Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Brands

Yoga Food, Nutrition, & Recipes

This Everyday Ingredient May Be Messing With Your Gut

Here's what you need to know about emulsifiers.

Get full access to Outside Learn, our online education hub featuring in-depth yoga, fitness, & nutrition courses, when you sign up for Outside+.

Skim the labels on nearly any packaged food in the supermarket and you’re bound to find a few ingredients that aren’t in your kitchen cabinets. But while you’re fretting about high-fructose this and artificial that, scientists have uncovered a potential new threat in your favorite energy bar: emulsifiers—ubiquitous food additives that are almost impossible to avoid.

Compared to the added sugars, salt and artificial colors or flavors pumped into many packaged foods, most people don’t give emulsifiers much thought. But emerging research is questioning whether we should be eating them so liberally.

Here’s what the latest science has to say about emulsifiers and if it’s time to say goodbye to spiking your morning coffee with oat milk.

What exactly are emulsifiers?

There are plenty of good reasons why food and beverage manufacturers have a fondness for emulsifiers. These food additives can extend shelf-life, alter the taste of the final product, improve structure and, most importantly, produce a consistent blend of two or more ingredients such as oil and water to allow for a better texture. There’s a reason why your favorite almond milk doesn’t separate and instead stays creamy. Emulsifiers also reduce stickiness and help foods like ice cream maintain a smooth texture.

Examples of emulsifiers, of which there are many, include polysorbate, lecithin, carrageenan, and anything with the word “gum” in it — including gellan gum, locust bean gum and guar gum. Emulsifiers can be man-made or naturally occurring in plants, animals and aquatic sources.

Nowadays, they’re everywhere, showing up in most package foods. Salad dressings, baked goods, mayo, hot sauce, bread, protein powders, deli meats, candy, plant-based meat products, margarine, nut butters, chocolates, dairy-free milks, baked goods, ice cream and even green powders commonly contain them — who knew? This makes emulsifiers the most common food additive in the American food supply. Due to their ubiquity, these substances are consumed daily at various levels by almost everyone and by the mega-ton by the country as a whole.

Should you worry about eating emulsifiers?

Though the Food and Drug Administration has deemed the various guises of emulsifiers in our foods as being Generally Recognized as Safe, concerns remain about their potential impact on our gut microbiome.

For a quick review, trillions of bacteria, viruses and fungi make up the microbiome in your digestive tract, some of which are associated with disease while others are extremely important for your health, including improving digestive, immune system, heart and brain functioning. They may even have a role in helping regulate body weight. There are more bacterial cells in your body than human cells. And, concerningly, emulsifiers may deliver a gut punch.

In a randomized controlled-feeding study published in the journal Gastroenterology, healthy adults who were housed at a designated study site for 11 days consumed an additive-free diet or an identical diet supplemented with 15 grams of carboxymethylcellulose (CMC), an emulsifier also known as cellulose gum that is added to a wide range of packaged foods. CMC consumption changed the make-up of bacteria populating the colon of participants, reducing select beneficial species. Fecal samples from CMC-treated participants showed a large depletion of bacteria-produced metabolites that are thought to help maintain a healthy colon. Lastly, the researchers noticed that a small subset of subjects consuming CMC displayed bacteria encroaching into the normally sterile gut mucus layer, which they say has previously been observed to be a feature of inflammatory bowel diseases like colitis and colon cancer as well as type 2 diabetes.

This is far from the only research to link dietary emulsifiers with the potential development of gut issues. A study of 20 commonly used emulsifiers by food manufacturers published in the journal Microbiome found that many of them appeared to have a negative impact on intestinal microbiota composition and function in a way that could drive up inflammation. Worth noting is that lecithin, an emulsifier used in various foods including dark chocolate, was not found to be problematic for microbiome health. This study using a model of the human intestinal ecosystem found that the emulsifiers carboxymethylcellulose (say that three times fast) and polysorbate 80 may increase the inflammatory potential of the microbiome. This occurred via the emulsifier’s power to alter microbiota to increase levels of flagellin, a protein that can lead to intestinal inflammation.

