CLA refers to a family of 8 geometric isomers of linoleic acid in which the two double bonds are contiguous. 9(E),11(E)-CLA is the 9,11 all-trans isomer of linoleic acid. CLA was originally identified in ground beef, but it is also present in a variety of dairy products. CLA is effective at reducing mammary tumors in rats at levels as low as 0.1% by weight of their diet.{1568}