Is Your Sunscreen Killing You? Probably Not!

I recently wrote an “Ask the Expert” column for a client of mine, a wonderful company dedicated to providing quality, evidence-based health information to the public. Although this topic is not related to nutrition, it is timely, so I wanted to share it with you here.

My passion is to help people make sense of the confusing mix of hype and fear that makes up the majority of mainstream media reporting about a variety of health topics.

What’s Worse for Health: Sun or Sunscreen?
Expert Advice from Suzanne Dixon, MPH, MS, RD, Epidemiologist and Registered Dietitian

Make a habit of using a broad-spectrum sunscreen or physical block

Recent news reports have highlighted a study out of Sweden, which found women who avoid sun exposure have higher instances of death due to any cause (all-cause mortality) compared with women who regularly get more sun. Somehow these findings have been getting buzz as “proof” that sunblock is deadly, despite that the research did not examine sunscreen use at all.

What did the new study actually find?

The Swedish researchers collected information on sun exposure and health habits from approximately 30,000 women who were 25 to 64 years old at the start of the study. The women were not asked about sunscreen use. Over 20 years of follow up, the women who had the least sun exposure were twice as likely to die of any cause compared with women with the most sun exposure.

On the surface, these results seem to suggest that avoiding sun exposure is bad for health, but the study authors failed to take into account important considerations. When compared with the group with “active sun exposure habits,” those women who indicated they were not exposed to sun were significantly more likely to:

  • be overweight or obese,
  • be sedentary, meaning they engaged in very little physical activity compared with the sun-exposed group, and
  • have a hereditary risk of melanoma.

None of these factors—all of which are important predictors of the risk of death due to any cause—were properly corrected or controlled for by the researchers. Further, they did not consider other diseases that may contribute to risk of death. While they assessed the use of medications for diabetes and cardiovascular disease, this approach does not provide information about other chronic diseases, such as autoimmune conditions or mobility issues that may increase risk of death, and which tend to make it less likely a woman will spend time in the sun.

Activities used to determine “active sun exposure”—sunbathing, winter holidays to the mountains, and vacations to warm, sunny locations—also are likely related to overall health as well; women who are frail or ill are less able to engage in these active, sun-seeking habits.

Separating truth from fiction

Until a better-designed study comes along, people should continue to heed the advice of dermatologists and other experts, as the evidence still points to the importance of avoiding excess sun exposure for good health.

  • Get the D. If you do not sunburn easily, for your health, aim to get 15 minutes of sun exposure three times per week. However, if you do sunburn, you shouldn’t engage in this practice (I’m a redhead, I sunburn easily, and I do not ever expose myself to the sun intentionally). You can adjust the amount to account for living at northern latitudes, but even people with darker skin can develop skin cancer, so don’t overdo it.
  • Screen, for sure. Make a habit of using a broad-spectrum sunscreen. It’s true the jury is still out on whether chemical-based sunscreens may have other long-term health effects, but for now the risks of not using appear to outweigh the risks of applying sunscreen. If you fear chemical sunscreens, try physical blocks. Some health experts have raised concerns about metal nano-particles in some physical formulas, but you can find zinc- or titanium-based sunscreens that do not contain nano particles (though they may form a white sheen when applied).
  • Move more. As noted, the women in the sun-exposed group were significantly more active than the sun avoiders. Regular physical activity is strongly linked to better overall health, so add movement into your day, every day. If you’re a couch potato, just 20 to 30 minutes of brisk walking will do the trick.
  • Stay slim and trim. The sun avoiders were more likely to be overweight or obese. Maintain a healthy body weight throughout adulthood, and if you’re already overweight, losing just a few pounds can significantly improve health and reduce risk of death. And even if you don’t lose a single pound, getting more physical activity will improve your health. Heavy active people are much healthier than heavy inactive people!

What’s the danger?

Finally, keep in mind that having adequate vitamin D levels is linked with better health. Sweden is very far north, so there is the possibility that in this population, which receives no sun exposure for much of the year, blocking sun exposure is more harmful than not blocking it; this may lower blood vitamin D to insufficient or deficient levels.

(Journal of Internal Medicine, 2014, 276; 77–86)

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