1. Home>
2. Specialties>
3. Women's Health>
4. Summary and Comment

Caloric Restriction in Early Life: Reduced Breast Cancer Risk

Women hospitalized for anorexia before age 40 were less likely than other women to develop breast cancer.

Animal models have demonstrated that caloric restriction extends longevity and reduces tumor formation; epidemiologic evidence suggests that lower body mass is associated with decreased breast cancer risk. Theoretically, caloric restriction at critical periods of breast development may reduce exposure to insulin and insulin-like growth factors and alter the expression of oncogenes and tumor suppressor genes.

These researchers used hospitalization for anorexia nervosa before age 40 as a proxy measure for severe caloric restriction in early life. In a retrospective cohort study, they examined the development of breast cancer among 7303 Swedish women who were cancer-free when they were hospitalized for anorexia between 1965 and 1998. The Swedish Cancer Registry, a database determined to be more than 95% complete, was used to identify incident breast cancer cases through 2000.

The incidence of breast cancer in previously anorexic women (7 cases) was 53% lower than the expected incidence (14.8 expected cases, as determined by rates in the general population). Among nulliparous women, the 23% reduction in breast cancer incidence was not statistically significant; however, among parous women, there was a significant 76% reduction (2 cases vs. 8.3 expected).

Comment: The applicability of these findings to a less ethnically homogeneous population and to patients without severe eating disorders is uncertain. In addition, there were no data on potential confounders (e.g., age at menarche, BMI, age at first birth, and number of births). Thus, this study may generate more questions than it answers. However, the data are a provocative contribution to our growing understanding of breast cancer pathogenesis and prevention.

— Jane E. Corboy, MD

Published in Journal Watch Women's Health May 5, 2004

Citation(s):

Michels KB and Ekbom A. Caloric restriction and incidence of breast cancer. JAMA 2004 Mar 10; 291:1226-30.

• Original article (Subscription may be required)
• Medline abstract (Free)