Emulsifiers and thickeners: the additive class under active research

Emulsifiers get little public attention, and right now they have the most active research behind them of any additive class.

They have no taste or colour and no obvious purpose to a shopper, so they slip past unexamined. Whether they affect the human gut is not yet known.

What they do

Oil and water separate. An emulsifier has one end that likes water and another that likes fat, so it sits at the boundary and holds the two together. That is why ice cream stays smooth, salad dressing does not split, chocolate flows in a mould and plant milks stay mixed in the carton.

Thickeners and stabilisers do a related job, giving body to something that would otherwise be thin. The three functions overlap so much that a label often lists them together, and they share a number range.

Where they come from

Most of them come from plants. Guar gum comes from a bean and locust bean gum from carob seeds. Pectin comes from apples and citrus peel, gum arabic is tree sap, and carrageenan and agar come from seaweed. Lecithin is usually from soy or sunflower.

A smaller group is manufactured: the polysorbates, carboxymethylcellulose, the mono- and diglycerides, DATEM. These are the ones the research has focused on.

The full list

Every emulsifier and thickener in our database, with its E number where it has one.

Food	Notes
Polysorbate 60E435	Polysorbate 60 (E435) is a emulsifier food additive.
Polysorbate 80E433	Polysorbate 80 (E433) is a emulsifier food additive.
CarboxymethylcelluloseE466	Carboxymethylcellulose (E466) is a emulsifier food additive.
Polyglycerol polyricinoleateE476	Polyglycerol polyricinoleate (E476) is a emulsifier food additive.
Gellan gumE418	Gellan gum (E418) is a emulsifier food additive.
Gum arabicE414	Gum arabic (E414) is a emulsifier food additive.
Locust bean gumE410	Locust bean gum (E410) is a emulsifier food additive.
DatemE472	Datem (E472) is a emulsifier food additive.
Propylene glycolE1520	Propylene glycol (E1520) is a emulsifier food additive.
Gelatin	Gelatin is a protein from animal collagen. A gelling agent used in desserts and candies.
Sodium stearoyl lactylateE481	Sodium stearoyl lactylate (E481) is a emulsifier food additive.
PectinE440	Pectin is a natural fruit gelling agent. A carbohydrate used to thicken jams and jellies.
Mono- and diglyceridesE471	Mono- and diglycerides (E471) is a emulsifier food additive.
Xanthan gumE415	Xanthan gum is a thickening and stabilizing agent. A polysaccharide used in gluten-free baking.
LecithinE322	Lecithin is a fatty substance emulsifier. A natural additive that helps ingredients blend smoothly.
CarrageenanE407	Carrageenan is a seaweed-derived thickener. A gelling agent extracted from red seaweed.
Agar-agarE406	Agar-agar is a gelatin substitute from seaweed. A plant-based gelling agent used in Asian desserts.
Maltodextrin	Maltodextrin is a emulsifier food additive.
Guar gumE412	Guar gum is a thickener from guar beans. A binding agent used in gluten-free baking.
Modified starchE1400	Modified starch (E1400) is a emulsifier food additive.

What the research found

In 2015 a study fed mice polysorbate 80 and carboxymethylcellulose at concentrations meant to approximate human intake. The mice showed thinning of the protective mucus layer in the gut, bacteria closer to the intestinal wall than they should be, low-grade inflammation and metabolic changes.¹

That result was striking enough to start a field, and it has been followed by work in cell cultures, in organoids and in a small number of human trials.

Three things temper it. Mice are not people, and mouse gut mucus behaves differently. The concentrations used have been debated. And the human trials so far are small, short and mixed. The most rigorous of them, a randomised controlled-feeding study of carboxymethylcellulose, found changes in the gut microbiota and its metabolites without a clear symptom effect in most participants.³

So there is a plausible mechanism, real animal data and thin human evidence, and the area is under active investigation, which means nobody can yet claim certainty in either direction.

Carrageenan and the degraded form

The argument about carrageenan is older and louder than the one about the other emulsifiers.

The concern comes from degraded carrageenan, a chemically modified form used to induce inflammation in laboratory animals precisely because it does so reliably. Food-grade carrageenan is a different, larger molecule, and whether meaningful amounts degrade during digestion is the crux of a long dispute.

Regulators have repeatedly concluded food-grade carrageenan is safe.² Some researchers disagree. It remains permitted almost everywhere and it was removed from organic certification in the United States for a period, which gives you a sense of how unsettled it is.

How to test them

Emulsifiers are harder to test than most classes, because they are nearly everywhere in processed food and almost nowhere in food you cook yourself.

That gives you the test: two weeks of cooking from scratch removes most emulsifiers along with a great deal else, so it tells you something has changed without telling you what. If that fortnight helps, reintroduce the specific suspects one at a time: an ice cream, a plant milk, a commercial sauce.

Anyone with inflammatory bowel disease has a particular reason to be interested here, since that is where most of the clinical attention has gone.

Journal your day in 30 seconds, find your triggers.

Where Triggerbites fits in

This list comes from the food data inside Triggerbites, where every emulsifier and thickener is graded by name and class.

Almost nobody reads this part of a label, so a written record helps more with emulsifiers than with most additives. You journal your day in plain words or by voice, in about 30 seconds: "an oat milk latte for breakfast, a supermarket pasta salad and a Coke Zero for lunch, ice cream after dinner, cramps in the night." The app finds each packaged product in a catalog of over a million and lists the emulsifiers and thickeners in it. Scanning the barcode or photographing the label works too.

If two weeks of cooking from scratch helps, the app already holds which emulsifiers you cut. As you bring back the ice cream, the plant milk and the sauce one at a time, it shows which of them your symptoms follow, including reactions that show up days later.

Log your day in 30 seconds

Text, voice or photo. Log as you go, or recap it all in the evening.

Your food, broken down

Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.

Everything in the same journal

Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.

See what repeats over time

Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Triggerbites Features

• Log your day in 30 seconds: Text, voice or photo. Log as you go, or recap it all in the evening.
• Your food, broken down: Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.
• Everything in the same journal: Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.
• See what repeats over time: Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Common questions

What do emulsifiers do in food?

They hold oil and water together, which would otherwise separate. That is why ice cream stays smooth, why salad dressing does not split, why chocolate flows in a mould and why plant milks stay mixed in the carton.

Are emulsifiers bad for your gut?

Nobody yet knows. A 2015 mouse study found thinning of the gut mucus layer and low-grade inflammation from polysorbate 80 and carboxymethylcellulose. Human trials since have been small, short and mixed. It is a plausible mechanism with thin human evidence.

Are emulsifiers natural or synthetic?

Mostly natural in origin. Guar gum comes from a bean, locust bean gum from carob, pectin from apples and citrus peel, gum arabic from tree sap, carrageenan and agar from seaweed. The polysorbates, carboxymethylcellulose and DATEM are the manufactured ones.

Is carrageenan safe?

Regulators have repeatedly concluded food-grade carrageenan is safe, and some researchers disagree. The concern comes from degraded carrageenan, a modified form used to induce inflammation in laboratory animals. Whether meaningful amounts degrade during digestion is the crux of a long dispute.

Which emulsifiers should I worry about most?

If you are going to watch any, the manufactured ones the research has focused on: polysorbate 80, carboxymethylcellulose and DATEM. The plant and seaweed gums have far less against them.

How do I test whether emulsifiers affect me?

Two weeks of cooking from scratch removes most of them, though it removes a great deal else too, so it tells you something changed without saying what. If that helps, reintroduce specific suspects one at a time: an ice cream, a plant milk, a commercial sauce.

Live, love, log. 🧡