I recently started to read more about the evils of trans fats. What are trans fats you ask? Well, I'll tell you.
According to the book What Einstein Told His Cook, you have to think of fat molecules being something like kites with three long tails. The three long tails consist of long chains of carbon atoms with a lot of loosely held hydrogen atoms on them... often with places where more hydrogen atoms can go. The spots where hydrogen atoms can be but aren't not present are chemically active, wanting to suck up hydrogen from anything else. This process is generally called hydrogenation, turning unsaturated fats into saturated fats. It is also this chemical process that turns fat rancid... and rancidity is BAD where commercial food processing and shelf life is concerned.
One way to reduce the problem of rancidity is to heat oils and destroy some of the more unstable fats that want to hydrogenate themselves. This is often called partial hydrogenation and is the source of that magic goo used in modern commerical baking -- partially hydrogenated soybean oil. It is also used to make vegetable shortening that is solid at room temperature, and margarine.
Unfortunately heat treatment has its down side too. Some of the fat molecules get their three tails tangled together in knots. Fats that display this property are called trans fats and, according to the Harvard School of Public Health are very bad for you. Evidently the human liver doesn't quite know what to do with a trans fat when it finds one, and tries to process it by turning it into LDL (bad) cholesterol. The kite end of the transfat also looks suspciously like something that the cells in the linings of blood vessels want to absorb, but can't because it's not anything they know about. This means that trans fats end up getting stuck on the walls of your arteries with their knotted ends sticking out. Those knotted ends snag other fats floating by in your blood, clogging arteries big time.
So... for all the bad news we've heard about butter for the last 30 years... it turns out that margarine is in some ways worse... as is all that Crisco vegetable shortening that's been used in America's kitchens.
Me, I thinking it time to really go old school where cooking with fats is concerned -- time to start cooking with lard. Manteca. Rendered hog fat. Yeah, it's hell on wheels where saturated fats are concerned, but at least the body knows what to do with it. Humans have been eating it for thousands of years. That and bacon fat... which is lard rendered from smoke cured pork. Mmmmm. Mom always used to keep an old glass peanut butter jar in the fridge with saved bacon fat when I was growing up (she's largely stopped since my Dad went on high blood pressure medication.)
So get out those pre-World War II cookbooks everybody... say no to heart disease by cooking with lard (but not too often....)!
on 2004-09-30 at 2:02 p.m.
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