PSYLLIUM

Psyllium and plantain, Plantago afra and P. ovata

Plantain Family, PLANTAGINACEAE

Species of Plantago known as psyllium or Indian plantago are annuals native to the Mediterranean region of southern Europe and North Africa and, most likely, P. ovata was an accidental introduction by the earliest Spaniards to the drylands of western North America, perhaps via the sand of ship ballast. Plantago (L., meaning the sole of the foot) refers to leaf shape of the common plantain species first described by Linneaus, and ovata (i.e., ovate) for that species refers to the shape of a translucent leafy structure (the bract) within the inflorescence. The word psyllium originated from a Greek word for a flea, referring to the size, shape, and whitish color of the seed, which is the commercially important part of this plant.

The typical species of plantain (Plantago, Family Plantaginaceae) is a stemless annual with leaves arranged alternately in a basal rosette, from the center of which arises an erect spike of nonshowy, wind-pollinated flowers. For a dicotyledon, the leaves are highly unusual in having several prominent longitudinal major veins, much as one would find in a monocotyledon. In addition to psyllium, other species of plantain are P. major (greater or common plantain) and P. lanceolata (English plantain or ribwort plantain). Plants of the plantain family should not be confused with the large, starchy bananas (Musa X paradisica, a monocotyledon in Family Musaceae), which are often also called plantains.

A special mucilage comprises about 30% of psyllium seed coat; this chemical swells with water to keep the embryo adequately wetted during germination. For humans, the mucilage, chemically colloidal polysaccharides consisting mostly of xylose, arabinose, and galacturonic acid, is used as a major ingredient in a number of commercial laxative products, the most famous of which is Metamucil but also is the active compound in Effer-syllium, Fiberall, Hydrocil, Konsyl, and Perdiem, among others. The main effect for humans is relief of chronic constipation. This is successful because the seed mucilage acts as a soothing lubricant and absorbs toxins in the digestive tract. Psyllium also can relieve chronic diarrhea, by absorbing excess water, and to alleviate bladder and kidney problems, urethritis, and hemorrhoids. Other early Old World uses of psyllium seeds were to treat sores of the mouth and throat, stop nosebleeds, treat complications of the liver, and help to fix loose teeth. Psyllium was administered to assuage complications from scurvy and worms.

Psyllium is cultivated primarily in West Pakistan and parts of India, but has also been experimentally planted elsewhere, especially in Arizona. Seeds are sown at a rate of fifteen to thirty pounds per hectare, and they are mixed into the uppermost soil surface using a weed broom and then irrigated. In India planting occurs during the dry season, but in France sowing occurs after winter, in March. Blooming begins two months later, and the seeds are harvested after about two months later. Seed harvesting is done using hand sickles; the spike of fruits is removed during early morning so that the wetness, caused by morning dew, keeps the spike from shattering. Seeds, less than three millimeters in length, are obtained by threshing and winnowing, causing the several seeds to be released from each small capsule. Then seeds are sifted until clean. Seeds may be marketed whole, or the husks, i.e., the seed coat, may be sold separately. Preparation of the seed coat is tedious, because cleaned seeds must be passed through stone and grinders and then sieved and screened repeatedly through a graded series of fine meshes. The highest quality husk-which is the most expensive-is white, with no particles of reddish embryo (kernel). Most of the annual imports to the United States, the number one consumer of psyllium, come from India, including 800 metric tons of whole seeds and 3000 tons of husks. The husk is often preferred to whole seed when treating children, and is often given with sodium bicarbonate.

Although in the United States consumption is mostly via laxative products, in India seeds are combined with fruit juice or stewed fruit. In India, crushed seed is added to oil and vinegar as a treatment for rheumatism and gouty swellings, and one folk remedy there is to apply vinegar with crushed seeds to the forehead for reducing fever. In Argentina psyllium seeds are boiled in hot water, and the resultant liquid is strained and then chilled, to be used as eyedrops to stop inflammation.

