A literature review on plant-based foods and dietary quality in knee osteoarthritis.

This literature review summarizes the role of plant-based foods and diet quality in osteoarthritis, particularly knee osteoarthritis, in observational studies and clinical trials published during 2015- 2020. The included studies have suggested favorable results on reducing the prevalence, pain, and cartilage changes related to osteoarthritis and inflammatory and oxidation markers such as inter- leukin-1, interleukin-6, tumor necrosis factor, and lipid peroxidation. Due to the lack of large longitudinal cohorts to study whole foods or diets concerning knee osteoarthritis, findings from the cross-sectional studies or clinical trials require further validation, particularly in well-designed clinical trials and a more extended follow-up period. Potential mechanisms on the role of plant-based foods in body weight, inflammation, and microbiome were explored to explain their protective associations with osteoarthritis. However, most evidence examining the relationship between the microbiome and osteoarthritis joint pain is conducted in preclinical animal studies, and few observational studies show a positive association between Streptococcus species and local joint inflammation in the knee. Given the close links of plant-based foods on obesity, inflammation, and microbiome, data on the role of whole foods or diets in the change in knee osteoarthritis pain through the lens of microbial composition can provide more certainty regarding the utilization of microbiome as a potential therapeutic target.