Increased dietary levels of α-linoleic acid inhibit mammary tumor growth and metastasis.

ABSTRACT

OBJECTIVE: The aim of this study was to determine whether α-linolenic acid (ALA ω-3 fatty acid) enriched diet affects growth parameters when applied to a syngeneic model of mammary carcinoma. MATERIALS AND METHODS: BALB/c mice were divided and fed with 1) a chia oil diet, rich in ALA or 2) a corn oil diet, rich in linoleic acid (LA ω-6 fatty acid). Mice were subcutaneously inoculated with a tumor cell line LM3, derived from a murine mammary adenocarcinoma. RESULTS: After 35 days, tumor incidence, weight, volume and metastasis number were lower in the ALA-fed mice, while tumor latency time was higher, and the release of pro-tumor metabolites derived from ω-6 fatty acids decreased in the tumor. Compared to the control group, a lower number of mitosis, a higher number of apoptotic bodies and higher T-lymphocyte infiltration were consistently observed in the ALA group. An ALA-rich diet decreased the estrogen receptor (ER) α expression, a recognized breast cancer promotor while showing an opposite effect on ERß in tumor lysates. CONCLUSION: These data support the anticancer effect of an ALA-enriched diet, which might be used as a dietary strategy in breast cancer prevention.