One recent published study assessed the validity of psyllium as a remedy for constipation versus docusate sodium, a synthetic, anionic laxative that is also marketed as a cure for constipation, and psyllium was shown to be a faster and a more consistent remedy for constipation by increasing water content.

Other research has shown that psyllium intake may reduce hunger feelings and energy intake. This effect may have been due to increasing the time required by the digestive tract for nutrient absorption, apparently by lowering the glucose and insulin responses associated with digestion and nutrient absorption, thus a delay for the nutrients reaching the small intestines and, eventually, the body cells. This is often beneficial for overweight people who have preferred dieting practices that result in constipation. It has also been demonstrated that the psyllium seed can affect fat intake, thus making psyllium a strong candidate in diets designed for overweight and obese people.

Potential drawbacks of psyllium use, as with other natural products, are allergic symptoms that may arise. Cases of asthma, rhinitis with swelling, and nausea have been reported. One experiment conducted on nurses and medical aides, people who often come in contact with psyllium products, showed that psyllium husk was directly involved in increased asthma attacks. Obviously, individuals sensitive to psyllium should not use these natural products, and therefore doctors must be careful when prescribing psyllium-containing laxatives, because of any possible allergic reaction. The seeds of the psyllium plant are non-toxic, but ingestion of unsoaked seeds may cause certain degrees of gastrointestinal irritation and inflammation. Chewed seeds can produce profuse diarrhea.

The seeds contain about 19% fiber, 18.8% protein, and 10-20% triglycerides. Seed mucilage, consisting of polysaccharides, is a "soluble fiber," a category of food substances made famous from oat bran and certain legumes. Recently, the American Heart Association gave its approval for food manufacturers to make a health claim that "eating soluble fiber from foods such as psyllium as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease." Furthermore, the effect of soluble fiber in one tablespoon of psyllium is equal to fourteen tablespoons of oat bran. Psyllium appears to lower blood cholesterol levels when included as part of a diet having low consumption of saturated fats and cholesterol. An article in Pediatrics (1995) also stated that consuming a high fiber diet, i.e., psyllium, from a young age may even decrease the future risk of cardiovascular disease, some cancers (especially colon types), and adult-onset diabetes.

Other parts of plantain can be used for food or medicinal purposes. For example, Hernandez reported from Mexico in the 1500s that Plantago was a good food for the Aztecs. Another lesser-used species, P. lanceolata, also called ribwort plantain, which is a widespread wide of meadows and waste places around the world, is an excellent remedy for coughs, and P. major (greater or common plantain), also a widespread weed, has been used as a cough remedy, but is inferior to the ribwort plantain. The broad leaves of greater plantain can be used as a remedy for wounds and inflamed areas, and in rural areas are used to treat insect bites and bruises. Native Americans tie the leaves of the introduced greater plantain around their forehead to soothe an aching headache, but the effectiveness of this is highly unlikely.

All the plants of the plantain family contain antibiotics; however, the amount obtained from Plantago is not enough to compare with penicillin and other widely used antibiotics, which are usually obtained from fungi. Nevertheless, the antibiotic factors present (perhaps the tannins, resin, or aucubin present in the seed) have stimulated individuals to manufacture a syrup made from plantain, (Yeah, they make syrup out of it too!), which does not go moldy even when stored for long periods of time. The syrup has been used as a cough remedy for children in many parts of the world. The antibiotics may contribute to the medicinal action of plantain in bronchitis.

Today, with the widespread use of the Internet, psyllium can be purchased online. One can "buy bulk" for low prices at the click of the mouse. There are dozens of Web sites promising "all-natural, 100% psyllium seed or husk." Thus, these plants that have been used for centuries for all kinds of uses are today more readily available to the public. Couple this with the recent studies that have shown that natural products made from the psyllium or other plantains are often more effective and serve their purpose more efficiently than synthetic products, and you can understand why psyllium use has become more popular than ever.

Andrei Sirabionian

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