Emulsifiers have gotten a very bad reputation lately, but have been around for a long time. HFG’s chief nutritionist Rose Carr explores the science behind this common food additive.
Did you know that when we make balsamic vinegar, we add the oil to the vinegar with a whisk to emulsify the two liquids? While this lotion is a wonderful combination, it is not stable. If we let the oil and vinegar sit long enough, the oil and vinegar will chemically repel each other and separate again. So we tried making the vinaigrette right before serving.
In homemade mayonnaise, the emulsion is more stable because the lecithin in the egg yolk acts as an emulsifier, suspending the vegetable oil and lemon juice.
Other common ingredients that can act as emulsifiers in the kitchen include ketchup, wasabi powder, and miso.
Emulsifiers are widely used in food production. Think of an emulsifier as a “handler” between the oil and water mixture. Chemically, emulsifiers are compatible with oil on the one hand and water on the other, enabling them to combine with both. This facilitates the preparation of emulsions. Some emulsifiers are also stable so the emulsion does not separate over time. Stabilizers are also added to some foods to maintain emulsification.
Many common ready-to-eat foods contain emulsifiers. Not only do they stabilize oil-water mixtures, they also affect the texture of our food. In ice cream, for example, emulsifiers improve the smooth, creamy texture and slow down the melting process.
How Will You Detect Emulsifiers In Your Food?
The Food Code stipulates that all food ingredients, including additives, must be listed on food labels. The function of an additive must be listed with its name or code, so you would see for example emulsifier (soy lecithin) or emulsifier (322). Fatty acid monoglycerides (472a-f)
Several common emulsifiers
Lecithin (322)
Emulsifiers naturally present in egg yolks and vegetable oils are usually obtained in food processing from soybean or sunflower oils.
Fatty Acid Monoglycerides and Diglycerides (471)
Made from glycerin and natural fats, which can be from vegetable or animal sources.
Fatty acid monoglycerides (472a-f)
Made from natural fats, glycerin and organic acids such as citric or tartaric. The fat is usually vegetable fat, but it can also be animal fat. Several common emulsifiers
Other commonly used emulsifiers:
407, 466, 477, 491, 433, 476, 481, 492
There are more. Look for “emulsifier” in the ingredients list.
Foods that often contain emulsifiers
- Margarine and low-fat spreads
- mayonnaise
- chocolate
- Ice cream and other frozen dessert mixes
- bread
- bakery products
- cream sauce
- processed meat
Why The Negative Press For Emulsifiers?
Intestinal inflammation
Carboxymethylcellulose (466), Polysorbate 80 (433)
In 2015, Atlanta researchers published a study in the journal Nature that supported their theory that emulsifiers used in food processing promote inflammatory disease.
In particular, they tested their theory in mice using two commonly used emulsifiers, carboxymethylcellulose (466) and polysorbate 80 (433).
The doses of emulsifiers in the mice’s diets were designed to mimic the widespread consumption of emulsifiers in many processed foods, the researchers said.
Other scientists described mice ingesting emulsifier concentrations higher than the average daily human intake. So let’s assume it might be on the high side. Especially if we don’t eat as much processed food as the average American.
However, the researchers found that these emulsifiers altered the composition of the mice’s gut microbiota. This change means the bacteria can now enter and disrupt the gut barrier, the thick layer of mucus that normally stops bacteria from entering the bloodstream. An altered microbiome also means more inflammatory molecules are produced.
So, taken together, these changes promote inflammation in the immune system of the mice.
Carrageenan (407), Processed Eucheuma Seaweed (407a)
These emulsifiers made from seaweed have been discussed for years. In 2018, the European Commission reassessed its use and looked at toxicology tests in rats and other studies.
They found no carcinogenicity or genotoxicity concerns, but noted some other data were missing.
Several studies have linked carrageenan to impaired glucose tolerance in mice and inflammatory responses in mouse and human tissues. A 2018 article highlighted knowledge gaps about these emulsifiers due to a) lack of information about how much people actually get in their diets, b) uncertainty about their effects on the microbiome and inflammation, and c) lack of knowledge about these emulsifiers. Knowledge of the difference affects vulnerable populations, such as older adults or people with irritable bowel disease (IBD).
In short, while these have been tested in mice, so we can get a good estimate of how much is not toxic to us, we really don’t have much direct information on how they might affect humans, and from the studies The problem was carried out.
