Marine fish oil is more potent than plant-based n-3 polyunsaturated fatty acids in the prevention of mammary tumors

• Published in: The Journal of nutritional biochemistry Vol. 55; pp. 41 - 52
• Main Authors: Liu, Jiajie, Abdelmagid, Salma A., Pinelli, Christopher J., Monk, Jennifer M., Liddle, Danyelle M., Hillyer, Lyn M., Hucik, Barbora, Silva, Anjali, Subedi, Sanjeena, Wood, Geoffrey A., Robinson, Lindsay E., Muller, William J., Ma, David W.L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2018
• Subjects: Breast cancer; Fatty acid composition; Human epidermal growth factor receptor 2; Mammary tumor development; n-3 PUFA; Fatty acid composition; Breast cancer; n-3 PUFA; Human epidermal growth factor receptor 2; Mammary tumor development
• ISSN: 0955-2863; 1873-4847
• DOI: 10.1016/j.jnutbio.2017.12.011

Marine-derived n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been shown to inhibit mammary carcinogenesis. However, evidence regarding plant-based α-linolenic acid (ALA), the major n-3 PUFA in the Western diet, remains equivocal. The objective of this study was to examine the effect of lifelong exposure to plant- or marine-derived n-3 PUFAs on pubertal mammary gland and tumor development in MMTV-neu(ndl)-YD5 mice. It is hypothesized that lifelong exposure to n-3 PUFA reduces terminal end buds during puberty leading to delayed tumor onset, volume and multiplicity. It is further hypothesized that plant-derived n-3 PUFAs will exert dose-dependent effects. Harems of MMTV-FVB males were bred with wild-type females and fed either a (1) 10% safflower (10% SF, n-6 PUFA, control), (2) 10% flaxseed (10% FS), (3) 7% safflower plus 3% flaxseed (3% FS) or (4) 7% safflower plus 3% menhaden (3% FO) diet. Female offspring were maintained on parental diets. Compared to SF, 10% FS and 3% FO reduced (P<.05) terminal end buds at 6 weeks and tumor volume and multiplicity at 20 weeks. A dose-dependent reduction of tumor volume and multiplicity was observed in mice fed 3% and 10% FS. Antitumorigenic effects were associated with altered HER2, pHER-2, pAkt and Ki-67 protein expression. Compared to 10% SF, 3% FO significantly down-regulated expression of genes involved in eicosanoid synthesis and inflammation. From this, it can be estimated that ALA was 1/8 as potent as EPA+DHA. Thus, marine-derived n-3 PUFAs have greater potency versus plant-based n-3 PUFAs.