Q. I am a breast cancer survivor. I play tennis and golf five days a week and smear a high SPF sunscreen all over my body. I also wear protective clothing to block the sun.

I have heard that some sunscreens may have estrogenic activity. I’m supposed to avoid estrogen, so I wonder if you can tell me more about sunscreens and estrogen.

A. Several common ingredients in sunscreens have been shown to act like estrogen. One test-tube study showed that breast cancer cells grew faster in the presence of such compounds.

Another study showed that sunscreen ingredients are absorbed through the skin and can be measured in the urine (Journal of Investigative Dermatology, July 2004). The significance of this finding for adults remains controversial, but the authors warn that young children may be vulnerable to hormonal disruption from such sunscreens.

Until this issue has been resolved it might be prudent to stick with protective clothing. (Check www.sundayafternoons.com or www.coolibar.com.) Sunscreens that contain physical blockers such as zinc oxide or titanium dioxide don’t have hormonal effects and are safe for young children and people with sensitive skin (The Lancet online, May 3, 2007).

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  1. Carla Powell
    Reply

    I am a breast cancer survivor who had a mastectomy, chemotherapy & 5 years of Arimidex. I have been told to avoid estrogen, including any cremes, etc. I also sunburn easily & have used high spf sunscreens for a long time. Could that have increased my chances for the breast cancer I developed? Also what ingredients or compounds should be avoided and are any others beside zinc oxide & titanium dioxide safe? I really need to know this for myself, my daughter, 3 granddaughters & several close friends who also had breast cancer. Thank you!

  2. Thomas W Childers
    Reply

    National Geographic June 06 page 116 article on Nano Technology stated that the titanium dioxide used in sunscrees creates free radicals when exposed to ultra-violet light. AARP newsletter May 07 supports this by saying that it is important to reapply every two hours because the Ti O2 is absorbed in the skin and creates free radicals. I think there is a connection between Sunscreen and increased skin cancer. Comments?

  3. Mary Elliott
    Reply

    Which sunscreen ingredients act like estrogen? I’m an avid gardener (and a cancer survivor) and am concerned now about whether the sunscreen I thought was protecting me is actually more harmful than the sun itself.

  4. Marion Lonegro
    Reply

    I read your article with much interest because my daughter had breast cancer. You say what ingredients in a sunscreen to look for that are ok but you don’t say what to look for that is not good. Could you please elaborate on this? Thank you.

  5. Joan Chasey
    Reply

    Surprised to read about the sunscreen and estrogen connection. Please keep me informed.

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