When you hear about all of the potential medicinal plants in a tropical rain forest, you probably picture an inconspicuous fern beneath the damp forest canopy or a dainty water lily floating in a steamy swamp. How about a tree-climbing, 100-foot vine that’s 12 inches around, with thorns as sharp and tenacious as a jaguar’s claws?
Cat’s claw is one of the newly discovered herbs of the Amazon. It’s actually new, however, only to Western civilization, since the Peruvian Indians of the region have used the vine medicinally for centuries.
If you follow the news on cat’s claw, you might think it’s the cat’s meow. It’s been called a superb immune system booster, a vigorous antioxidant, a plant able to flush chemical toxins from the body, and a kind of scrubber that removes plaque buildup in clogged arteries.
Health food stores in North America brim with products that contain cat’s claw, but there really isn’t much known about this herb. The labels make many claims that may be exaggerated, warns Eran Ben-Arye, M.D., a researcher at the natural medicine research unit at Hadassah University Hospital in Jerusalem.
"Right now, all we have are anecdotal reports and very preliminary findings regarding the herb’s immunological and antifungal properties," Dr. Ben-Arye says. "Cat’s claw may have very good potential as a medicine, or it may not. We just don’t know yet."
Putting Teeth into Immunity
In the burgeoning marketplace of herbal products and nutritional supplements, cat’s claw has gained a reputation as a cure-all for conditions such as lupus, arthritis, bursitis, fibromyalgia, chronic fatigue syndrome, and chemical and environmental allergies.
Although there are many theories about how it fights these conditions, the one most often cited is stimulation of the immune system, says Tirun Gopal, M.D., an obstetrician and gynecologist who practices holistic and Ayurvedic medicine in Allentown, Pennsylvania.
"It’s used mostly for degenerative diseases where there is a significant loss of immunity," says Dr. Gopal. When people have diseases like cancer, lupus, or rheumatoid arthritis, their immune systems take a hard knock, leaving them open to secondary infections from colds and flu. Such infections—manageable for healthy people—can be life-threatening for people battling a chronic illness, he says.
"I’ve found that cat’s claw can make the body more tolerant and better able to fight an infection, especially at its initial onset," he says. "You can use cat’s claw by itself or with echinacea and astragalus—two other immune system stimulators—to boost its effectiveness."
The Jaguar’s Claw
Historically, the Peruvian Indians made a tea from the root and inner bark of the plant to treat arthritis, tumors, ulcers, and inflammation. But since the Indians have an oral rather than a written tradition, the methodologies and uses of the plant remain obscure.
The first references in literature to this woody vine date back to the late 1700s, but it wasn’t until the 1970s that an Austrian doctor drew attention to the herb in the West. The name cat’s claw, or uña de gato in Spanish, comes from the vine’s sharp, curved thorns that resemble the claws of a jaguar or cat.
SUPPLEMENTSNAPSHOT
| Cat’s Claw Botanical names: Uncaria tomentosa, U. guianensis; also known as uña de gato. May help: Heart disease, low immunity, bursitis, rheumatoid arthritis, chemical poisoning, fibromyalgia, chronic fatigue syndrome, and lupus. Origin: Found in the Peruvian rain forest. Cautions and possible side effects: Don’t use if you have hemophilia or are pregnant. May cause headache, stomachache, or difficulty breathing; also has contraceptive properties. |
Chemical analysis has revealed that the plant contains several important medicinal ingredients. Some of its alkaloids are known to be immune stimulants, and the plant appears to stimulate the activity of T cells, a type of white blood cells, says Dr. Gopal. These blood cells hunt down and act against virus-infected cells and tumor cells.
One alkaloid in particular seems to reduce blood pressure and may reduce the risk of stroke and heart attack.
The herb also contains compounds called glycosides that exhibit antiviral and anti-inflammatory activity. Some researchers suggest that cat’s claw is effective at relieving swelling. "Because of this anti-inflammatory effect, some people have advocated its use with rheumatoid arthritis," comments Dr. Gopal.
Three of the glycosides in the herb have antioxidant activity, meaning that they have the ability to scavenge free radicals, the free-roaming, unstable molecules that cause aging and cell damage. An Italian study in 1992 suggested that cat’s claw can also stop cells from mutating, which may mean that it could have value as a cancer treatment.
As good as all of this sounds, it’s important to remember that these analyses and studies have been done using laboratory tests. No published study has looked at how the herb works in the human body, says Dr. Ben-Arye.
"Even though there have been some important ingredients found, we have no idea if the herb and those ingredients are actually beneficial to people," says Dr. Ben-Arye. "That has to be studied in a clinical setting, and those studies have not been published to date."
In other words, looking at the individual active ingredients can only partially explain why cat’s claw works as well as it does. The healing power may actually come from a combination of these chemicals working together, says Dr. Ben-Arye.
Soap for Your Innards
Although the science may still be inconclusive on cat’s claw, many herbalists and health professionals believe that this Amazonian plant has healing properties. Julie Clemens, N.D., a naturopathic doctor in Sagle, Idaho, says cat’s claw is one of her workhorse herbs. She uses it frequently, usually as part of detoxifying therapy.
Dr. Clemens believes that many lifestyle diseases—arthritis, diabetes, headaches, and chronic constipation—are a result of chemical toxicity. The chemicals come from the environment, diet, or a person’s lifestyle choices, such as smoking and drinking, she says.
"What eventually happens is that your body is unable to process and eliminate the toxins at the same rate they are coming in," she explains. "That can cause all types of problems."
Cat’s claw has a reputation for diminishing a person’s chemical sensitivity. It’s also been used to cleanse and detoxify the intestinal tract, says Dr. Clemens. Typically, she prescribes cat’s claw to an overweight person who has high blood pressure, problems with digestion and stomach acidity, and an unhealthy lifestyle. Her aim is to lower the toxic load, start cleaning plaque out of the arteries, and convince the person to make healthier lifestyle choices, she says.
"Cat’s claw works on the entire system of the body. I like to call it an internal scrubber. Think of it as soap for your insides," she says.
Get the Real Cat
Cat’s claw has grown so quickly in popularity that supplies of the herb are not consistent. Only the inner bark and root have medicinal value, but analysis of some cat’s claw products have found outer bark, stems, and twigs mixed in.
The popularity of the herb has caused the Peruvian government to declare it a threatened species and to ban the harvesting of the root. Today, people are leaving the root, taking only the inner bark, and allowing the plant to recover.
In North America, cat’s claw is available as a tincture, in capsules, and in raw bark form for brewing tea. Cat’s claw tea tends to be very bitter, so most people prefer capsules. "I’d look for a product that contains at least a 0.3 percent alkaloid content," says Dr. Clemens.
Although you may hear cat’s claw referred to as uña de gato, that can be a generic name for more than 20 herbs from Peru, some of which are toxic. Cat’s claw belongs to the genus Uncaria, of which there are some 60 species in the world. Only 2, however—U. tomentosa and U. guianensis—from Peru are known to have the medicinal value discussed here.
