Balancing health with taste has long been a challenge for food manufacturers. In the 1980ís, on scientistsí advice, the industry replaced saturated fats like coconut oil and butter with oil containing trans fat. Now nutritionists have changed their edict.
"There was a lot of resistance from the scientific community because a lot of people had made their careers telling people to eat margarine instead of butter," said Walter Willett, chairman of the Department of Nutrition at the Harvard School of Public Health and one of a handful of medical researchers who have led the fight against trans fat. "When I was a physician in the 1980ís, thatís what I was telling people to do and unfortunately we were often sending them to their graves prematurely."
He and other researchers say that cells rely on natural fatty acids to function. Trans fat is artificial, and acts in the body like grains of sand do in the workings of a clock.
The strongest argument against trans fat is its role in heart disease. Like lard, beef fat or butter, trans fat increases low-density lipoprotein, or LDL, the so-called bad cholesterol. But it also decreases HDL, the good cholesterol that helps clean arteries, several studies have shown.
Food companies have, for the most part, accepted the word of scientists and are working to remove trans fat, even though they know finding a new oil is going to cost them. Not only does equipment need to be retooled, budgets must be re-examined.
Taste and TechnologyFood companies argue that completely eliminating trans fat might be impossible given the cost and the fact that consumers do not want the taste of favorite foods to change. That is why a coalition of edible oil producers and food manufacturers persuaded both the Agriculture and Health and Human Services Departments to soften the federal governmentís stance on trans fat consumption in the latest version of the dietary guidelines released in January.
The scientific advisory committee that created the guidelines originally warned that trans fat consumption should be "limited to less than 1 percent of total calories," or about the amount in half a doughnut. But the numeric value was replaced with the phrase "keep trans fatty acid consumption as low as possible."
Food companies are also fighting a campaign by the Center for Science in the Public Interest, which frequently criticizes the industry, and a group of cardiologists and researchers to ban trans fat altogether, a proposal similar to one snaking through Canadaís legislative system.
Faced with the lack of trans fat free vegetable oil alternatives, some companies are gingerly turning back to palm oil, a saturated fat that was taken out of many products in the late 1980ís after an effective campaign waged in part by the American Soybean Association and the Center for Science in the Public Interest helped turn Americans away from all forms of "tropical grease."
Kraft is using a combination of palm fruit oil and high-oleic canola for the filling in its three trans-fat-free Oreo varieties - a reduced-fat version and two with yellow, rather than chocolate, wafers. Without the firmness of palm oil, getting the consistency that Oreo lovers expect would have been nearly impossible, said Jean Spence, Kraftís executive vice president for technical quality.
The trade-off was an extra half-gram of saturated fat per serving. The company still has not figured out how to make the traditional Oreo taste the same without trans fat or significantly higher saturated fat levels. So far the new versions make up 9 percent of Oreo sales, according to data from Information Resources, an industry research firm.
Some companies are experimenting with new blends of liquid oil and fully hydrogenated oil, which does not contain trans fat. Others are using an enzyme method called intersterification to blend the oils.
Critics say that these offerings are still artificial, highly processed ingredients that may not be much safer than oils produced by partial hydrogenation. And nutritionists wonder whether consumers know enough to distinguish good fat from bad, and natural oils from artificial.
"I donít know that they will look at a label that has low trans fat and high saturated fat and be able to figure out if it is healthy or not," Joanne Ikeda, a nutrition professor at the Center of Health and Weight at the University of California, Berkeley.
And consumers might not even care.
"I know there are healthy fats and there are unhealthy fats and that trans fats are the unhealthy ones, but I donít know what they are supposed to do to you," said Thai Bu, 32, who was buying whole-grain bread and eggs recently at a West Seattle grocery store. "If I want a cookie and it has it in it, Iíll still eat one or two."