Other common name(s): capsaicin, cayenne, chili pepper, hot pepper, red pepper, paprika, pimiento, long pepper, conoids
Scientific/medical name(s): Capsicum annum, Capsicum frutescens
Capsicum is the name of a group of annual plants in the nightshade (Solanaceae) family. They are native to Mexico and Central America but are cultivated for food in many warmer regions of the world. Capsicum varieties include the cayenne pepper, jalapeño pepper, other hot peppers, and paprika. Capsaicin is the most-studied active ingredient in the plant and has been approved by the U.S. Food and Drug Administration (FDA) for use on the skin.
Although little research has been reported using the whole Capsicum annum or Capsicum frutescens plant for people with cancer, capsaicin (a major active ingredient) has been studied in oral and topical forms. Several studies have shown that capsaicin may be somewhat useful for managing pain related to surgery and mouth sores due to chemotherapy and radiation therapy. However, more research is needed on other uses of capsaicin and to find out whether the whole herb is helpful for treating or preventing illness.
How is it promoted for use?
Capsaicin in topical form is promoted mainly for pain caused by conditions such as arthritis and general muscle soreness. The FDA approved a topical form of capsaicin for treating pain more than twenty years ago that is still sold without a prescription. There is some evidence that capsaicin may be useful in managing post-surgical pain from mastectomy, thoracotomy (chest surgery), amputation, and other surgery related to mainstream cancer treatment. Researchers have found that capsaicin may provide temporary relief for pain from mouth sores caused by chemotherapy and radiation therapy.
Some proponents claim that capsaicin has antioxidant properties that help to fight the carcinogen nitrosamine, a cancer-causing agent. An antioxidant is a compound that blocks the action of free radicals, activated oxygen molecules that can damage cells. Still others claim that it may prevent DNA damage and lung cancer due to cigarette smoke. Available evidence does not support claims of protection from the effects of smoking.
Over the years, the Capsicum annum or Capsicum frutescens herb has been used by alternative medicine practitioners as a remedy for a variety of conditions, such as upset stomach, menstrual cramps, headaches, shingles, diarrhea, loss of appetite, stomach ulcers, poor digestion, sore throat, itching, alcoholism, motion sickness, toothache, malaria, and yellow fever. Some practitioners also claim it can prevent colds, heart disease, and stroke; increase sexual potency; foster weight loss; and strengthen the heart.
What does it involve?
The capsaicin cream, ointment, gel, lotion, or stick is rubbed directly onto the skin over painful areas. Depending on the strength of the preparation, it may be recommended for use for as little as 2 days or as long as 2 months. It can be obtained with or without a prescription.
Capsicum is available in health food stores as a tonic, a capsule, or in tea. There are some recipes available over the Internet that advocate making a candy with cayenne pepper to relieve the pain of mouth sores from chemotherapy and radiation. Peppers are available fresh, canned, frozen, and dried in food stores.
What is the history behind it?
As far back as 5000 BC, Indians in South America ate meals prepared with hot peppers. Native Mexican Indians and some Chinese (Hunan and Szechuan) are also known to have used hot peppers in many dishes and continue to do so. These cultures have also used hot peppers in herbal medicine to treat numerous conditions over the years.
While foods made with different kinds of peppers are popular in a variety of ethnic cuisines, it is only in recent years that interest in using capsaicin from hot peppers to manage pain and other symptoms or illnesses has grown. Medical researchers are now looking at the use of capsaicin as a possible cancer treatment.
What is the evidence?
Although there is little available research on the use of the whole Capsicum herb for people with cancer, capsaicin has been intensively researched for use on the skin. Extracted chemicals such as capsaicin are not the same as the whole plant, so study results of extracts are unlikely to be the same as studies using the whole plant.
A study in 1989 found topical capsaicin to have pain-relieving effects among 50% of a small group of women who had undergone mastectomies for breast cancer. A 1991 study concluded that capsaicin cream reduced the amount of pain caused by diabetic neuropathy (a nerve disorder). Nerve pain (also called neuropathic pain) is often experienced by patients after cancer surgery and may be felt as numbness, tingling, burning, shooting, or electric-shock-like pain. In 1994, a review of previous research concluded that while topical capsaicin is not satisfactory as a therapy by itself, it may be used with other medicines to ease pain. A 2004 review of 6 clinical trials of patients with chronic long-term pain found that topical capsaicin was helpful to some. However, about a third of the patients using capsaicin had side effects that were not experienced by the placebo groups. Studies continue on new ways to use capsaicin for pain and itching.
