William and James lived in Ohio in the late 19th century. William manufactured soap. and James’ business was in candles. Both were frustrated by the rising cost of the main ingredient in their products – animal fat. This led to a search for a cheaper alternative, and they found it in cottonseed oil, which was mainly used to grease machinery. After experimenting with the oil, they were able to produce a solid fatty substance that looked like lard but was pure white and didn’t have any odor.
The men formed a partnership, named their product “Crisco,” and began to promote it to housewives as a modern and superior alternative to lard. William Proctor and James Gamble would go on to oversee an empire of consumer products. 
The public “bought” both the Crisco and the story that it was a big improvement over lard, but they were not aware that cotton plants are drenched in pesticides and herbicides and use many caustic chemicals in processing. 
Fast forward to the 1960s and traditional fats – lard, suet, bacon grease, palm oil – were dealt another blow.  This time the criticism came from the vegetable oil industry, which did a remarkably effective job of convincing American consumers, and countless “experts” that saturated fat was the enemy of health, and their various vegetable oils promoted good health.
Despite overwhelming evidence that vegetable oils are harmful, they still line supermarket shelves and are featured by TV chefs.  The corn oil industry was a major player in the beginning of the disinformation campaign, but today it’s the canola manufacturers who are especially vocal.  Studies promoting the oil can be found in scientific journals, but a growing number of independent researchers are finding a long list of serious health problems from canola and other vegetable oils.  
Canola oil is a genetically modified version of the rapeseed plant, which is high in erucic acid, a potentially toxic chemical.  Like so many plants grown by Big Agriculture, it is treated with Monsanto’s notorious Round Up. 
Here’s a likely reason why many researchers report damaging effects from canola oil.   In order to extract the oil, processors use an assortment of toxic chemicals, including hexane, a byproduct of the petroleum industry.  Chloroform and methanol can be used as solvents too.  
The mix is then treated with neutralizers, bleach, de-waxers, and deodorizers.  The last stage – deodorizing — is needed because the high temperatures that are used cause the omega 3 fatty acids in the canola seeds to become rancid – very smelly!  Whatever beneficial Omega 3’s that were once in the plant are now gone.  
Another chemical that may be used is a petroleum-based preservative.  This can be BHA or BHT, but more likely, it is TBHQ (1).  All three are linked to health and behavior problems, including ADHD.  Since these chemicals are used in processing, rather than being added to the oil at the last stage, they don’t have to be included in the ingredient label.
The finished product, having very little color and no odor, looks innocent, but most of the commonly used vegetable oils contain “trans-fats” which have been found to cause serious health problems.  They include coronary heart disease (2) (3) (4), nonalcoholic fatty liver disease, inflammatory bowel disease, rheumatoid arthritis, Alzheimer’s disease (5)obesity (6), stroke (7)sudden death and possibly diabetes mellitus. (8)
Now that trans-fats are known to be so harmful, some vegetable oil manufacturers advertise “no trans-fats,” but this is misleading since the Food and Drug Administration allows this claim if the trans-fat amount is less than 0.5 gram per serving.  Since canola and soy oils are so widely used in processed foods and restaurant foods, it’s easy to exceed that amount.
These cautions apply to other vegetable oils, not just canola.  Better options are unrefined coconut oil, avocado oil and clarified butter (ghee) for cooking with high heat.  Extra virgin olive oil is good for low heat cooking, but so many olive oils are adulterated with cheaper oils, it’s tricky to find one that is genuine.   Happily, Aldi’s sells both coconut oil and ghee at low prices.
  1. Journal of the American Oil Chemists’ Society, August 2017
  2. Atherosclerosis Supplements, May 2006
  3. European Journal of Clinical Nutrition, May 2009.
  4. Circulation, April 2007.
  5. Journal of Nutrition and Metabolism, April 2012.
  6. Nutrients, March 2016.
  7. Lipids in Health and Disease, October 2011.
  8. Atherosclerosis Supplements, May 2006