The inception and evolution of trans fats
In the early part of the 20th century we started to import soybeans because they were an inexpensive source of protein. The protein was extracted from the soybean leaving a huge surplus of soybean oil. Soybean oil gets rancid very quickly so the food industry found a way to stabilize the liquid oil. They chemically altered unsaturated fat by hydrogenating (adding hydrogen to) the oil creating trans fats.
Everyone thought this was a great idea since:
1) We were consuming “unsaturated” fat instead of butter and lard.
2) It was very economical since it can be produced in a lab avoiding all of the time, effort, and money spent on obtaining it from animals.
3) Convenience was an issue also since margarine, made with hydrogenated soybean oil, could be spread on food as soon as it was removed from the refrigerator because it remained soft even while cold. The new fat (e.g. Crisco) became liquid when heated, which made it even better than lard for frying food.
4) The stability of this new oil solved the problem of oils becoming rancid. Inexpensive, stabile oil allowed the food companies to develop a variety of economical packaged foods. A lot of hydrogenated vegetable oils are used in packaged foods.
The production and consumption of trans fats steadily rose through the 20th century. In 1994, it was estimated that trans fats caused 20,000 deaths annually in the US from heart disease. What started as a “healthy, unsaturated fat alternative” turned out to be much worse than the saturated fat products we were trying to avoid.
In 2002 the National Academy of Science (NAS) stated that:
1) “dietary trans fatty acids are more deleterious with respect to coronary heart disease than saturated fatty acids”
2) “trans fatty acids are not essential and provide no known benefit to human health” whether of animal or plant origin.
The NAS goes on to say that while both saturated and trans fat increase the levels of LDL (bad) cholesterol, trans fat also lowers levels of HDL (good) cholesterol, thus increasing the risk of coronary artery disease.
Identifying trans fats on product labels should be pretty easy since the U.S. government, in January 2006, required food manufacturers to list them on the Nutrition Facts panel. Consumers now know how much of all three—saturated fat, trans fat, and cholesterol—are in the foods they choose.
Since food manufacturers had to adhere to the law, they removed most of the trans fat from their products.
Interestingly, trans fats have not disappeared from packaged foods in 2011. A label from a recently purchased box of Saltine Crackers states it has 0 trans fat. However, in the ingredient list there is “partially hydrogenated cottonseed oil,” which is bad fat. Cottonseed oil is inexpensive and naturally high in saturated fats. In this case, it is hydrogenated to further extend its shelf life.
It’s difficult but not impossible to avoid trans fats. Since we cannot avoid every single gram of bad oil, we can consume omega-3 oil to help reverse the negative effects of bad fats.