A study from Harvard Medical School on almost 33,000 women in the Nurses' Health Study shows that eating a diet high in partially hydrogenated fats triples a woman's chances of suffering heart disease (Circulation, April 10, 2007). Researchers can tell how much partially hydrogenated fat a person eats by measuring its content in red blood cells. In this study, the women with high levels of partially hydrogenated fats in their red blood cells were far more likely to have high blood levels of the bad LDL cholesterol and low blood levels of the good HDL cholesterol.
Many manufacturers are eliminating trans fats from their products, but they are still found in many processed foods such as cookies, doughnuts, cakes, chips and fried foods. New York City passed laws banning restaurants from serving foods containing trans fat, and other cities are following their lead. When you shop, remember that nutrition labels can proclaim "zero grams of trans fat" if a single serving contains less than half a gram. That can add up to a lot of trans fats when you eat several servings. You can protect yourself by reading the list of ingredients on all packaged foods, and avoiding those that include the words "partially hydrogenated" before any type of vegetable oil. Tests for heart attack risk