Press Releases

2001 Releases

Study Finds Increased Fruit and Vegetable Consumption Does Not Reduce the Risk of Breast Cancer

For immediate release: February 13, 2001

Boston, MA.-- In the largest study of diet and breast cancer to date, researchers from the Harvard School of Public Health and institutions from four countries have concluded that breast cancer risk is not reduced by consuming fruits and vegetables. The study findings appear in the February 14, 2001 edition of the Journal of the American Medical Association (

The study examined the association between fruit and vegetable consumption and breast cancer. The researchers drew participants from eight separate studies that spanned four countries and involved more than 350,000 women. For each participant diagnosed with invasive breast cancer, ten controls were randomly selected from the subset of participants who had the same year of birth and had not been diagnosed with invasive breast cancer. The studies included 7,377 women with breast cancer at the start of the study. 

The team analyzed the participants’ consumption of green leafy vegetables, eight botanical groups that included lettuce, squash, broccoli, apples, grapefruits and tomatoes, and seventeen specific fruits and vegetables. Servings were measured in grams consumed per day and were examined in various groupings such as fruits, vegetables and juices, to try to detect any association with breast cancer. One serving size equaled 100 grams. 

Women who consumed the highest amount of fruits and vegetables were compared with those who consumed the lowest amount. The analysis revealed no significant difference in the risk of breast cancer between the two groups. The team also did not find any specific groupings of fruits or vegetables that had strong associations with breast cancer risk reduction.

The authors concluded that increased consumption of fruits and vegetables among adults does not lower the risk of breast cancer for women. Lead author and HSPH research scientist Stephanie Smith-Warner said, "Although we did not find an association between fruit and vegetable consumption and breast cancer risk in our study, higher fruit and vegetable consumption has been associated with a lower risk of heart disease and other health conditions and continues to be an important part of a healthy diet. However, further studies are needed to find strategies for reducing the risk of breast cancer."

The study, "Fruits and Vegetables and Breast Cancer: A Pooled Analysis of Cohort Studies," was supported by a grant from the National Institutes of Health. 

For further information, please contact:

Robin Herman
Office of Communications
Harvard School of Public Health
677 Huntington Avenue
Boston, MA 02115
Phone: 617-432-4752