Doing the Math Whether you know it or not, you're probably getting plenty of trans-fatty acid (TFA) in your diet. And in case you haven't heard: a little TFA is way too much. Right now, it's not easy to tell exactly what the TFA content of a loaf of bread or a box of crackers might be because "trans fats" aren't listed on the "Nutrition Facts" panel of processed foods. Not yet anyway. Last July, the FDA announced that by January 2006 all nutrition labels must reveal trans fat content. But until then, there are a few key items listed on food packaging you can look for to avoid a diet heavy in this "franken-fat."
Trans fats are created by the hydrogenation of vegetable oil; a process that gives the oil a longer shelf life and makes it less… well, oily. These qualities also make hydrogenated vegetable oil an appealing choice for "quick service" restaurants and snack foods such as cookies, crackers, and chips. But many studies over the past decade have shown trans-fatty acids to be associated with artery damage and a high risk of heart disease.
And that's only part of what makes TFA dangerous. In a review article published in the American Journal of Clinical Nutrition, nutritionists at the Harvard School of Public Health wrote that trans fats inhibit the natural process by which alpha-linolenic acid is converted into EPA and DHA, the omega-3 fatty acids that are critical to so many facets of good health. And in a study of more than 800 subjects conducted at Chicago's Rush University Medical Centre, seniors who had a high trans fat intake were found to be twice as likely to suffer from Alzheimer's disease compared to those with the lowest intake. But how high is a high intake? Bruce Holub, a professor of nutritional sciences at Canada's University of Guelph, told the Toronto Globe and Mail that ingesting a daily gram of trans fat over several years is enough to significantly boost your risk of heart disease. And professor Holub points out that as few as two crackers can contain an entire gram of TFA.
So until Nutrition Facts panels start revealing trans fat contents in 2006, there's a relatively simple way to figure out the TFA content of processed foods. First check the list of ingredients. If the product contains hydrogenated oil or partially hydrogenated oil, that's obviously your first trans fat tip-off. Next go to the Nutrition Facts panel where you'll see grams of "Total Fat" listed. Below that, the fats will be broken down into saturated, monounsaturated, and polyunsaturated fats. If the "Total Fat" number is higher than the other three combined, the difference between the two totals equals the grams-per-serving of trans fat. Some products, however, aren't required to list monounsaturated and polyunsaturated fats. In that case, if the grams of "Total Fat" are higher than the grams of "Saturated Fat," it's time to go back to the list of ingredients. If "hydrogenated" appears high on the list of ingredients, you're definitely getting some trans fat. If "hydrogenated" appears lower on the list, the trans fat content is probably low. Let's take a look at a popular brand of "natural light" microwave popcorn. Total fat is 5 grams, saturated fat is one gram, and no other fats are listed. So with 4 fat grams unaccounted for, we check the ingredients and find only three items, in this order: popcorn, partially hydrogenated soybean oil, and salt. That's a pretty good indication that you're getting at least a gram or two of trans fat, and maybe even four. But be sure to also check the serving size. This 3-ounce bag of popcorn claims to be 2.5 servings. So if you sit down and eat the whole bag, you might end up getting well over 4 grams of trans fat. And because trans fat is present in so many food products, it's easy to see how you could pick up a dozen or more grams every day without even trying.
In the e-Alert "The New Big Oil" (8/20/02) I told you about a 2002 report from a National Academy of Sciences panel that attempted to set a safe intake level for trans-fatty acids. The report confirmed previous findings about the relationship of trans-fatty acids and the risk of heart disease, and concluded with this recommendation: "The only safe intake of trans-fat is zero."
The bad reputation of this dangerous fat is on the rise, and every day we're seeing more and more products claiming to be "trans fat free." I'm sure this trend will probably continue, and the result could be better health for millions. But what about restaurants? You'll know we've officially entered the Trans Fat Free Era when menus start boasting, "No trans fats."
To Your Good Health,
Jenny Thompson
Health Sciences Institute
Sources:
"Health Effects of Trans Fatty Acids" American Journal of Clinical Nutrition, vol. 66, 1006S-1010S, ajcn.org "Dangerous Fats Lurk in Seemingly Healthy Snacks" Paul Taylor, Toronto Globe and Mail, 10/28/03, theglobeandmail.com
"Exposing Trans Fats" Lyrysa Smith, Albany Times Union, 10/28/03, timesunion.com "Research Update: Trans Fatty Acids" Christian Finn's Research Update, Issue 133, 7/16/03, thefactsaboutfitness.com "NAS Panel: Only Safe Intake of Trans Fat is Zero" Center for Science in the Public Interest, 7/10/02, cspinet.org | 
