Consuming red meat can increase the chances of breast cancer, a study published in International Journal of Cancer this week revealed. The Sister Study was a US and Puerto Rico-based nationwide prospective cohort study that evaluated environmental and genetic risk factors for breast cancer. The enrollment period was between 2003 and 2009; eligible participants were 35- to 74-year-old women who had no previous diagnosis of breast cancer and are sisters or half-sisters of women diagnosed with breast cancer. It was jointly done by Columbia Mailman School of Public Health, New York, National University of Singapore, National Institute of Environmental Health Sciences and National Cancer Institute, Bethesda.
Under the study, total of 50,884 women completed the extensive baseline enrollment process, which consisted of a comprehensive interview and self-completed questionnaires covering medical and family cancer history as well as lifestyle and demographic characteristics, including diet and a home exam during which height, weight and weight and hip circumference were measured.
The findings revealed that study participants with higher red meat consumption had worse health behaviors overall and stronger family history of breast cancer compared to those with lower red meat consumption. In terms of poultry consumption, study participants with higher poultry consumption had more years of education and had stronger family history compared to those with lower poultry consumption.
“Red meat consumption increased the risk of invasive breast cancer, whereas poultry consumption was associated with reduced risk, particularly for postmenopausal invasive breast cancer. These associations were more pronounced in substitution models, indicating that substituting poultry for red meat decreases breast cancer risk when the total consumption of red meat and poultry is fixed and substituting red meat for poultry increases breast cancer risk when total consumption of red meat and poultry is fixed,” the study said.
Beef, veal, pork, lamb and game meat come under red meat while white meat includes the poultry chicken, turkey, Cornish hens, duck, goose, quail and pheasant/game birds. “An association between red meat and breast cancer may be due to dietary heme iron, fat and N-glycolylneuraminic acid as these compounds found in red meat are indicated to possibly increase tumor formation,” the study said.
The study holds significance in context to India as red meat is a part of diet in Indian households. According to a Lancet study published last year, India has a low survival rate for breast cancer, with only 66.1% women diagnosed with the disease between 2010 and 2014 surviving. According to the Union health ministry, breast cancer ranks as the number one cancer among Indian females with rate as high as 25.8 per 100,000 women and mortality of 12.7 per 100,000 women. According to estimates, at least 17,97,900 women in India may have breast cancer by 2020.
“Breast cancer is the leading cancer among women, not only in India but worldwide. While this observational study doesn’t prove that red meat causes breast cancer or that chicken prevents it, the authors suggest the switch may be worth considering,” said Ravi Mehrotra, Chief Executive Officer (CEO), Indian Cancer Research Consortium –Indian Journal of Medical Research (ICMR).
“Random clinical trials with a very long follow-up to study the relationship between diet and breast cancer are warranted. Other factors that increase the risk of breast cancer are genetics, obesity, tobacco, alcohol consumption, less number of children and absence of breast feeding,” he said.