Gender Perspectives on the Relationship between Red and Processed Meat Intake and Colorectal Cancer: A Systematic Review and Meta-Analysis

ABSTRACT

BACKGROUND: Men and women choose different food items, and consume different amounts of food, due to biological, cultural, and social differences. However, when dietary assessment instruments are developed, gender differences in food selection and/or the portion sizes are often not considered. METHODS: Prospective cohort studies with men and women that examined the association between red or processed meat intake and colorectal cancer and published up to July 2017, were identified using PubMed. Studies were categorized as gender-specific (GS) group if the Food Frequency Questionnaire was developed using gender-specific data, and as not gender-specific (NGS) group if not gender-specific data were used. RESULTS: For cohort studies that reported combined intake estimates of men and women, a 100 g/day increment in red and processed meat intake was positively associated with a risk of colorectal or colon cancer in GS group (relative risk [RR], 1.23; 95% confidence interval [CI], 1.14–1.32) but not in NGS group (RR, 1.13; 95% CI, 0.90–1.35). For processed meat, the RR for 50 g/day increase was 1.28 (95% CI, 1.15–1.40) in GS group and 1.15 (95% CI, 1.03–1.27) in NGS group. CONCLUSIONS: Gender differences need to be considered during development of dietary assessment tools because this may improve the quality of the findings of nutritional epidemiological studies.