Salt’s Fat Chance

Salt. iStockphoto.

Salt, a precious commodity since ancient history and the most abundant non-metallic mineral in the world, has recently come under attack from public-health practitioners. iStockphoto.

The lipid hypothesis became increasingly established in research agendas, funding streams, school curricula, and federal food programs in the 1980s. Activist groups also increasingly targeted food corporations for using saturated fat. Phil Sokolof, an Omaha cholesterol crusader, took out full-page national newspaper advertisements in the late 1980s asking, “Who is poisoning America? Food processors are by using saturated fats! . . . YOUR LIFE MAY BE AT STAKE.” Sokolof accompanied his indignant messages with photos of killer products like Goldfish crackers, Oreos, and Fig Newtons.

But what could food companies use to replace saturated fats? In the 1980s the Center for Science in the Public Interest (CSPI) routinely praised food manufacturers for switching from saturated fats to partially hydrogenated vegetable oils, which contain trans fat. CSPI described Burger King’s switch to vegetable oils for its Chicken Tenders as “a boon to Americans’ arteries.” Sokolof likewise praised Burger King’s switch in his newspaper ads, and CSPI publicly expressed hope that other chains would follow suit.

Indeed, nearly every chain restaurant and packaged-food manufacturer eventually replaced them with partially hydrogenated soybean oil. This was not only because of pressure from activist groups. Partially hydrogenated oils also offer many functional advantages in frying, baking, food formulation, and shelf life. They are highly customizable for different manufacturing applications. Unlike palm or coconut oils, partially hydrogenated soybean oil is free of saturated fats and made in the USA. It’s also vegetarian and pareve—kosher with both meat and milk.

But in 1990 the New England Journal of Medicine published a clinical study from the Netherlands arguing that trans fats were probably worse for human health than saturated fats because they both raise “bad” LDL cholesterol and lower “good” HDL cholesterol. That research was confirmed in 1994 by industry-sponsored USDA research and by epidemiological findings from the Nurses’ Health Study. That same year, CSPI petitioned the FDA to add trans fats to nutrition labels on packaged foods.

Almost immediately seed companies and trade associations began to develop trans fat alternatives. Scores of manufacturers have replaced trans fats since the FDA announced labeling in 2003. Many are using soybean oils that do not require partial hydrogenation because they are crushed from beans bred to minimize linolenic acid, therefore slowing oxidation and raising their smoke point in finished products. Some companies are using sunflower oils bred for higher oleic acid, which offer similar manufacturing advantages. For baking many manufacturers have returned to palm oil, despite its saturated fat content. But many critics have consistently pointed out that a causal relationship between saturated fats and heart disease has never been proven, either clinically or epidemiologically. Walter Willett, probably America’s most important epidemiologist, has argued that the lipid hypothesis, long dominant in American nutrition research, “was overly simplistic” because diet affects heart disease through many biological pathways beside total serum cholesterol or LDL cholesterol. Willett, a lead researcher on the Nurses’ Health Study, publicly lamented the replacement of saturated fat with trans fats, telling the New York Times that a lot of doctors “had made their careers telling people to eat margarine instead of butter. . . . When I was a physician in the 1980s, that’s what I was telling people to do, and unfortunately we were often sending them to their graves prematurely.”