Re: Dietary omega-3 polyunsaturated fatty acidspromote colon carcinoma metastasi

[Guest guest]

Here's a 2005 study that contradicts the 1998 study:

Effects of a flaxseed mixture and plant oils rich in alpha-linolenic

acid on the adenoma formation in multiple intestinal neoplasia (Min) mice.

Oikarinen SI, Pajari AM, Salminen I, Heinonen SM, Adlercreutz H,

Mutanen M.

Department of Applied Chemistry and Microbiology (Nutrition), PO Box

66, FIN-00014 University of Helsinki, Finland. seija.oikarinen@...

Flaxseed is a dietary source of possible chemopreventive compounds

such as lignans and alpha-linolenic acid (ALA). To study the effects

of a flaxseed mixture on adenoma formation in multiple intestinal

neoplasia mice, the mice were fed a diet containing 2.7 % flaxseed,

4.5 % fibre and 3.7 % ALA. To elucidate the effect of oils of the

mixture we also composed a diet without flaxseed but with the same oil

composition. The median number of adenomas in the small intestine was

fifty-four for the control group, and thirty-seven (P=0.023) and

forty-two (P=0.095) for flaxseed and oil groups, respectively.

Compared with controls (1.2 mm), the adenoma size was smaller in the

flaxseed (0.9 mm; P=0.002) and oil (1.0 mm; P=0.012) groups. Both

diets changed the proportions of n-3 and n-6 fatty acids in the

colonic mucosa. Membrane beta-catenin and protein kinase C (PKC)-zeta

levels were reduced in the adenoma v. mucosa (P<0.05), and an inverse

association was found between the membrane PKC-zeta in the mucosa and

the adenoma number (r -0.460, P=0.008, n 32). Only the flaxseed diet

increased lignan levels in the caecum (P=0.002) and in plasma

(P=0.002) but they were not associated with tumour formation. The

results suggest that the preventive effect of flaxseed on colon

carcinogenesis may be due to the oil part of flaxseed, and the loss of

beta-catenin and PKC-zeta from the membranes of the mucosal tissue may

play a permissive role in intestinal tumour development.

PMID: 16197574 [PubMed - indexed for MEDLINE]

http://snipurl.com/t6kr