It's estimated that allergies affect 40 to 50 million Americans, and about 20 million have asthma. While dietary supplements and other complementary and alternative therapies, such as hypnosis and acupuncture, may ease symptoms in some of these cases, experts say people have to be cautious about what they ingest, inject or practice when it comes to treating the sneezing, coughing and wheezing caused by asthma and allergies. Not only are some people with allergies particularly susceptible to adverse drug reactions, there is also a chance that dietary supplements may interact with other medications.

Why Go Alternative?
Given the many medications available that can successfully treat asthma and allergies, you may wonder why people are seeking out alternatives. Like many other chronic medical conditions that have no cure, people who suffer asthma and allergies them are particularly interested in trying new things. And as is well known, many Americans in the 21st century are interested in using what's perceived as "natural" even though natural doesn't necessarily mean without side effects. Just like synthetic pharmaceutical compounds, natural compounds are biologically active in the body.

But another driving force may be the high cost of allergy and asthma medicines, says Gailen Marshall, MD, PhD, a professor of medicine and director of the division of clinical immunology, asthma and allergy at the University of Mississippi in Jackson. Someone who has both allergies and asthma but chooses to only treat their asthma to cut costs, for example, may run into trouble quickly because flaring allergies can worsen asthma. At that point, Dr. Marshall says, people are inclined to think, "This isn't working for me," and turn CAM therapies that are typically, though not always, less expensive than the prescription alternatives.

Safety Concerns
Because the manufacturers of herbs and other dietary supplements do not have to present information about their products' safety and effectiveness to the Food and Drug Administration prior to marketing them to consumers, little is known about many dietary supplements, which may even contain mold spores that could trigger reactions in people with allergies.

In a study published recently in a supplement devoted to CAM in the Annals of Allergy, Asthma and Immunology, Leonard Bielory, MD, of the UMDNJ-New Jersey Medical School in Newark reviewed the medical literature to find information about popular CAM therapies for asthma, allergies and immune system conditions, such as echinacea, garlic, ginkgo and other herbal supplements.

"Many of my patients were taking complementary and alternative therapies," Dr. Bielory explains. "I wanted to learn more about what's real and not real. Physicians shouldn't downplay CAM if people feel better, even if it's a placebo effect. However, there are some herbal supplements that have adverse effects."

Dr. Bielory found that a number of the herbal supplements had side effects, most of which were allergic reactions, such as hives or contact dermatitis, which usually appears as an itchy rash.

Specifically, Dr. Bielory found that echinacea, used for the common cold and for upper respiratory tract allergies, such as congestion and a runny, itchy nose, carries some risk of liver toxicity. There have been reports of asthma attacks and of life-threatening anaphylactic reactions, as well as a worsening of asthma and allergies symptoms. People with pollen allergies, as well as people who are sensitive to sunflower seeds or melons, may be more likely to have an adverse reaction to echinacea.

Likewise, bee pollen, a CAM therapy sometimes used for asthma and allergies, has been shown to trigger a sore throat, breathing problems and, if someone is allergic to bee pollen, anaphylactic shock.

Ginkgo biloba, which has been shown to expand the air passages in the lungs, is sometimes recommended to people with asthma. But Dr. Bielory points out that ginkgo interacts with warfarin, a medication taken to prevent blood clots, making it less effective. Physicians also caution people about using ginkgo in combination with aspirin and other non-steroid anti-inflammatories and anti-clotting drugs.

Asthma sufferers specifically should be aware of another potential herb-drug interaction: St. John's Wort, a supplement often recommended for anxiety and depression, may interact with oral asthma medications such as theophylline.

One group of relatively side-effect-free CAM therapies for people with asthma is stress reduction techniques, such as biofeedback and hypnosis. Some studies, including one conducted by Dr. Marshall, have demonstrated that chronic anxiety and depression play a role in asthma. So stress management, Dr. Marshall says, from counseling to antidepressants to CAM approaches, may help certain patient control their asthma and perhaps their allergy symptoms.

What Now?
According to Dr. Bielory, the next step for many of these herbal supplements are clinical trials that may never be done because manufacturers do not see such studies as a good investment. In meantime, allergists need to familiarize themselves with CAM treatments, and patients need to be open with their doctors about their use of these therapies.

"Patients with asthma and allergies should insist on an open-mindedness in their practitioners about discussing complementary and alternative therapies," Dr. Marshall says. "If their healthcare practitioner is not open-minded, the patient should find someone who is."