Now that the Food and Drug Administration has moved to banish most trans fats from the nation's diet, some public health advocates are hopeful that two other beloved ingredients -- sugar and salt -- will be subject to similar scrutiny.
"Sodium is next," said Dariush Mozaffarian, a Harvard University epidemiologist and cardiologist at Boston's Brigham and Women's Hospital.
In acting to remove artificial trans fats from the food supply, Dr. Mozaffarian said, the FDA has acknowledged a scientific consensus that they are hazardous to the public's health. The same case could be said about excess dietary sodium, and that should be an equally powerful prod to FDA action, he said.
Tom Neltner, an analyst with the Natural Resources Defense Council in Washington, D.C., said sugar, too, may become a target in the wake of Thursday's FDA action.
In regulating food additives, the FDA has historically focused on removing chemicals that cause death and acute injury, Mr. Neltner said. Now the agency has demonstrated that it's ready to step in when a food additive contributes to chronic diseases that kill many people slowly.
Even compared to saturated fat -- a frequent fellow traveler -- trans fatty acid is a bad actor, knocking the blood's lipid levels into dangerous territory on two fronts. Not only does it raise levels of LDL cholesterol, the bad kind; trans fat consumption depresses levels of HDL cholesterol, which is considered protective against heart disease.
Walter Willett, a Harvard University public health professor, and colleagues estimated in 1994 that consumption of trans fatty acids caused 30,000 Americans to die prematurely of coronary heart disease each year. Other estimates have soared as high as 100,000 premature deaths per year.
In a more recent update of trans fat's toll, the Centers for Disease Control and Prevention reckoned that eliminating the remaining trans fat from American diets would prevent the premature cardiovascular deaths of 7,000 Americans and head off three times as many nonfatal heart attacks.
In an interview Thursday, Mr. Willett cautioned that regulating sodium and sugar as additives would hardly be as easy as making a decision to ban trans fats.
While trans fats have no nutritional value, salt is an essential nutrient. And sugar, when consumed at reasonable levels, is not harmful, he said. If it is to act on mounting scientific concern about dietary sodium and sugar, the FDA will have to rethink the assumption that an additive it considers to be as safe "is safe in any amount," Mr. Willett said.
The FDA's regulation of food additives has come under growing criticism in recent years, and again on Thursday with the release of a three-year assessment of the FDA's program by the Pew Charitable Trusts.
As the number and variety of substances added to food in the United States has exploded, the agency's resources -- as well as its regulatory powers under the 1958 Food Additives Amendment -- have been overwhelmed, the Pew report concluded.
The FDA has the legal authority to scrutinize any new chemicals before they are added to food and are introduced to the market, and to approve or deny their use. But in 1997, the agency acknowledged it was sitting on an overwhelming backlog of requests, and announced that it would accept voluntary notifications of planned additive use from food manufacturers.
That policy would allow a food company pondering use of a new chemical in its product to make the case that the proposed additive was "generally recognized as safe," or GRAS. Unless the FDA challenged the company's argument, the company would then be free to use the additive as it saw fit.
The review by Pew's experts found that many manufacturers of foods and food additives have bypassed the voluntary notification process altogether. The result, the report estimates that about 1,000 new chemicals have been introduced into the U.S. food supply without any FDA oversight at all.
And it's not often that the FDA kicks a food additive off the list of edibles that are "generally recognized as safe," as it did Thursday with artificial trans fats. The agency last did so three years ago, when it warned three makers of alcoholic beverages that it considered caffeine an "unsafe food additive" when mixed with alcohol and ordered their products off the market.
The last wholesale removal of an additive was in 1969, when the agency took cyclamate -- a potent artificial sweetener -- off the GRAS list. That decision was prompted by a 1966 study that found cyclamate increased the risk of bladder cancer, liver damage and birth defects in rats. Subsequent research found that cyclamate's health dangers do not extend to humans, and in 1982 there was a request to reinstate the sweetener to the GRAS list. The FDA said Thursday that the request is "not actively being considered."