In the kitchen, an ingredient’s taste is sometimes less important than its function. Cornstarch has rescued many a watery gravy; gelatin turns juice to Jell-O. Yet the substances that make bread fluffy, hold mayonnaise together, and keep the cream in ice cream have, according to the new stance of the United States government, “no culinary use.”
These natural and synthetic substances, called emulsifiers, are added to processed foods to give them the textures that Americans have come to love. They’ve also become targets in Health Secretary Robert F. Kennedy Jr.’s push to remove many food additives from the American diet. The “Make America Healthy Again” report, published in May, groups emulsifiers with other additives, some of which it says are linked to mental disorders, metabolic syndrome, and cancer. Online, the MAHA crowd echoes claims that emulsifiers are helping drive America’s chronic health problems.
Like seed oils and food dyes, emulsifiers have raised some real health concerns, particularly about gut health. But distinguishing their ill effects from those of the foods they’re in is challenging—and probably a distraction from the diet changes that would really make Americans healthier.
To anyone who’s attempted (and failed) to make a smooth vinaigrette using only oil and vinegar, MAHA’s assertion that emulsifiers have no culinary use is an affront. Any recipe that calls for blending two substances that don’t mix well together requires emulsifiers’ magic touch. Their molecular structure is drawn to watery substances on one end and fat-based ones on the other, bridging ingredients that would otherwise separate. In a vinaigrette, a dollop of mustard does the trick. Mayonnaise, essentially a blend of oil and a water-based acid, such as vinegar, is spreadable thanks to a natural emulsifier: egg yolks. Similarly, adding eggs to milk prevents ice cream from separating into solid milk fat studded with ice shards (yum).
Not all emulsifiers are as recognizable as eggs and mustard. Many commercial ice creams swap eggs for cheaper synthetic emulsifiers. Cake mixes are foolproof because chemicals called propylene glycol esters prevent powdered fats from clumping. Monoglycerides and diglycerides add structure to and extend the shelf life of bread. Xanthan gum thickens creamy salad dressings. The MAHA report makes no distinction between purely chemical emulsifiers and those that are naturally occurring, such as egg yolks and soy lecithin. So far, studies have not definitively identified differences in their effects on human health.
Perhaps because they are so useful, emulsifiers are in about half of supermarket foods sold in the United Kingdom, according to a 2023 study of the country’s four largest supermarkets; one study in France found that they account for seven of the top 10 most-consumed food additives among adults. So far, their prevalence in the U.S. food system hasn’t been studied, but given the dominance of processed food in the American diet, it’s safe to say that we eat a lot of them.
In Kennedy’s view, that abundance of emulsifiers is at least partly responsible for America’s chronic-disease epidemic. In May, he promised to investigate and ban food additives that are “really dangerous.” But so far, the research on emulsifiers doesn’t justify such a label. In 2017, an FDA-led study concluded that seven common emulsifiers didn’t raise any safety concerns at the usual levels of consumption. The agency’s calculations have “a lot of safety built in,” says Renee Leber, a food scientist at the Institute of Food Technologists, a trade group. There’s no reason to expect that Americans would ever consume enough emulsifiers to spark serious health concerns.
Still, looking further into emulsifiers’ health impacts isn’t a bad idea. A growing number of studies suggest that some can harm the gut, perhaps by shifting the balance of the gut microbiome. They may also damage the gut’s protective mucus layer, leaving it more vulnerable to inflammation and bacteria. A few studies suggest a link between the inflammation that some emulsifiers cause and certain illnesses, including Crohn’s disease, metabolic syndrome, and type 2 diabetes. But other research has turned up conflicting results; a study published last year linked a high-emulsifier diet to a better-protected gut.
Even emulsifier experts aren’t sure exactly what the substances do in the body. Research on how they affect intestinal health is “very much a work in progress,” Benoit Chassaing, a professor at the Institut Pasteur, in Paris, told me. It also still isn’t clear which ones, if any, have the most potential for harm. In a 2021 study, Chassaing and his colleagues used a model to test the effects of 20 common emulsifiers on the gut microbiome. Only two of them—the synthetic emulsifiers carboxymethylcellulose (found in vitamins and dietary supplements) and polysorbate 80 (usually in edible oils and cake icing)—were determined to have lasting negative consequences. Chassaing has also found that some people’s microbiomes are more sensitive to emulsifiers—which is to say, conceivably emulsifiers could have different effects on different people. Without large-scale human trials, none of the research on emulsifiers can be considered conclusive. As the authors behind the 2024 study wrote, “For now, do not feel guilty if you eat ice-cream!” (At least, not because you’re consuming emulsifiers.)
None of this has deterred Kennedy from fearmongering about additives like emulsifiers. Instead, he’s continuing a pattern that by now has become a MAHA signature: In the health secretary’s campaigns against seed oils and food dyes, he has exaggerated modest scientific findings to justify grand allegations that additives drive chronic disease. Some skepticism of these ingredients may be warranted. But Kennedy’s critiques lack nuance at a stage when nuance is all that the current research can provide.
A MAHA-led deep dive into these questions could turn up some genuinely useful information. If certain emulsifiers are especially gentle on the gut, the food industry could use them to replace the ones that might be more irritating. Identifying what makes certain people more sensitive to them could shape criteria for prescribing emulsifier-free diets.
But what Kennedy plans to do about emulsifiers beyond investigating their safety is anyone’s guess. When I asked the Department of Health and Human Services about it, Emily G. Hilliard, a press secretary, told me that “Secretary Kennedy is committed to ensuring transparency in the food supply so that Americans know exactly what’s in their food.” Banning any emulsifiers that might be found to cause serious harm would be prudent, but then foods that contain them would have to be reformulated—a costly, time-consuming endeavor. For some foods, that might not even be an option: Without an emulsifier, natural or synthetic, ice cream “just wouldn’t be plausible,” Leber told me.
If Kennedy aggressively pursues bans or some other type of restrictions, it will be worth stepping back and asking what the administration is really trying to achieve. The health effects of emulsifiers haven’t yet been fully distinguished from those of the foods they’re in (which tend to have high levels of fat, sugar, or both), nor have those of seed oils and food dyes. In fact, the science points to the likelihood that emulsifiers’ potential harms are minor in comparison with more basic nutritional problems. But maybe ditching emulsifiers could act as some roundabout way of nudging Americans toward eating healthier, if Kennedy is prepared to rob us all of ice cream.
In May, Kennedy announced that food additives and processed foods would be the “central focus” of his health administration. But really, that indicates just how unfocused his movement is. The MAHA report rails against American overconsumption of high-sugar, high-fat, ultra-processed foods, yet so far, it hasn’t been able to do much to limit their consumption beyond eliciting a nonbinding promise from Kraft-Heinz and General Mills to remove dyes from foods like mac and cheese and Kool-Aid, and encouraging people to cook french fries in beef tallow. Removing or replacing emulsifiers could result in some health gains, but none that are likely to outweigh the health consequences of eating the foods that contain them.
