Diet Is an Independent Causal Variable in Osteoarthritis

A 2016 study by A.Yoshinori et al  divided mice into four groups. Normal loading-pattern with a normal diet (NL+ND), normal loading-pattern with a western-style diet (NL+HFD), tail-suspension with a normal diet (TS+ND) and tail-suspension with a western-style diet (TS+HFD). The model allowed the researchers to separately study the effects of diet and load on the development of osteoarthritis in the hindlimb. The most interesting finding of the study was that a western-style diet were able to cause osteoarthritis through a mechanism that was independent on mechanical load, shown by worse disease-score in TS-HFD compared to the TS+ND. They also showed that a western-style diet potentiated the effect of loading on disease-development in the NL+HFD group. These results strongly argue against osteoarthritis being a simple wear-and-tear problem, and sheds light on the fact that impaired cellular function through inflammatory pathways plays a major etiological role.