Pectins are a class of plant cell wall polysaccharides that are water-soluble and form gels when mixed with sugars and water at the proper pH. In plants, pectin helps ripening fruits stay firm and retain their shape. As fruit becomes overripe, the pectin is broken down into simple sugars and the fruit becomes soft and begins to lose its shape. Purified forms of pectin, derived from apple peels and the inner rinds of citrus fruits, are used in the preparation of jams and jellies and as a suspending agent in pharmaceutical preparations. As a dietary supplement, pectin serves as a concentrated source of soluble fiber.
Clinical trials on pectin supplementation have commonly used dosages of 15 grams per day. Pectin has very low toxicity and is generally well tolerated at this dosage. Because increases in dietary fiber can cause flatulence and abdominal discomfort in individuals unaccustomed to high fiber diets, some nutrition experts recommend starting with a dosage of 1 or 2 grams (with meals) and gradually increasing the dosage to 5 grams. It is important to consume adequate amounts of water when taking any fiber supplement, especially in pill form. Pectin pills are not recommended for individuals with esophageal disorders because the pills may expand in the esophagus, leading to obstruction of the intestinal tract.