Inflammatory Bowel Disease and Metabolic Syndrome
Carboxymethylcellulose (466), Polysorbate 80 (433)
In the Atlanta study, a group of mice were genetically predisposed to colitis, a form of IBD, and their exposure to an emulsifier induced chronic colitis. But normal mice with normal immune systems were also affected by the emulsifier.
They experienced mild gut inflammation, elevated blood sugar levels and weight gain, summed up as metabolic syndrome in mice.
The scientists also reported that removing the emulsifier from their diet reversed most of the effects in mice.
In short, while these have been tested in mice, so we can get a good estimate of how much is not toxic to us, we really don’t have much direct information on how they might affect humans, and from the studies The problem was carried out.
Inflammatory Bowel Disease and Metabolic Syndrome
Carboxymethylcellulose (466), Polysorbate 80 (433)
In the Atlanta study, a group of mice were genetically predisposed to colitis, a form of IBD, and their exposure to an emulsifier induced chronic colitis. But normal mice with normal immune systems were also affected by the emulsifier.
They experienced mild gut inflammation, elevated blood sugar levels and weight gain, summed up as metabolic syndrome in mice.
The scientists also reported that removing the emulsifier from their diet reversed most of the effects in mice.
colon cancer
Carboxymethylcellulose (466), Polysorbate 80 (433)
Further research by the Atlanta group also supports the notion that changes in the microbiota of mice induced by consumption of the two emulsifiers, leading to chronic inflammation, may also contribute to the development of colorectal cancer (CRC). That doesn’t mean they see the CRC going, but they can see the way the CRC is going. So it’s plausible in mice, but it hasn’t shown up yet.
What Does This Mean For Us?
In humans, a rough correlation between emulsifier intake and Crohn’s disease (a type of IBD) has been demonstrated in many countries, but this is weak evidence for the effect of emulsifiers. Processed foods that contain emulsifiers can also be high in fat and sugar, and there is stronger evidence linking general dietary patterns to IBD. The so-called “typical Western diet” — high in sugar, fat, animal protein and processed foods, and low in plant foods — was more strongly associated with IBD. It’s also been linked to mild inflammation, which has been linked to many common diseases, such as cardiovascular disease, macular degeneration, and Alzheimer’s.
It is not possible to conduct studies in mice and conclude that emulsifiers have the same effect in humans. However, it can be hypothesized that emulsifiers may have some degree of detrimental effects on our diets and are particularly detrimental to those genetically predisposed to IBD.
The reason for using mice in research is that they are often a good indicator of how things are going to work out for us. But it doesn’t always work that way. Must see what laboratory studies on mice are: a starting point. Remarkably, humans have used natural emulsifiers in food preparation for thousands of years, but mice have not. They are not part of the normal diet of mice.
A previous laboratory study using tissue from patients with Crohn’s disease supported the theory that the emulsifier polysorbate 80 (433) has adverse effects in IBD patients. The study showed that the emulsifier used in the Atlanta mouse study facilitated the movement of E. coli bacteria in the relevant cells. This effect was only observed in tissues from IBD patients.
Scientists will undoubtedly do more work to study the link between human gut health, inflammatory disease, and consumption of various emulsifiers. In the meantime, if we want to reduce our risk, however uncertain, the easiest way is to limit our consumption of processed foods. You will find that this fits perfectly with the usual advice we give about healthy eating.
Focusing on a plant-based diet doesn’t mean eliminating everything else, leaving less room for processed foods with a long list of ingredients we don’t know about. We’ll also cut back on energy-dense foods in favor of nutrient-dense foods. We can still enjoy an ice cream or two!
