In vivo animal and human cells indicate that CLA may protect against prostate, mammary and colon cancer. In one impressive study researchers induced experimental mammary cancer in rats. They then fed the animals either high CLA butter fat or a free fatty acid mixture of CLA isomers (typical of that found in supplemental CLA) during the time of pubescent mammary gland development. Only 53% of the animals given CLA, both in the form of butter and free fatty acids, developed mammary tumors compared to 93% of controls!

The researchers concluded that CLA could be beneficial in reducing the risk of breast cancer. According to Dale Bauman, one of the lead authors of this study, 'Most dietary substances exhibiting anti-carcinogenic activity are of plant origin and are only present at trace levels. However, CLA is found almost exclusively in animal products and is among the most potent of all naturally occurring anti-carcinogens.' In another study of animals with experimental breast cancer, the spread of the tumors was inhibited in proportion with increasing concentrations of dietary CLA. CLA was nearly as effective as indomethacin, a pharmaceutical suppressor of tumor growth and metastasis.

Conjugated linoleic acid has been shown to inhibit ACF, a biomarker of colon cancer, in rats.

In another study involving prostate cancer, immunodefecient mice were injected with human prostate cancer cells. Mice fed a CLA enhanced diet had smaller tumors and a reduction in metastases.


Gene C.