Missing anti-proliferative effect of fish oil on rectal epithelium in healthy volunteers consuming a high-fat diet: potential role of the n-3:n-6 fatty acid ratio
Bartram, H.P.; Gostner, A.; Reddy, B.S.; Rao, C.V.; Scheppach, W.; Dusel, G.; Richter, A.; Richter, F.; Kasper, H.
European Journal of Cancer Prevention the Official Journal of the European Cancer Prevention Organisation 4(3): 231-237
1995
ISSN/ISBN: 0959-8278 PMID: 7647691 Document Number: 442663
Rectal cell proliferation as an intermediate biomarker of cancer risk was shown to be reduced by dietary fish oil (FO) in patients with adenomatous polyps and healthy subjects consuming a low-fat diet. Because the synthesis of prostaglandins (PG) which seem to be involved in this process is dependent on the ratio of n-3:n-6 fatty acids in the diet, this study was designed to investigate whether this FO effect is also detectable in subjects eating a high-fat diet (50% of energy) with a low n-3:n-6 ratio of 0.25. 12 healthy subjects (23 to 30 years old) received in addition to a basal diet FO (4.4 g n-3 fatty acids/day) or maize oil supplements (double-blind, crossover) for two 4-week periods. No significant differences between the 2 study periods were found for rectal cell proliferation as assessed by bromodeoxyuridine immunohistochemistry and ornithine decarboxylase activity, as well as for mucosal PGE2 release and mucosal membrane fatty acid composition. The results emphasize the importance of dietary n-3:n-6 ratio in determining the effects of FO on rectal cell proliferation.