High dairy diet may up ovarian cancer risk

There is "some support" for an association between ovarian cancer and the consumption of milk products, Swedish researchers report in the International Journal of Cancer.

Animal studies and ecological studies have suggested a positive relationship between dairy foods and ovarian cancer, but other studies have reported mixed results, Dr. Susanna C. Larsson and colleagues at the Karolinska Institute, Stockholm, explain in the report.

Using a statistical approach called meta-analysis, they combined data from three large cohort studies involving more than 180,000 subjects and found an association between ovarian cancer and a high consumption of milk products and lactose (milk sugar).

These large studies were consistent and indicated a significant positive association between total dairy food, low-fat milk and lactose levels and risk of ovarian cancer.

However, combined data from 18 case-control studies involving more than 10,000 subjects do not appear to support ties between dairy foods and ovarian cancer.

The case-control findings varied widely, Larsson and colleagues report, and the only positive link that could be established was a 27 percent increased relative risk in the highest versus the lowest category of whole milk drinkers.

Larsson's team concludes that there is "some support" for the dairy-ovarian cancer hypothesis. However, they suggest that future studies consider specific subtypes of ovarian cancer, and the interrelation between intakes of dairy foods and lactose, genetic variants and ovarian cancer risk.

SOURCE: International Journal of Cancer, January 15, 2006.