Dietary purified cis-9,trans-11 conjugated linoleic acid isomer has anticarcinogenic properties in chemically induced mammary tumors in rats.

To determine whether the purified 9c,11t conjugated linoleic acid (CLA) isomer, the main dietary isomer, is biologically active on mammary tumor growth, we carried out a dietary intervention study designed to compare its effects with those of a mixture of CLA isomers on the incidence and growth of autochthonous mammary tumors induced by methylnitrosourea in rats. After the initiation step, rats were fed a sunflower oil-based diet (5%) and separated into three experimental groups supplemented with either a 1% homemade synthesized 9c,11t isomer, a 1% CLA isomer mixture, or free fatty acids prepared from sunflower oil for the control group. We found that, in the two CLA groups compared with the control group, CLA levels were about 30 times higher in mammary fat pads and about 10 times higher in tumor tissues.

Effect of an alpha-linolenic acid-rich diet on rat mammary tumor growth depends on the dietary oxidative status.

To investigate whether the oxidative status of an 18:3(n-3) polyunsaturated fatty acid (PUFA)-enriched diet could modulate the growth of chemically induced rat mammary tumors, three independent experiments were performed. Experiments I and II examined the variation of tumor growth by addition of antioxidant (vitamin E) or a prooxidant system (sodium ascorbate/2-methyl-1,4-naphthoquinone) to a 15% linseed oil diet rich in 18:3(n-3). Experiment III addressed the role of PUFA in the tumor growth modulation by vitamin E.

Low alpha-linolenic acid content of adipose breast tissue is associated with an increased risk of breast cancer.

Data derived from experimental studies suggest that alpha-linolenic acid may have a protective effect in breast cancer. Observations obtained from epidemiological studies have not allowed conclusions to be drawn about a potential protective effect of dietary alpha-linolenic acid on breast cancer, possibly because of methodological issues. This case-control study conducted in an homogeneous population from a central area in France was designed to explore the hypothesis that alpha-linolenic acid inhibits breast cancer, using fatty acid levels in adipose breast tissue as a biomarker of past qualitative dietary intake of fatty acids.