No matter how unaware you may be about the difference between soluble and insoluble fiber or why vegetarians who wish to optimize iron absorption from food should refrain from drinking tea or coffee with a meal, you surely know about trans fats. Or, at the very least, you know you should avoid them. How could you not? Popular snacks and fast food chains love to boast that their products are now “free of trans fats”.
How did trans fats become public enemy number one? As Marion Nestle, PhD, Paulette Goddard Professor in the Department of Nutrition, Food Studies, and Public Health at New York University explains, it took over a decade of lobbying by consumer interest groups like the Center for Science in the Public Interest to the Food & Drug Administration to get trans fats listed on food labels.
However, the zeitgeist occurred when “a Harvard group published a study [in 2006] estimating that trans fats were responsible for 30,000 excess deaths a year. That was enough to get public health agencies moving,” Nestle recalls.
That is, of course, only part of the equation. Step two consisted of major food companies altering their products’ formulas. Frito-Lay almost immediately removed trans fats from their line of products following the publication of that Harvard study, in turn being the first domino piece that set off a long chain of events. After all, what company wants to be known as “the one that still has trans fats in its chips”? Step three, however, was perhaps the most important — consumers noticed and cared.
Does the removal of trans fats (mainly in the form of partially hydrogenated oils) from a substantial percentage of processed foods on the market mean that consumers – and their pantries — are now safe? Not necessarily.
Many partially hydrogenated oils in shelf-stable snacks and shortening products have been replaced with interesterified fats. Whereas the partial hydrogenation of a liquid oil transforms its chemical structure in such a way that it yields a solid, yet pliable texture (i.e.: easy to spread on toast,) full hydrogenation results in a solid mass that is difficult to manage.
Cue interesterified fats. This process combines solid oils and liquid oils in vats, hydrogenates them, breaks them down to their most basic form (triglycerides) and then manipulates or reconstructs them in order to achieve a desired consistency.
While not trans fats, interesterified fats still raise a variety of health concerns. A small 2007 human study co-authored by researchers in Malaysia and the United States – sponsored by the Malaysian Palm Oil Board — concluded that interesterified fats decrease HDL (”good” cholesterol), raise blood sugar, and, suppress insulin secretion. The “one, two punch” of simultaneously raising blood sugar and lowering levels of insulin (the hormone that moves glucose out of the bloodstream and into cells) is a significant risk factor for the development of Type 2 diabetes.
I highlight the involvement of the Malaysian Palm Oil Board because most processed food manufacturers have two options when it comes to replacing partially hydrogenated oils – interesterified fats or palm oil. While there is no doubt the Malaysian Palm Oil Board has a vested interest in calling to question the use of interesterified fats, one doesn’t have to grasp for straws to conclude that the interesterification of fats does not yield anything remotely healthful.
Meanwhile, other larger studies have come to a variety of conclusions, none of them positive. Some confirm these fats’ capacity to decrease HDL cholesterol and raise blood sugar, but not suppress insulin secretion; some categorize interesterified fats as equally damaging as trans fats, while others found that interesterified fats are no more damaging than untreated saturated fats.
In the case of fast food restaurants, their supply of partially hydrogenated frying oils has simply been replaced by crop subsidy darlings corn and soybean oi, both of which offer hefty amounts of omega-6 fatty acids — the last thing the average American needs more of in their diet.
While the science sorts itself out, let common sense prevail. Reduce your intake of laboratory-created fats by making your consumption of packaged, shelf-stable snacks an occasional exception, rather than the norm. Even if free of trans fats, most of these foods offer minimal nutrition (and, in many cases, are a vessel for artificial dyes/flavorings/sweeteners, genetically modified organisms, and sketchy additives).
Remember — a banana and a handful of almonds don’t need stickers boasting the absence of trans fats because they never had them (and, therefore, don’t need to find an artificial alternative that is “not as bad”).