Sunshine cuts risk of breast cancer

Published on Sunday 5 August 2007 00:43

SUNSHINE could help women in the fight against breast cancer, according to new research.

For years, experts have warned that spending too much time in the sun can increase the risk of developing skin cancer. But now it seems that women who avoid sunlight altogether are putting themselves at greater risk of being diagnosed with breast cancer.

The majority of vitamin D comes from exposure of the skin to sunlight but many women - exposed less in winter and reluctant to bare themselves in summer because of the dangers - are deficient.

There has been anecdotal evidence to suggest that breast cancer is less common among women who live closer to the Equator, where the sunshine is stronger.

But a new study provides the firmest evidence yet that the lower the levels of vitamin D in a woman's blood-stream, the greater the risk of her developing breast cancer if she has passed the menopause.

Of more than 1,000 women who took part in a trial, those who were given both calcium and vitamin D supplements had less than half the chance of developing breast cancer than those given a placebo.

A team from Creighton University in Omaha, Nebraska, enrolled 1,179 women all 55 or older, who had no history of cancer.

The women were divided randomly into groups and given either supplements of calcium alone, calcium plus vitamin D or a placebo for four years.

When the researchers repeated the analysis for those women who were free of cancer after the first year of the study, the results were even more striking, with the risks being reduced by more than three-quarters.

"Our findings of decreased all-cancer risk with improved vitamin D status are consistent with a large and still growing body of data showing that cancer risk, cancer mortality, or both are inversely associated with solar exposure, vitamin D status or both," the researchers said.

"Findings from this study suggest that higher intakes of calcium and vitamin D may be associated with a lower risk of developing premenopausal breast cancer."

Vitamin D is also present in foods including milk, eggs, oily fish, green vegetables and fortified margarines.