Polyphenols are a diverse group of naturally occurring compounds found in plants, known for their antioxidant and anti-inflammatory properties. Scientific research has investigated the potential benefits of polyphenols in supporting kidney health, particularly in the context of chronic kidney disease (CKD) and protection against renal injury. Some polyphenols, such as resveratrol (found in grapes), epigallocatechin gallate (EGCG, found in green tea), and curcumin (from turmeric), have demonstrated nephroprotective effects in preclinical studies, including animal models and limited human trials. These effects are thought to be mediated by the ability of polyphenols to reduce oxidative stress, modulate inflammatory pathways, and inhibit fibrotic processes in kidney tissues.

However, the evidence base is still emerging. While laboratory and animal studies are promising, robust clinical trials in humans are limited and results are sometimes inconsistent. Polyphenols are not part of conventional kidney disease treatment protocols, and their use as a primary therapy is not widely endorsed by nephrology guidelines. Nonetheless, there is scientific rationale and some preliminary evidence suggesting they may be supportive as part of a dietary pattern rich in plant-based foods. More research is needed to clarify optimal sources, doses, and long-term safety in those with compromised kidney function.