Sunday, 26 February 2012
Murder by French Fry
Trans fats aren't as rampant as they were a few years ago, but their ability to accumulate over a lifetime still makes them dangerous. The term "saturated" doesn't refer to how densely fatty something is. It refers to the amount of hydrogen in a fat molecule.
A fat molecule is made up of carbon, hydrogen and oxygen. When all of the open slots in the molecule are filled with hydrogen ("hydrogenated"), that fat is hydrogen saturated, or just "saturated." Hydrogenation makes oil a solid at room temperature, as in margarine, and keeps it from going bad so quickly on store shelves. Whether a fat is "saturated" or "trans" refers mostly to the arrangement of those carbon and hydrogen atoms. The placement of hydrogen atoms in saturated fats makes the molecules bend; the placement in trans fats keep them straight. That's the big chemical difference. The health difference is much bigger.
Saturated fat molecules, found in foods like beef, butter and doughnuts, tend to increase bad cholesterol and decrease good cholesterol. Trans fats do the same, but worse. A study of 80,000 women showed that a 5 percent increase in daily calories from saturated fat can increase the risk of heart disease by 17 percent. That same study found that a 2 percent increase in trans fat can increase the risk of heart disease in women by more than 93 percent (in men, that number is closer to 25 percent). Another study found that high intake of trans fat increases the risk of death by heart attack by 47 percent. The USDA recommends limiting trans fat intake to 1 percent of your daily calorie intake. So if you eat 2,000 calories a day, you should only consume 20 calories of trans fat, which is about 2 grams. So check nutrition labels -- as of 2006, food manufacturers have to put the amount of trans fat on their packaging.
Now, lots of commercial foods contain trans fats. Why the focus on french fries, then? Until recently, here's why:
Food (one serving) - Trans Fat Content
Stick of margarine = 3 grams
Potato chips = 3 grams
Shortening = 4 grams
Doughnut = 5 grams
French fries = 8 grams
Not long ago, eating a single serving of fast food french fries got you more than four times your daily healthy allotment of trans fats. These days, major fast food chains don't use trans fats because of health concerns. Unfortunately, fats can start building in the arteries from the preteen years, so we're not exactly out of the woods.
Which brings us back to our initial question: Which is deadlier, french fries or car accidents? We're far more likely to die from over-consumption of trans fat. In the United States, people have a one-in-84 chance of dying in a car accident, and one-in-five chance of dying from heart disease. That's greater than the risk of dying from cancer, which is one-in-seven.