Since the foundation of the Danish Brewery Workers' Union (BWU) in 1898, an integrated issue in the labour contract between the BWU and the employers implied that the breweries provided 6 bottles of beer to each brewery worker per day. The objective of our study is to investigate if this presumably high daily consumption of beer is associated with increased risk of cancer, particularly cancer of colon and rectum. The cohort has previously been followed until 1972, but with our study we add further 27 years of follow-up. The cohort comprises all male members of BWU employed for 6 months or longer in a brewery between 1939 and 1963. From the original cohort of 14,313 workers, it was possible to identify 13,051 brewery workers (91.2%). The identified brewery workers were linked to the Danish Cancer Registry for any cancer diagnoses during 1943-1999. The incidence rate of all Danish men was applied to calculate the expected number of cancers, standardised incidence ratios for age and time trend (O/E) were computed. A total of 3,928 cases of cancer were observed compared to 2,835.8 expected (O/E, 1.39; 95%-CI, 1.34-1.43). Significantly elevated risk of cancers was seen for cancer sites such as the buccal cavity, the digestive organs, the respiratory system and the urinary system. Members of the cohort were at a slightly but highly significant increased risk of both colon cancer (O/E, 1.26; 1.11-1.42) and rectum cancer (O/E, 1.31; 1.14-1.49). Our study shows that a high beer consumption is related to increased risk of several specific cancers, which supports that the relationship is of a causal nature.
(c) 2005 Wiley-Liss, Inc.