Functional classes and examples of additives in foods
| Functional class | Description | Example additive (E number*) |
|---|---|---|
| Acidity regulators | Alter or control the acidity or alkalinity pH of a foodstuff | E325 Sodium lactate |
| Acids | Increase the acidity of a foodstuff and/or impart a sour taste to it | E507 Hydrochloric acid |
| Anti‐caking agents | Reduce the tendency of individual particles of a foodstuff to adhere to one another | E341 Calcium phosphate |
| Anti‐foaming agents | Prevent or reduce foaming | E905aMineral oil |
| Antioxidants | Prolong the shelf‐life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes | E300 Ascorbic Acid |
| Bulking agents | Contribute to the volume of a foodstuff without contributing significantly to its available energy value | E336 Potassium tartrates |
| Carriers | Dissolve, dilute, disperse or otherwise physically modify a food additive or a flavouring, food enzyme, nutrient and/or other substance added for nutritional or physiological purposes to a food without altering its function (and without exerting any technological effect themselves) to facilitate its handling, application or use | E1200 Polydextrose |
| Colours | Add or restore colour in a food, and include natural constituents of foods and natural sources, which are normally not consumed as foods as such and not normally used as characteristic ingredients of food | E100 Curcumin |
| Emulsifiers | Make it possible to form or maintain a homogenous mixture of two or more immiscible phases such as oil and water in a foodstuff | E322 Lecithin |
| Emulsifying salts | Convert proteins contained in cheese into a dispersed form and thereby bring about homogenous distribution of fat and other components | E325 Sodium lactate |
| Firming agents | Make or keep tissues of fruit or vegetables firm or crisp, or interact with gelling agents to produce or strengthen a gel | E333 Calcium citrates |
| Flavour enhancers | Enhance the existing taste and/or odour of a foodstuff | E620 Glutamic acid |
| Flour treatment agents | Added to flour or dough to improve its baking quality | E927b Carbamide |
| Foaming agents | Make it possible to form a homogenous dispersion of a gaseous phase in a liquid or solid foodstuff | E999 Quillaia extract |
| Gelling agents | Give a foodstuff texture through formation of a gel | E441 Gelatine |
| Glazing agents | When applied to the external surface of a foodstuff, impart a shiny appearance or provide a protective coating | E901 Bees wax |
| Humectants | Prevent foods from drying out by counteracting the effect of an atmosphere having a low degree of humidity, or promote the dissolution of a powder in an aqueous medium | E965 Maltitol |
| Modified starches | Obtained by one or more chemical treatments of edible starches, which may have undergone a physical or enzymatic treatment, and may be acid or alkali thinned or bleached | E1404 Oxidised starch |
| Packaging gases | Gases other than air, introduced into a container before, during or after the placing of a foodstuff in that container | E938 Argon |
| Preservatives | Prolong the shelf‐life of foods by protecting them against deterioration caused by micro‐organisms and/or which protect against growth of pathogenic micro‐organisms | E200 Sorbic acid |
| Propellants | Gases other than air that expel a foodstuff from a container | E942 Nitrous oxide |
| Raising agents | Substances or combinations of substances that liberate gas and thereby increase the volume of a dough or a batter | E500 Sodium carbonate |
| Sequestrants | Form chemical complexes with metallic ions | E385 Calcium disodium ethylene diamine tetraacetate |
| Stabilisers | Make it possible to maintain the physico‐chemical state of a foodstuff | E415 Xanthan gum |
| Sweeteners | Impart a sweet taste to foods or in table‐top sweeteners | E955 Sucralose |
| Thickeners | Increase the viscosity of a foodstuff | E1400 Dextrin |
Common food additives present in a Western diet and their suggested impact on the gut microbiota and/or host physiology (not an exhaustive list)
| Type of additive | Additive and dose | Model | Effect on microbiota | Effect on host physiology | Reference |
|---|---|---|---|---|---|
| Colour | Titanium dioxide (2.3 x 105–2.3 x 109 particles/ml) | Human colon cells | Not determined | Decrease in absorptive microvilli, decreased nutrient uptake | Guo et al. (2017) |
