New York City’s pioneering ban on all but the smallest amounts of trans fats in restaurant food has led to a significant reduction in consumption, a change that should translate into better cardiovascular health in the nation’s largest city, according to a new report. It also demonstrates that coffee shops, fast-food joints and other eateries can play a major role in improving the health of the public, the study authors said.
Officials from the New York City Department of Health and Mental Hygiene conducted the study to assess whether the regulation that took effect in 2008 — which prohibits all restaurants from serving food prepared with partially hydrogenated vegetable oil or dishes that contain more than 0.5 gram of trans fat per serving — was making a difference for diners.
Public health officials had zeroed in on trans fats because they pose a uniquely potent health risk. Adding fewer than 4.5 grams of them to a 2,000-calorie daily diet can increase the risk of coronary heart disease by 23 percent, studies have found.
Researchers fanned out across Manhattan in 2007 and examined the receipts of 6,969 diners as they left fast-food restaurants at lunchtime. (The researchers went to fast-food chains because the nutrition information on the items sold there was readily available.) In 2009, they repeated the exercise with 7,885 receipts. They found that diners consumed 2.4 fewer grams of trans fat per lunch after the ban went into effect, according to their study published in Tuesday’s edition of Annals of Internal Medicine.
That decline was offset by only a slight 0.55-gram increase in consumption of saturated fats, which are also associated with elevated cholesterol levels.
"Given that one-third of calories in the United States comes from food prepared away from home, this suggests a remarkable achievement in potential cardiovascular risk reduction through food policy," the authors reported.
Alice Lichtenstein, director of the Cardiovascular Nutrition Laboratory at Tufts University in Boston, said the findings showed "that public health initiatives, if done right, seem to work." A key factor, she said, was that diners didn’t have to choose: "The environment has been shifted so that you automatically will get the healthier option."
New York Mayor Michael R. Bloomberg has taken an active role in efforts to improve public health. In addition to leading the fight against trans fats, he has required chain restaurants to post calorie information on their menu boards and called for a ban on super-sized sugary drinks.
Trans fats are found naturally in meat and dairy products, but the biggest source in the American diet is processed oils, commonly partially hydrogenated vegetable oils. Favored for their shelf-stable qualities, such oils were widely used in baked and fried foods.
The researchers found that the proportion of meals purchased that contained zero grams of trans fat rose from 32 percent before the ban went into place to 59 percent afterward. And they found that the benefits were shared equally by diners in working-class neighborhoods and patrons in tonier sections of the city.
Other cities and states followed New York City’s lead, including California in 2008. The federal government also required manufacturers to list the amount of trans fats contained in processed foods, beginning in 2003.
The food industry has responded by reformulating its products.
Nationwide, the average daily consumption of trans fats has gone from 4.6 grams in the 1990s to 1.3 grams in 2010, said Kelley Scanlon, an epidemiologist with the Centers for Disease Control and Prevention. "Things are clearly much better."
However, in a report this month in the Journal of the American Medical Association, Scanlon and a CDC colleague noted that trans fats are still found in many processed foods, including up to 7 grams a serving in some microwave popcorns. More needs to be done, she said.
The changes made by restaurants were costly but necessary, said Joy Dubost, director of nutrition and healthy living at the National Restaurant Association.
"The science is very convincing with regard to consumption of trans fats, so the industry had been working on this," she said.