Regardless of family history of breast cancer or other set risk factors, women who follow more of AICR's Recommendations for Cancer Prevention have a lower risk of breast cancer compared to women who follow the fewest, suggests a new study. Staying a healthy body weight and drinking no more than one alcoholic drink a day are the two recommendations that independently linked to decreased risk independently.
The study, published yesterday in the International Journal of Cancer, was conducted independent of AICR.
AICR and the World Cancer Research Fund reports have found that for postmenopausal women, excess body fat and alcohol increase risk; physical activity lowers risk. Breastfeeding also lowers risk.
This study included almost 37,000 women who were part of the Iowa Women's Health Study. The women were ages 55 to 65 when they entered into the study back in 1986. At that time, they filled out questionnaires about their diet, physical activity and other lifestyle habits. Study researchers used a point system for whether a woman adhered to each recommendation: each was assigned either no point, a partial or full point depending upon the level of adherence. The study used eight of the ten Recommendations for Cancer Prevention (they did not include recommendations related to supplements, breastfeeding and limiting energy dense foods due to lack of data).
Then researchers analyzed how the different levels of adherence to the AICR recommendations related to women who had non-modifiable risk factors. The non-modifiable risk factors included family history of breast cancer, tallness and years of fertility.
By the end of 2010, 3,189 of the women had been diagnosed with breast cancer. For all women combined, the more recommendations women followed, the lower their risk. Women who followed six or more recommendations had a 24 percent lower risk compared to women who followed four or fewer recommendations. When recommendations were analyzed independently, the recommendation to stay lean and limit alcohol linked to lower risk.
Among the women who had non-modifiable risk factors, adhering to the recommendations was not linked significantly with lower risk. One possible explanation for this, the authors write, is that the effects of the non-modifiable risk factors moderate the benefits of adherence. It's also important to note, the authors add, that adherence overall links to lower risk of other cancers as well as better health.
The Iowa Women's Health Study and the lead author (at time of analysis) was funded by the National Cancer Institute.
Source: Sarah J. O. Nomura et al. WCRF/AICR recommendation adherence and breast cancer incidence among postmenopausal women with and without non-modifiable risk factors. International Journal of Cancer. Accepted manuscript online: 12 JAN 2016.
Published on January 14, 2016