of that is unchanged by our results,” Mitra said. “But our results suggest that in addition to that UV effect there is an intrinsic risk of melanoma in individuals who primarily have this red color...so our data does not contradict what was known before but it adds a new dimension.”
According to Fisher, the next stage in advancing this research involves identifying specific traits of molecules that could block the damage caused by this red pigment.
“The class of molecules that we expect might have this activity are actually antioxidants—and though antioxidants are quite popular, we emphasize that not all antioxidants are the same and some may even increase the oxidative damage,” he said. “So we do not under any circumstances recommend that people try their own antioxidant remedies and pour pomegranate juice on their skin, because not only may it not work but it may actually worsen the process.”