The snow is melted and the sun is out (at least in my part of the world). I’m excited to spend more time outside enjoying the garden and visiting my friends. A sunny day gives me much more energy and puts me in a great mood. Over the last few months of winter, many of my patients have been feeling the blues of scarce winter sun and craving the rays of the coming summer sun. As we welcome the sun, we do need to be careful about potential dangers that come with sunshine.
So what’s the connection between sunshine and breast cancer? Sun exposure has no known effect on breast cancer risk; its major effect on skin cancer risk is well-established. There are concerns, however, about sunscreens and breast cancer risk. What goes on you, goes in you. Many personal products we use in our everyday life can be absorbed through the skin and get into our bodies. Some families with an inherited abnormal breast cancer gene might be prone to develop melanoma (a serious form of skin cancer) as well as breast cancer.
(Tanning in salons is a whole other topic. As wonderful as it might make you feel, it’s very dangerous and increases the risk of skin cancer. This is of particular concern if you have a predisposition to skin cancer.)
If I’m going to be outside for more than 15 minutes in the mid-day sun, I always make sure to protect my skin from the sun. You might think this means I slather on sunscreen, but I’m more likely to wear a wide-brimmed hat, a lightweight long-sleeved shirt, and lightweight long pants. Some people say that I look like a bee-keeper. For sure, my summertime attire during prime sunshine totally messes with the glam look that I’ve been trying cultivate. But it’s an easy choice for me because I have a family history of melanoma and have had a few funky moles removed already. Plus, I don’t like covering myself with lotions and oils.
Still, if I go swimming or bike riding or am doing some other sporty thing during prime sun exposure (10 a.m. to 3 p.m.), I can’t cover up with clothes. So I try to choose the safest sunscreen I can, usually a mineral or physical sunscreen (more on that in just a minute).
Some of the ingredients in certain sunscreens are considered hormone disruptors. Hormone disruptors can affect how estrogen and other hormones act in our bodies, by blocking them, mimicking them, or messing with the balance of normal hormones. We know estrogen can make hormone-receptor-positive cancers grow, so many women want to avoid anything that contains hormone disruptors.
There are basically two kinds of sunscreen: physical/mineral and chemical.
Physical/mineral sunscreens sit on top of your skin and work by reflecting the sun’s ultraviolet rays away from your skin. The minerals in physical sunscreens are either titanium dioxide or zinc oxide. Mineral sunscreens used to be white — remember lifeguards with white noses? New formulas aren’t white because the mineral particles are smaller. Some people are concerned that these smaller particles may be absorbed by the body, but so far research hasn’t found any evidence of it.
Chemical sunscreens work by absorbing ultraviolet radiation. These sunscreens can be absorbed through the skin. And while we don’t know if this exposure causes health problems, we do know a lot of people are absorbing these chemicals. Research shows that 96.8% of people older than 6 have benzophenone 3 (a hormone disruptor and the common chemical in these sunscreens) in their urine. Women had higher concentrations than men. Sunscreen chemicals also have been found in wildlife and in the environment.
The Environmental Working Group (EWG) is an environmental health advocacy organization based in the United States and a Breastcancer.org collaborator. The EWG has released a sunscreen ranking guide based on possible harmful ingredients as well as the products’ ability to protect you from sun damage. To learn more, visit the EWG Sunscreen Guide.
At the federal level, the U.S. Food and Drug Administration evaluates and approves sunscreens and is currently reviewing its regulations. Right now, the SPF number (sun protection factor) is required to be on the label, but this number only tells how much UVB protection the sunscreen provides. UVB is one type of ultraviolet light; UVA is the other. The FDA soon may require more specific information on sunscreen labels, including how well the product protects against UVA.
We need more research about sunscreen, but until then I‘m sticking to my sun protection precautions. I avoid going out during prime sun exposure, I wear a 5-inch brim hat (there are some very stylish options — just think about Kate Middleton, Prince William’s new bride — don’t look to the Queen for glamorous options, however). Covering up is a good strategy — as is wearing a mineral sunscreen when I can’t. I’m also careful to take my daily vitamin D supplement since avoiding or blocking the sun can lead to vitamin D deficiency. Update: Read about the Importance of Vitamin D. I wish you all a happy, healthy summer!