Background: The determinants and biologic significance of IgE-mediated sensitization to cross-reactive carbohydrate determinants (CCDs) are not entirely known. An association between alcohol consumption and CCD sensitization has been reported in studies from Spain and Portugal. Objective: To investigate the relationship of alcohol consumption with CCD sensitization, the role of alcohol dehydrogenase gene polymorphisms, and the clinical consequences of CCD sensitization. Methods: Serum-specific IgE sensitization (≧0.1 kU/l) to a CCD (the N-glycan from bromelain) was assessed in 1,197 adults participating in a population-based study in Copenhagen, Denmark. Alcohol consumption and atopic symptoms (rhinitis, asthma and oral allergy syndrome) were assessed by questionnaire. Examinations included skin prick tests (SPTs), qualitative multiallergen IgE test (Phadiatop®), methacholine bronchial hyperreactivity, eosinophil cationic protein and alcohol dehydrogenase (ADH) gene polymorphisms. Results: Alcohol consumption was significantly associated with CCD sensitization and this was particularly evident in SPT-negative individuals. The fast-metabolizing allele of the ADH1b polymorphism was significantly associated with CCD sensitization in alcohol drinkers. CCD sensitization was associated with atopic symptoms, but associations attenuated markedly when adjusting for SPT reactivity. Conclusions: Our results suggest that the positive association between alcohol consumption and CCD sensitization is universal and not specific to certain populations. The observed association between the ADH1b polymorphism and CCD sensitization may support that alcohol is causally related to the risk of CCD sensitization. The observed association between CCD sensitization and atopic phenotypes did not appear to be independent of SPT reactivity indicating limited significance of CCD sensitization per se.