Liberty Hyde Bailey, the father of modern horticultural science, once said that there is only one constant factor in the plant kingdom—endless variation. If there is one plant group that embodies this concept of endless diversity, it is the New World peppers: about twenty species and hundreds of varieties in the genus Capsicum. In their native habitat of tropical America, capsicums are perennial and woody, growing to 7 feet tall; in American gardens, where they are grown as annuals, their maximum height is closer to 3 feet.
Five species had already been domesticated in Latin America centuries before the arrival of Columbus: C. frutescens, C. annuum, C. chinense (native to the Amazon region despite its name), C. pubescens, and C. baccatum. The last two are pungent Andean species, and C. chinense is extremely pungent and popular in the West Indies. Tabasco peppers, grown commercially in the Gulf states and New Mexico, belong to C. frutescens. C. annuum is the source of the vast majority of peppers grown commercially or in gardens. Mild, large-fruited types include paprika, pimento, and bell peppers; pungent kinds include cayenne, jalapeño, and serrano, to name a few.
Historical Medicinal Uses
While the culinary uses of peppers are well known and highly appreciated, their medicinal uses are no less enticing. The ancient Mayans used cayenne to treat gum sores and inflammations. By the mid–sixteenth century, Europeans were using capsicum as a local stimulant, gargle, and counterirritant liniment. These “guinea peppers” were also taken to “prevent flatulence from vegetable food, and have a warm and kindly effect in the stomach, possessing all the virtues of the oriental spices, without producing complaints of the head which the latter are apt to occasion,” as Robert John Thorton wrote in his Family Herbal (1814).
In North America, cayenne remained principally a culinary herb until it was catapulted into popularity as a home remedy by the self-styled physician Samuel Thomson (1769–1843), who used cayenne to “produce a strong heat in the body” and to restore digestive powers. “A teaspoonful of Cayenne may be taken in a tumbler of cider and is much better than ardent spirits,” he proclaimed. “There is scarce any preparation of medicine that I make use of, in which I do not put some of this article.”
Thomson’s work influenced the teachings of John Christopher, a popular promoter of herbs during the 1970s. Of cayenne, Christopher wrote in his School of Natural Healing (1976), “This herb . . . feeds the necessary elements into the cell structure of the arteries, veins and capillaries so that these regain the elasticity of youth again, and the blood pressure adjusts itself to normal.”
While herbalists may value cayenne for its reputed ability to stimulate the gastrointestinal system, expel gas from the alimentary canal, and improve blood pressure and circulation, no positive effects on the digestive system, blood pressure, or circulation have been scientifically established. In Germany, therefore, products containing cayenne are not allowed to carry therapeutic claims for these conditions.
Current Accepted Uses
Capsaicin, a highly pungent compound, is responsible for the hot bite of red peppers. Amounts of this substance vary from 0.1 to 1.5 percent; mild peppers such as paprika and bell peppers contain little or none, whereas hot peppers such as cayenne contain the highest percentages.
A single dose of capsaicin elicits pain, producing the familiar burning sensation, along with inflammation and hypersensitivity. However, repeated long-term applications lead to desensitization and analgesia along with reduction of inflammation.
The specific mechanism of capsaicin-induced desensitization and analgesia has yet to be established definitively. One theory is that small amounts of capsaicin may act by disrupting “substance P”, a protein that relays pain messages from nerve endings to the brain. Capsaicin initially causes a release in substance P, which is announced by pain and burning. With repeated doses of capsaicin, nerve endings somehow stop replenishing their supplies of substance P, resulting in desensitization of the nerve endings. Another theory attributes capsaicin’s effects to the release and depletion of neuropeptides, amino acid derivatives that influence neural activity.
Pure capsaicin or its analogs are now used in over-the-counter topical cream products for the treatment of pain associated with diabetic neuropathy, rheumatoid arthritis, and osteoarthritis. It is also used in the treatment of shingles (herpes zoster), an acute viral inflammation of the nervous system that affects 4 out of every 1000 Americans each year. In addition, it is currently under study as a topical treatment for psoriasis, vitiligo, intractable itching, phantom pain syndrome, postsurgical pain, and sciatica.
Before using capsaicin-containing products, consult a physician or pharmacist to learn which form and dosage would best treat your condition. Nonprescription products contain 0.025 and 0.075 percent capsaicin. Generally, they produce complete pain relief within fourteen days of application, but relief may be delayed in some cases as long as four to six weeks. (Don’t try to substitute cayenne or powdered red peppers of any sort for standardized products containing capsaicin—their capsaicin content is so variable that there’s no way of knowing how much you’re getting.).
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