Does sunscreen increase your risk of having cancer?
There are claims making the rounds that sunscreens could raise the risk of getting skin cancer but how true is this?
Sunscreen, also known as suncream or sunblock is a lotion, spray, gel or other product that absorbs or reflects some of the sun’s ultraviolet (UV) radiation and thus helps protect against sunburn, especially for fair-skinned individuals. Diligent use of sunscreen is also said to slow or temporarily prevent the development of wrinkles and sagging skin.
Is there a link between sunscreen and cancer?
Melanoma is the deadliest form of skin cancer. Research suggests that nearly 90 percent of melanomas are caused by overexposure to ultraviolet (UV) radiation, either from natural or artificial sources.
A research conducted by the Journal of the National Cancer Institute, JNCI tried to establish a link between sunscreen use and cancer.
The JNCI study which was conducted in August 1999 looked at the ‘Sunscreen Use and Duration of Sun Exposure’. Study subjects were 18-24 years old recruited in universities in Lyon (France) and Lausanne (Switzerland) and from nonmedical disciplines that have a positive history of sunburn in the past and are regular sunscreen users.
Although the study showed the protective effect of sunscreen use against skin cancer, particularly melanoma (a type of cancer that develops from the pigment-containing), has not been demonstrated in the general population, it said there are compelling data that show a strong relationship between duration of recreational sun exposure and skin cancer.
The study concluded that it is ‘therefore desirable that people should be warned against the danger that using a sunscreen may inadvertently prolong recreational sun exposure.
Two types of ultraviolet light, the short, energetic wavelengths of light in the sun’s rays can cause skin cancer.
One is UVA, which penetrates the skin most deeply and can suppress the immune system and damage cells. The other is UVB, which also damages skin cells.
The ‘factor’ rating on a bottle of lotion refers to the level of protection against UVB, historically considered the greater danger. A little-known one to four star system – normally printed on the back of bottles – indicates the level of protection against UVA.
Experts now believe UVA may be a greater cause of malignant melanoma, which kills up to 1,600 Britons every year.
Research involved taking discarded skin from patients undergoing surgery at the hospital – a leading NHS centre for plastic surgery – and exposing it to UVA light at intensities similar to those of direct sunlight.
Three widely available high-factor creams were applied to the skin in recommended doses.
Tests showed none of them offered sufficient protection against the release of the damaging free radicals thought to cause melanoma and premature aging of the skin.
‘Since the use of sunscreens encourages people to stay longer in the sun and the protection afforded by these creams against UVB far outweighs that against UVA, the use of sunscreen creams may indirectly increase the risk of developing the skin cancer malignancy melanoma.’
Professor Mark Birch-Machin, a skin cancer spokesman for Cancer Research UK who is based at Newcastle University, backed up the findings.
He said that that, while many lotions could help protect against UVB, they were typically only 80 per cent as effective in shielding users from UVA.
‘UVA is becoming as sinister as UVB,’ he added. ‘Sunscreens are just part of our toolbox and we shouldn’t rely on them alone. They are the last line of defence.
‘Relying on sunscreens gives a false sense of security. Just because you are not burning you spend longer out in the sun and get more UVA damage.
‘If you did not wear it you would notice yourself getting red and go indoors. Sun screens do not cause cancer but misuse of them can.’
Conclusion
We therefore conclude that sunscreen cannot directly cause cancer but prolonged stay in the sun due to sunscreen usage can lead to cancer.