Claim: A recent study disproved a link between sun exposure and skin cancer.
Example: [Collected via e-mail, June 2010]
Is this website legitimate? How about the "studies" it quotes?
Origins: In May 2014 the popular press reported on an article that had recently been published in the Journal of Internal Medicine entitled "Avoidance of sun exposure is a risk factor for all-cause mortality." The common reporting on that article generally mentioned that a study conducted by Swedish researchers had found that women who avoided sunbathing actually had twice the mortality rate of women who had significant exposure to the sun:
The study, conducted by researchers at the Karolinska Institute in Sweden, followed nearly 30,000 women over
They found that the results "showed that mortality was about double in women who avoided sun exposure compared to the highest exposure group".
The researchers who performed the study tracked a group of 29,518 women in Sweden across twenty years and charted their typical exposure to sunlight and other potentially related factors. At the end of that period, they found that those women who avoided exposure to the sun had a mortality rate apprximately twice that of women who had the most exposure to the sun:
There were 2545 deaths amongst the 29,518 women who responded to the initial questionnaire. We found that all-cause mortality was inversely related to sun exposure habits. The mortality rate amongst avoiders of sun exposure was approximately twofold higher compared with the highest sun exposure group, resulting in excess mortality with a population attributable risk of 3%.
The strongest conclusion that might be drawn from the study is the rather narrow one that people with characteristics of the study
"As the authors comment, our bodies need sunlight to make essential
Dr Andrea Darling, Post-doctoral Research Fellow from the University of Surrey, said there was still strong evidence that skin cancer is caused by sunbathing.
"The findings from Dr Lindqvist's team are interesting, but it is possible that the women in the study who had high sun exposure differed from the women who had low sun exposure in ways that may explain their reduced cancer risk."
Yinka Ebo, senior health information officer at Cancer Research UK, said striking a balance was important.
"The reasons behind higher death rates in women with lower sun exposure are still unexplained, as unhealthy lifestyle choices could have played a part," she added.
"Overexposure to UV radiation from the sun or sunbeds is the main cause of skin cancer."
Our study population of women born in Sweden before 1966, that is, before widespread immigration took place, consisted almost entirely of light-skinned Caucasian women. If avoidance of sun exposure is a major risk factor for all-cause mortality in the case of Caucasian women, the problem may even be more serious amongst women who traditionally cover their skin or women more densely pigmented. In the USA, black women were reported to have a 26% excess all-cause mortality, as compared to Caucasian women. Such data should direct our attention to a risk group whose health we may be in a position to improve.
Last updated: 8 July 2014
Knapton, Sarah. "Why Avoiding Sunshine Could Mean an Early Death in Women." The Telegraph. 7 May 2014. Lindqvist, P.G. et al. "Avoidance of Sun Exposure Is a Risk Factor for All-Cause Mortality." Journal of Internal Medicine. July 2014. Payne, Tom. "Major Study Suggests Mortality Rate Higher for People Who Stay Out of the Sun ..." The Independent. 8 May 2014.