Years ago, young Chef Boy Ari and his Mama got kicked out of a Nantucket tourist café. Mama wanted to make sure her pancakes came with butter—not margarine. But when the food arrived, she simply could not believe it was butter. Soon, the whole restaurant knew about it, and we got the heave-ho.
Why didn’t Mama want the fake fat? Well, first and foremost, it tasted like plastic dog crap. And while she couldn’t yet cite any scientific evidence to support her intuition (that margarine is gross), it turns out she was right, despite all the health-hype that margarine used to garner.
Since then, a growing body of research indicates that turning vegetable oil into margarine (a process called hydrogenation) creates a species of chemical monster known as trans fatty acids. And after years of pressure from scientists, the FDA has recently announced labeling requirements for all foods that contain trans fatty acids. This includes much more than margarine—most processed foods, like french fries and candy bars, and many baked goods contain hydrogenated vegetable oils. To understand the significance of this labeling policy, some background in fat-ology is necessary.
Fat is an energy storage molecule—the most concentrated form of biological energy storage there is. The basic unit of fat is the triglyceride molecule, which contains three chains of carbon atoms of varying lengths. To these carbon atoms, varying numbers of hydrogen atoms are attached.
The bond between carbon and hydrogen is where energy is stored. Thus, more hydrogen means more calories, i.e., more energy. When the maximum possible number of hydrogen atoms has been incorporated into a triglyceride, it is said to be “saturated.” If the molecule has fewer than the maximum number of hydrogen atoms it can accommodate, it is called “unsaturated.”
The difference between oil and fat is a matter of degrees—oil is liquid at room temperature, and fat is solid. The more saturated the triglyceride, the higher its melting point, and the more likely it is to be solid at room temperature. Most vegetable oils are unsaturated; most animal fats are saturated. That’s why you seldom hear terms like “animal oil” and “vegetable fat.”
For years, humans have enjoyed spreading butter on food. But as we began to understand the link between obesity and caloric intake, the idea arose that vegetable oil, less saturated than animal fat, would be less fattening on your toast.
But since vegetable oil doesn’t spread like butter, food companies figured out how to force more hydrogen into it, raising the melting point and turning vegetable oil into fat. This process of hydrogenation makes the product more spreadable—as well as fattier.
Astute readers may be wondering at this point what is gained by artificially turning an oil to a fat, rather than using a naturally occurring fat (that tastes better) to begin with. That’s what Mama wanted to know.
And ironically, contrary to decades of low-fat food industry hype, growing evidence suggests that in practice, fat is not as fattening as sugar or carbohydrates. That’s right, it’s the bread, not the butter, that’s making people obese! (See Flash in the Pan, “The skinny on fat,” July 18, 2002).
Fat, despite being demonized, is natural and good. Fat is flavor, and we need it—however, fat’s benefits are contingent upon the specific fat in question. Is it rancid trimmings scraped from the floor of a slaughterhouse? Is it pressed from organic flax seeds? Fat-soluble toxins are known to concentrate in the flesh of predatory animals, like swordfish, accumulating from prey whose flesh contains trace quantities; LSD is known to linger in the fat cells of users, to be released years later when that fat is broken down—aka a flashback. When I say fat is good, I mean natural, uncontaminated fat.
Meanwhile, the process of hydrogenation produces triglycerides with the same number of hydrogen atoms as their naturally occurring counterparts, but they are shaped differently. These are trans fatty acids.
For the body, dealing with trans fatty acids is like trying to shake hands with someone’s outstretched left hand: same number of fingers and thumbs, same size…but it just doesn’t work.
Yet trans fatty acids are similar enough to the naturally occurring cis fatty acids that they can cause all kinds of trouble. They become embedded in cell membranes, along with their cis counterparts, and can lead to degenerative effects at the cellular level.
And trans fatty acids have been shown to elevate levels of “bad” cholesterol and reduce the “good” cholesterol in your blood, increasing your chances of heart disease—the number one killer in America. That’s why the FDA is demanding that all food labels detail the trans fatty acid content.
These new labels won’t come on-line until 2006, so don’t hold your breath. But if you read the ingredients, and avoid anything “hydrogenated,” “partially hydrogenated,” or “hardened,” then you will be sans the trans.
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