Newswise — WASHINGTON – Sugary soft drink consumption contributes not only to weight gain, but also may play a role in the progression of knee osteoarthritis, especially in men, according to new research findings presented this week at the American College of Rheumatology Annual Meeting in Washington, D.C.

Knee osteoarthritis is caused by cartilage breakdown in the knee joint. Factors that increase the risk of knee osteoarthritis include obesity, age, prior injury to the knee, extreme stress to the joints, and family history. In 2005, 27 million Americans suffered from osteoarthritis, and one in two people will have symptomatic knee arthritis by age 85.

Researchers at Brigham and Women’s Hospital and Tufts Medical Center in Boston, and Brown University in Providence, R.I., looked at data on 2,149 participants in a multicenter osteoarthritis study. Participants were determined to have knee OA by X-ray. At the beginning of the study, each participant’s soft-drink consumption, not including sugar-free drinks was measured using a Food Frequency Questionnaire. The researcher followed up with the participants 12, 24, 36 and 48 months later to track their OA progression as measured by joint space change in their medial knee compartments. Body mass index (also called BMI) was also measured and tracked and data for men and women were analyzed separately.

After controlling for BMI and other factors that may contribute to knee OA, men who consumed more soft drinks per week had worse knee OA progression. The joint space became narrower by an average of 0.29 millimeters in men who drank no soft drinks to 0.59 millimeters in men who drank more than five soft drinks a week. Interestingly, men with lower BMI, less than 27.5 kg/m2, showed more knee OA progression with increased soft-drink consumption than men who had higher BMI scores. By contrast, only women in the lowest BMI segment of the study, less than 27.3kg/m2, showed an association between more soft-drink consumption and knee OA progression.

The researchers concluded that men who drink progressively more soft drinks each week may see their knee OA worsen progressively as well. "Little is known about the course of disability over time in patients with osteoarthritis,” says Bing Lu, MD, DrPh, the lead investigator in the study. “This study may offer the potential to identify a modifiable dietary risk factor for disease progression, enable evaluation of prevailing recommendations of healthy diet, and thus have potential public health implications."

It is unclear whether this problem is due to high-calorie soft drinks leading to excess weight burdening knees, or if there are other ingredients in soft drinks that contribute to OA progression.

Funding for this study was provided by the National Institutes of Health. Private funding partners include Pfizer, Inc.; Novartis Pharmaceuticals Corporation; Merck Research Laboratories; and GlaxoSmithKline.

The American College of Rheumatology is an international professional medical society that represents more than 9,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Meeting is the premier meeting in rheumatology. For more information about the meeting, visit or join the conversation on Twitter by using the official hashtag: #ACR2012.

Learn more about living well with rheumatic disease as well as rheumatologists and the role they play in health care. Also, discover the ACR’s Simple Tasks campaign, which highlights the severity of rheumatic diseases and the importance of early and appropriate referral to a rheumatologist.

Editor’s Notes: Bing Lu, MD, DrPH will present this research during the ACR Annual Meeting the Walter E. Washington Convention Center at 3:30 PM on Sunday, November 11 in Room 202 B. Dr. Lu will be available for media questions and briefing at 1:30 PM on Tuesday, November 13 in the on-site press conference room, Room 203 A–B.

Presentation Number: 745

Soft Drink Intake and Progression of Radiographic Knee Osteoarthritis: Data From the Osteoarthritis Initiative

Bing Lu (Brigham and Women's Hospital, Boston, Mass.)Jeffrey Driban, Tim McAlindon (Tufts Medical Center, Boston, Mass.)Charles Eaton (Warren Alpert Medical School at Brown University, Providence, R.I.)

Background/Purpose: Soft drink consumption has been associated with weight gain and obesity which is a significant risk factor of osteoarthritis (OA), but its role in the progression of OA is unclear. We examine the prospective association of soft drink consumption with radiographic progression of OA.

Methods: In the Osteoarthritis Initiative (OAI), 2149 participants (3066 knees) with radiographic knee OA and having dietary data at baseline were followed up to 12, 24, 36 and 48 months. The frequency of soft drink (not including diet drinks) consumption was assessed with a Block Brief Food Frequency Questionnaire that was completed at baseline. To measure the OA progression, we used the change of a precise quantitative joint space width (JSW) in medial compartment over time between the adjacent bones of the knee 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 (BMI) and baseline disease severity and potential confounding factors.

Results: In stratified analyses by gender, we observed a significant dose-response relationship between soft drink intake and adjusted mean changes of JSW in men (p trend<0.001) after controlling for BMI and potential confounding factors. With increasing levels of soft drink intake, the mean changes in JSW were 0.29mm, 0.39mm, 0.36mm and 0.59mm respectively. When we further stratified by BMI tertiles, stronger dose-response relationship was found (changes in JSW were 0.21mm, 0.38mm, 0.40mm, 0.75mm respectively) in the lowest BMI tertile (BMI<27.5 kg/m2). In men with BMI ≥27.5 kg/m2, only highest soft drink level (≥5 times/week) was associated with increased JSW compared to no use. By contrast in women, a significant association and dose-response relationship was only observed with the lowest BMI tertile (BMI<27.3 kg/m2, p trend <0.001).

Conclusion: 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 prospective studies demonstrating the reduction in soft drink consumption leads to delay in OA progression are needed to test this hypothesis.

Disclosure: B. Lu, None; J. Driban, None; T. McAlindon, None; C. Eaton, None.

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