July 01, 2015

Researcher skeptical about effect of trans fat ban

by Andrea Hahn

CARBONDALE, Ill. – A nutrition expert at Southern Illinois University Carbondale says a recent government mandate to phase out artificial trans fats will do little to improve the health of Americans. 

The U. S. Food and Drug Administration announced that food manufacturers have three years to phase out partially hydrogenated oils (PHOs) – the primary source of trans fats in processed food – from food products or petition the FDA for specific approval to use them. 

In a statement to the press, the FDA’s acting commissioner, Dr. Stephen Ostroff, said, “The FDA’s action on this major source of artificial trans fats demonstrates the agency’s commitment to the heart health of all Americans. This action (banning PHOs in foods) is expected to reduce coronary heart disease and prevent thousands of fatal heart attacks every year.” 

Jeremy Davis, assistant professor of animal science, food and nutrition at Southern Illinois University Carbondale, is unimpressed. 

“You can’t just single out one ingredient and say, ‘There, that’s what’s causing heart disease,’” he said. “The fact is, partially hydrogenated oils are in foods that are high energy-low nutrition – foods like canned frosting and Twinkies. If your diet includes a lot of these foods, then PHOs are not the only problem in your diet.” 

PHOs are vegetable oils treated with hydrogen gas to change the consistency from liquid to solid or semi-solid, and include margarine and shortening. PHOs are relatively inexpensive for food manufacturers, and increase the shelf-life of products. They also are the leading source of artificial trans fats in the food supply. 

Researchers link trans fats to coronary artery disease and Type 2 diabetes. In addition, some studies show that trans fats raise “bad” cholesterol levels and lower “good” cholesterol levels. Polyunsaturated fats and monounsaturated fats, by comparison, can have the opposite effect – raising “good” cholesterol, lowering “bad” cholesterol, and combatting heart disease. 

Beginning in 2006, food manufacturers have been required to list trans fat content in the nutrition facts on their food labels. The FDA estimates that consumer trans fat consumption decreased by about 78 percent from 2003 to 2012.  Despite that decrease, the FDA considers artificial trans fats a continuing public health concern. 

Davis, a registered dietitian and a nutrition researcher, expressed skepticism that the new FDA ruling will have the effect FDA officials claim it will. He said foods are intrinsically neither good nor bad, but some are certainly over-consumed. The real nutritive problem facing many Americans, he said, is a diet that doesn’t deliver nutrition but over-delivers energy, which, combined with a sedentary lifestyle, contributes to obesity and related health problems. 

“Let me say this: No, I don’t think people should consume high levels of PHOs; they are in highly processed foods that don’t deliver on nutrients,” he said. “But we should understand that the whole development of partially hydrogenated oils – artificial trans fats -- was a reaction to erroneous data and research. In light of that, I’m apprehensive where the FDA went with this, where they set the bar. To state what they have about banning artificial trans fats leading to a reduction in heart attacks, to say that as a fact – I have a problem with that.” 

A little history sheds light on Davis’ objections. Food manufacturers developed PHOs beginning in the early 1900s to increase the use of vegetable oils as a supposedly healthier alternative to animal fats such as butter. FDA-commissioned research reviews in 1976 and 1985 found that trans fats and PHOs were healthy. In the mid-1990s, however, new studies reversed those findings, indicating that less processed polyunsaturated and monounsaturated fats were in fact more healthy than the PHOs developed to replace them. 

Davis said this research-reversal and the hype that goes with it make him and some other scientists hesitant to jump on the PHO-banning bandwagon. He noted that scientific research is an on-going process and rarely delivers simple, black-and-white answers. 

“Not all research is good science, not all studies are of equal weight in the scientific community,” he said. “Agencies that fund research emphasize certain types of research, and that can be problematic.” 

When it comes to food, nutrition and health, a few other factors enter the picture, Davis said. Everyone has some experience with food, and therefore has some sort of opinion about what food does. Also, people tend to want easy solutions to health problems, and the media tend to want to deliver news of those “easy” solution. All of that sometimes carries into public policy. 

“I’m not against reducing PHOs in the diet,” Davis said. “The foods they are in are highly processed and high-energy. Many American consume more energy than our sedentary lifestyles require, and at the same time, we don’t consume enough nutrients. So, yes, reducing PHOs is likely to have a healthy effect. However, to say that reducing that one factor will reduce disease – I don’t think it’s that simple. Cardio-vascular disease is not simple.” 

(For the media:  Jeremy Davis, assistant professor of animal science, food and nutrition at Southern Illinois University Carbondale, is available for media and other interviews. Contact him at jedavis@siu.edu. Davis’ recent research focuses on dietary flax in the prevention of nonalcoholic fatty liver disease, for which he earned an SIU Collaborative Seed Grant. His research appears in the Journal of Nutritional Biochemistry, Nutrition and Cancer-An International Journal, Annals of Nutrition and Metabolism, and elsewhere.)