New evidence supports value of fruits and vegetables in reducing breast cancer risk

Fruits and vegetables are known to reduce the risk of some cancers. Their antioxidant properties have been found to inhibit the generation of reactive oxidant species (ROS) that can damage and change DNA and lead to cancer.

Researchers at Roswell Park Cancer Institute (RPCI) evaluated myeloperoxidase (MPO), a major enzyme involved in generating ROS. The results, reported in the October 15 issue of Cancer Research, indicate that a specific type of MPO gene appears to reduce breast cancer risk in women who consumed higher amounts of fruits and vegetables, and that this reduction was most pronounced in premenopausal women.

Jiyoung Ahn, MS, RD, and Christine Ambrosone, PhD, Division of Cancer Prevention and Population Sciences, evaluated this hypothesis in a population-based, case-control study of 1,037 women with breast cancer and 1,086 healthy subjects in Nassau and Suffolk Counties, New York. The study was originally conducted by Marilie Gammon, PhD and colleagues from the University of North Carolina.

A specific type of MPO gene was present in 38 and 41 percent of breast cancer cases and population-based controls respectively. Analysis of data found women with this gene type who followed a diet high in fruits and vegetables (more than four servings per day) had a 25 percent lower risk of developing breast cancer. Women with this gene type who ate fewer fruits and vegetables had no risk reduction. Furthermore, when the data was analyzed by menopausal state, premenopausal women who followed diets high in fruits and vegetables had a 60 percent reduction in their risk of breast cancer.

“This study adds to the growing body of evidence on the importance of diet,” said Ms. Ahn. While we can not control our DNA, this study demonstrates women can effectively modify their risk of breast cancer by eating a diet high in fruits and vegetables.”

“This is the first paper to examine the role of specific MPO genes and breast cancer risk,” noted Dr. Ambrosone. “These findings are significant because they may be helpful in the development of new breast cancer prevention strategies.”