Another emulsifier, sodium stearoyl lactylate, was shown to alter the microbiome population away from beneficial species and more towards potentially detrimental critters that result in what is known as gut dysbiosis and a resulting decrease in the production of short-chain fatty acids. Also known as postbiotics, short-chain fatty acids have a beneficial impact on human health. The common emulsifier carrageenan may favor a pro-inflammatory environment in our bodies by messing with the micro-critters in our guts.

This report in the journal Nature suggests acute exposure to the emulsifiers carboxymethylcellulose and polysorbate 80 can harm the mucus layer of our digestive tract, changing the ways that our microbes can function and contributing to the development of intestinal inflammation. Sometimes this is known as a “leaky gut” where inflammatory molecules are allowed to enter the bloodstream because the ease with with molecules can enter and exit the intestines is compromised. By altering the barrier between the body and the food and pathogens that enter the gastrointestinal tract, it is possible that dietary emulsifiers might play a role in conditions such as coronary artery disease, type 2 diabetes, colon cancer, irritable bowel syndrome, colitis and Crohn’s disease.

What’s more, it’s been suggested that by harming the lining of your gut, emulsifiers interfere with the way neurons in the digestive tract trigger the release of appetite-regulating hormones. This could then make it harder to regulate your appetite and lead to overeating that could spiral into weight management problems and metabolic conditions. This might be one reason why people are prone to overeating ultra-processed foods, which almost universally contain emulsifiers. But this science is still in its infancy and we need more evidence before we can say the gum arabic and carrageenan in the food supply can make it harder to practice portion control.

For these reasons, some scientists believe these additives are correlated to the rise in inflammatory bowel diseases such as ulcerative colitis and metabolic syndrome since the mid-twentieth century when emulsifier consumption via package food shot upwards.

Studies have shown that populations around the world that eat fewer packaged foods in favor of lesser processed whole foods tend to have a lower risk for several chronic diseases and overall live longer in good health. Maybe limiting the intake of emulsifiers in processed foods could be playing a role?

But before we should deem emulsifiers a health pariah, there are a few things you should keep in mind. To date, most of the research has been conducted on animals or isolated human intestinal cells and tissue — not many studies have been conducted on the gut flora of living, breathing humans. Some research uses levels far in excess that what we typically would consume day to day. The FDA still maintains that they have not uncovered any safety concerns with common emulsifiers at current consumption levels.

Also, it is not well known whether these effects are generalizable across all emulsifiers — perhaps some are more harmless than others. Since there’s a dizzying array of approved emulsifiers in the food supply, sussing this out will take a lot of research dollars. We need to better understand what threshold emulsifier exposure is problematic. If the only emulsifiers you consume each day is from a glass of oat milk and protein bar, is this problematic?

There could be an additive effect at play here, and pre-existing conditions may make a person more susceptible to the ill effects of emulsifiers. So if a person already has irritable bowel syndrome, high intakes of these additives may compound the problem, whereas a healthy person may get away with more exposure. Responses could be highly personalized, with people responding differently to different food additives.

Finally, it should be stressed that, though these additives may contribute to health problems, they likely aren’t the main culprit in processed foods — that spot is likely still reserved for added sugars, saturated fat and sodium.

Action point

Still, it would be wise not to brush off this preliminary research. Instead, use it as a good motivator to trim some of the emulsifiers from your diet until we have a better grasp on their role in our long-term health. Your number one way to do so is to limit your intake of processed packaged foods, especially those that can be considered ultra-processed. And read food labels looking for options that are made without these food additives. Some products may contain three or more emulsifiers in their ingredient list, which should be a red flag.

You can also take a DIY approach to reduce your intake of emulsifiers. This means getting in the kitchen and preparing homemade energy bars, salad dressings, baked goods and dairy-free milks. It is not likely that a lot of home cooks are reaching for the gellan gum when making a batch of chocolate chip cookies.