The consumption of sugary soft drinks has become widespread in our culture, so much so that sweetened sodas and juices are a ubiquitous part of the American diet. The increased number of calories, however, can have a negative impact on our health, increasing our risk for obesity while also contributing to tooth decay.

Now researchers have found that consumption of sugar-sweetened soft drinks may also be a factor in the onset of knee osteoarthritis (OA), particularly in men. Knee OA is a problem that stems from the breakdown of the cartilage in the knee joint. There are several risk factors that increase a person's chances of developing the condition, including obesity, age, injury, and constant stress on the joint.

To arrive at their findings, doctors looked at over 2,100 men and women who were part of a large multi-center OA study. Initial OA status was determined by X-ray analysis, and baseline sugar-sweetened beverage (not including sugar-free drinks) consumption was noted at the beginning of the program. Researchers then took follow-up OA measurements at 12, 24, 36, and 48 months. OA progression was measured by the change in the joint space of the medial knee compartments, with a decrease indicating progression of OA. Body mass index (BMI) was also measured separately.

What they found was that, after controlling for BMI and other risk factors, men who regularly consumed greater quantities of soft drinks each week had greater knee progression to OA. In fact, men who drank five or more soft drinks per week experienced twice as much shrinkage of the joint space compared to men who drank no soft drinks (0.59 millimeters versus 0.29 millimeters, respectively). Men with lower BMI scores (less than 27.5 kg/m2) showed greater OA progression than men with higher BMI scores. For women, only those with the lowest BMI scores showed any association between soft drink consumption and OA progression.

The authors of the study stress that more work needs to be done, because it is not clear whether sugary soft drinks increase the weight burden on the knees, or if some ingredient in the beverages contributes to OA progression. However, they do suggest that soft drink consumption appears to add to the problem, and that the findings may offer a modifiable dietary risk factor that could have significant public health implications in terms of a what constitutes a healthy diet.

Knee OA is a common physical malady in this country. The condition affects millions of Americans each year, and it is estimated that one in two people will come down with knee OA by the age of 85 years.

If you have joint pain or think you may be suffering from OA, consult with your doctor. For more information, visit the website for the Center for Disease Control and Prevention (CDC).