Alcohol intake and risk of colorectal cancer: results from the UK Dietary Cohort Consortium

Abstract

Background: Epidemiological studies have suggested that excessive alcohol intake increases colorectal cancer (CRC) risk. However, findings regarding tumour subsites and sex differences have been inconsistent.

Methods: We investigated the prospective associations between alcohol intake on overall and site- and sex-specific CRC risk. Analyses were conducted on 579 CRC cases and 1996 matched controls nested within the UK Dietary Cohort Consortium using standardised data obtained from food diaries as a main nutritional method and repeated using data from food frequency questionnaire (FFQ).

Results: Compared with individuals in the lightest category of drinkers (>0-<5 g per day), the multivariable odds ratios of CRC were 1.16 (95% confidence interval (95% CI): 0.88, 1.53) for non-drinkers, 0.91 (95% CI: 0.67, 1.24) for drinkers with 5-<15 g per day, 0.90 (95% CI: 0.65, 1.25) for drinkers with 15-<30 g per day, 1.02 (95% CI: 0.66, 1.58) for drinkers with 30-<45 g per day and 1.19 (95% CI: 0.75, 1.91) for drinkers with >or=45 g per day. No clear associations were observed between site-specific CRC risk and alcohol intake in either sex. Analyses using FFQ showed similar results.

Conclusion: We found no significantly increased risk of CRC up to 30 g per day of alcohol intake within the UK Dietary Cohort Consortium.

Figure 1

Comparison of odds ratios (ORs) in a log scale for categories for alcohol intake data (0, >0–<5 (reference), 5–<15, 15–<30, 30–<45 and ⩾45 g per day) obtained by food diaries or FFQs. A total of 2305 study participants had complete alcohol intake information from both diaries and FFQs (n=496 cases and 1809 controls). Ors for each category were plotted against the mean alcohol intake (g per day) for each category (0, 2.6, 9.4, 21.7, 36.4 and 64 g per day for food diaries and 0, 1.9, 9.1, 21.7, 35.6 and 61.3 g per day for FFQs, respectively) and were adjusted for age, weight, height, smoking status, social class, intakes of fibre and folate.