Recent FDA action on trans fats, moving toward a ban and signaling the beginning of the end of the trans fat era, is very welcome and, if anything, overdue. Trans fats are not just harmful in their own right but vividly illustrate much of what bedevils modern nutrition, or as Michael Pollan has called it, "nutritionism." Before getting back to getting rid of trans fat and what lies ahead, let's look back to see how we got into this mess in the first place.
Trans fat was first introduced into the food supply in an apparently innocent attempt to reduce the adverse effects and mimic the desirable commercial properties – stability and high melting point – of saturated fats. The trans fat era was ushered in by food packages that boldly proclaimed "no tropical oils!" The so-called tropical oils, coconut and palm, had in turn been introduced in the late 1980s to replace highly saturated animal fats. Palm kernel oil and coconut oil are among the very few highly saturated plant oils.
Eventually, and without much help from food labels, the word about "tropical oils" got out. In 1990, the Council on Scientific Affairs of the American Medical Association published a position statement calling for clear disclosure to the public that tropical oils were highly saturated and potentially dangerous.
With the writing on the wall, if not the food package, the creative food industry solution was to invent a new kind of fat.
An industrial process called partial hydrogenation produces trans fat. The trans configuration causes fat molecules to pack closely together, resulting in the desirable commercial properties found in saturated fat. Regrettably, while trans fat reliably extends the shelf life of foods, it clearly shortens the shelf life of people eating those foods – and more so than saturated fat ever did.
[Read: The Myth of Healthy Processed Food.]
The science implicating trans fat in raising the risk of serious chronic disease is essentially ironclad. Numerous research papers and reviews implicate trans fat in raising blood markers of inflammation, adversely affecting blood lipid levels and damaging the lining of blood vessels. Population studies suggest a strong link between trans fat intake and the risk of heart disease, diabetes and cancer. It is, in a word, poison. A slow poison, admittedly, but so are lead, mercury, and arsenic.
As for the misguided tendencies that got us into this mess, here they are in no particular order.
In nutrition, if not more generally, we routinely fail to differentiate baby from bathwater. The introduction of trans fats into the food supply resulted from what increasingly appears to be an excessive fixation on saturated fats in the first place. We recognized harms of diets high in saturated fat and pinned all that harm on the saturated fats rather than the overall dietary pattern.
The evidence was indeed strong that populations eating lots of animal foods and the saturated fats they contained had worse health outcomes than populations eating mostly plants. But the implications of that were that we should all have started eating mostly plants, not that we should have gorged ourselves on Snackwell cookies. Saturated fat has not been fully exonerated of potential harms by any means, but it is clear both thatsaturated fats are not all created equal and that we can cut saturated fat and fail to improve our diets.
[See: 7 Reasons to Choose a Plant-Based Diet.]
Similarly, we indicted dietary cholesterol, mistakenly in my opinion, with the apparent result that America now runs on donuts while avoiding eggs– and just look around to tally all the good that's done us!
Diets and foods can offer pros and cons depending on quantity and context. Summary judgments about nutrient classes or food groups that fail to differentiate baby from bathwater have caused years of opportunity to improve public health nutrition to go down the proverbial drain.
2. The Law of Unintended Consequences
The precautionary principle argues that potential harm must be presumed when new exposures are imposed on populations and that the burden of proof resides with demonstrating safety. When trans fat was blithely put into every kind of processed food, we did not have experience with it to know that it would be safe – and had no valid reason for assuming it would be. The warm welcome trans fat received into our pantries was born of market forces, not public interest. The abundant experience we have with the unintended consequences of food supply trends in the modern era argues strongly against waiving the precautionary principle.We have done so repeatedly, alas, and to our collective detriment every time.
We became preoccupied with saturated fat, replaced it and got fatter and sicker. We became preoccupied with carbs, cut those and got fatter and sicker. We became so preoccupied with sugar that when it was first introduced, high-fructose corn syrup was thought to be an improvement, even as it has now evolved into something of a scapegoat. There is a basic way of eating well and lots of ways to eat badly – and we keep inventing more of the latter. The trans fat boondoggle replicated, and propagated, the follies of recent nutrition history.
[Read: Best Diets for Healthy Eating.]
