Dietary polyphenols and the risk of colorectal cancer in the prospective Southern Community Cohort Study
Menée aux Etats-Unis entre 2002 et 2009 auprès de 71 599 personnes, cette étude analyse l'association entre un apport de polyphénols d'origine alimentaire et le risque de cancer colorectal, en fonction de l'origine ethnique
Polyphenols are antioxidants with promising anti-cancer properties, but few studies have examined the associations of specific dietary polyphenols with colorectal cancer (CRC) risk or among Black individuals in the United States (US).We examined the associations between dietary polyphenols and CRC and assessed differences in these associations or polyphenol intakes by subgroups including Black and White individuals that may contribute to cancer disparities.The Southern Community Cohort Study prospectively enrolled individuals from the southeastern US during 2002-2009 most of whom have low income or are Black. Validated food frequency questionnaire data and polyphenol databases were used to estimate polyphenol intake. Cox proportional hazards models were used to obtain hazard ratios (HRs) and 95% confidence intervals (CI95%) for the highest compared to the lowest intake quintile (Q) of specific polyphenols. Median intakes of quintiles were used to obtain linear trends, and restricted cubic splines were used to obtain non-linear trends. Subgroup analyses were conducted by cancer site, sex, race, household income, and Body Mass Index (BMI)-defined obesity status.Among 71,599 participants, median polyphenol intake was lower for Black individuals [452 mg/day; Interquartile Range (IQR) 277-672 mg/day] than White individuals [958 mg/day; IQR 587-1597 mg/day]. A significant inverse non-linear association was observed for total polyphenol intake with CRC risk (HR = 0.57; CI95% = 0.38, 0.86; P = 0.008 comparing 650 mg/day of intake to 0 mg/day). In addition, inverse linear associations were observed for tyrosols and CRC risk (HRQ5vsQ1 = 0.68; CI95% = 0.50, 0.91; P = 0.0014) and for hydroxybenzoic acids and rectal cancer risk (HRQ5vsQ1 = 0.49; CI95% = 0.29, 0.82; P = 0.0007). Associations were consistent by sex, race, income, and BMI.Increasing intakes of total polyphenols, tyrosols, and hydroxybenzoic acids were associated with decreased CRC or rectal cancer risk, and associations were consistent across subgroups. Differences in polyphenol intakes may contribute to increased CRC incidence among Black US individuals.