Skin cancer and lower risk of Alzheimer's disease
Non-melanoma skin cancer may be linked to lower risk of Alzheimer’s disease
16th May 2013 - People who have non-melanoma skin cancer may be less likely to develop Alzheimer’s disease, according to new research published in the medical journal of the American Academy of Neurology.
The link does not apply to melanoma, a less common but more aggressive type of skin cancer.
Researchers at the Albert Einstein College of Medicine in New York, followed 1,102 people who did not have dementia. They had an average age of 79 and were followed for an average of 3.7 years. 109 people reported that they had skin cancer in the past. During the study, 32 people developed skin cancer and 126 people developed dementia, including 100 with Alzheimer’s.
The study found that people who had skin cancer were nearly 80 per cent less likely to develop Alzheimer’s disease than people who did not have skin cancer. Of the 141 people with skin cancer, two developed Alzheimer’s disease.
The association was not found with other types of dementia, such as vascular dementia and the link does not apply to melanoma.
Dr Doug Brown, director of research and development at the Alzheimer’s Society says in a statement: "This study is not suggesting that skin cancer should be considered as a preventative factor and we do not recommend that people stop taking measures to protect against sun exposure. However, the link between skin cancer and Alzheimer’s suggests that there may be interesting underlying factors that play a role in the development of both diseases. We need to further investigate these links to help us understand more about the causes of Alzheimer’s."
Author of the study, Dr Richard Lipton, said in a press release, the reason for the possible protective effect of skin cancer is not yet known. "One possible explanation could be physical activity," he said. " Physical activity is known to protect against dementia, and outdoor activity could increase exposure to UV radiation, which increases the risk of skin cancer."
Dr Lipton said biological factors including genetic factors are also likely to play a role, as physical activity does not reduce the risk of Alzheimer’s disease to the extent found in the link between skin cancer and Alzheimer’s disease.
He agrees with the Alzheimer's Society and says the findings do not mean that people should stop taking measures to avoid skin cancer: "People should continue to wear sunscreen, avoid the sun during midday and wear clothing to protect their skin.
"The hope is that these results help us learn more about how Alzheimer’s develops so we can create better preventive methods and treatments."