January 16, 2014
Having skin cancer is never a good thing. But it may have a silver lining. New research shows that having the most common forms of skin cancer may lower your Alzheimer’s risk.
In the study, researchers at Albert Einstein College of Medicine of Yeshiva University in New York reviewed medical records of more than 1,000 elderly men and women, average age 79, who were part of the large and ongoing Einstein Aging Study. The study recruits English-speaking seniors living in the Bronx who do not have Alzheimer’s or other forms of dementia, then conducts annual checkups to assess mental functioning and medical problems.
The researchers found that among the group of 1,012 seniors in the current analysis, 109 came into the study having been diagnosed with basal cell carcinoma or squamous cell carcinoma, and an additional 32 developed either condition during the 16 year course of the study. The two cancers are the most common form of skin cancer, and far more common than melanoma, a particularly lethal type of skin cancer. An additional 32 developed either condition during the 16 year course of the study.
During the same time, 126 people developed dementia, including 100 with Alzheimer’s disease.
Those who had non-melanoma type skin cancers were 80 percent less likely to develop Alzheimer’s disease compared with those who did not have skin cancer, the study found. There was no link between skin cancer and other types of dementia.
Though the study found a link between skin cancer and decreased Alzheimer’s risk, the findings do not prove any kind of cause and effect. The findings were published in the journal Neurology.
The researchers speculate that several factors may account for the link between skin cancer and reduced Alzheimer’s risk. “One possible explanation could be physical activity,” said Dr. Richard Lipton, the study’s senior author. “Physical activity is known to protect against dementia, and outdoor activity could increase exposure to ultraviolet radiation, which increases the risk of skin cancer.”
Exposure to sunlight also increases the body’s ability to make vitamin D. Higher vitamin D levels have been linked to a wide range of health benefits, including a possible lower risk of dementia.
Genetics may also play a role. Genes that make someone susceptible to skin cancer could, in theory, offer some kind of protection against Alzheimer’s, though the genetics of Alzheimer’s and cancer remains poorly understood.
Finally, said Dr. Lipton, the findings certainly should not encourage people to abandon their skin-cancer prevention efforts. “People should continue to wear sunscreen, avoid the sun during midday and wear clothing to protect their skin,” he said.
Source: Robert S. White, Richard B. Lipton, MD, Charles B. Hall, PhD, Joshua R. Steinerman, MD: “Non-melanoma skin cancer is associated with reduced Alzheimer’s risk.” Neurology, Volume 80, Number 21, May 21, 2013.