The anticarcinogenic conjugated fatty acid c9, t11-c18:2, or rumenic acid, in human milk: amounts and effects.

The conjugated linoleic acid (CLA) c9, t11-C18:2 has been detected in human milk by gas-liquid chromotography (GLC) using standards for tentative identification. The amounts found were: 5.5 mg/g fat, Australia, 1988; and 3.6 mg/g fat, Idaho, 1997. We also employed GLC and standards and confirmed the identity of coeluting peaks by mass spectrometry. Our values were 1.8+/-0.02 mg/g fat. CLA inhibits growth of several cancers, is antiatherosclerotic, partially overcomes catabolic responses to endotoxin injection, enhances weight gain and improves feed efficiency in rats, and modulates immune response and bone deposition. The dietary sources are ruminant-derived foods, particularly aged cheese.