Objectives We examine the prospective association of soft drink consumption with radiographic progression of knee osteoarthritis (OA).

Design Prospective cohort study.

Setting This study used data from the osteoarthritis initiative (OAI).

Participants In OAI, 2149 participants with radiographic knee OA and having dietary data at baseline were followed up to 12, 24, 36 and 48 months.

Measures The soft drink consumption was assessed with a Block Brief Food Frequency Questionnaire completed at baseline. To evaluate knee OA progression, we used quantitative medial tibiofemoral joint space width (JSW) based on plain radiographs. The multivariate linear models for repeated measures were used to test the independent association between soft drink intake and the change in JSW over time, while adjusting for body mass index and other potential confounding factors.

Results In stratified analyses by gender, we observed a significant dose–response relationship between baseline soft drink intake and adjusted mean change of JSW in men. With increasing levels of soft drink intake (none, ≤1, 2–4 and ≥5 times/week), the mean decreases of JSW were 0.31, 0.39, 0.34 and 0.60 mm, respectively. When we further stratified by obesity, a stronger dose–response relationship was found in non-obese men. In obese men, only the highest soft drink level (≥5 times/week) was associated with increased change in JSW compared with no use. In women, no significant association was observed.

Conclusions Our results suggest that frequent consumption of soft drinks may be associated with increased OA progression in men. Replication of these novel findings in other studies demonstrating the reduction in soft drink consumption leads to delay in OA progression is needed.