The findings, which appear online in the Annals of the Rheumatic Disease ahead of print, focus on two population-based case-control studies from Sweden and Denmark looking at the environmental and genetic risk factors behind the disease. Head researcher Henrik Källberg of the Karolinska Institute in Stockholm, Sweden, said the research highlighted the impacts that modifiable lifestyle factors can have on our health when consumed at sensible levels. "The main message remains that cessation of smoking is the most effective way to diminish the risk of RA, irrespective of genetic constitution," he stated. "But this recommendation should not necessarily be combined with a recommendation to stop moderate alcohol consumption." According to the research, both studies found a link between higher alcohol consumption and a dose-dependent reduction in the risk of contracting RA. The affects of the wider detrimental impacts on human health from alcohol consumption were not focused on in the studies. Of the participants tested in the studies, the quarter found to more regularly consume alcohol were 40 to 50 per cent less likely to develop RA over participants with a lower intake, the findings stated. Of the two studies, the Sweden-based Epidemiological Investigation of Rheumatoid Arthritis (EIRA) test suggested that the link between drink and RA risk was the same both in male and female participants. However, in the smaller Danish Case-Control Study on Rheumatoid Arthritis (CACORA) test the inverse link between alcohol consumption and RA risk was to be significant only when the presence of peptide antibodies (ACPA) were found, researchers said. ACPA is believed to be an indicator of RA. Method In conducting the EIRA test, 1419 cases of RA were studied in patients between 18 and 70 from 19 clinics situated in Mid and Southern Sweden from May 1996 until December 2003. All the patients tested had been diagnosed by rheumatologists. A further 1674 control cases were randomly selected for the study from the general population to match the age, sex and residential areas of the RA cases, the researchers said. The CACORA study looked at 515 prevalent cases of RA and 769 controls recruited between August 1998 and July 2003. EIRA study The information compiled by the Sweden-based study was based on an self-administered questionnaire handed to patients shortly after being diagnosed with RA. Patients and control subjects were each asked to produce blood samples, researchers said. In terms of participation rates, 96 per cent of case studies and 82 per cent of controls completed questionnaires. "Concomitant genetic and questionnaire information on alcohol and smoking was obtained for 1204 cases - 879 female and 325 male - and 871 controls - 645 female and 226 male," the researchers said. CACORA study The Danish testing used a structured telephone interview to ascertain the environmental exposures of its participants. They were also required to supply a blood sample for genotyping and serological analysis as conditions of the study. Patients were additionally sub grouped into whether they were ACPA-positive or negative. Participation for the testing was 83 per cent in terms of cases and 64 per cent for controls. Combined genetic and questionnaire information was supplied by 444 case subjects - 312 female, 132 male - and 533 control participants - 327 female, 206 male, researchers said. Source: Annals of the Rheumatic Diseasedoi:10.1136/ard.2007.086314 1 "Alcohol consumption is associated with decreased risk of rheumatoid arthritis: results from two Scandinavian case-control studies"Authors: H Källberg, S Jacobsen, C Bengtsson, et al.