What Are Emulsifiers?

Medically Reviewed by Dany Paul Baby, MD on November 07, 2022
5 min read

Emulsified food is becoming increasingly common. Processed and packaged foods are the main sources of emulsifiers. This article looks into the different emulsifiers commonly used in food and skin care products and how they affect your health.

An emulsion is a mixture of two or more liquids that are usually not mixable but mix under specific circumstances — generally by using substances that help them mix. These substances are called emulsifiers. In an emulsion, one liquid is dispersed in the other.

As water and oil don’t usually mix, emulsifiers help mix them. Emulsifiers are traditionally prepared from plant and animal sources, but many synthetic emulsifiers exist. Emulsifiers are added to processed foods like mayonnaise, ice cream, chocolates, peanut butter, cookies, creamy sauces, margarine, and baked goods to prevent the separation of their oil and water components. Emulsifiers also give these foods a smooth texture and increase their shelf life.

The Food and Drug Administration (FDA) approves the emulsifiers used in foods in the U.S. Hydrocolloids are currently the most widely used emulsifiers made from natural sources. They’re also known as gums because of the texture of the foods containing hydrocolloids. Hydrocolloids can be modified to support the texture of the specific food product, increase its shelf life, and add flavor. Using emulsifiers in food products makes them less sticky and easier to eat.

Hydrocolloids are usually made from multiple sources. Plants, including locust bean gum, carrageenan, pectin, and starch, are the most common sources of emulsifiers. Animal sources include crustacean shells and microorganisms. Many synthetic emulsifiers may have some harmful health effects.

In addition to food products, pharmaceutical, personal hygiene, and cosmetic products also contain emulsifiers. Creams, ointments, balms, pastes, and films contain emulsifiers to blend water-based and oil-based ingredients. Medicines use emulsions to enclose their active ingredient to prolong its shelf life and prevent interaction with other chemicals before its intended use. This helps safeguard the effectiveness of the specific dosage and makes the medicine easily enter the digestive system.

An emulsion contains two phases — a dispersed phase and a continuous phase. The continuous phase in the emulsion typically holds the dispersed phase. In an oil-in-water emulsion, water is the continuous phase, and oil is the dispersed phase. In a water-in-oil emulsion, the continuous phase is oil. Emulsifiers make both types of emulsions.

Milk is the perfect example of a natural oil-in-water emulsion. The oil in the milk is suspended as tiny droplets in the aqueous (water) phase. On the other hand, margarine is a water-in-oil emulsion, where drops of water are held within the margarine fat.

The ends of the emulsifiers vary in their constitution. One end is hydrophilic (water-loving), and the other is hydrophobic (oil-loving). This specific quality helps emulsifiers build a physical boundary to prevent oil and water droplets from mixing while dispersing them within each other to create a stable and homogeneous mixture called an emulsion.

When you add emulsifiers to an oil-in-water emulsion, they envelop the oil droplet with their hydrophobic ends, while their hydrophilic ends point in the other direction and are attracted to the water molecules. In a water-in-oil emulsion, the emulsifier orientation is reversed.

Several processed and packaged foods contain emulsifiers. Some of the most common emulsifiers in food products include soy lecithin, carrageenan, mono- and diglycerides, carboxymethylcellulose, and polysorbate. Emulsifiers in skin care products include sodium lauryl sulfate (SLS), benzalkonium chloride, cetearyl alcohol, stearic acid, glyceryl stearate, and ceteareth-20.

Lecithins are made of phospholipids extracted from soybeans and egg yolk. They're common in salad dressings, baked products, and chocolates. The concentration of the emulsifier depends on the preparation. Fatty acids extracted from vegetable oils are another popular source of emulsifiers. Sometimes, animal fats may serve as an alternative to vegetable oils. Ice creams and cakes typically contain emulsifiers extracted from fatty acids. Bread and margarine use synthetic emulsifiers sourced from glycerol.

According to early studies, emulsifiers could have a negative impact on your health. Your gut is home to trillions of microorganisms, called microbiota. Most of these microorganisms improve gut health by aiding intestinal processes and digestion. The microbiota lowers the harmful effects of potentially toxic substances in your gut, produces essential vitamins and amino acids, and supports your body’s immune response.

Some potentially harmful microorganisms exist, but beneficial organisms outnumber the harmful ones in a healthy gut. When this balance is skewed, it could impact gut health.

According to a 2021 study, food emulsifiers increase intestinal inflammation risk. The study found that two synthetic emulsifiers — carboxymethylcellulose and polysorbate 80 — drastically affect the gut microbiome and increase the risk of inflammation.

Another 2017 study identified the harmful effects of emulsifiers. According to the study, emulsifiers increase the risk of inflammatory bowel diseases like Crohn’s disease and ulcerative colitis, which could lead to severe symptoms. The study also found that emulsifiers cause obesity-related conditions like type 2 diabetes and cardiovascular and liver diseases.

But more research is needed to understand the impact of food emulsifiers on health. Until then, it’s better to avoid processed and packaged food with synthetic emulsifiers.

Research has also revealed the potentially harmful effects of skin care products containing emulsifiers. Emulsifiers made of lauryl sulfates and lauryl ether sulfates cause skin irritation and damage the skin barrier.

Emulsifiers make up a tiny portion of a food product. As the modern-day diet includes many packaged and processed foods, people's intake of emulsifiers has also spiked. That’s why it’s vital to be aware of what you eat.

The U.S. Food and Drug Administration (FDA) mandates that food manufacturers list all the ingredients in their products, including emulsifiers. Make sure the product you buy contains emulsifiers approved by the FDA. Look for a “generally recognized as safe” certification for the emulsifier.

But when it comes to skin care products, emulsifiers are mostly unregulated. Personal care product manufacturers don’t need to pre-approve products like skin moisturizers, perfumes, lipsticks, makeup, shampoos, hair colors, and deodorants (except color additives) before selling them. Make sure you purchase quality skin care products and verify the integrity of their ingredients.