By Jimmy Downs

Sunday Nov 11, 2012 (foodconsumer.org) -- A new study in Asian Pacific Journal of Cancer Prevention has confirmed that women who have a short menstrual cycle may have to face a higher risk of breast cancer.

The study led by C. Yanhua of The First Peoples' Hospital of Kunming in Yunnan province, PR China and colleagues found a positive association between having a short menstrual cycle and risk of breast cancer. 

The study of 263 breast cancer cases and 457 controls who were enrolled in the study from 2009 and 2011 was actually intended to examine the associations between reproductive characteristics and risk of breast cancer.

In addition to menstrual cycle, old age at first live birth, never breastfeeding, history of oral contraception use, increased number of induced abortion, postmenopausal status, and nulliparity were all positively associated with breast cancer risk.

Increased exposure to estrogen associated with short menstrual cycle, older age at the first live birth, never breastfeeding, nulliparity and induced abortions is the reason why women with these reproductive characteristics are at higher risk of breast cancer.

It's not the first time that menstrual cycle was associated with risk of breast cancer.

Dr. Dale P. Sandler of National Institute of Environmental Health Sciences Research Triangle Park, NC and colleagues published a study in American Journal of Epidemiology that found short menstrual cycle associated with elevated risk of breast cancer.

The study was based on data from 997 women who had recorded menstrual events.  The authors found that compared with women with a median menstrual cycle of 26 to 29 days, women who had  menstrual cycle of less than 26 days or longer than 34 or more days were found 90 percent more likely to be diagnosed with breast cancer.