Scientists point fingers at a little-known group of substances called trans-fatty acids
Weighing the worries of fats
Scientists point fingers at a little-known group of substances called trans-fatty acids
What’s in a label? Not enough, as far as Douglas Chipperfield is concerned. The retired pharmacist from Richmond, B.C., has been trying to avoid butter and other animal products that contain saturated fats. That helps reduce his cholesterol, a waxy substance in the blood that can clog arteries and lead to heart disease. But just when he thought he had nutrition all figured out, Chipperfield heard about a report that made him throw his hands up in frustration. In a strongly worded article in the American Journal of Public Health last week, two Harvard scientists warned against the cholesterol-promoting properties of something called transfatty acids. The little-known group of vegetable fats is found in most brands of that old butter substitute, margarine, as well as in cookies, crackers, french fries, microwave popcorn, waffles and other products. Chipperfield says it is difficult to know which brands contain these artificially produced substances, because Canadian regulations do not require the listing of trans-fatty acids on food labels. To make matters worse, some of these products are labelled cholesterolfree, or “light,”
because they contain no animal fats. “Sometimes, I feel like I’m being fooled and it makes me angry,” says the 72-year-old Chipperfield. “I guess a few cookies made with these bad fats won’t kill me, but how are you supposed to know?”
Good question. Many Canadians are well aware that they should reduce the level of fat in their diets. But there are many kinds of fat, some healthy, some not, and deciding
which to eat and in what quantities grows more confusing with each new scientific report. In the past, margarine and other foods made with vegetable oils were widely thought to be a healthy alternative to saturated fats. But as the report from Harvard points out, study after study has found that trans-fatty acids—contained in vegetable oils converted into solid fats using a process called partial hydrogenation—are as bad, or worse, than saturated fats. Despite contrary opinions, especially from the food processing industry, the preponderance of research • supports the conclusion that a “higher intake of transfatty acids increases the risk of coronary heart disease,” wrote Harvard physicians Walter Willett and Albert Ascherio. Or, as Ascherio told Maclean’s: “We think it is time to phase out these products or provide better labelling. The research will never be conclusive enough for the food industry.” In Canada, some dietitians and doctors hailed the article as a longneeded step in the right direction. “We run the risk of losing hundreds of thousands of people to premature heart attacks if the government does not act quickly to change labelling requirements,” said Bruce Holub, a professor of nutrition at the University of Guelph who has studied trans-fatty acids for 15 years. “Now, the worst of the fats are marketed as cholesterol-free and that is a gross disservice to the consumer.” But Ruth McPherson, a physician and director of the Lipid Clinic at the University of Ottawa Heart Institute, says the study may have overstated the role of trans-fatty acids in promoting heart disease. “These fats are detrimental,” she says, “but not as bad as saturated fats, because Canadians tend to eat much less of them—two to three per cent of total calories for trans, compared with about 15 per cent for saturated fats.”
The food industry was even less impressed. Laurie Curry, a dietitian for the Grocery Products Manufacturers of Canada, calls the controversy over trans-fatty acids “a tempest in a teapot.” Says Curry: “People are losing sight of the larger dietary issue, which is the need to reduce total fat.” And labelling relatively unknown substances like trans-fatty acids, she argues, may overload consumers with too much information. “Do we want to encourage micro-management of the diet?” Curry asks. “At what point do consumers shut off and at what point do they no longer understand?” Lucia Weiler, nutrition services manager for margarine producer Thomas J. Lipton in Toronto, says that consumers should examine labels for socalled good fats, such as polyunsaturates and monounsaturates.
WHAT LABELS DONT SAY
Canadian food labels list levels of saturated fats, which are known to raise blood cholesterol. But they do not list trans-fatty acids, which many researchers now believe are equally harmful. As a result, the harmful fat content of many familiar foods may be substantially higher than labels indicate. A sampling:
Saturated fat Trans-fatty acids
(grams per serving)
Fast-food french fries (100 gm) Frozen french fries (100 gm) Frozen waffles (78 gm or 2 waffles) Pancake mix (50 gm or 2 pancakes) Potato chips (55 gm or small bag) Snack crackers (25 gm or 7 crackers)
“The choices are as healthy as they were before this information came out,” Weiler insists. She Campbell: deciding what to eat is confusing particularly recommends soft margarines, which have less hydrogenated fats, and brands like Becel, which have none.
