Crop History

Since World War II, global production of rapeseed and canola has grown dramatically. During WWII, inedible rapeseed oil was used as a high-temperature lubricant on steam ships, but with the switch to diesel engines in the following decade, industrial demand declined. Initially, consumer demand for rapeseed oil was negligible because it naturally contains high amounts of erucic acid. Erucic acid was enough of a concern that in 1956, the U.S. Food and Drug Administration (FDA) banned rapeseed oil for human consumption. In addition, demand for rapeseed meal was low because of high levels of glucosinolates, a compound that at high doses depresses animal growth rates.

http://www.ers.usda.gov/topics/crops/soybeans-oil-crops/canola.aspx