Polyphenols are a diverse group of naturally occurring compounds found in plants, such as flavonoids, phenolic acids, and stilbenes. Scientific evidence suggests that polyphenols may support joint health, primarily due to their anti-inflammatory and antioxidant properties. Chronic inflammation is a key factor in the progression of joint disorders like osteoarthritis and rheumatoid arthritis. Polyphenols, such as those found in green tea (epigallocatechin gallate, EGCG), turmeric (curcumin), and resveratrol (from grapes), have demonstrated the ability to inhibit inflammatory pathways (e.g., NF-κB signaling) and reduce the production of pro-inflammatory cytokines in both in vitro and animal studies.

Several small clinical trials have explored the effects of specific polyphenols on joint pain and function, with some showing modest improvements in pain and mobility for individuals with osteoarthritis. For example, curcumin supplementation has been associated with reduced joint pain and stiffness in randomized controlled trials. However, the majority of human studies are limited by small sample sizes, short durations, and heterogeneity in formulations and dosages.

Overall, while there is promising scientific evidence—particularly from preclinical and some clinical studies—supporting the use of certain polyphenols for joint health, more high-quality, large-scale clinical trials are needed to confirm their efficacy and establish optimal dosing.