Carrageenan is a common food additive derived from red seaweed, and it has become a subject of public debate regarding its safety. Concerns linking it to health issues, including cancer, have led to consumer confusion and questions about its place in the food supply.
What is Carrageenan?
Carrageenan is a natural polysaccharide, a type of complex carbohydrate, extracted from various species of red edible seaweeds, such as those in the Rhodophyceae family. For centuries, people have used seaweeds like Chondrus crispus, also known as Irish moss, in traditional foods and remedies. The modern food industry values carrageenan for its versatile physical properties. It functions as a thickening, gelling, and stabilizing agent, improving the texture and consistency of many processed foods.
Its ability to bind strongly with food proteins makes it particularly useful in a wide range of products. In chocolate milk, it prevents the cocoa from settling at the bottom of the container, ensuring a uniform mixture. It is also frequently used in dairy-free milk alternatives like almond and soy milk to create a creamier mouthfeel. You can find carrageenan in other common items such as processed deli meats, ice cream, yogurt, and even some infant formulas to suspend nutrients.
The Source of the Cancer Concern
The controversy surrounding carrageenan and cancer originates from a distinction between two different forms of the substance: food-grade carrageenan and degraded carrageenan, also known as poligeenan. The scientific studies that first raised alarms about a potential link to cancer exclusively used poligeenan, a substance that is not approved for use in food. These animal studies indicated that poligeenan could cause gut tumors and ulcers.
Poligeenan is created through a different chemical process than its food-grade counterpart. It is produced by treating seaweed extract with strong acid at high temperatures, a process called acid hydrolysis. This harsh treatment breaks down the large polysaccharide molecules into much smaller ones. The primary difference lies in their molecular weight; food-grade carrageenan consists of large, heavy molecules, while poligeenan has a very low molecular weight.
This lower molecular weight is significant because it allows poligeenan to be absorbed through the intestinal lining and enter the bloodstream, where it can trigger an inflammatory response. In laboratory settings, researchers use poligeenan to induce inflammation in animals to test the effectiveness of new anti-inflammatory drugs. Because of its known harmful effects, the International Agency for Research on Cancer has classified poligeenan as a “possible human carcinogen” based on animal evidence.
In contrast, food-grade carrageenan is processed using alkaline substances, which preserves its high molecular weight. These larger molecules are not readily absorbed by the digestive tract and are largely excreted unchanged. The functional properties that make carrageenan useful as a thickener and stabilizer in foods are directly tied to its large molecular size; the smaller molecules of poligeenan do not provide these thickening effects and therefore have no application in food production.
Regulatory Stance on Food-Grade Carrageenan
Major food safety authorities around the world have reviewed the scientific literature on carrageenan and have affirmed the safety of the food-grade version. Their conclusions are based on decades of toxicological studies and safety evaluations.
In the United States, the Food and Drug Administration (FDA) lists carrageenan as a direct food additive that is Generally Recognized as Safe (GRAS). This status, first established in the 1960s, has been periodically reviewed and upheld. The FDA’s regulations specify the sources and processing methods for food-grade carrageenan, ensuring that it meets strict purity criteria and has a high molecular weight.
The European Food Safety Authority (EFSA) has re-evaluated carrageenan’s safety multiple times, most recently in 2018. The EFSA concluded there is no evidence of adverse effects in humans from consuming food-grade carrageenan at the levels currently used in foods. They assigned it an “Acceptable Daily Intake (ADI) not specified,” which is the most favorable category for a food additive. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has also reached similar conclusions, finding its use in foods, including infant formula, to be safe.
Identifying Carrageenan in Foods
Consumers can find carrageenan on the food label. Regulations require that intentionally added ingredients must be listed in the ingredients list. Ingredients are listed in descending order by weight.
Carrageenan will be listed by its name, “carrageenan,” or sometimes by its E-number in Europe, which is E407. It is commonly found in a variety of food categories. Dairy and dairy-alternative products are frequent users, so check the labels of items like cottage cheese, ice cream, chocolate milk, and plant-based beverages such as almond, soy, and coconut milk.
You may also find it in processed meats like deli turkey and ham, where it helps retain moisture and improve texture. Desserts are another common category, especially vegan versions of jellies and puddings where it serves as a plant-based alternative to gelatin. It is sometimes used in nutritional drinks and certain infant formulas to ensure the nutrients remain evenly suspended.