If you’re a woodworker, you may be familiar with lapacho, a dense, extremely hard tropical wood. It makes beautiful, fine-grained furniture, but by woodworking standards, it’s a challenge. Lapacho resists sawing and bending. To put a nail in it, you have to prebore a hole. It doesn’t take paint well and is impermeable to most wood preservatives. In the wild, lapacho is practically indestructible, yielding to neither termites nor decay.
The tree’s resilience in the midst of the damp South American rain forest may have been what first attracted the attention of natives to its medicinal properties. Brazilian Indians used its inner bark to treat colitis, dysentery, snakebite, wounds, sore throats, ulcers, cancer, and a number of other ailments.
Pau d’arco, the phytomedicine made from the bark, is used today by herbalists to treat bacterial, fungal, viral, and parasitic infections. It’s a common herb in health food stores and drugstores that carry herbal supplements.
Smothering the Bugs
You may hear the tree referred to interchangeably as pau d’arco and lapacho. In South America, the common name is trumpet tree. There are some 100 species native to tropical America.
The tree, which can grow 125 feet tall, has been well-studied by plant scientists because of its value as a hardwood. The wood is believed to contain between 2 and 7 percent of a compound called lapachol, which is considered by herbalists to be the most active ingredient. On microorganisms, lapachol acts as a respiratory poison, interfering with their oxygen and energy production.
When researchers purified an extract of the herb in an attempt to increase the amount of lapachol, however, the chemical was less effective. This led them to believe that other ingredients, such as beta-lapachone and quercetin, were also active medicinally. One theory holds that beta-lapachone inhibits certain enzymes that viruses require to spread and grow. If that’s the case, having more beta-lapachone in our bodies would be an effective way to block viruses, says Debra Gibson, N.D., a naturopathic doctor in Woodbury, Connecticut.
Fungus Fighter
Whatever its active ingredients, pau d’arco poses a death threat to a type of fungus called Candida albicans. Candida is always present to a small degree in our bodies, but it can reproduce uncontrollably under some circumstances. If your immune system is weak, you have diabetes, or you are pregnant, candida is more likely to take every opportunity to spread. You’re also more open to candida if you are taking antibiotics or anti-inflammatory drugs.
"When you take antibiotics, you kill many of the bacteria in your body, including the good bacteria," says Dr. Gibson. "That leaves an opening for Candida albicans. It’s an opportunistic organism. When there’s no competition, it will grow."
Usually the fungus occurs on the skin or in the mouth, respiratory tract, or vagina. Many women know candida simply as a yeast infection.
Many people find relief by drinking a tea made with pau d’arco bark, says Kathleen Head, N.D., a naturopathic doctor in Sandpoint, Idaho, and senior editor of Alternative Medicine Review. A supplement will work as well, she adds. "If you’re a woman who has recurring yeast infections, this would be a very good herb to try," she says.
SUPPLEMENT SNAPSHOT
| Pau d’Arco Botanical name: Tabebuia species; also known as lapacho. May help: Fungal infections, including candidiasis; viral, bacterial, and parasitic infections; and cancer. Origin: Native to the West Indies and Central and South America; there are some 100 known species. Cautions and possible side effects: Generally regarded as safe. |
Shrinking Tumors?
If you read up on pau d’arco, you’re likely to come across references to its cancer-fighting properties. Although it’s true that lapachol was studied by the National Cancer Institute and found to reduce tumors in rats, there’s no evidence that it’s effective against cancer in humans.
Some clinical trials used the compound lapachol on human cancers, but the trials were stopped after side effects, which included nausea, vomiting, , and bleeding, were found to be too severe. Still, there are anecdotal reports of cancer patients who have had positive results after taking the herb, which doesn’t cause the side effects associated with the isolated compound lapachol. Some herbalists and naturopaths still use pau d’arco as one of their cancer-fighting phytomedicines.
It’s in the Bark
The active ingredients in pau d’arco seem to be most present in the bark, the part traditionally used by the South American Indians.
Pau d’arco is available as a tincture, in capsules, and as dried bark, from which you can make a tea. You can find lapachol in capsules and tincture. "It’s really quite safe. It would be pretty hard to do yourself harm with it," Dr. Gibson says.
Although some animal studies of long-term, high-dose consumption of lapachol have shown that it may cause —a reduction of red blood cells that can lead to extreme fatigue and other symptoms—Dr. Gibson says that is very unlikely if you take typical medicinal doses.
