Study Links Chemical Emulsifiers to Obesity

The act of emulsion is one of the wonders of nature. It's taking at least two insoluble liquids -- liquids that don't mix -- and combining them until they come together. Sometimes this is caused by adding another ingredient, and sometimes it's caused by another action (whisking furiously, for example). This is how we get things like mayonnaise, butter, and salad dressings.

As science has advanced, so have the options for what can be used as an emulsifier. Now there are chemical synthesizers that quicken the process of emulsification, doing it much more cheaply and consistently than using a natural emulsifier such as egg yolks or mustard. But a new study suggests that these chemical emulsifiers are leading to obesity.

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The study, courtesy of a team of microbiologists at Georgia State University, went as follows: Feed laboratory mice two commonly used chemical emulsifiers (polysorbate 80 and carboxymethylcellulose, both considered "generally safe" by the FDA) in doses that "model the broad consumption of the numerous emulsifiers that are incorporated into almost all processed foods," and see what happens.

Let's take a step back for a moment. In our digestive tracts are a whole bunch of microorganisms that help us do all of the things our intestines need to do. (Actually, we have more than just a whole bunch: There are ten times as many microorganisms in our intestines as there are cells in our bodies.) It's only recently been acknowledged that increased instances of obesity have been linked to this "gut bacteria." Perhaps our diets are making the bacteria less effective, or maybe our sedentary lifestyle is keeping them from remaining active. But one aspect that's agreed upon is that the bacteria is important, and should remain inside of our intestinal tract.

However, when the microbiologists examined the mice after feeding them the chemical emulsifiers:

The chemical emulsifiers were allowing the gut bacteria to escape from the gut. In mice with normal immune systems, this meant mild intestinal inflammation, which lead to overeating, obesity, and eventual insulin resistance. For mice with compromised immune systems, this lead to chronic colitis. Either is not a good result. (The team is now working to see how naturally-forming emulsifiers affect the mice's intestines, with results expected later in the year.)

Perhaps the scariest aspect of this study, though, is just what it means for us. See, the two chemical emulsifiers used in the study are found in a whole lot of processed foods. Polysorbate 80 is in chewing gums, ice creams, condiments, soaps, vitamins, and medicines. Carboxymethylcellulose (or CMC) is found in the same products, as well as in toothpastes, laxatives, and diet pills.

Complicating matters is the fact that they don't always go by those names on nutritional labels. Polysorbate 80 is sometimes referred to as by its brand names, which are "Alkest," "Canarcel," "Poegasorb," or "Tween." CMC is often listed as "E466." Not only are they ubiquitous in foods, but unless you bring a decoder ring to your grocery store, they're tough to spot as well.

What's a consumer to do? Luckily, the answer is a pretty simple and commonly-used piece of advice around these parts. The chemical emulsifiers are used in processed foods, so stay away from processed foods.

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