Unrestrained eating behavior and risk of digestive system cancers: a prospective cohort study

Authors: ZHANG, YIN - Dana-Farber Cancer Institute; SONG, MINGYANG - Harvard School Of Public Health; CHAN, ANDREW - Harvard Medical School; SCHERNHAMMER, EVA - Harvard Medical School; WOLPIN, BRIAN - Dana-Farber Cancer Institute; STAMPFER, MEIR - Harvard Medical School; MEYERHARDT, JEFFREY - Dana-Farber Cancer Institute; FUCHS, CHARLES - Yale Cancer Center; ROBERTS, SUSAN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; WILLETT, WALTER - Harvard School Of Public Health; HU, FRANK - Harvard School Of Public Health; GIOVANNUCCI, EDWARD - Harvard School Of Public Health; NG, KIMMIE - Dana-Farber Cancer Institute

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2021
Publication Date: 7/22/2021
Citation: Zhang, Y., Song, M., Chan, A.T., Schernhammer, E.S., Wolpin, B.M., Stampfer, M.J., Meyerhardt, J.A., Fuchs, C.S., Roberts, S., Willett, W.C., Hu, F.B., Giovannucci, E.L., Ng, K. 2021. Unrestrained eating behavior and risk of digestive system cancers: a prospective cohort study. American Journal of Clinical Nutrition. 14(5):1612-162. https://doi.org/10.1093/ajcn/nqab235.
DOI: https://doi.org/10.1093/ajcn/nqab235

Interpretive Summary: Unrestrained eating behavior is defined as eating with little attention paid to the healthfulness and calorie content of food. In a prospective cohort study following 70,450 participants in the Nurses Health Study for up to 18 years, unrestrained eating behavior was associated with a significant increase in the risk of overall digestive system cancer. The risk elevation was predominantly driven by gastrointestinal tract cancers including buccal cavity and pharynx, esophagus, stomach, small intestine, and colorectum. These findings, if confirmed by further studies, suggest benefits of restrained eating behavior for primary prevention of digestive tract cancers.

Technical Abstract: Background Unrestrained eating behavior, as a potential proxy for diet frequency, timing, and caloric intake, has been questioned as a plausible risk factor for digestive system cancers, but epidemiological evidence remains sparse. Objectives We investigated prospectively the associations between unrestrained eating behavior and digestive system cancer risk. Methods Participants in the Nurses' Health Study who were free of cancer and reported dietary information in 1994 were followed for <=18 y. Cox models were used to estimate HRs and 95% CIs for unrestrained eating (eating anything at any time, no concern with figure change, or both) and risk of digestive system cancers. Results During follow-up, 2064 digestive system cancer cases were documented among 70,450 eligible participants in analyses of eating anything at any time, In total, 2081 digestive system cancer cases were documented among 72,468 eligible participants in analyses of no concern with figure change. In fully adjusted analyses, women with the behavior of eating anything at any time had a higher risk of overall digestive system cancer (HR: 1.22; 95% CI: 1.10, 1.35), overall gastrointestinal tract cancer ((HR: 1.33; 95% CI: 1.18, 1.50), buccal cavity and pharynx cancer (HR: 1.50; 95% CI: 1.02, 2.21), esophageal cancer (HR: 1.62; 95% CI: 1.01, 2.62), small intestine cancer (HR: 1.92; 95% CI: 1.02,3. 59), and colorectal cancer (HR: 1.20; 95% CI: 1.04, 1.38), and a non-statistically significant increased risk of stomach cancer (HR: 1.54; 95% CI: 0.96,2.48), compared with women without this behavior. No statistically significant association was observed for pancreatic cancer and liver and gallbladder cancer. The combined effect of eating anything at any time and having no concern with figure change was associated with a significantly increased risk of overall digestive system cancer (HR: 1.27; 95% CI: 1.10, 1.46), overall gastrointestinal tract cancer (HR: 1.45; 95% CI: 1.23, 1.71), and colorectal cancer (HR: 1.34; 95% CI: 1.11, 1.63), compared with women exhibiting the opposite. Conclusions Unrestrained eating behavior was independently associated with increased risk of gastrointestinal tract cancers. The potential importance of unrestrained eating behavior modification in preventing gastrointestinal tract cancers should be noted.