EPA Reduces Rectal Polyps
West, N.J. et al., Gut : in press , 2010
St. Mark’s Hospital, London, UK and Leeds Inst. of Molecular Medicine , Leeds ,UK
The present clinical study was conducted on 55 patients having a condition known as FAP (Familial Adenomatous Polyposis) which predisposes them to the development of multiple polyps (known as adenomas) and a considerably higher risk for rectal cancer.
The present study evaluated the potential for supplementation with EPA (eicosapentaenoic acid) in a free fatty acid form to offer chemopreventive efficacy in patients with FAP. One group of patients received 2 grams of EPA daily while the other group (controls) received a placebo. The number and size of the polyps and overall rectal polyp burden was assessed by endoscopic surveillance of their retained rectum postcolectomy after 6 months of daily supplementation.
The findings showed a highly significant reduction (by 22.4 %) in polyp number and a 29.8 % decrease in the sum of polyp diameters in the EPA –supplemented group. The authors concluded that EPA (as provided in the form given) has chemopreventative efficacy in FAP and that ‘EPA holds promise as a colorectal cancer chemoprevention agent with a favourable safety profile’.
This very exciting clinical study raises the possibility of a treatment efficacy using EPA in FAP patients which approaches that as reported for pharmaceutical agents (such as ‘celecoxib’) in reducing polyp number. The mechanism(s) of EPA’s action may well involve the reduced formation of the 2-series prostaglandin as formed by cyclo-oxygenase (COX) activity using AA (arachidonic acid ) as the substrate. It remains to be seen if the free fatty acid form as used herein offers any superior efficacy relative to other EPA forms (triglyceride or ethyl ester) and if EPA can act synergistically with pharmaceutical agents as compared to either when used singly. Finally, the potential efficacy of EPA in reducing rectal polyps in those without FAP is worthy of further study.