Is sunscreen dangerous? An actual scientist weighs in

There's a viral news story going around that claims scientists have found that using sunscreen increases your risk of death. As a redhead, this is relevant to my interests. But it turns out that the paper being cited was vastly misconstrued and wasn't even about sunscreen at all.

Andrew Maynard of the University of Michigan's Risk Science Center rebuts:

The original paper by Lindquist et al. (Avoidance of sun exposure is a risk factor for all-cause mortality: results from the Melanoma in Southern Sweden cohort, 2014, J. Internal Medicine, DOI: 10.1111/joim.12251) recorded mortality rates from all causes in a group of 29,518 Swedish women between the early 1990′s and the early 2010′s, and related these to sun exposure evaluated using four criteria (more on this below).

Overall, 8.6% of the women (2545) died over the course of the 20 year study. What caught the researchers’ attention in particular though was that women who did not actively seek sun exposure were slightly more likely to die. Over a 15 year period, the researchers found that 96% of women who most actively sought sun exposure were still alive, compared to a survival rate of 95% for women who were moderately active in seeking sun exposure, and a survival rate of 93% for those who did not actively seek sun exposure.

The study's authors don't even mention sunscreen in relation to these findings, writes Maynard. Instead, they speculate that the difference in death rates is about finding the right balance between getting enough Vitamin D and not getting so much sun exposure that you up your chances of skin cancer. At higher latitudes (as in Sweden) that can be a fine line.

The survey asked about how frequently respondents sunbathed in the summertime, how frequently they sunbathed in the wintertime, how often they used tanning beds, and how often they went on winter holidays with a goal of swimming and sunbathing. Based on those questions, there could also be socioeconomic factors at play, because wealthier people are generally more healthy and generally have more free time and monetary resources to spend on frequent sunbathing, winter vacations, and tanning beds. I'd also be curious about how much of an overlap there is with people who just generally have a more active lifestyle — another factor that could affect health and survival.

Basically, there's nothing here that proves (or even really suggests) that sunscreen is dangerous.

Notable Replies

  1. I was 26 when I had my first basal-cell carcinoma removed. Since then I've had all of the other minor ones, and last year at 61 I had my first brush with melanoma [1]. All curable by outpatient surgery -- so far.

    I'll take my chances with sunscreen.

    [1] In situ, thank you, so not a big threat. This time.

  2. The reason some people don't spend a lot of time outdoors is due to having an illness to begin with. Let's face it sickly people are unable to spend as much time outside or exercising compounding their illness even further which means they are more likely to die sooner than healthy people. This study reminds me of that bogus study equating breastfeeding with increased intelligence in children. Later it was found out that women most likely to breast feed were on average higher in intelligence, more affluent and better educated than those who didn’t and those smart women passed on that intelligence to their offspring through their DNA and rich nurturing environment. Breastfeeding didn't have anything to do with the kids IQ. I am not saying breastfeeding doesn't have any benefits but increased intelligence in offspring isn't one of them. You won't make a genius out of a kid by simply breastfeeding them.

  3. My sunscreen is Factor: Bricks and Mortar.

  4. I have light skin, freckles, and a ton of moles. Moles that are inspected every six months. Pretty much every six months I have 1-3 of them removed, often one of is found "pre-cancerous." This happened this week actually.

    So I wear sunscreen and cover my skin. My doctor tells me to, and I listen. BUT, the real reasons I wear sunscreen is that I burn if I don't. And burning hurts. And too much tanning and sun makes you look older earlier. I generally don't wear it if I'm just biking to work or mowing the lawn, but more than 30-45 minutes in the sun and the sunscreen and hat go on.

  5. So, the paper being cited as proving that sunscreen is bad for you never actually mentions sunscreen, and even its most reasonable conclusion -- getting out in the sun now and then is probably good for you -- could easily be an artifact of other underlying factors.

    Also: Sweden.

    Stockholm is at 59ºN. How much more oblique are the sun's rays in Sweden as compared to the rest of Europe and N. America? How much less intense is the UV radiation so far north? How much more critical an issue is Vitamin D deficiency in southern Sweden, which gets only 3 - 5 hours of daylight for months of the year? If I wanted to do a study on the effects of sunlight exposure on human health, and guarantee that the conclusions of that study could not be reliably extrapolated to most of the Northern Hemisphere's population, Sweden would be a great place to do it.

Continue the discussion bbs.boingboing.net

22 more replies

Participants