In about 1980, while I was still a student in chiropractic college, I read an article in the American Journal of Clinical Nutrition about a particular type of dietary fat known as
partially hydrogenated oil or
trans fat.
I found the article quite troubling.
These trans fats were made by taking ordinary grain, seed and bean oils (such as corn, sunflower, soybean, safflower, peanut oils) and chemically altering them in a way that was mainly intended to extend shelf life.
Another perceived benefit of these fats was that they gave baked goods a texture and consistency similar to animal-based fats such as butter and lard.
The trans fats were considered to be a healthier alternative to the saturated animal fat as well as coconut oil, which is also a saturated fat.
For a quick explanation of how oils are partially hydrogenated,
read this.
I do not believe there was any evil intent to create an especially unhealthy product when partially hydrogenated oils were invented. I don’t believe their increased use was intended to cause harm. However the research article I first read, which is now over 30 years-old, and almost three decades of more of research have proven these to be uniquely unhealthy. Predictably, commercial food manufacturers and restaurants tried to ignore the damaging effects of these fats and tried to keep the public in the dark. The edible oil industry (the other oil industry) apparently did not want to lose market share, even with public health at risk.