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Rachel Dyckman
Rachel DyckmanRegistered Dietitian

The Impact of Dietary Emulsifiers on Gut Health

Published on October 3, 2021

If you’ve looked at the ingredient label of a packaged food lately, chances are you’ve seen food additives like maltodextrin, carrageenan, polysorbate-80, and carboxymethyl cellulose (CMC). These additives have become ubiquitous in our food supply and are commonly referred to as “dietary emulsifiers.” But what exactly are they and how do they impact our health?

What are dietary emulsifiers?

Dietary emulsifiers are a type of food additive that helps hold food particles together. They improve the texture and extend the shelf-life of many packaged foods. You have dietary emulsifiers to thank for preventing your ice cream from melting too quickly, keeping the oil and water in your salad dressing from separating, and preventing the cocoa butter from separating out of your chocolate bar.

While certain foods naturally have emulsification properties, like egg yolks, soybeans, and sunflower seeds, emulsifiers can also be chemically synthesized and added to foods. The naturally-occurring emulsifiers are benign, but certain chemically synthesized emulsifiers seem to have different effects on our bodies.

Common dietary emulsifiers​

  • Maltodextrin is derived from corn, rice, potato, or wheat starch. The starch goes through multiple processing methods, including treatment with acid and enzymes to eventually achieve a white powdery substance.
  • Carrageenan comes from seaweed that’s treated with alkaline solutions for a prolonged period.
  • Polysorbate-80 is produced through chemical processing of sorbitol, a type of sugar alcohol.
  • Lastly, carboxymethyl cellulose is made via a two-step process involving alkalinization and esterification of plant fibers.

Notice a theme here? All of these dietary emulsifiers are heavily processed, no longer resembling the ingredients they’re derived from. If you see one of these emulsifiers listed on a food label, it’s likely that that food is heavily processed too.

Where are dietary emulsifiers present?

You can find chemically synthesized dietary emulsifiers in a variety of packaged foods including (but not limited to):

  • Ice cream and frozen desserts
  • Yogurt
  • Non-dairy milks
  • Foods labeled as “low-fat”, “reduced fat”, or “fat-free”
  • Margarine
  • Mayonnaise   
  • Baked goods
  • Packaged snack foods
  • Sauces, dips, and salad dressings
  • Processed meats and meat alternatives
  • Chocolate
  • Candy
  • Icings
  • Gelatin desserts
  • Coffee creamer
  • Peanut butter
  • Spice mixes

What the research shows about dietary emulsifiers

While many dietary emulsifiers exist, maltodextrin, carrageenan, polysorbate-80, and carboxymethyl cellulose have received the most attention. Studies have alluded that these food additives may negatively impact our health. Specifically, they appear to reduce the number of good gut bacteria, increase the number of bad gut bacteria, damage the intestinal lining, and promote intestinal inflammation. Although the majority of these studies have been conducted on mice and not humans, they still raise valid concerns. 

2019 mouse study demonstrated that feeding mice maltodextrin-enriched diets caused increased susceptibility to colitis (inflammation of the colon) compared to a control group. The researchers attributed this to reduced production of mucus that’s present in the lining of healthy colons as a protective barrier. Another mouse study from 2017 found that feeding mice carboxymethyl cellulose and polysorbate-80 led to detrimental changes in their gut bacteria that are commonly found in individuals with Inflammatory Bowel Disease (IBD).

Among human studies, a 2019 randomized placebo-controlled trial of 12 participants found that adults with ulcerative colitis who consumed carrageenan capsules had an increased likelihood of developing a flare up, or period of active inflammation, after a year compared to those following a carrageenan-free diet and a control group. While the exact mechanisms behind the apparent ability of chemically synthesized dietary emulsifiers to promote gut microbiome changes and intestinal inflammation are not entirely understood, it seems likely that these additives are not doing any favors for our gut health.

Interestingly, many therapeutic diets developed for those with IBD exclude these emulsifiers, such as the Crohn’s Disease Exclusions Diet, Specific Carbohydrate Diet, and IBD-AID. These diets have shown promise in helping to promote remission in those with IBD. While their efficacy is likely multifactorial, the elimination of dietary emulsifiers may be a contributing factor.

What about gums and lecithins?

By now, you may be wondering if gums and lecithins have the same effect, as they seem to be in practically every packaged food these days—even the “healthy” ones. 

Interestingly, gums (like guar gum, locust bean gum, and xantham gum) seem to be potentially beneficial for our good gut microbes. Some preliminary animal studies suggest that these gums may have a prebiotic effect, meaning they selectively feed our good gut bacteria. 

Lecithins contain a compound called phosphatidylcholine, which is a component of the protective mucus barrier lining our colon. Some studies suggest that by strengthening this mucus barrier, lecithins may actually help to reduce intestinal inflammation. This may be particularly relevant for those with ulcerative colitis, a condition associated with a sparse protective mucosal layer lining the colon.

Should you avoid dietary emulsifiers?

Before you decide to banish maltodextrin, carrageenan, carboxymethyl cellulose, and polysorbate-80 from your diet entirely, it’s important to note that the research in this area is still evolving. While mouse studies provide helpful insight, their findings cannot necessarily be generalized to humans. Further, the studies conducted on humans have small participant sample sizes. Additionally, the threshold for which consumption of these additives becomes harmful in humans is unknown.

Taking these factors into consideration, it is likely that individuals with conditions stemming from intestinal inflammation, such as IBD, would benefit from avoiding them as much as is feasible. Those who may be genetically predisposed to developing IBD, such as individuals who have a first degree relative with IBD, may also want to consider avoiding these additives. Additionally, those at increased risk for colon cancer would likely benefit from avoiding these emulsifiers.

Will a little maltodextrin or carboxymethyl cellulose every so often make or break your gut health? No. But if foods containing these additives are staples in your diet, you may want to find alternatives.

Tips for avoiding emulsifiers

If you choose to avoid dietary emulsifiers, the easiest way to do this is to eat mostly whole, minimally processed foods. You won’t find maltodextrin in olive oil and balsamic vinegar, but you will likely find it in a bottle of flavored salad dressing.

“Reduced fat” or “fat free” foods are notorious for containing emulsifiers, since they improve food texture and mouthfeel to compensate for the lack of fat. Luckily, it’s required by law that dietary emulsifiers be listed on food ingredient labels. When checking ingredient labels, do a quick scan for the words “maltodextrin”, “carrageenan”, “polysorbate-80”, and “carboxymethyl cellulose” (sometimes listed as “CMC”).

The Fig mobile app make this easy by scanning ingredient lists for you, helping you to identify foods free from dietary emulsifiers. You can also input any other dietary needs you have, including diets, allergies, and any ingredient.

The bottom line

The research on chemically synthesized dietary emulsifiers is still in its early stage. However, those with or at risk for developing inflammatory conditions of the GI tract would likely benefit from avoiding them. If you frequently rely on foods that contain dietary emulsifiers, opting for alternatives that contain gums and lecithins or naturally occurring emulsifiers instead, is likely a healthier option. Consuming mostly whole, minimally processed foods is not only the easiest way to avoid emulsifiers, but it is also something that we should all strive for to promote overall health.

Have you heard of the Fig app? Simply tell Fig any ingredients you wish to avoid, and Fig will show you thousands of products that don’t have those ingredients. You can also scan products at the grocery store to see if they fit your needs!