It’s tough to be a soft drink lover these days. You’ve got cities such as New York banning jumbo-sized servings of them, and scientific studies linking them with high blood pressure and stroke. Then of course there is their role in obesity, which is itself a factor in many other diseases such as diabetes. And now there is new research that indicates that if you’re a man who, like nearly 20% of men in America, suffers from osteoarthritis of the knee, your love of sugary soft drinks may be making the condition worse.
Knee osteoarthritis may seem like a minor problem compared to heart attack, stroke, and diabetes, but according to the Centers for Disease Control and Prevention, it is so widespread that as many as 50% of Americans may eventually develop it. It can be caused by stress to the knee joints, by injuries, by heredity, or by aging, but whatever the cause, it manifests the same way – stiffness and swelling of the knee joints, pain that increases with activity and subsides with rest, decreased mobility, and occasionally creaking or grating noises when you move your knee. The actual physical cause of knee osteoarthritis is detectable in X-rays, an erosion or wearing away of the cartilage surface that provides a cushion between the bones of the knee. The severity of your osteoarthritis is clearly revealed in the X-rays; the more narrow the space between the joints of the knees, the more severe it is.
What the new study found
Curious as to the effect of diet on this condition, researchers from Brown University in Providence, RI and Tufts Medical Center and Brigham and Women’s Hospital in Boston, MA followed the medical progress of 2,149 male and female patients suffering from osteoarthritis of the knee. They conducted dietary surveys to determine what the patients regularly ate and drank, and compared them to the progressive degeneration from the disease that they saw in X-rays taken every year of their four-year study.
What they found was that in patients – especially men – who drank high-calorie sugary soft drinks, there was evidence that their osteoarthritis was getting worse. Men who consumed more than five soft drinks a week exhibited twice as much narrowing of the joint space as men who did not consume these drinks, an average of 0.59 millimeters. Interestingly enough, no such link was found in the women patients in the study.
Doctor Bing Lu, assistant professor at Harvard Medical School and one of the researchers in the study, says, “Our main finding is that in general, the more sugary soda men drink, the greater the risk that knee osteoarthritis will get worse.”
Could factors other than the soft drinks cause this?
Naturally, this was one of the first things that the researchers considered, and examined. One known risk factor for osteoarthritis of the knee, after all, is obesity, and soft drinks have been linked to obesity. So to rule this out, all study participants were weighed and had their body mass index (BMI) measured before the statistical analysis of their findings was undertaken. When the men in the study were divided into categories of obese and non-obese, the surprise was that the association between the sugary soft drinks and worsening of the men’s osteoarthritis still appeared, and only in the men who were non-obese. This suggests to the researchers that the worsening damage to the knee joints was not as a result of being obese, and having to support excess weight.
Dr. Lu feels so strongly about the strength of their study and its findings that when asked what a man with osteoarthritis of the knee but who really loves his soft drinks should do, he says, “There’s an easy answer. Just don’t drink soda.” Other medical experts are not so sure, and point out that this study does not conclusively prove cause and effect, but all agree that cutting down on sugary soft drinks is a good idea for many reasons, this being only the latest.
As they did when studies linking sugary colas to increased blood pressure and heart attack risk appeared, the American Beverage Association takes issue with what they called the study’s “novel findings.” They point out – correctly – that these are only preliminary findings, and that further research is necessary. Then again, this is the industry that removed a carcinogenic ingredient from its cola products only after the Food and Drug Administration threatened to require them to put a cancer warning label on each can. We are, after all, talking about a 100 billion dollar per year business.
Me, I’m more concerned about my health than their “bottom line,” so I have stopped drinking soft drinks, and feel much, much better as a result. That’s mere anecdotal evidence, not scientific evidence, but it sure works for me.