The trans fat brouhaha has been hot news, even if it's about an old hat. Researchers at Harvard and elsewhere have made it plain that trans fatty acids have been a health risk since the 1930s, when the swift expansion of margarine consumption put trans fat firmly on the breakfast table. Little guessing the harm they would cause, food chemists took vegetable oils and through the application of extreme heat and the addition of hydrogen reconfigured the chemical structure of the fat; the distorted molecule that resulted was a trans fatty acid. Its inventors dubbed it "partially hydrogenated vegetable oil," and it exists on food labels under that name. For a long time you could not find a cracker, a doughnut or a french fry in this country that did not contain trans fats.
Why did the industrial food industry do this? Well, the practical benefits of hydrogenation were immense. Vegetable oils solidify during the hydrogenation process and become almost impervious to spoilage. They ensure a long shelf life and a texture that doesn't crumble, ideal qualities in foods that are transported long distances and stacked in supermarkets. Furthermore, huge soybean crops meant low prices for soybean oil. Restaurants were ready. The demonization of saturated fat took its toll. Home cooks and institutions alike dropped butter and lard; hydrogenated oil became the cooking oil of choice in nearly every fast food restaurant in America. And if a nutritionist tells you there isn't a food on the American menu more unhealthy than fast-food french fries, that's largely because they know about trans fats.
More than 10 years of published research shows trans fats adversely affect cholesterol levels in the human body, causing ("bad") LDL cholesterol to go up and ("good") HDL cholesterol to go down. The all-important HDL/LDL ratio is therefore twice as unfavorable when trans fats are consumed as when plain old saturated fat is eaten in its place. And while saturated fat is something the human body needs, nobody needs a fat that didn't even exist before it was invented. Moreover, studies now show that lipoprotein, a particularly bad factor when it comes to arterial health, is significantly increased by consumption of trans fats. Need more bad news? Trans fats push up triglyceride levels.
This collection of grim warnings is almost certainly not a false alarm. In 1993, Dr. Walter Willett and his team at Harvard decided to measure the effects of margarine versus butter on the 80,000 women being tracked by the Harvard Nurses' Study. They were stunned to discover that women who were eating the equivalent of four or more teaspoons of margarine daily had a 66 percent greater risk of developing heart disease than women whose consumption was very low. They found no increased cardiovascular risk among women who ate butter, a saturated fat.
Willett's team estimated then that approximately 30,000 premature deaths from heart disease annually might be attributed to trans fat consumption. They now think 100,000 deaths a year is more accurate.
The Food and Drug Administration (FDA) has finally taken a position on this critical issue. Since 1999, the FDA had been considering a regulation that all labels must list trans fat quantities. Not surprisingly, the proposal was vigorously challenged by food manufacturers. But the FDA finally mandated the change in labels; the new labeling will not go into effect until 2006.
The implications of the new ruling go far beyond product labeling. Now that manufacturers will have to list the amount of trans fats in their products, most will likely make an effort to reduce that amount.
The winds of change are blowing. McDonald's has announced that it will now fry its foods with corn oil instead of hydrogenated oil; estimates are that this will drop the trans fat content of its foods by 48 percent. And Frito-Lay has taken the hydrogenated oil out of its potato chips.