News - How sugary drinks can give you sore knees (especially if you're a skinny man)
View the Mail OnLine article here
One of the most frequently asked questions I get from patients who seek my help with conditions such as arthritis involving either painful knees or hips is about diet. I get asked if changing the diet would improve their quality of life, reduce pain and reduce the effects of the condition. My answer has always been a consistent 'I do not know, you would be better off asking for the views of a dietician'. This answer has always been based upon the fact that not much is really known about the effects of diet on degenerative conditions and most reported anecdotal evidence has not been clinically significant enough to consider it workable for all patients. Importantly, discussions about diet are outside my remit as a Physiotherapist.
The research reported in this newspaper article is exciting. However, without knowing much more about the methodology of the study there are too many questions about what the news item is actually trying to suggest. I suppose that one of the main questions is; did the item consider if skinny men showed more degenerative change because they may have been more active than other men of different physical build. The item does report that the authors made allowance for other factors such as BMI but I feel that there may be some confusion about one of their presumed possible causes for the link. Although the title of the item suggests fizzy drinks are more harmful in skinny men, they say that this may be because of the increase weight the knees carry due to the high calorific content of the drinks. So if adjustments were made for the BMI at what point did the BMI become significant enough within this group on individuals and how was this reflected within their conclusions? Furthermore, mechanical pain caused by joints requires movement. Degenerative change (unless it is going through an active phase) may not cause pain during movement. It would be great to know if the research took this into consideration too! Especially when they thought about how the results would be measured. The news item only reports measurement of the joint space and not pain. Most patients with OA consider how much pain they are in or how much their quality of life is reduced as a measure of how bad their arthritis has got. Indeed this appears to be reflected in the lead title of the article. Also why was there a difference between sexes? OA is not gender specific by affecting either male more than females or vice versa.
Many people suffer intolerable pain from this condition and I believe that unless we are absolutely sure about the cause for the effects of clinical presentation there is the risk that the message from news items may be misunderstood by patients desperate for answers. If fizzy drinks and other dietary requirements have an influence on health we need to be absolutely sure about how the information is presented and how any caveats are qualified. We owe it to patients and future researchers alike.
© Dr A. A. Aluko, November 2012
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