Could Wine Save Your Knees?
Saturday, March 14, 2015 01:44 PM

Regular wine drinkers are less likely to develop knee osteoarthritis (OA), but the risk of OA increases among those who drank beer, suggests British researchers.

Compared with individuals who never drank wine, the odds ratios for knee OA were 0.55 among those who drank four to six glasses per week and 0.48 for those who consumed seven or more, but for beer drinkers, the odds ratios for knee OA were 1.76 for those who drank eight to 19 half-pints per week and 1.93 for those drinking 20 or more half-pints.

These contrasting results for wine and beer suggest "that alcohol itself is not necessarily the factor that influences the risk of OA but that other factors contained within wine and beer may exert differential effects on the risk of OA," researchers observed.

Most interest in modifying risk for OA to date has focused on the biochemical and mechanical effects of adiposity, and little research has focused on the role of individual foods and nutrients. A few studies have looked at alcohol consumption as a risk factor, but the results have been inconclusive.  They noted that several explanations have been proposed for why individual beverages might influence OA risk.  "Recent in vivo experiments using human fecal samples have shown regular moderate consumption of red wine polyphenols to inhibit nonbeneficial bacteria from human microbiota and significantly increase the growth of select beneficial bacteria such as bifidobacteria." 

In addition, obesity can be associated with increased permeability of the intestinal mucosa, and these intestinal factors in combination with the high levels of inflammation seen in obese individuals could contribute to disease pathogenesis and progression, according to the authors.

A further factor could be chondroprotection exerted by resveratrol, a polyphenol found in red wine.  "Therefore, the inverse association between wine and OA observed in this study may be partly explained by potential beneficial antioxidant activity and favorable modification of gut microbiota conferred by dietary polyphenols in wine," the authors suggested.

As to why beer drinking might be associated with an increased risk for OA, they noted that beer has been linked with elevated serum uric acid, which in turn has been linked with worse knee OA.  "Furthermore, many people who drink beer end up with a 'beer belly,' which might increase the risk of OA via biomechanical loading to the weight bearing joints," they wrote.