Polyphenols, a diverse group of naturally occurring compounds found in plants (including flavonoids, phenolic acids, and stilbenes), have been investigated for their potential role in supporting Crohn’s Disease (CD), a type of inflammatory bowel disease (IBD). The rationale for their use is grounded in their anti-inflammatory, antioxidant, and immunomodulatory properties, which are relevant to the pathogenesis of CD, characterized by chronic intestinal inflammation and oxidative stress.

Preclinical studies (in vitro and animal models) have demonstrated that various polyphenols, such as curcumin (from turmeric), resveratrol (from grapes), and epigallocatechin gallate (from green tea), can reduce inflammatory markers and oxidative damage in models of IBD. Some small-scale human studies and pilot clinical trials have suggested that dietary supplementation with certain polyphenols could reduce disease activity or improve symptoms in patients with IBD, including Crohn’s Disease. For example, curcumin has been studied as an adjunct to conventional therapy and shown some promise in reducing disease activity indices in mild-to-moderate CD, though results are mixed and research is limited.

However, the overall evidence base remains limited, with most clinical studies being small, heterogeneous in design, and often lacking standardized dosages or formulations. There is a need for larger, well-controlled randomized trials to confirm efficacy and safety. Therefore, while there is scientific rationale and preliminary evidence, the support is moderate at best, justifying a rating of 2.