| Emulsifier | Carboxymethylcellulose (2% w/v within drinking water for 3 weeks) | Mice (Il10−/−) | Bacterial overgrowth | Intestinal (small bowel) inflammation | Swidsinski et al. (2009) |
| Emulsifier | Carboxymethylcellulose, or Polysorbate 80 (0.1 to 1% v/v within drinking water for 12 weeks) | Mice (Il10−/−, Tlr5−/− & C57BL/6) | Microbiota encroachment, altered species composition, increased pro‐inflammatory potential | Colitis, metabolic syndrome | Chassaing et al. (2015) |
| Emulsifier | Carboxymethylcellulose, or Polysorbate 80 (0.1 to 1% v/v faecal suspension culture) | M‐SHIME human colon model | Not determined | Increased levels of bioactive flagellin (increased pro‐inflammatory potential) | Chassaing et al. (2017) |
| Emulsifier | Polysorbate 80 (1% v/v per kg bodyweight via gavage, daily for 4 weeks) | Mice (C57BL/6) | Altered microbiota composition | Intestinal inflammation, obesity, impaired glycaemic tolerance, liver dysfunction | Singh et al. (2016) |
| Emulsifier | Polysorbate 80 (1% w/v in drinking water for 8 weeks) | Mice (C57BL/6J) | Altered microbiota composition | Enhanced indomethacin‐induced intestinal damage | Furuhashi et al. (2019) |
| Emulsifier | Glycerol monolaurate (basal diet supplemented with 150 mg/kg ingested daily for 8 weeks) | Mice (C57BL/6) | Altered microbiota composition | Metabolic syndrome, systemic low‐grade inflammation | Jiang et al. (2018) |
| Emulsifier | Methylcellulose (150 g/kg in chow for 7 days) | Mice (Rag1‐/‐ & C57BL/6J) | Not determined | Increased severity of colitis | Llewellyn et al. (2018) |
| Preservatives | Silver nanoparticles (0, 11.4, 114 and 1140 μg Ag NP/kg bodyweight/day for 28 days) | Mice (C57BL/6) | Altered microbiota composition | Not determined | Van Den Brûle et al. (2016) |
| Sweetener | Sucralose (by oral gavage 100, 300, 500, or 1000 mg/kg/day for 12 weeks) | Rats (Sprague Dawley) | Altered microbiota composition | Not determined | Abou‐Donia et al. (2008) |
| Sweetener | Sucralose (0.1 mg/ml within drinking water for 6 months) | Mice (C57BL/6J) | Altered microbiota composition | Altered bile acids, elevated pro‐inflammatory gene expression in the liver | Bian et al. (2017b) |
| Sweetener | Sucralose (1.08, 3.5 and 35 mg/ml within drinking water for 6 weeks) | Mice (SAMP, AKR, and C57BL/6J) | Altered microbiota composition | Increased ileal tissue myeloperoxidase activity | Rodriguez‐Palacios, et al. (2018) |
| Sweetener | Saccharin (0.1 mg/ml within drinking water for 5 weeks) | Mice (C57BL/6) and humans | Altered microbiota composition (mice only, humans not studied) | Glucose intolerance (mice and humans) | Suez et al. (2014) |
| Sweetener | Saccharin (0.3 mg/ml within drinking water for 6 months) | Mice (C57BL/6J) | Altered microbiota composition | Liver inflammation | Bian et al. (2017c) |
| Sweetener | Aspartame (5–7 mg/kg/day for 10 weeks) | Rats (WT) | Altered microbiota composition | Glucose intolerance | Palmnäs et al. (2014) |
| Sweetener | Acesulfame K (37.5 mg/kg/day for 4 weeks) | Mice (CD‐1) | Altered microbiota composition | Weight gain (male mice only) | Bian et al. (2017a) |
| Thickener | Maltodextrin (1 to 5% w/v within drinking water over a period of 45 days) | Mice (Balb/c) | No effect on microbiota composition | Altered mucus barrier, increased intestinal inflammation | Laudisi et al. (2019) |
Low‐calorie intervention diets provided to volunteers on the FADiets study
| Low calorie, high emulsifier diet * | |||||
|---|---|---|---|---|---|
| Day | Energy † (kcal) | Fat (%) | Protein (%) | Carbohydrates/fibre (%) | Choline ‡ (from diet & lecithin supplement) (mg) |
| 1 | 2000 | 30 | 15 | 55 | 3717.4 |
| 2 | 2000 | 30 | 15 | 55 | 3698.2 |
| 3 | 2000 | 30 | 15 | 55 | 3810.1 |
| 4 | 2000 | 30 | 15 | 55 | 3707.7 |
| 5 | 2000 | 30 | 15 | 55 | 3783.2 |
| 6 | 2000 | 30 | 15 | 55 | 3722.7 |
| 7 | 2000 | 30 | 15 | 55 | 3725.7 |
| Average | 3737.9 | ||||
| Low calorie, low emulsifier diet | |||||
| Day | Energy † (kcal) | Fat (%) | Protein (%) | Carbohydrates/fibre (%) | Choline ‡ (from diet only) (mg) |
| 1 | 2000 | 30 | 15 | 55 | 270.4 |
| 2 | 2000 | 30 | 15 | 55 | 263.1 |
| 3 | 2000 | 30 | 15 | 55 | 367.1 |
| 4 | 2000 | 30 | 15 | 55 | 261.6 |
| 5 | 2000 | 30 | 15 | 55 | 339.9 |
| 6 | 2000 | 30 | 15 | 55 | 273.1 |
| 7 | 2000 | 30 | 15 | 55 | 265.6 |
| Average | 291.5 |
*Low‐calorie test diet supplemented with 2 daily servings of 7.5 g Lamberts® soya lecithin granules in fruit smoothies (total 15 g/day).
