EFFECTS OF DIFFERENT DOSES OF FISH-OIL ON RECTAL CELL-PROLIFERATION IN PATIENTS WITH SPORADIC COLONIC ADENOMAS

Background/Aims: Fish oil supplementation can reduce cytokinetic anoma lies in the flat rectal mucosa of patients with sporadic colorectal ad enoma. This study attempted to identify an optimum dose for fish oil s upplementation and evaluate the persistence of its effects during long -term administration. Methods: In a double-blind study, 60 patients wi th sporadic adenomas received 2.5, 5.1, or 7.7 g of fish oil per day o r placebo for 30 days. [H-3]thymidine autoradiographic labeling indice s were calculated in flat rectal mucosal biopsy specimens collected be fore and after supplementation. In a subsequent study, 15 patients wit h polyps received 2.5 g of fish oil per day. Proliferative parameters, mucosal fatty acids, and mucosal and plasma alpha-tocopherol levels w ere evaluated before, during, and after 6 months of supplementation. R esults: Mean proliferative indices and mucosal arachidonic acid levels decreased significantly (and to similar degrees) in all treated group s, whereas mucosal eicosapentaenoic and docosahexaenoic acid levels in creased. Significantly reduced proliferation was observed only in pati ents with abnormal baseline patterns. These effects persisted during l ong-term, low-dose treatment. A transient reduction in mucosal (but no t plasma) alpha-tocopherol levels was observed after 1 month of treatm ent. Side effects were insignificant. Conclusions: Low-dose fish oil s upplementation has short-term and long-term normalizing effects on the abnormal rectal proliferation patterns associated with increased colo n cancer risk.