Seaweeds have been a traditional source of nutrients for people around the world for hundreds of years. For example, according to the Food and Agricultural Organization of the United Nations, the extracted gelatinous components of Irish moss (Chondrus crispus) and other seaweed varieties have been used as food additives and for medical purposes for centuries. Seaweeds have not only retained their traditional place as a direct source of human food, but have also been used as fertilizers, in the manufacturing of iodine, and in X-ray imaging diagnostics. Today, the seaweed business has gone international, and for this article I want to focus on the food additive business. Specifically, I’ll be looking at carrageenan, a little known seaweed-derived food additive that is common in the Western diet and is growing in popularity within the cosmetic and pharmaceutical industries.
As global food production has expanded in breadth and scope, carrageenan has emerged as a potent and effective ingredient in many of the off-the-shelf products that we consume every week. Where Japan was the primary supplier of seaweeds for the world leading up to World War II, particularly for agar production (another seaweed derivative), the subsequent upending of global trade relations led Canada and Europe to look for their own sources of seaweed. In Canada they began to harvest Irish moss, the properties of which have been used in jams and jellies since the 1800s. However, as global financial and trading systems regained and expanded their importance to the world economy, seaweed harvest and production activities moved from countries like Canada to new countries in tropical regions where economies of scale could be exploited. These new production locations were primarily in Asia and Oceania, where seaweeds could be harvested much more frequently than in colder climates. Not only were the growing and harvesting conditions better, the labour was cheaper too. Today, carrageenan production is dominated by three major companies: Gelymar (Chile), Dupont (USA), and FMC (USA). Tailor-made carrageenan formulations are used for specific products, and each company carefully guards their carrageenan extraction and processing methods. The American carrageenan market was worth over USD $290 million in 2013.
Carrageenan is exclusively extracted from red seaweeds and is a water-soluble polymer, but can be more easily conceptualized as a ‘gum’ with strong gelling and thickening properties. You can find it in your toothpaste, ice cream, cheese, processed meat, baby formula, Jello, and cake mixes. It’s also viewed as a good alternative to gelatine for vegetarians (gelatines are animal-derived gelling agents with similar food-uses as carrageenan). I was very surprised to find out from Dr. Thierry Chopin, a world-renowned seaweed expert, that carrageenan is also a ubiquitous and unparalleled additive in store-bought chocolate milk. It forms a microscopic mesh, invisible to the human eye, which allows cocoa powder to be evenly distributed throughout the product without settling to the bottom. When Dr. Chopin told me this I had a childhood flashback to trying to make homemade chocolate milk from regular milk and chocolate sauce, only to find all the chocolate would sink to the bottom (no matter how hard I stirred!) … maybe I was just missing seaweed.
As the global marketplace has moved to expand the use of carrageenan in processed food products, cosmetics, and pharmaceuticals, studies have been examining the health impacts of this product. Carrageenan has been linked to mammary carcinoma and the inflammation of the gut in animals and in human-modeled intestinal tissue. But while controversy over the human health impacts of carrageenan continue to exist, major health-governing bodies around the world (Food and Drug Administration, World Health Organization, European Parliament and Council, and Food and Agricultural Organization Expert Committee on Food Additives) maintain that carrageenan is not harmful to human health as currently employed by food manufacturers. A missing link often found in debates over the health effects of carrageenan comes from the distinction between degraded carrageenan (known as poligeenan and currently used for industrial purposes) and non-degraded carrageenan (known simply as carrageenan and used in food-stuffs). Whereas food-grade carrageenan (the only kind used in food) has been shown to have no credible toxicological impacts via oral ingestion, poligeenan has been shown to have toxicological effects. To simplify this entire paragraph – carrageenan as a food additive has not been shown to have toxic effects when consumed by humans, and it is important to distinguish between poligeenan and carrageenan when discussing matters of health and safety.
But aside from seaweed’s potential as a food additive and the debate over carrageenan’s health impacts, it is important to remember that seaweed can be beneficial from an environmental perspective, particularly around fish farms and coastal areas. Where some marine-based intensive fish farming has been demonstrated to contribute to excessive nitrogen and phosphorus levels in the local marine environment, seaweeds have been shown to reduce that ecological effect. Because of this environmental benefit, along with economic and social benefits, seaweeds have been proposed as an important species to consider for culturing alongside existing marine aquaculture operations. Seaweeds have also been shown to extract carbon from local coastal environments, which may have important implications for shellfish culture in coastal communities due to increasing ocean-acidification. While not all of these seaweeds will necessarily be carrageenan-yielding species, the potential for integrated aquaculture methodologies and multiple value-streams associated with seaweed production may be significant. Carrageenan may be an important consideration for fish farmers considering an integrated aquaculture option.
Seaweed production has grown at an average annual rate of 7.7% in recent years and it makes up nearly 50% of global aquaculture production. In 2012, over 95% of global seaweed production came from cultivation – less than 5% was harvested from wild seaweed beds. The estimated value of this harvest was USD $6.4 billion for 23.8 million metric tonnes of seaweeds, 96.3% of which was cultured in 6 Asian countries (China, Indonesia, the Philippines, Korea, Japan, and Malaysia). I can only imagine how the value of seaweed culturing could increase over the years with the introduction of nutrient pricing or nutrient trading credits – an idea similar to carbon pricing, but that would include nutrients such as phosphorus and nitrogen.
Carrageenan, and by extension, seaweeds, are now a part of our daily life. Aside from their crucial role in sushi (no citation required!), they also have been found to be useful as an alternative to meat derived additives. Some seaweed is even getting the organic stamp of approval, and research is increasingly demonstrating the ecological benefits of co-culturing seaweeds with existing aquaculture operations (i.e. a salmon, mussel, and kelp aquaculture operation). Further, seaweed culture has been shown to have positive socio-economic effects in some developing countries. Top that off with seaweed’s potential role in mitigating global-warming induced ocean acidification and their critical role in coastal ecosystems, and the case for seaweeds, and their fun-loving friend carrageenan, becomes quite compelling.
And now you know what's in your chocolate milk (kind of).
This article was originally posted by Sustainable Collective, which has since joined forces with The Starfish Canada.