Dr. Fred Kummerow warned against synthetic trans fats in the 1950s. Eventually, in 2013 (at 98) he personally sued the FDA to ban synthetic trans fats. Both Dr. Kummerow (a research scientist studying fat metabolism) and Dr. Mary Enig (another research scientist studying fat metabolism) were harsh critics for years and showed there was no sound evidence to demonize dietary saturated fats. Dr. Enig was vilified and had her research funding cut for going against dogma. Both have since been vindicated, as several recent studies have shown dietary saturated fat is benign with regard to cardiovascular disease, contrary to last century's dogma.

The trans fats in dairy and ruminant fat have the trans bonds in biologically appropriate locations. Conjugated linoleic acid (CLA) in particular has been shown to have numerous health benefits. Mammals, including humans, produce CLA in the mammary glands. Synthetic trans fats have trans bonds at random locations along the carbon chain.