Resource Study shows smoking and being overweight affect RA A study in Canada has shown that being a current smoker or being overweight or obese negatively affects RA symptoms over time. Print 2017 A recent study in Canada has shown that being a current smoker or being overweight or obese negatively affects RA symptoms over time. The study used the ‘disease activity score’ (DAS) as a means of measuring the severity of disease activity in over 1,000 patients over a 3-year period. The study found that the average rate of improvement in patients’ disease activity was greater in males versus females, healthy weight versus overweight and non-smokers versus current smokers. Interestingly, people who had smoked previously but were no longer smokers also benefited from a greater improvement in disease activity over time, demonstrating the importance of trying to quit smoking for people with a diagnosis of RA. This large-scale study adds to the large body of evidence for the importance of making lifestyle changes, particularly with regards to weight and smoking for people with RA.