Are there are any nutrients or supplements with good/ strong evidence for improving joint health? Most I find seem to have only a neutral or small positive impact (despite some places making very big claims, which seem unfounded; like collagen for example, where the evidence on it doing anything seems weak?).
In SNP16 Alan uses the term "causal risk factor" a couple of times. Knowing how precise you guys are with language, inclusion of "causal" has got to be deliberate here. Can you please enlighten a newbie as to what specifically a "causal" risk factor is, and how that differs from other nutritional risk factors, if at all? Thanks.