Does polyphenol supplementation improve Crohn's symptoms?

Polyphenol from Wikipedia

Antioxidant effect of polyphenols and natural phenols from Wikipedia

"Polyphenol Supplementation as a Complementary Medicinal Approach to Treating Inflammatory Bowel Disease" in Current Medicinal Chemistry (2011)
"Polyphenols have been acknowledged to be anti-oxidant and anti-inflammatory and therefore, have been proposed as an alternative natural approach to prevent or treat chronic inflammatory diseases. Most studies have been in animal models of colitis, using chemical inducers or mice defective in anti-inflammatory mediators and in intestinal cell lines treated with pro-inflammatory cytokines or lipid oxidation products.
These studies provide evidence that polyphenols can effectively modulate intestinal inflammation. They exert their effects by modulating cell signaling pathways, mainly activated in response to oxidative and inflammatory stimuli, and NF-kB is the principal downstream effector. Polyphenols may thus be considered able to prevent or delay the progression of IBD, especially because they reach higher concentrations in the gut than in other tissues. However, knowledge of the use of polyphenols in managing human IBD is still scanty, and further clinical studies should afford more solid evidence of their beneficial effects."

"Use of dietary phenols to modulate inflammatory bowel response" in Gastroenterol Hepatol (2010)

"Crohn's disease and ulcerative colitis are two forms of inflammatory bowel disease (IBD). Genetic and environmental factors influencing the onset and course of this disease have recently been identified. Among the environmental and dietary factors involved in the development of inflammatory colon diseases, dietary polyphenols have been proposed as protective agents in distinct models of colon inflammation. However, despite the huge number of studies on the beneficial effects of polyphenols on health, their dietary effectiveness is unclear. In this review, we examine some of the evidence linking dietary polyphenol intake with protection against IBD."