Essential Fatty Acids References
UC Berkeley Wellness Letter, May 2005
The End of the Line for Trans Fats
Will trans fats one day disappear from the American food supply? It’s possible. Food manufacturers are scrambling to reduce or eliminate them altogether before trans-fat labeling becomes mandatory January 1, 2007. After all, having to disclose the presence of these fats, which are even worse for your health than saturated fats, is not good for sales. But being able to declare a food free of these harmful fats can boost sales. A quick run through a supermarket reveals a bevy of products already boasting “zero grams trans fats,” including Triscuits, a new version of Crisco, and all Frito-Lay snacks. But what’s being used instead? Are the substitutes better for you than trans fats?
While small amounts of trans fats are found naturally in meat and dairy foods, these fats are mostly found in processed foods that contain partially hydrogenated oils, including many baked goods (such as donuts and cookies), snack foods (chips and crackers), margarines (especially stick), microwave popcorns, frozen meals, and even some peanut butters. They’re created when vegetable oils undergo a chemical process (“hydrogenation”) that makes them more solid. Manufacturers like hydrogenated oils for obvious reasons—they make foods crisp, creamy, moist, flavorful, and shelf-stable. Much fast food is also fried in partially hydrogenated oil, because the oil stands up well to repeated use. But the trans fats that result act like saturated fats in the body, raising total and LDL (“bad”) blood cholesterol. In addition, trans fats lower protective HDL (“good”) cholesterol. They may also increase triglycerides and inflammation and have been linked to an increased risk of diabetes. A 1999 Harvard report estimated that replacing trans fats with unsaturated vegetable oils could prevent at least 30,000 heart disease deaths in the U.S. each year.
It’s not easy to remove partially hydrogenated oils from foods without compromising taste, texture, and shelf life. Sometimes manufacturers can simply use healthier liquid oils, such as canola, olive, corn, sunflower, or soybean—what many health-food manufacturers have been doing for years. But that doesn’t work for all products. Much effort and money is going into developing new oilseed varieties (some genetically modified) and new chemical processes that produce oils that mimic hydrogenated oils in function, but don’t contain trans fats. Some potential contenders include “high-oleic” oils, “interesterified oils,” and a sunflower oil blend called NuSun. But sunflower oil, for one, is in short supply and is expensive. And critics argue that, like hydrogenated oils, many of these alternatives may have unknown health consequences.
Tropical oils—the very oils that hydrogenated oils replaced two decades ago because of health concerns—are re-emerging as well, because they have the same desirable qualities as hydrogenated fats, and they’re cheap. These oils, including palm (sometimes called palm fruit oil, from the pulp of the fruit), palm kernel (from the fruit’s nut), and coconut, were shunned starting in the late 1980s because they are high in saturated fat. But they may not all be as bad as once thought. Palm oil contains a significant proportion of heart-healthy monounsaturated fats, vitamin E, and other antioxidant compounds, and research now indicates that it behaves like an unsaturated fat in the body—that is, it may help reduce blood cholesterol levels. In other studies palm oil’s main fatty acid, palmitic acid, has had no effect on blood cholesterol. Coconut oil may also have a neutral cholesterol effect in most people, and its main fatty acid, lauric acid, may even have some health benefits. This doesn’t mean these oils get a green light. Their health effects are still debated, and how they’re processed may make a difference.
Even less is known about palm kernel oil, which is more saturated than palm oil and contains little monounsaturated fat. Moreover, this oil is often further processed (“fractionated”) to remove the liquid portion, leaving behind even more saturated solids. You may have noticed “fractionated palm kernel oil” as an ingredient in several energy bars, where it makes the coatings less likely to melt, and in other reformulated products. It isn’t known if this processed oil is any better for you than hydrogenated fats.
• Until mandatory labeling goes into effect next January, trans fats in many foods will remain hidden. If a label doesn’t already list trans fats, the only way to detect their presence is by checking the ingredients list for partially hydrogenated oils—but you still won’t know how much trans is there.
• Some foods that claim to be trans-free may still have hydrogenated oils in the ingredients. How can this be? The FDA allows products with less than half a gram of trans fats per serving (and low saturated fat) to list trans fats as zero. But if you eat several servings, the trans fats add up. No amount is desirable.
• Don’t assume that if one product is trans-fat free, similar products made by the same company are. Even if a company plans to change all its products, this will take time.
• Trans-free foods may still be high in heart-damaging saturated fats, so check labels. Some reformulated products may even have slightly more saturated fat than before, if food manufacturers use highly saturated substitutes.
• Limit foods made with tropical oils. Their effects on blood cholesterol are still debatable. Palm oil is a better choice than palm kernel oil.
• For a bigger selection of trans-free foods, check out such health-food brands as Barbara’s, Bearitos, Hain, and Health Valley, which do not contain hydrogenated oils.
• Because restaurants don’t have to label trans fats, they’re less likely to reduce or eliminate them. Some chains have changed their frying oils (a big source of trans fats) or have promised to, but you have to ask to know for sure. Some fast-food restaurants provide trans-fat information in brochures and on the Internet.
Keep in mind: Most processed foods that contain trans fats are high in calories and low in nutrients to begin with. Even if the trans fats are removed, junk food is still junk food. The less processed a food is, the better.
UC Berkeley Wellness Letter, May 2005
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