Chitin is not exactly a household word, but most are familiar with its source. It is found naturally in the shells of crustaceans, such as crab, shrimp and lobster, as well as in the exoskeleton of marine zoo-plankton, including coral and jellyfish. Insects, such as butterflies and ladybugs, have chitin in their wings. And the cell walls of yeast, mushrooms and other fungi also contain this natural substance. 

Chitin and its derivatives have many properties that make them attractive for a wide variety of applications, from food, nutrition and cosmetics to biomedicine, agriculture and the environment. Their antibacterial, anti-fungal and anti-viral properties make them particularly useful for biomedical applications, such as wound dressings, surgical sutures and as aids in cataract surgery and periodontal disease treatment. Research has shown that chitin and chitosan are non-toxic and non-allergenic, so the body is not likely to reject these compounds as foreign invaders. Chitin's biodegradable and anti-fungal properties are a plus for environmental and agricultural uses. 

Chitin is one of the three most abundant polysaccharides in nature, in addition to cellulose and starch. It ranks second to cellulose as the most plentiful organic compound on earth. Cellulose and starch are key carbohydrates which plants use as a food source and to build cell walls. In addition, they have widespread use in the industry. Researchers and entrepreneurs see similar potential for chitin. 

Chemically, cellulose, starch and chitin are polysaccharides -- polymers, or large molecules consisting of smaller sugar molecules strung together, like pearls on a strand. Chitin can be processed into many derivatives, the most readily available being chitosan, which is formed when chitin is heated with a chemical solution.  

Oligosaccharides are among the most popular functional food components in Japan, but they are relatively unknown in the U.S. A number of health benefits result from ingestion of oligosaccharides, according to an article in the October 1994 issue of Food Technology. According to the article, oligosaccharides may increase the production of Bifidobacteria and thereby reduce harmful bacteria, help reduce toxins and detrimental enzymes, prevent diarrhea and constipation, protect liver function, reduce serum cholesterol, protect against cancer and help produce nutrients. 

Unlike most polysaccharides, chitosan has a strong positive charge which allows it to bind to negatively charged surfaces such as hair and skin. This makes it useful as an ingredient in skin and hair care products. Several studies indicate that chitosan's charge also helps it bind to fats and cholesterol and initiate clotting of red blood cells. 

Over the past decade, researchers in Korea, Japan, Europe and the United States have tested chitin and its derivatives in biomedical applications. Researchers also have focused on the food and nutrition arenas, including edible films and coatings to preserve the quality and texture of foods. 

  Dr. Sam Hudson, associate professor of polymer chemistry at North Carolina (NC) State University, an academic center engaged in significant chitin research, says researchers are "on the edge of a brave new world" as far as the number of products that can be made from chitin and its derivatives. 

History of Chitosan
Chitin was first found in mushrooms in 1811 by Professor Henri Braconnot while he was Professor of Natural History and Director of the Botanical Gardens at the Academy of Sciences in Nancy, France. In the 1830's, it was isolated in insects and named chitin. Professor C. Rouget discovered chitosan in 1859, and over the next century, much fundamental research took place on these compounds. An intense interest in new applications grew in the 1930s and early 1940s, as evidenced by almost 50 patents; however, the lack of adequate manufacturing facilities and competition from synthetic polymers hampered commercial development. Renewed interest in the 1970s was encouraged by the need to better utilize shellfish shells. Scientists worldwide began to chronicle the more distinct properties of chitin and its derivatives and understand the potential of these natural polymers. Since then, numerous research studies have been undertaken to find ways to use materials. 

Chitosan Today
Many countries already use chitin and chitosan in a variety of products, yet a whole array of possible materials could be made from these compounds. In Japan, chitosan was first used for waste water treatment because of its metal-binding properties, but today chitin and chitosan are found in everything from antibiotics and surgical sutures to dietary supplements, foods and cosmetics. It also can be found in pet foods and is used to make cloth for undergarments and socks. In the U.S., chitin and chitosan are being used in seed treatment, animal feed supplementation and water purification, as well as in hair care products and dietary supplements. Natural substances such as chitin and chitosan demand a closer look at a time when synthetic compounds are losing their appeal. This brochure explores some of the research and more popular applications of chitin and its derivatives. 

Nutritional Applications
For years, chitin and its derivatives have been used for nutritional and medicinal purposes in the Far East. In fact, many people take dietary supplements made from chitin and chitosan to improve their health. Many of those individuals believe the supplements help them combat a number of ailments, including high blood cholesterol, high blood pressure, allergies and arthritis. They also cite improvements in skin, hair and nail health. 

Studies have suggested that chitin and chitosan have a number of health benefits, including the ability to promote the growth of Bifidobacteria, healthy intestinal bacteria that help ward off disease. Chitin derivatives such as chitin oligosaccharides and chitosan oligosaccharides (smaller components of the chitin and chitosan molecules) also are believed to have many important health dividends, including promotion of bowel health, anti-tumor properties and promotion of these same beneficial Bifidobacteria. 

Benefits of Chitosan Oligosaccharides and Bifidobacteria
Research has shown that fructose, galactose and soy oligosaccharides impart many health benefits in the diet. Fructose oligosaccharides, for instance, promote the growth of Bifidobacteria, thereby enhancing intestinal health and regularity and preventing diarrhea and other ailments. It is thought that chitosan oligosaccharides may have similar benefits. Animal research has shown that chitosan oligosaccharides enhance bowel function. Other animal research has suggested that chitosan oligosaccharides and chitosan stimulate a non-specific immune response in mice, resulting in the production of T-cells, which attack tumor cells. Researchers speculate that chitosan oligosaccharides may act in the same way. 

