The scientific case for banning trans fats

The inventors of the margarine-making process won a Nobel Prize. Now we know that its byproduct is deadly

Topics: Scientific American, trans fats, Science, U.S. Food and Drug Administration, , ,

This article was originally published by Scientific American.

Scientific AmericanIn November 2013 the U.S. Food and Drug Administration made the welcome, belated determination that partially hydrogenated oils—the primary source of trans fats—could no longer be “generally regarded as safe.” At press time, the ruling is preliminary but expected to become permanent. If it does, it will virtually eliminate industrially produced trans fats in the U.S, saving thousands of lives every year, with minimal cost to industry.

In 1901 German chemist Wilhelm Normann discovered the process of partial hydrogenation, which converts inexpensive liquid vegetable oils into shortenings and margarines and creates trans fats as a by-product. Because these cheaper, longer-lasting products mimicked the traditional cooking fats of European and North American cuisines, many countries quickly incorporated them into their food supplies. In 1912 the inventors of partial hydrogenation received the Nobel Prize. It took decades for scientists to realize how deadly trans fats could be, partly because the food industry and the cardiovascular prevention community dismissed concerns over adverse effects on health, but the evidence continued to mount.

In 1980 my colleagues and I set out to examine in greater detail the relation between intake of trans fats and risk of coronary heart disease. We included trans fats in a comprehensive assessment of diet in the Nurses’ Health Study cohort of more than 100,000 women and developed a regularly updated database of the trans-fat content of foods. After eight years of follow-up and after accounting for known risk factors for heart disease, we found that women with the highest intake of trans fats had a 50 percent higher risk of hospitalization or death attributable to coronary heart disease. Margarine, the primary source of trans fat in 1980, was also associated with greater risk.

Around the same time, Dutch researcher Martijn Katan and his colleagues were investigating the metabolic effects of trans fats among healthy volunteers in carefully controlled feeding studies lasting several weeks. They found that trans fat and saturated fat increased “bad” LDL cholesterol to a similar degree—but unlike any other type of fat, trans fat also reduced “good” HDL cholesterol. Other researchers confirmed these findings and documented additional adverse metabolic effects, including increases in blood concentrations of triglycerides and inflammatory factors. Calculations suggested that eliminating industrially produced trans fats would prevent up to 20 percent of avoidable cardiac disease deaths in the U.S.



By 2003 the fda found the evidence compelling enough to require that trans fats be included on food labels. Most manufacturers responded by eliminating them entirely. Soon thereafter New York City banned their use in restaurants, and other cities nationwide followed. By 2012 approximately 75 percent of trans fats had been removed from the U.S. food supply. Blood cholesterol levels responded nationally, just as expected.

The U.S. Centers for Disease Control and Prevention has estimated that the 25 percent of trans fats still coursing through the American food supply account for approximately 7,000 premature deaths a year. The FDA’s recent decision would prevent those deaths. The food industry most likely will take the new ruling in stride. It has already phased out the large majority of trans fats, and in Denmark they have already been banned for a decade, proving that full elimination is feasible.

The FDA’s action is cause for some celebration. It means that the efforts of many scientists from many disciplines will soon lead to the elimination of a major cause of premature death. Because of the fda’s global leadership role, the ruling is even likely to stimulate similar changes worldwide. But we should not get too carried away. It is sobering that it has taken more than a century for this moment to arrive. The case of trans fats should provoke us to consider how future risks might be prevented, detected or eliminated more quickly.

More Related Stories

Featured Slide Shows

  • Share on Twitter
  • Share on Facebook
  • 1 of 11
  • Close
  • Fullscreen
  • Thumbnails
    Burger King Japan

    2014's fast food atrocities

    Burger King's black cheeseburger: Made with squid ink and bamboo charcoal, arguably a symbol of meat's destructive effect on the planet. Only available in Japan.

    Elite Daily/Twitter

    2014's fast food atrocities

    McDonald's Black Burger: Because the laws of competition say that once Burger King introduces a black cheeseburger, it's only a matter of time before McDonald's follows suit. You still don't have to eat it.

    Domino's

    2014's fast food atrocities

    Domino's Specialty Chicken: It's like regular pizza, except instead of a crust, there's fried chicken. The company's marketing officer calls it "one of the most creative, innovative menu items we have ever had” -- brain power put to good use.

    Arby's/Facebook

    2014's fast food atrocities

    Arby's Meat Mountain: The viral off-menu product containing eight different types of meat that, on second read, was probably engineered by Arby's all along. Horrific, regardless.

    KFC

    2014's fast food atrocities

    KFC'S ZINGER DOUBLE DOWN KING: A sandwich made by adding a burger patty to the infamous chicken-instead-of-buns creation can only be described using all caps. NO BUN ALL MEAT. Only available in South Korea.

    Taco Bell

    2014's fast food atrocities

    Taco Bell's Waffle Taco: It took two years for Taco Bell to develop this waffle folded in the shape of a taco, the stand-out star of its new breakfast menu.

    Michele Parente/Twitter

    2014's fast food atrocities

    Krispy Kreme Triple Cheeseburger: Only attendees at the San Diego County Fair were given the opportunity to taste the official version of this donut-hamburger-heart attack combo. The rest of America has reasonable odds of not dropping dead tomorrow.

    Taco Bell

    2014's fast food atrocities

    Taco Bell's Quesarito: A burrito wrapped in a quesadilla inside an enigma. Quarantined to one store in Oklahoma City.

    Pizzagamechangers.com

    2014's fast food atrocities

    Boston Pizza's Pizza Cake: The people's choice winner of a Canadian pizza chain's contest whose real aim, we'd imagine, is to prove that there's no such thing as "too far." Currently in development.

    7-Eleven

    2014's fast food atrocities

    7-Eleven's Doritos Loaded: "For something decadent and artificial by design," wrote one impassioned reviewer, "it only tasted of the latter."

  • Recent Slide Shows

Comments

Loading Comments...