Calcium and cancer prevention

Conflicting opinions relating to the benefits of dairy foods become more vociferous each month. A striking study released this week suggests that women who consume a large amount of dairy foods may reduce their risk of ovarian cancer.

Women who consume a large amount of dairy foods may reduce their risk of ovarian cancer, finds a recent study.

Researchers at the University of Hawaii in Honolulu found that women with the highest intake of dairy products were 54 per cent less likely to be diagnosed with ovarian cancer than those who ate the lowest amounts of dairy products.

"These results suggest that intake of low-fat milk, calcium, or lactose may reduce the risk of ovarian cancer," Dr Marc Goodman and colleagues wrote in the American Journal of Epidemiology.

Researchers said that findings have been inconsistent regarding the association of dietary fat, dairy products, and lactose with the risk of ovarian cancer. The authors conducted a case-control study in Hawaii and Los Angeles, California, to examine a population with a broad range of dietary intakes.

A total of 558 patients with ovarian cancer diagnosed in 1993-1999 and 607 healthy women were interviewed about their diet.

Women who consumed the most dairy products overall, including low-fat and skimmed milk, were the least likely to be diagnosed with ovarian cancer. Ethnicity had no effect on the results. Drinkers of whole milk however were not found to have a lower risk and the team found no relationship between a woman's intake of yoghurt, cheese or ice cream and risk of the ovarian cancer.

The team explained that it was both the high intake of calcium and lactose that lowered the cancer risk. Lactose, the sugar in dairy foods, is thought to increase calcium absorption and promote the growth of bacteria that fight cancer-causing chemicals.

"Although these results are intriguing, we cannot rule out the possibility that both calcium and lactose are surrogates for another, unidentified component of dairy foods," the researchers concluded.

Calcium intake is already an important factor in preventing osteoporosis and other diseases so the researchers suggested that women maintain a recommended daily intake of around 1,000 - 1,200 mg calcium, which could be enough to lower ovarian cancer risk.