Mark Henderson, Science Correspondent

The Sunday Times (London)

The main chemical used in sun lotions to filter out ultraviolet light may be TOXIC, particularly when exposed to sunshine.

Octyl methoxycinnamate (OMC), which is present in 90 per cent of sunscreen brands, was found to kill mouse cells even at low doses in a study by Norwegian scientists.

It is not certain that the effects on mice are repeated in human beings, although the findings reported in New Scientist magazine suggest that human cells could be damaged if a sunscreen containing OMC penetrates the outer layer of dead skin and comes into contact with living tissue.

Terje Christensen, a biophysicist from the Norwegian Radiation Protection Authority, near Oslo, said her research showed that sunscreens should be treated with caution, and used only when it was impractical to stay indoors or to shield the skin from the sun with clothes.

The chemical is used as a filter for the more harmful UVB light. In Dr Christensen's study, mouse tissue grown in culture was treated with a solution of OMC at five parts per million - a much lower concentration than in sunscreens. Half the cells treated with OMC died, compared with fewer than 10 per cent in a control experiment.

When researchers shone a lamp for two hours to simulate midday sunshine, more cells died. Dr Christensen suggested that the reaction between OMC and sunlight created an effect that was twice as toxic as the chemical alone.

The Cosmetic Toiletry and Perfumery Association, which represents sunscreen manufacturers in Britain, said that OMC "has been thoroughly tested for safety" and was approved by regulatory authorities in Europe and the US.

Dr. Mercola's Comments:

We ALL need sunshine to stay healthy. It is one of the essential ingredients for staying healthy. It is not the perniciously evil item that traditional medicine suggests that it is. That does not mean that we should all go out and get sunburned. That should be avoided as it is likely to lead to an increase in skin cancer. However, prudent exposure to the sun, integrating the listening to your body concept, will not. Adding sun screens is NOT a good way to limit your sun exposure. Staying out of the sun early on in the season and limiting your exposure until your system adjusts by increasing melanin pigmentation in your skin is. Additionally, consuming many whole vegetables will increase antioxidant levels in the body which will also provide protection against any sun induced radiation damage. So the bottom line is to avoid the sun screens. They are not necessary and will actually increase your risk of disease. Related Articles: Absorbing Titanium from Sunscreens Sunscreens Don't Prevent Melanoma