A small 2006 study tested the effects on cholesterol of chili peppers using raw chilies. Out of 27 test subjects, one group consumed raw chopped chilies every day for 4 weeks, and the other group consumed a bland diet. No differences in cholesterol were noted between the 2 groups.
In a pilot study conducted at the Yale University School of Medicine, oral capsaicin (mixed with taffy) reduced pain in eleven patients with mouth sores caused by chemotherapy or radiation therapy. For most of the patients, however, the pain relief was incomplete and did not last long. A later controlled study looked at larger doses of capsaicin for 50 patients with a condition called burning mouth syndrome. The researchers reported that some patients got relief from the mouth pain and burning, but more than 30% of patients taking capsaicin had fairly significant stomach pain. No patients in the placebo group had stomach complaints.
Studies have also been conducted to examine capsaicin’s potential to relieve itching, reduce the size of nasal polyps, and protect against substances that cause cancer. However, researchers have found it difficult to conduct these studies because of the burning sensation caused by oral or topical use of capsaicin. The discomfort has caused some patients to stop using it. It also makes it difficult for researchers to conduct controlled studies of the drug, since the patient can often tell the active substance from the placebo.
Capsaicin has been shown to slow the growth of prostate cancer cells in laboratory studies and rodents. Researchers are looking into the use of capsaicin for prostate cancer in humans. Even though a treatment may look promising in animal and laboratory studies, further studies are required to find out whether the results apply to humans.
Available scientific research does not support claims for the effectiveness of capsicum or whole pepper supplements in preventing or curing cancer at this time. Claims that capsicum can help addiction, malaria, yellow fever, heart disease, stroke, weight loss, poor appetite, and sexual potency are not supported by available scientific evidence. The pepper extract capsaicin appears to have some value as a pain reliever, but its side effects limit its usefulness for some people.
Are there any possible problems or complications?
This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must provide the FDA with results of detailed testing showing their product is safe and effective before the drug is approved for sale), the companies that make supplements do not have to show evidence of safety or health benefits to the FDA before selling their products. Supplement products without any reliable scientific evidence of health benefits may still be sold as long as the companies selling them do not claim the supplements can prevent, treat, or cure any specific disease. Some such products may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). Though the FDA has written new rules to improve the quality of manufacturing processes for dietary supplements and the accurate listing of supplement ingredients, these rules do not take full effect until 2010. And, the new rules do not address the safety of supplement ingredients or their effects on health when proper manufacturing techniques are used.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.
Cayenne and other peppers are considered safe to eat in moderate amounts for those who are not allergic to peppers. The FDA includes peppers on their "generally recognized as safe" list of food ingredients. However, capsicum supplements taken by mouth can cause stomach upset or diarrhea. Direct contact between peppers and the mouth or other mucous membranes can cause stinging, burning, or pain. Sweating, skin flushing, runny nose, and tears are also fairly common effects of taking capsicum supplements. Long-term use of supplements or chiles can cause stomach irritation.
Oleoresin of capsicum (OC), commonly called “pepper spray,” is used in spray form as a way to incapacitate people in threatening situations. Usually the spray causes burning of the eyes, nose, mouth, and skin. Some people cough and have trouble breathing for a short time. Those with asthma or other breathing problems may have worse effects. Generally, pepper spray does not cause permanent damage, but there are exceptions. Deaths have been reported due to pepper spray.
Some animal studies have shown that capsicum induced liver tumors, and capsaicin caused cancerous tumors (adenocarcinomas) of the intestine, although these effects have not been shown in humans.
Capsaicin in cream or other topical form often causes temporary stinging, burning, or itching when applied directly to the skin. In severe cases, blisters or rash may result. Capsaicin cream can increase the absorption of other substances through the skin, so other chemicals, lotions, and substances should be kept away from capsaicin-treated areas. Contact with eyes, mucous membranes, or broken skin should be avoided, as severe burning and irritation can occur. After applying the cream, wash hands thoroughly (unless applying to the hands). Some recommend using plastic gloves when applying the cream.
In addition, possible interactions between herbs and drugs or other herbs should be considered. Capsicum supplements may cause the body to absorb more theophylline (an asthma medicine) and acetaminophen (pain medicine). They can also interfere with or worsen side effects of certain blood pressure medicines and other drugs. Some combinations may be dangerous. Always tell your doctor and pharmacist about any herbs you are taking.
Those who are allergic to peppers should not take or use capsaicin or other pepper extracts. Children and women who are pregnant or breastfeeding should avoid taking this supplement internally. Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation
Last Revised: 11/30/2008