The controversy has been a long time in the making. Partially hydrogenated vegetable
oils were first used around the turn of the century as an inexpensive alternative to animal fat. Hydrogenation uses heat and hydrogen to change the molecular structure of liq-
uid vegetable oils, creating solid vegetable fats. In addition to resisting burning, they also have a longer shelf life than natural vegetable oils. Later, as North Americans began to steer clear of artery-clogging animal fats, these new fats were promoted as healthy alternatives. Soon, margarines and partially hydrogenated cooking oils became popular replacements for butter and beef tallow, a fat that was widely used by restaurants for deep frying.
But the trans-fatty acids are found only in small amounts in nature and, until recently, their effects were poorly understood. Partial hydrogenation converts some healthy elements of vegetable oils into a combination of saturated fats and trans-fatty fats. Saturated fats have long been known to contribute to an increase in so-called bad cholesterol in the blood. Now, scientists believe that trans-fatty acids have a similar effect. Even more worrisome is a second characteristic not shared by saturated fats. In recent studies conducted in Holland and the United States, scientists found that transfatty acids also lower the level of “good” cholesterol, which helps to protect against heart disease. Holub is unequivocal in his condemnation. ‘Trans-fatty acids are worse than saturated fats,” he says. “I find it indefensible that their use without proper labelling has been allowed to go on, and in fact, to increase.”
Almost everyone now agrees that at least some changes in nutritional labelling are overdue. One of the first is likely to be the establishment of new criteria for the claim that a product is “cholesterol-free.” Ann Campbell, who works as a data-collection clerk in downtown Toronto, would appreciate some clarification. Campbell, 50, who keeps a close watch on her fat intake, says that the recent spate of reports about good and bad fats has left her thoroughly confused. “I can never figure out the listing of fats and I’m not sure what they mean,” she says. “But I still buy the ones that say ‘no cholesterol,’ because I imagine that they are better than the ones that don’t say that.”
Unfortunately, that is not necessarily the case, as even government officials admit. Margaret Cheney, chief of nutrition evaluation at Health Canada’s health protection branch, says that the “cholesterol-free” definition encouraged manufacturers to change to partially hydrogenated oils, which have high trans-fatty acid content, but no cholesterol. (Cholesterol occurs only in animal products.) In fact, a lengthy consultation with consumers and food industry representatives ended in April, reaching no consensus on labelling changes. “I see a long period of discussion before we arrive at new regulations,” Cheney says.
In the meantime, there are steps that consumers can take to protect themselves. Rosie Schwartz is a consulting dietitian in Toronto for the Heart and Stroke Foundation of Ontario. The best way to check for trans-fatty acids, she says, is simply to add up the other fats on the food label and subtract that sum from the total amount of fat. The difference is the approximate amount of trans-fatty acid in the product. Schwartz also warns that hydrogenated oils have a melt-in-your-mouth taste that makes them particularly attractive. Groups like teenagers, who may pay little heed to their health, “are eating tremendous amounts of this stuff,” she says. “We have a whole generation that could be facing heart disease at an earlier age. We have to do something about the kids.”
As always, the best advice seems to be moderation. The Heart and Stroke Foundation of Ontario recommends that men should consume no more than 90 grams of fat per day, and women just 65 grams. A 3'A oz. serving of steak contains 30 grams of fat. One cup of plain, low fat yogurt contains 3.5 grams. Peter Jones, director of the school of dietetics and human nutrition at Montreal’s McGill University, has recently completed research on the relationship between trans-fatty acids and cholesterol. Even when types of fats are monitored, Jones says, it remains important to maintain a balanced diet and to exercise regularly. “You can’t get fat unless you eat too much and those extra calories usually come as fat,” he says. “Simply cutting down on weight is a good way to cut down on cholesterol.” In other words: no pain, no gain.
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