Emulsifying agents are common food ingredients added to ice cream, peanut butter, salad dressings and many other popular foods to prevent separation.
Take, for instance, Reese’s Peanut Butter Cup Bar, a frozen peanut butter ice cream product. In addition to sugar and high-fructose corn syrup, it contains the emulsifying agents polysorbate 80, polysorbate 65, carrageenan, and mono- and diglycerides. The addition of emulsifiers prevent separation of oils from the solids, as well as preserving the smooth mouthfeel of the ice cream, especially upon melting and refreezing. If you have ever made natural peanut butter by grinding peanuts without adding emulsifiers, you can see how readily the oil separates from the solids and rises to the top. Likewise, ice cream made without emulsifiers after partial melting and refreezing will separate into inedible ice and solids.
Emulsifiers therefore serve a purpose, making consumer food products more palatable, easier to eat, more pleasurable. But they also have substantial effects on your health.
The capacity for a compound to emulsify a solution varies from minimal to dramatic. Even some natural compounds in whole, unprocessed foods can exert modest emulsifying effects, such as acacia (acacia seeds), pectin (apples, peaches), and lecithin (egg yolks), and mustard. The most powerful emulsification effects, however, occur with synthetic or semi-synthetic emulsifying agents, such as polysorbate-80, carboxymethylcellulose, methylcellulose, sodium stearoyl lactylate, and carrageenan. In one study, for instance, polysorbate-80 increased intestinal permeability to bacteria by 59-fold. If bacteria are permitted to enter the intestinal wall, it also means that bacterial breakdown products, such as lipopolysaccharide or LPS, are also able to penetrate the intestinal lining and enter the bloodstream, thereby adding to endotoxemia, the process that drives body-wide inflammation.
The toxic effects of emulsifiers begin with disruption of the protective mucus lining of the gastrointestinal tract. The human intestinal tract is covered by a protective mucus layer that keeps bacteria and other factors away from the intestinal lining itself. The mucus barrier is continually being regenerated, but is susceptible to emulsification, like adding soap or detergent to oil. Emerging evidence suggests that synthetic emulsifiers, polysorbate-80 and carboxymethylcellulose, disrupt the mucus lining, allowing microorganisms to penetrate into the intestinal wall, a phenomenon believed to be the inciting event in ulcerative colitis. But the effects of emulsifiers don’t stop there. Once the mucus lining is emulsified, the composition of bacterial species changes, shifting it towards species that cause insulin resistance and type 2 diabetes including enrichment in Proteobacteria and Enterobacteriaceae, the species of small intestinal bacterial overgrowth, SIBO. Couple this with the increase in endotoxemia of this shift in bacterial species. While the evidence remains preliminary, I don’t believe it is a stretch to predict that synthetic emulsifiers will be shown to increase potential for autoimmune diseases, food intolerances (e.g., FODMAPs, nightshades, lectins, histamine-releasing foods, etc.), diverticulitis, as well as obesity and type 2 diabetes.
As mentioned above, there are natural, less-potent emulsifiers in otherwise healthy foods, such as eggs (lecithin) and mustard, that are unavoidable and have not been shown to exert the effects imposed by synthetic emulsifiers. We therefore opt for whole, single-ingredient foods as often as possible, thereby not containing synthetic emulsifiers.
You can also further protect yourself by being sure to include a minimum of 20 grams of a variety of prebiotic fibers per day in your diet, as prebiotics increase intestinal mucus production and favor proliferation of healthy bacterial species.