In the abstract you're right, however in this case there are actually links between eating sugar and inflammation in the body. Sugar affecting arthritis is not

In the abstract you're right, however in this case there are actually links between eating sugar and inflammation in the body. Sugar affecting arthritis is not a new concept; there's plenty of studies on the topic already out there and the relationship between sugar and cytokines in the body. I'd say that's fairly far from a placebo effect.