The worst fat

A proposed ban on trans fats in New York and Chicago restaurants has attracted national attention and posed a question for cities like Boston: Are such bans the best way to make people healthier?

Trans fats, also known as partially hydrogenated oils, were created as a replacement for saturated fats, long known to cause heart disease. Like saturated fats, trans fats are tasty, partially solid, and don't spoil, making them ideal ingredients in cookies, candy bars, and that crispy outer coat of a French fry. Many restaurants use them in deep fryers, where they can be stored and reused, and the fats are ingredients of many solid margarines.

But a now-ponderous stack of research has shown that trans fats raise heart disease risk four to five times more sharply than do saturated fats. Trans fats both raise "bad" cholesterol, or LDL, and cause "good" cholesterol, or HDL, to drop, while saturated fats only raise LDL. Moreover, trans fats are linked to ailments such as diabetes and dementia, said Walter Willett, chairman of the department of nutrition at Harvard University's School of Public Health.

"We calculate that tens of thousands of people are dying every year because of trans fats," said Willett, whose research was among the first to indict the fats as causes of chronic disease.

When it comes to banning trans fats, he said, "the bottom line is it is indeed a very good idea."

Yet many restaurant owners have criticized the proposed legislation, saying it would make restaurants struggle while failing to protect consumers from the bulk of trans fats on the market.

Cooking without trans fats will be costlier, restaurant owners say, and fries made with pure vegetable oils -- the healthier alternative -- tend not to taste as good.

Plus, owners argue, restaurants are not the primary source of trans fats in people's diets.

"People consume trans fats to a much higher scale through junk food," said Jeffrey Gates , co-owner of Union Bar and Grille in Boston, which has not tried to remove trans fats from its menu items. Legislators "are putting pressure on an industry that's already very challenged."

Boston isn't yet considering an outright ban on trans fats in restaurants, said Anne McHugh of the Boston Public Health Commission. But voluntary efforts have sprung up citywide to remove trans fats from restaurants and food services.

In August the commission launched a voluntary program to promote healthier foods. Participating restaurants can place a "BestBites" designation next to menu items that meet a set of nutritional requirements, including low-calorie, low-sodium, low in saturated fats, and trans fat-free.

"We're watching with interest what other cities are doing . . . at the same time as we're pushing ahead with our voluntary efforts," said McHugh, the project's director.

So far, about 50 of the city's 2,000 restaurants have responded to the program, and 15 have received designations for menu items. The city has focused only on local restaurants and small chains and has not yet included larger chains like McDonald's, she said.

Removing trans fats is costly, said Frank Guidara, CEO of Uno Chicago Grill, a Boston-based national chain of pizza restaurants. Uno has pledged a completely trans fat-free menu, but Guidara said he favors voluntary compliance over legislation. He said Uno's spent more than $1 million and a year of research developing tasty, trans fat-free French fries, which it launched this month.

Restaurants "will have difficulty trying to reproduce the taste and texture of the food they're currently serving," Guidara said.

Massachusetts General Hospital also struggled to eliminate trans fats from its food service's frying oils and french fries, said Lorraine Allan, the hospital's senior manager for food production. At first, Allen said, the hospital had trouble buying trans fat-free fries. More have come on the market lately, but the hospital has yet to find a healthy, trans fat-free frosting for its desserts.

Frostings "that are free of trans fats, they tend to be high in saturated fats," she said -- a problem for some other trans fat-free products as well.

Willett and other nutritionists counter that there is a plethora of healthier alternatives to trans fats, such as canola oil, olive oil, and even coconut oil, which contains saturated fat but has been linked to unusually low heart disease risk. Successful efforts include the entire nation of Denmark, which has banned the fats. Disney last week also announced that its theme parks would be trans fat-free by the end of next year.

Americans now eat more than one-third of their meals outside the home, nutritionists add, making restaurant foods a significant source of trans fats in their diet. And unlike grocery store food -- which now must list any trans fat content over 0.5 grams per serving -- restaurant food is rarely labeled.

"Frankly, this is a toxin," said Dr. David L. Katz of the Yale University School of Public Health, adding that some companies have dodged the labeling law by shrinking their serving sizes to disguise the amount of partially hydrogenated vegetable oils in their products. "I think it should be banned from the food supply outright, nationally."

But Alice H. Lichtenstein , a nutritionist at Tufts University, says the focus on trans fats is overblown and ignores other problems that contribute even more to heart disease, such as obesity. She praises the breadth of the Boston program and legislation proposed in New York that would require restaurants to list calorie content alongside menu items.

Trans fats " get a disproportionate amount of attention," Lichtenstein said. They are "only one piece of the whole puzzle. We still need to get people to eat more fruits and vegetables, to eat more whole grain."