†Energy intakes matched to the closest calorie to each volunteer resting metabolic rate assessed at baseline by indirect calorimetry (range 1500 to 3000 kcal). Example 2000 kcal matched diets are shown.
‡Choline values from USDA food composition tables (USDA, 2019). EFSA Adequate Daily Intake (ADI) of choline, 400 mg/day for adults (EFSA NDA Panel 2016) and USDA ADI, male 550 mg/day and female 425mg/day (USDA 2019).
Fat and phospholipid composition of Lamberts® soya lecithin granules used to supplement the FADiets study low‐calorie, high‐emulsifier test diet
| Component | Amount (g) per 7.5 g serving* |
|---|---|
| Phosphatidyl choline | 1.7 |
| Phosphatidyl ethanolamine | 1.5 |
| Phosphatidyl inositol | 1.1 |
| Phosphatidic acid | 0.6 |
| Phosphatidyl serine | 0.075 |
| Fatty acids | 3.8 |
| of which:– saturated | 0.9 |
| – monounsaturated | 0.3 |
| – polyunsaturated | 2.5 |
Full composition can be found at http://www.lambertshealthcare.co.uk
*Participants on low‐calorie, high‐emulsifier diet will ingest within food a 7.5 g serving twice daily.
Article sources and references
- Aponso MM et al. 2017. Emulsifiers as food additives: An overview on the impact to obesity and gut diseases. Journal of Pharmacognosy and Phytochemistry 6:485-7
https://www.researchgate.net/publication/317603829_Emulsifiers_as_food_additives_An_overview_on_the_impact_to_obesity_and_gut_diseases - Chassaing B et al. 2015. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature 519:92
https://www.ncbi.nlm.nih.gov/pubmed/25731162 - Coughlan M & Kellow N. 2015. Food additives and chronic disease risk: What role do emulsifiers play? The Conversation, April 23, 2015, theconversation.com Accessed August 2018
http://theconversation.com/food-additives-and-chronic-disease-risk-what-role-do-emulsifiers-play-38492 - European Food Information Council (EUFIC). 2005. The perfect mixture: Emulsifiers make our food enjoyable, www.eufic.org Accessed August 2018
https://www.eufic.org/en/whats-in-food/article/the-perfect-mixture-emulsifiers-make-our-food-enjoyable - Fahoum L et al. 2016. Digestive fate of dietary carrageenan: Evidence of interference with digestive proteolysis and disruption of gut epithelial function. Molecular Nutrition and Food Research 61:1600545
https://onlinelibrary.wiley.com/doi/pdf/10.1002/mnfr.201600545 - Food Additives and Ingredients Association. 2012. faia.org.uk/ emulsifiers-in-food/ Accessed August 2018
https://www.faia.org.uk/emulsifiers-in-food/ - Ministry for Primary Industries. mpi.govt.nz/food-safety/whats-inour- food/food-additives Accessed August 2018
https://www.mpi.govt.nz/food-safety/whats-in-our-food/ - Roberts CL et al. 2010. Translocation of Crohn’s disease Escherichia coli across M-cells: Contrasting effects of soluble plant fibres and emulsifiers. Gut 59:c1331-9
https://www.ncbi.nlm.nih.gov/pubmed/20813719 - Shlot D et al. 2018. Revisiting the carrageenan controversy: Do we really understand the digestive fate and safety of carrageenan in our foods? Food & Function 9:1344-52
https://www.ncbi.nlm.nih.gov/pubmed/29469913 - Viennois E et al. 2016. Dietary emulsifier-induced low-grade inflammation promotes colon carcinogenesis. Cancer Research, canr-1359
https://www.researchgate.net/publication/309753286_Dietary_Emulsifier-Induced_Low-Grade_Inflammation_Promotes_Colon_Carcinogenesis
