SAN ANTONIO, TEX—Herbal remedies, relaxation therapy, chiropractic care, and other forms of complementary or alternative medicine (CAM) have increased tremendously in popularity in the United States. “Only 10% to 30% of our health care is actually delivered by what we consider conventional or biomedical-oriented practitioners,” claims Leonard Bielory, MD, Director of the Asthma and Allergy Research Center at the New Jersey Medical School in Newark.

At a provocative symposium held during the recent annual meeting of the American College of Allergy, Asthma and Immunology, Dr. Bielory and other researchers explored the safety and efficacy of CAM in the management of allergy and asthma.[1,2] The primary goal of the symposium was to provide “scientific integrity” to the relationship of CAM in the field of allergy, asthma, and immunology. Their findings suggest that there are some interesting data to support the use of CAM for these conditions—but safety remains a concern, particularly when herbal therapies are used.

For example, anaphylaxis is a potential side effect of the popular remedy echinacea, which has been used to treat rhinitis and the common cold. Bee pollen, a CAM treatment ostensibly effective for asthma and allergies (as well as for prostatism, cancer, and heart disease), has been associated with sore throat, stridor, breathing difficulties, and other symptoms of an acute hypersensitivity reaction.

There are no known adverse effects of tincture of benzoin (also known as balsam) when it is applied topically as a mucosal protectant or administered through steam inhalation for sinus problems. “However, ingestion leads to severe gastritis,” Dr. Bielory noted.

Products containing ginkgo biloba have been shown to produce bronchodilation, smooth muscle relaxation, and other positive effects on the lungs of patients with allergy and asthma. A major problem with such products remains, however: “You do not know what you are taking, because they are not standardized,” cautioned Dr. Bielory.

EFFECTS OF STRESS

Evidence is mounting to support what physicians have suspected all along—that anxiety, depression, and other forms of psychological stress may worsen asthma and allergies. “Most of us who take care of patients would say, ‘That is absolutely true,’ ” stated Gailen D. Marshall, MD, PhD, Director of the Division of Allergy and Clinical Immunology at the University of Texas Medical School in Houston.

In a study designed to test that belief, 24 patients with mild to moderate asthma were compared to an equal number of age-matched controls.[3] Both groups were exposed to stress in two ways: They were asked to complete subtraction problems while someone pressured them, and they viewed emotionally charged films and slides. The asthma patients responded to the stress with greater increases in respiratory resistance, minute volume, blood pressure, and skin conductance than the control group experienced; they also reported higher levels of depression, arousal, and shortness of breath.

In a previous study, Dr. Marshall and his colleagues found that the stress of medical school examinations triggered immune dysregulation.[4] This finding may help explain the increased incidence of asthma, allergy, and other type-2 cytokine-mediated conditions often linked to high stress. Recent unpublished data by Dr. Marshall’s group show that employees who are highly anxious about returning to work in a previously “sick” building (one that used to contain high mold levels) have twice the rate of respiratory symptoms than do other employees.

Not all types of stress have the same effects, though. Periodic episodes of acute stress may actually be beneficial because they activate the innate immune system, Dr. Marshall noted, whereas chronic stress has been linked to a worsening of asthma and allergies. He added that it may be possible to alleviate chronic stress, and thereby reduce the severity of asthma and allergies, with very simple stress management techniques, such as having patients write about their stressful experiences.

CAN CAM ALTER THE IMMUNE SYSTEM?

Like Dr. Marshall, Rosalind J. Wright, MD, has seen firsthand evidence of the negative effect of stress on respiratory and immune function. In a prospective study of 496 new mothers and their infants, she showed that an infant was 60% more likely to have two or more episodes of wheeze within the first 14 months of life when the mother perceived herself to be under high stress.[5]

The association between maternal stress and infant wheezing remained significant—albeit slightly lower (40%)—even when the analysis was controlled for myriad confounders. Furthermore, the association persisted until the offspring reached age 5 to 6 years, reported Dr. Wright, Instructor in Medicine at Harvard Medical School in Boston.

Many randomized controlled trials have attempted to assess the ability of stress management and other types of CAM to favorably alter the immune system, but these trials have been fraught with limitations, such as the failure to clearly define the populations under stress or to standardize the treatment modality in question. Perhaps that is why even the best of these investigations, a recent meta-analysis by Miller and Cohen,[6] revealed only modest evidence in support of four CAM modalities—relaxation therapy, hypnosis, behavioral conditioning, and disclosure of stress-related feelings.

“There was a better effect with hypnosis and conditioning interventions than with the other modalities, and there was some indication that there was some impact on immune function,” related Dr. Wright. Physicians should not be disheartened by the results of the meta-analysis, she said, because the limitations of the pooled data make it premature to conclude that the immune system is unresponsive to CAM.

CHIROPRACTIC CARE IN ASTHMA AND ALLERGIES

With the number of chiropractors now exceeding 65,000 in the United States and 6,000 in Canada, chiropractic care has grown to be the third largest primary health care profession in North America. The many reports from chiropractors and their patients suggesting that chiropractic care is beneficial for a variety of conditions, including asthma, have undoubtedly contributed to that growth.

But how reliable are these anecdotes, and are there any hard data to justify the chiropractic treatment of asthma? “Currently, there is insufficient evidence to support or refute the use of manual therapy for patients with asthma,” asserted Jeffrey Balon, MD, a chiropractor and family physician practicing in Ottawa. “I do not feel that manual therapy is a first-line treatment for asthma or allergy,” added Dr. Balon, who is also a research associate at the Canadian Memorial College in Toronto.

He based those statements on the three existing randomized controlled trials of chiropractic care for asthma, including one that he performed himself.[7] These trials all showed that manual therapy does not significantly alter pulmonary function tests, peak expiratory flow, or other objective measures of asthma severity in patients with mild to moderate stable asthma.

“But, we do see significant subjective improvement with less symptoms, less bronchodilator use, and better quality-of-life measures,” pointed out Dr. Balon. It is possible that chiropractic treatment only produced subjective improvement because the patients’ asthma was already so well controlled that there was not much room for further objective improvement, he suggested.

—Timothy Begany