It is common knowledge that blondes and redheads get burnt easily, evidenced by that ubiquitous redhead lounging at the pool with a lobster-red stomach or the blonde at the beach with raccoon eyes. But Dr. Douglas Brash, a professor of therapeutic radiology and genetics at the Yale School of Medicine, took this fairly obvious observation one step further.
In a report recently released in the Proceedings of the National Academy of Sciences, Brash stated there is something in the melanin — hair and skin pigmentation — of blondes and redheads that actually magnifies the harmful effects of ultraviolet rays on their skin.
“We’ve always known that there are more incidents of melanoma and non-melanoma skin cancer [in blondes and redheads], but we’ve been looking for the genetic reasons why,” said Dr. David Leffell ’77, a professor of dermatology and Brash’s longtime colleague. “Brash has marked specific molecular evidence.”
Brash, who has been working at Yale for 15 years, started this study three years ago. He said his research was spurred by the known heightened risk of blondes and redheads for obtaining skin cancer. The accepted logic was that this increased risk resulted from lighter skin, and therefore less melanin, which protects against sunlight and UV rays. Brash, however, opted to look for the underlying molecular cause.
“We were really just looking for clues,” he said. “We kept trying new things. There were ups and downs along the way, but we kept finding things out.”
Brash and his fellow researchers used mice in their research, some engineered with pigmentation for yellow hair and some for black hair. There was a control of albino mice without pigmentation as well. The mice were then subjected to UV rays similar in strength to those that affect humans. Brash said he had expected more cell death in the black-haired mice because there is more melanin per microgram in yellow than in black. Contrary to his hypothesis, the prevalence of cell death, especially around the hair follicles, was much greater in the yellow-haired mice.
Brash’s results were surprising, as melanin is generally considered to have positive effects on preventing cell death. These results showed that not all melanin combats UV radiation, and the color of the melanin determines its effects on the skin.
“The report has kind of struck everyone’s fancy,” Brash said. “Almost everyone in dermatology has said, ‘Hey, can you send me [a copy of the report]?’ I think it’s kind of a visual thing.”
With the help of the FDA, Brash said he hopes to check his results using human skin samples in lieu of mice for the same experiment. The results of Brash’s study could be used to create more effective sunscreens.
Leffell said Brash’s findings have many practical implications, as the data points to new strategies in sun protection for patients with light or fair skin and red or blond hair.
“It also allows us to emphasize the importance of sunscreen to these patients,” Leffell said. “People tend to think that most of the damage is done to the skin before the age of 18.”