If you know that you have a BRCA1 or BRCA2 genetic mutation, you know that your risk is already increased. However, weight loss during your fertile years may help reduce your risk of developing breast cancer. A study published in 2005 in Breast Cancer Research found that women who had a family history of breast and ovarian cancers could protect themselves against early onset breast cancer by dropping 10 pounds. "A loss of at least 10 pounds in the period from age 18 to 30 years was associated with a decreased risk of breast cancer between age 30 and 49," said Joanne Kotsopoulos, who directed the study. "Weight gain should also be avoided, particularly among BRCA1 mutation carriers who elect to have at least two pregnancies." For women who had the mutated BRCA1 gene, "… change in body weight later in life (at age 30 to 40) did not influence the risk of either premenopausal or postmenopausal breast cancer."
Bottom Line: Maintain a Healthy Weight
If you have a BMI over 24.9, you are considered overweight or obese, and at higher risk for several diseases, including breast cancer. That said, being slightly overweight during adolescence and adulthood seems to offer some protection against developing breast cancer, if you don't have a BRCA mutation. Once you enter menopause, shed the excess weight to reduce your exposure to estrogen that can be stored in extra fat, to keep your risk of breast cancer low. If you do have a BRCA mutation, stay as lean as possible during your fertile years, and try not to gain more than 10 pounds after age 40. If you need help planning a healthy diet or losing weight, see a nutrionist or consult your doctor about ways to slim down and achieve a healthy weight.
Weight, Breast Cancer Risk and Menopausal Status
Sources:
National Cancer Institute. Obesity and Cancer: Questions and Answers. Reviewed: 03/16/2004.
National Cancer Institute. Weight Gain Increases Risk of Breast Cancer After Menopause. Reprinted from the NCI Cancer Bulletin, vol. 3/no. 29, July 18, 2006.
American Cancer Society. Diet and Physical Activity: What's the Cancer Connection? Revised: 10/02/06.
Breast Cancer Research. Changes in body weight and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers. Joanne Kotsopoulos, et. al. 7:R833-R843. 2005.
Cancer Epidemiology Biomarkers & Prevention Relative Weight at Age 12 and Risk of Postmenopausal Breast Cancer.
Aditya Bardia, et. al. CEBP 17, 374-378, February 1, 2008. Published Online First February 4, 2008.
Vainio H, Bianchini F. IARC handbooks of cancer prevention. Volume 6: Weight control and physical activity. Lyon, France: IARC Press, 2002.
Yoo KY, Tajima K, Park S, et al. Postmenopausal obesity as a breast cancer risk factor according to estrogen and progesterone receptor status (Japan). Cancer Letters 2001; 167(1):57–63.
