Eating fish can increase risk of breast cancer.

Factors like environmental pollutants and mercury levels in fish have led some to question recommendations to eat more fish to reduce risk of heart disease. A recent study raised another red flag--fish appears to be associated with increased risk of breast cancer in post-menopausal women. More than 23,000 Danish women who were 50-64 years old at the start of the study were followed for close to five years. During the study, 424 women developed breast cancer. When the women were divided into groups based on the amount of fish they reported eating, women who ate more than two ounces of fish per day had a 47 percent higher rate of breast cancer than women eating one ounce of fish or none daily. The fat content of the fish and the way it was prepared did not appear to affect breast cancer risk. This is the first study to show this association, and additional studies are needed to discover what substances in fish led to these results. This study adds weight to the need to rethink recommendations calling for eating more fish.

For more information about recommendations related to fish consumption, see Vegetarian Journal Sept/Oct 2001, American Heart Association Calls for Eating Fish Twice Per Week--What's a Vegetarian To Do? This article is on the web at <www.vrg.org/journal/vj2001sep/2001sepomega3.htm>.

Stripp C, Overvad K, Christensen J, et al. 2003. Fish intake is positively associated with breast cancer incidence rate. J Nutr 133:3664-69.