Hearing that your LDL cholesterol value is perfect would be of little comfort if you were on a gurney in the emergency department following a gunshot or car crash. With health, it's the big picture that matters, and no single metric can capture it. The same is true of nutritional quality. Pure trans fat is both cholesterol and fructose free; so what? Fructose is trans fat free for that matter.
We have focused far too excessively on single nutrient properties and missed the dietary forest for the trees again and again. Even health care professionals have propagated this "one nutrient at a time," or ONAAT fallacy, with endocrinologists warning their diabetic patients away from sugar and cardiologists warning about saturated fat and cholesterol. The truth is, and always was, that wholesome foods making up a healthful diet tend to be good for us all, no matter what does or might ail us, and that foods can avoid any given nutrient and still be junk. Health, and nutrition, are holistic – or devolve into nonsense.
Given where we are now with trans fat, it may stun people to recall that in 2006, when New Jersey state Sen. Ellen Karcher proposed a statewide ban on trans fats, she received death threats that made national news. Sen. Karcher was emulating the actions of Tom Frieden, New York City health commissioner at the time and now director of the U.S. Centers for Disease Control and Prevention.
This reaction to the senator's proposal epitomizes yet another impediment to dietary health: polarized ideology. Some of us are so concerned about the intrusion of nannies into our lives that we turn into abject ninnies.
Consider, for instance, if lead improved the texture of ice cream, arsenic made French fries crispier or a dollop of dioxin gave your salad dressing extra zest. Would it be acceptable to add these known poisons to our food? Should you, as the consumer, need to inquire about them at every restaurant?
[Read: 10 Things the Food Industry Doesn't Want You to Know.]
Like dioxin, trans fat contributes to cancer risk. Like lead, arsenic and mercury, trans fat is a slow poison. Chefs are not permitted to explore the culinary properties of known poisons in their recipes, and nobody seems to be railing against it. Trans fat, quite simply, should be added to the list. It seems now it will be, but that doesn't mean there won't be resistance to regulation this time, or next. The trans fat experience invites us all to put epidemiology ahead of ideology, to recognize that we can have too little or too much regulation and to consider coming together on a patch of common ground somewhere between nannyism and ninnyhood.
The removal of trans fat from the food supply – a process underway but not yet completed – has the potential to prevent thousands of heart attacks and deaths each year. So yes, the news is good as far as it goes.
But it doesn't go far enough to get us entirely out of the woods, because food formulations and labeling alike still often serve the interests of sellers rather than eaters. A multigrain bread may or may not be whole grain. An apricot jam may contain more sugar than apricot yet list apricot as the first ingredient because the sugar is divvied up into four different aliases, each one alone less abundant than apricot but substantially more abundant if all added together and just called "sugar."
[Read: How and Why to Rid Sugar From Your Diet.]
Low-fat peanut butter may imply a nutritional virtue while staying silent about the fairly copious additions of sugar and salt that make it far less nutritious overall than regular peanut butter. Not only that, but such "pseudo-nutritious" foods tend to cost more, adding insult to injury and propagating the urban legend that you have to spend more to get better nutrition. You don't; but you do need to be able to identify those more nutritious choices in the first place.
For now, we can welcome the beginning of the end of the trans fat era and bid this misadventure in modern food processing good riddance. But the history of recent decades suggests we will need to remain vigilant if we hope to love food that loves us back. While trans fats are going, it's far from clear that true transparency in food labeling is coming any time soon. Until true food and the whole truth about food both prevail, it isn't quite time for champagne and confetti. We are still in the era of "caveat emptor."
[See: Top-Rated Diets Overall.]
Hungry for more? Write to eatandrun@usnews.com with your questions, concerns, and feedback.
David L. Katz, MD, MPH, FACPM, FACP, is a specialist in internal medicine and preventive medicine, with particular expertise in nutrition, weight management, and chronic-disease prevention. He is the founding director of Yale University's Prevention Research Center, and principal inventor of the NuVal nutrition guidance system. Katz was named editor-in-chief of Childhood Obesity in 2011 and is president-elect of the American College of Lifestyle Medicine. His latest book, "Disease Proof: The Remarkable Truth About What Makes Us Well," was released in September.