MELISSA BLOCK, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block in Washington D.C.
AUDIE CORNISH, HOST:
And Audie Cornish, this week in California. The mysterious words partially hydrogenated vegetable oil may soon disappear from food product labels. The reason, that kind of oil contains artificial trans fats and they're the worst kind of fat. They raise the risk of heart disease. For years now, under pressure, food companies have been reducing their use of trans fats.
Today, the Food and Drug Administration proposed to get rid of them once and for all. NPR's Dan Charles has more.
DAN CHARLES, BYLINE: Partial hydrogenation is what it sounds like. You add some hydrogen atoms to a molecule of oil, often it's soybean oil. Kantha Shelke, a scientist with the Institute of Food Technologists in Chicago, depending on how you introduce hydrogen, you can make liquid oil a little more solid or a lot more solid.
KANTHA SHELKE: So we could literally dial the needle to as solid as you wanted it, and get the kind of results we were looking for.
CHARLES: Results like baked goods that don't start tasting rancid after a few weeks. Cookies or donuts that don't leave a ring of oil behind on a paper towel. Also, this oil doesn't have a strong taste of its own. You can use lots of it without noticing any change in taste.
SHELKE: It's really absolutely perfect, and then it's also perfect for the American style of shopping, which is you buy boxes and boxes of crackers, leave them in your pantry. You open this box six months, or eight months or a year later.
CHARLES: And it's still good. Now, partially hydrogenated oil came on the market about a century ago. By the time the government came up with laws regulating such things, people had been eating it for decades with no apparent problems.
DAVID SCHLEIFER: Products that were in the food system before that generally got a pass.
CHARLES: David Schleifer is a researcher at a nonprofit group called Public Agenda, in New York, and he wrote is dissertation on the history of trans fats. The government put these ingredients into an unregulated category called generally recognized as safe. Schleifer says most scientists at the time actually thought this kind of oil was probably safer than lard or palm oil.
McDonald's, for example, used to fry things in beef tallow.
SCHLEIFER: People freaked out about beef tallow because it had saturated fats and McDonald's responded to that public outcry by replacing beef tallow with trans fat.
CHARLES: Everything changed in the mid-1990s. New studies showed that trans fats raised bad cholesterol and increased the risk of heart disease. In fact, they were even worse than saturated fats. In 2006, after a campaign by public health advocates, the Food and Drug Administration required food companies to add trans fats to food labels.
Most companies responded by drastically cutting their use of partially hydrogenated oil, but not every company and not every product. You can still find them in microwavable popcorn, frozen pies and pizzas, all kinds of baked goods, in fact. Often, food companies use just a little bit. If there's less than half a gram of trans fats per serving, they can put zero trans fats on the label.
Today, Margaret Hamburg, the FDA commissioner, announced that the agency is now taking the next step.
MARGARET HAMBURG: The agency has made a preliminary determination that partially hydrogenated oils are not generally recognized as safe for use in food.
CHARLES: If the FDA makes this preliminary decision final, it will mean a complete ban on this ingredient.
SHELKE: Is this a big deal for our food manufacturers? Yes, it's a very good deal.
CHARLES: Kantha Shelke from the Institute of Food Technologists says food companies can drop the trans fats, but their products won't be quite the same.
SHELKE: They have to go back to re-educating consumers that cookies and crackers don't last forever.
CHARLES: The cookies will have a shorter life, but your life may be longer. Dan Charles, NPR News.