Certain types of cancer may be bad news for your skin but good news for your brain, new research suggests. A study of 1,102 individuals with an average age of 79 found that participants who developed non-melanoma skin cancers were 80 percent less likely to develop Alzheimer’s disease (AD) than those who did not develop those cancers. Non-melanoma skin cancers are the most common cancers in the U.S., with new cancers diagnosed in more than two million people each year.
Thee study participants—109 of whom reported a history of skin cancer—were healthy and without dementia at the outset of the investigation. Once a year over the course of about four years, the participants’ memory and cognitive abilities were tested and they were asked whether they had developed non-melanoma skin cancer. During the study, 32 participants developed skin cancer, 100 developed AD, and 26 developed other forms of dementia, according to a report in the May 15, 2013 online issue of Neurology. Among the 141 participants who had a history of skin cancer, only two developed AD; of the 961 participants without a history of skin cancer, 98 developed AD. The cause of the association between non-melanoma skin cancers and lower risk for AD is unknown, but some experts theorize that a weak immune response—which allows for the development of skin cancer—may protect the brain from destructive levels of inflammation that are associated with AD.