Black Americans have the highest incidence of colorectal cancer of any racial/ethnic group in the United States. Although diets high in red and processed meat have been associated with increased colorectal cancer risk, studies have not reported associations specifically for Black Americans. However, a new prospective study, published in The Journal of Nutrition, found that higher consumption of red meat – specifically, unprocessed red meat – was associated with a 33% increased risk of colorectal cancer among women that participated in the Black Women’s Health Study.
To assess the association between diet (intakes of total red meat, unprocessed and processed red meat, saturated fatty acids, and monounsaturated fatty acids) and colorectal cancer risk, Dr. Jessica Petrick (Slone Epidemiology Center at Boston University) and colleagues utilized data from the Black Women’s Health Study, an ongoing prospective cohort study designed to assess risk factors for disease outcomes in US Black women. At study baseline, women aged 21 – 69 years of age completed a self-administered questionnaire on demographics, medical history, lifestyle factors and diet. Follow-up has been ongoing for more than 25 years, with participants completing a questionnaire every 2 years. A validated food frequency questionnaire was used to collect dietary data. Colon or rectal cancer diagnoses were ascertained by self-report on follow-up questionnaires, linkage with cancer registries and the National Death Index. Pathology data were obtained from hospitals or cancer registries for 75% of cases, of which 95% of colorectal cancer cases were confirmed.
Among the 52,695 participants, 564 women developed colorectal cancer. Higher intake of unprocessed red meats was associated with a 33% increased risk of colorectal cancer. More specifically, unprocessed red meat intake was associated with 2-times increased risk of rectal cancer. Processed red meat was not associated with colorectal cancer risk, and there were little to no associations with saturated or monounsaturated fats. These results update and support the recommendation by the World Cancer Research Fund and American Institutes for Cancer Research to limit consumption of red meat for cancer prevention.
In a companion commentary, Dr. Kathryn Bradbury (University of Auckland) comments that a reduction in meat production and consumption is beneficial to the human health as well as the health of the planet given the considerable methane gas contribution from ruminant animals.
References
Ioanna Yiannakou, Lauren E Barber, Shanshan Li, Lucile L Adams-Campbell, Julie R Palmer, Lynn Rosenberg, Jessica L Petrick, A Prospective Analysis of Red and Processed Meat Intake in Relation to Colorectal Cancer in the Black Women’s Health Study, The Journal of Nutrition, Volume 152, Issue 5, May 2022, Pages 1254–1262, https://doi.org/10.1093/jn/nxab419.
Kathryn E Bradbury, Red and Processed Meat Consumption: What’s at Stake?, The Journal of Nutrition, Volume 152, Issue 5, May 2022, Pages 1181–1182, https://doi.org/10.1093/jn/nxac036.
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