Since the early 1950s, Bifidobacteria have been recognized for their important role in promoting human health. Researchers believe that Bifidobacteria prevent and counteract harmful bacteria, such as E. coli and Salmonella, by producing acetic and lactic acids that suppress the growth of these microbes and by producing antibacterial compounds. They also are thought to aid in the production of B vitamins and folic acid. 

Some researchers believe that bifidobacteria have anti-cancer properties, which may be due to immunity enhancement by the cells, cell wall components and extracellular components of Bifidobacteria, according to the Food Technology article. 

Clinical and laboratory studies have suggested that a deficiency in Bifidobacteria may induce aging, decrease immunity and contribute to adult disease, including cancer and arthritis. While adding live Bifidobacteria to the food supply would result in health benefits, researchers point out that they would not survive many food-processing techniques. Instead, nominal amounts of oligosaccharides can be added to the diet directly, as a supplement or in food, to promote the growth of these friendly bacteria. 

Cholesterol-Lowering Effects
Research has shown that chitosan may be effective in reducing blood cholesterol levels. In 1980, Japanese scientists demonstrated that incorporation chitosan into diets designed to raise blood cholesterol levels in rats, led to decreased blood cholesterol levels in the animals. Subsequent animal work showed that chitosan also may bind cholesterol in the bowel. Preliminary results of a supplementation trial conducted in Norway showed that blood cholesterol levels decreased about 25 percent in adults who consumed chitosan daily for eight weeks in addition to their self-selected diets. Although the mechanism for lowering blood cholesterol is not completely understood, it is thought that the chitosan molecule acts as fat scavenger in the digestive tract, trapping both fat and dietary cholesterol, which are then excreted. 

Fiber and Weight-Loss Effects
Since chitin acts like a fiber, it is largely indigestible and passes through the gut mostly unchanged. These fiber-like properties can be used to replace calories in foods. Research has shown that chickens fed a microcrystalline from of chitin with their feed were leaner than chickens fed regular feed. 

As an added benefit, the study also found that chitosan relieved the lactose intolerance caused by feeds containing whey, a cheese by-product containing 70 percent lactose, says Dr. John Zikakis, professor emeritus of the University of Delaware, who performed much of the research on chitosan-fed chickens. Normally, whey has limited use in animal feed, since it can lead to diarrhea. But chickens fed a substantial level of whey and chitin did not develop diarrhea, he notes. It is thought that this same effect may be achieved in humans. 

Research also has shown that general bowel function and regularity improve with the use of dietary chitosan. In animal studies, when gerbils were fed diets supplemented with chitosan, the animals became healthier, with improved vigor. Other experiments demonstrated that when chitosan was added to bread and then fed to gerbils, the same health benefits resulted. Similar benefits have been reported with chitinous supplements in cattle feed. 

Researchers speculate that improved regularity also would result in humans who ingest modest amounts of chitosan. 

Chitosan also has been shown to have antacid and anti-ulcer activity in rats and dogs. It is believed that chitosan has physical and chemical properties that are similar to the natural substances which coat the gastric tract. 

Summary
The current and potential applications of chitosan and its derivatives in fields such as biomedicine, nutrition, food processing, pharmacology, microbiology, agriculture, and cosmetics are vast and exiting. Nearly 1,000 research papers have been published on chitin and its derivatives and nearly 200 patents have been issued in the U.S., in addition to those issued in several other countries worldwide.  Chitosan has an international following: scientists from dozens of countries, including the U.S. and Russia, gather every three years to present the newest research on chitin and its derivatives. Many believe these natural compounds are poised to make waves, especially in biomedical, nutrition and food industries. 

"Chitosan and chitosan oligosaccharide are ideal biomaterials which hold much promise for the future," notes Prodex's Joseph Nichols. "There has been increased interest by scientists worldwide and industry is beginning to recognize their possibilities. They could very well be important biomaterials in the next decade. The day has come for these natural polymers to come into their own." 

click here  for about complete list of Chitosan books

• Guide to Chitin 

• Chitin: Healing Power from the Sea 

by Dr. Nobuhide Hoashi 

Dr. Nobuhide Hoashi, Chitin: Healing Power from the Sea (Los Angeles, California: Will Productions 1995). 

• Asaoka, Koji, Chitin-Chitosan: The Choice Food Supplement for over 10,000 Physicians in Japan (New York, New York: Vantage Press, Inc., 1996).  

• "Chitin: A Natural Product for the 21st Century" 

(Atlanta, Georgia: International Commission on Natural Health Products) 
• "Seaborne's Guide to Chitin and Other Ingredients" 

(Alpharetta, Georgia: Seaborne, Inc., 1997, 770.663.6633. 

• Zamperion, Eugene R. and Kamhi, Ellen J.: Healthy & Natural Journal / Volume 3 Issue 5 , page 32 (Sarasota, Florida: Healthy & Natural Journal, 1996)  
• Pennisi, Elizabeth, "Chitin: Trash or Treasure?" Science News, vol. 144, No.5, pages 65 - 80 (July 31, 1993)  
• Mater, Thomas: "Out Of Its Shell" Newsday, ( September 26, 1995)  
• Tomomatsu, Hideo: "Health Effects of Oligosaccharides" Food Technology, pages 61 - 65 ( October, 1994)