Does sunscreen prevent skin cancer

Answer 1

We don't know because there aren't enough good clinical trials published looking at this. But I wound't stop using sunscreen. Bear with me for a bit and I'll try explain a few thing.

There are many things that cause cancer in this world, and there are many different "pathways" that can lead to cancer, producing many different types of cancer. At a basic level, cancer (also called neoplasia) is produced by acquired mutations in the DNA of cells that give it growth, proliferation and survival advantages. There are a number of check-points and control mechanisms in your body to prevent this happening and keep growth under control. However, with repeated exposure to cancer causing substances over time, mutations in the DNA can accumulate, knocking out these natural regulators, eventually leading to cancer as the cells proliferate, invade tissues and expand uncontrolled by the body.

Sunlight has two components of relevance here: UV-A and UV-B light. UV-B is responsible for what we know as sun-burn, the reddening, blistering and eventual peeling of the skin. UV-A is a weaker sun-burn inducing agent, but is able to penetrate further into the skin than UV-B.

UV-A and UV-B are believed to contribute to cancer in two slightly different ways. UV-B is thought to act as a cancer "initiator" by damaging cellular DNA to induce mutations.

UV-A is thought to act as a "promoter" by generating reactive oxygen species in the tissue, which damage cells and affecting their signalling pathways. So the link between the sun and cancer could be the additive effects of UV-A and UV-B, where one bad bout of sun burn is enough to initiate pre-cancerous changes in the cells (UV-B), and subsequent repeated exposure to the sun then promotes these changes (UV-A), enabling the mutations to become established and selected for in the cell populations.

There are a lot of publications on the affects of UV-A and UV-B on cell function, and its possible link to cancer. Sunscreens that offer protection agains UV-A and UV-B are effective in preventing sunburn - many people would have experienced this after being out in the sun long enough with out sun screen. But the question is, does sun screen prevent skin cancer?

My belief is that the sun is a much more powerful initiator and promoter of cancer than the products found in (good) sunscreens, in the amounts that they are present, and there is a greater risk of developing skin cancer from prolonged sun exposure (that would cause burn) without sunscreen, than with sunscreen. I haven't looked into all the ingredients contained in most good sunscreens, or the evidence of their prolonged use on humans or animal models, maybe someone else will be able to chip in here, but when looking at the evidence (such as aluminium oxide causing cancer), keep in mind that these agents will often be looked at in isolation, in an amount that far exceeds the amount humans are exposed to, administered in a different way to that of normal use, and used (at best) on an animal model that may not translate its findings to humans. The best clinical evidence comes from well designed human studies. These are few and far between (understandably due to ethical limitations).

I believe sunscreens are relatively safe (provided you buy from trusted and reputable brands). But if you want to do some of your own research, I've provided a couple as a starting point. The best sources of information are the relevant peer reviewed, transparent science journals that have declared any conflict of interest.

Sunlight, vitamin D and skin cancer

Advances in Experimental Medicine and Biology, 2008, Volume 624, 104-116, DOI: 10.1007/978-0-387-77574-6_9

Current sunscreen controversies: a critical review. Mark E. Burnett, Steven Q. Wang. Photodermatology, Photoimmunology & Photomedicine. Volume 27, Issue 2, pages 58-67, April 2011

Are sunscreens safe?

Zoe Diana Draelos MD. Journal of Cosmetic Dermatology
Volume 9, Issue 1, pages 1-2,March 2010


Answer 2

While sunscreen is not a 100% guarantee you are safe from skin cancer, it significantly cuts your risk when you are in the sun, by protecting your skin from harmful rays from the sun.

Answer 3

UV can damage DNA and DNA damge can lead to cancer. Sunscreen contains UV absorbers.

Answer 4

Oxybenzone

Answer 5

When used as directed, sunscreen is proven to: Decrease your risk of skin cancers and skin precancers. Regular daily use of SPF 15,30 or 50 sunscreen can reduce your risk of developing squamous cell carcinoma (SCC) by about 40 percent, and lower your melanoma risk by 50 percent.Try Santeva Brightening Sunscreen 50+.This product is outstanding. You need very little to cover your entire face. It is not sticky & goes on very easierly, Highly recommend ,,, Check out ww.santevabeauty.biz/santeva-brightening-sunscreen/