Trans-fats Are Out, But What Are The Replacements?

Health & Wellness on 02.11.13
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The grand experiment with industrial foods continues. When studies first found that saturated fats in the diet lead to heart disease, food producers tried to help us out with better alternatives. But using the healthy fats causes problems for industrial food processing: the healthy fats give less desirable textures, are harder to handle, and do not store as long before going rancid.

Trans-fats for Better Health: FAIL

When food chemists came up with the idea of hydrogenating oils to give them a longer shelf life, they could also imagine that the reduction in saturated fats would be good for public health. Margarine, a miracle of modern technology, replaced butter on the tables of concerned parents everywhere.

Unfortunately, the evidence has mounted that putting artificial trans-fats in our bodies gums up the works. The bans began locally, and as the news spread, trans-fats began being widely replaced or legally forbidden.

Now products proudly boasting "Trans-fat Free!" proliferate on grocers' shelves. Never mind that it is legal to say trans-fat free on products containing up to half a gram of trans-fats per serving. Never mind that studies show the "halo effect" of claims like trans-fat free lure people to eat more of the foods that are still high-fat and low in nutritional content. The question on our minds now is: what are they using to replace the trans-fats?

Enter Interesterified Fats

...another hard-to-pronounce and harder-to-understand label ingredient. The number one replacement for trans-fats are named after a process that swaps out the parts of the fats to produce yet another range of food ingredients that cannot be found anywhere in nature. And that is concern number one: since these new fats are not natural, we have no historical evidence for what eating them will do to our bodies.

This fact alone suffices for interesterified fats to make internet lists such as the 11 scariest things in your food, or headlines like The Dangerous Replacement for Trans Fats. But are these claims true?

Could Interesterified Fats Be a Real Health Miracle?

You can think of a fat molecule like a bicycle with three seats. Three fatty acids can sit on the bicycle, which has the fitting name "triglyceride". Interesterification allows food chemists to swap out the fatty acids sitting on each bicycle seat. By replacing the kinky polyunsaturated fatty acids in vegetable oils with a straighter fatty acid (most commonly stearic acid, the predominant fatty acid in animal fats), food scientists get a new fat molecule that goes rancid more slowly and has the properties food processors need. So here is the interesting point: are we getting close to the point where we can build fats that are even better for human health than what nature produces?

As scientists learn more about how we metabolize fats, and how they affect good and bad cholesteral levels, tendencies to diabetes, or inflammation reactions that are suspected contributors to a whole range of illnesses, one thing is clear. The case is not as simple as saturated fats versus unsaturated fats.

It makes a difference which fats (fatty acids) sit in which places on the bicycle. It makes a difference whether the unsaturated fats are omega-3, omega-6 or omega-9 -- as well as what ratio of omegas we eat. And recent research has shown that stearic acid, the "secret ingredient" in most transesterified fats, does not increase the risk of heart disease as other saturated fats do.

Messing With Mother Nature

You can't blame the food chemists and marketers for thinking they are doing good in the world. But that brings us back to where we started: do we really know what we are doing when we mess around with mother nature?

While most of the (relatively small amount of) scientific literature on interesterified dietary fats shows that consumption of interesterified fats have no negative effects, one study backed by the Malaysian Palm Oil Board found that interesterified fats were just as bad as trans-fats for cholesterol levels. Worse, the report found fasting blood glucose levels "rose to a range that could be considered prediabetic after only 4 weeks" on the interesterified fat rich diet. Critics point out the fats used in the study had much higher saturated fatty acid percents than typical interesterified fats, and of course, the study sponsor  would want to see results that defend the naturally saturated palm oil.

So, as usual, we are stuck with frankenfoods that have insufficient scientific data to make a good decision on food safety. While we await further studies on interesterified fats, we recommend the precautionary principle. Most of the foods containing these processed fats are not good for our kids anyhow, so they should not be so hard to avoid or minimize in a healthy diet.

Finding Interesterified Fats on Labels

Manufacturers proud of their new ingredient may actually put "interesterified fat" or "interesterified oil" on their labels. Other code words to look for include "high stearate" or "stearic rich". If you see the term "fully hydrogenated", it means there are no trans-fats (which occur only with partial hydrogenation), but it may mask interesterified fats -- at least you have the clue that you are dealing with a processed food.

And, of course, "trans-fat free" should raise alarms. It is a marketing gimmick, not a health claim. Bottom line: Keep a diet rich in healthy fats, and the bad fats from an occasional snack should not cause you worry.


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