Alternative Medicine Under the Microscope

As millions of Americans turn to alternative therapies for aging-related conditions, scientists are holding these treatments up to increased scrutiny.

The ginkgo tree's primitive characteristics entranced Charles Darwin, who dubbed it a living fossil. Today the plant has drawn the attention of millions of Americans who down extracts of Ginkgo biloba in hopes of aiding their memory, making the herbal remedy one of the nation's most popular supplements. Yet whether ginkgo's purported mind-boosting powers are anything more than a placebo effect remains an open question.

Puzzles like this one spurred Congress to create the National Center for Complementary and Alternative Medicine (NCCAM) within the National Institutes of Health in October 1998. The use of treatments such as herbal supplements, meditation, vitamins, and acupuncture is on the rise, and a full 36% of American adults report they have tried some form of complementary and alternative medicine. "It's a public health issue," says physician Brian Berman of the Center for Integrative Medicine at the University of Maryland School of Medicine in Baltimore. "With so many people using [complementary and alternative medicine], we really need to find out what's effective and what isn't and what's safe and what isn't."

Much of NCCAM's $123 million budget funds research into complementary and alternative treatments for aging-related conditions such as arthritis, cognitive decline, menopause, heart disease, and prostate cancer. With so many people turning to alternative therapies, these treatments warrant greater scrutiny and should be subjected to the same rigorous scientific standards of evidence that are applied to conventional therapies, says an Institute of Medicine (IOM) report released in January, which calls for thorough scientific testing of popular CAM treatments.

NCCAM is striving to do just that by funding scientific studies into popular complementary and alternative therapies, says endocrinologist Marc Blackman, chief of NCCAM's Endocrine Section. For instance, researchers should have an answer to the ginkgo question in the next few years after the completion of an NCCAM-funded, 5-year trial to test the herb's ability to stave off age-related changes in memory, thinking, and personality. The investigation--conducted in collaboration with the National Institute on Aging and the National Heart, Lung, and Blood Institute--has enrolled more than 3000 participants. And like the best clinical trials, the study is double-blind: Neither the patients nor their doctors know who is receiving the ginkgo supplement and who is getting a placebo. "This is the largest and most carefully conducted trial of its kind," says Blackman, who calls the ginkgo study a model of NCCAM's mission to subject such remedies to scientific inquiry.

But not every alternative treatment comes in pill form, which can make designing a placebo-controlled study a challenge. Take, for instance, acupuncture. NCCAM recently funded a study of acupuncture for osteoarthritis of the knee, a common ailment of old age. The trial, the largest ever to examine acupuncture, involved more than 500 patients who were randomly assigned to receive either the treatment or a carefully designed sham procedure. The placebo, in this case, involved fake needles that produced a tingling sensation without piercing the skin and a shield that prevented participants from seeing whether the needles were real or not.

The study, published in the Annals of Internal Medicine in December 2004, showed that compared to the placebo group, those who got the real acupuncture treatments improved their knee mobility at 8 weeks and had less pain by the end of the trial. Acupuncture was no cure, says Berman, who led the investigation. But its benefits were of the same magnitude found with mainstream treatments such as anti-inflammatory drugs like aspirin and ibuprofen. Berman says that the goal is not necessarily to substitute acupuncture for conventional treatments but to augment their benefits. "If you can get a number of different small effects, that adds up to large effects," says Berman.

Proponents of complementary and alternative medicine believe that many more therapies will prove similarly beneficial. However, deciding which treatment to test next is no easy task, especially given the large number of such remedies in use. NCCAM-funded studies must meet rigorous criteria, says Blackman. The therapy under investigation must treat a major health problem and some evidence, such as a preliminary study or case reports, should warrant the study. The condition must also be one for which complementary and alternative treatments are frequently used.

But some critics charge that NCCAM's standards should be higher. The center is currently funding treatments with little scientific rationale, simply because they're popular or are someone's pet project, says physician Stephen Barrett of Quackwatch, a watchdog group that campaigns against unproven therapies. As an example, Barrett points to a $30 million, large-scale study under way to test the benefits of chelation therapy for treating heart disease. The therapy involves injecting a synthetic amino acid called EDTA into the blood, which advocates hope will remove calcium from the plaques that clog arteries. By NCCAM's own admission, preliminary tests of chelation therapy have shown no benefit. "They're spending millions of dollars on it, and there's not a shred of evidence that it works," says Barrett.

But Berman, who served on the IOM panel, says that a lack of strong evidence should not disqualify something from study: "It's not scientific to say there's nothing here, nothing of scientific merit, so we shouldn't study it." In the case of chelation therapy, the decision to fund a thorough study was made in large part because of its popularity: Practitioners doled out more than 800,000 chelation sessions in 1997 alone.

Well-designed studies are the best way to determine, once and for all, a treatment's merits, says Blackman. Besides, something considered alternative today could become mainstream tomorrow, he says. As an example, he points to the drug digitalis, originally derived from the foxglove plant and widely used to treat heart disease. The plant was used as a remedy for heart conditions long before scientists understood how it worked. "Now we give digitalis and don't think about it," Blackman says.

The widespread use of alternative medicine makes the need to study it all the more pressing. "The IOM report says that [complementary and alternative medicines] are pervasive and here to stay," says Berman. That being the case, he says, "we need to study these things in a scientifically rigorous way." Only careful scientific study will tell whether Darwin's living fossil can also claim modern medicinal powers.

Christie Aschwanden is a freelance writer who can live with her forgetfulness until she sees published proof of gingko's memory-saving abilities.