Xanthan gum is a polysaccharide made by the bacteria Xanthomonas camprestris. When this bacteria is placed into a culture containing carbohydrates, the fermentation process begins, and xanthan gum is produced as a by-product. Once xanthan gum is formed, it's isolated, dried and processed into a fine powder. Carbohydrates used to make xanthan gum usually come from soy, wheat or corn.
Xanthan gum is approved by the United States Food and Drug Administration as an additive for food products. When xanthan gum is added to liquids, it thickens them. That's why xanthan gum is commonly added to foods and beverages that require a thicker, more substantial texture such as puddings, salad dressings, chocolate milk, yogurt and some non-dairy beverages. Xanthan gum is added to ice cream to give the product a smoother consistency and reduce the formation of ice crystals and to egg substitutes to thicken them. As a thickener, xanthan gum is usually only needed in small amounts.
Salad dressings are made with ingredients that are water-soluble like vinegar and fat-soluble ingredients like oil. Xanthan gum helps to stabilize products that contain both fat and water-soluble ingredients so they don't separate and destroy the integrity of the product. It also helps to keep additives like spices and herbs from separating from the product. Xanthan gum is an ingredient in some low-fat foods and diet foods since it gives products the mouth texture and feel of full-fat foods without the additional calories and fat.
Cooks and chef usually keep a container of xanthan gum on hand to thicken sauces, dressings and soups. Vegans like it because it's not made from animal products, and people with gluten-sensitivity appreciate it because it's gluten-free and is frequently used as a substitute for gluten in gluten-free pastas and bread. It works well for this purpose because it doesn't alter the flavor or color of food. When cooking, xanthan gum should only be used in small amounts and agitated as its added to foods since it can quickly form a clump. Many grocery stores and health food stores now carry bags of xanthan gum for home use.
Xanthan gum is also an ingredient in cosmetic and personal care products. Just as it thickens gravies and salad dressings, it adds viscosity and texture to skin and personal care products. In addition, it helps to stabilize cosmetic emulsions so that water and oil-soluble ingredients don't separate from one another and reduce the performance of the product. Only tiny amounts of xanthan gum, as little as 0.1%, are needed to thicken personal care products and stabilize emulsions. Xanthan gum gives products like body lotions, shower gels and liquid soaps a more substantial texture and "feel," which consumers enjoy. Some products that contain xanthan gum include facial moisturizers, facial cleansers, body washes, bath gels, toothpaste, liquid soap, shampoos and anti-aging products. It's also an ingredient in artificial saliva products made for people who suffer from dry mouth.
Is it safe? The United States Food and Drug Administration classifies xanthan gum as "generally recognized as safe." The only people who shouldn't consume food products that contain xanthan gum are people who are allergic to corn. Xanthan gum may also be produced by fermenting wheat or soy so people allergic to either of these should avoid foods that contain it as an additive. Even for people who aren't allergic to corn, wheat or soy, xanthan gum can cause abdominal bloating, diarrhea and nausea because it expands in the digestive tract, acting similarly to fiber. It also slows down the absorption of sugar from foods, which makes it beneficial for diabetics. In addition, it helps to lower cholesterol levels.
In the amounts found in cosmetic and personal care products, xanthan gum appears to be safe. The Environmental Working Group's Skin Deep Cosmetics Database classifies it as a low-hazard cosmetic ingredient. It's usually not irritating to the skin when applied topically and is well tolerated even by people with sensitive skin.
All in all, xanthan gum is an effective thickener and emulsion stabilizer needed only in small amounts. It's also safe for people who aren't allergic to corn, wheat or soy.