The most commonly reported reason for using herbs varied by type of herb, although for five of the herbs, promotion of general health and well-being was the primary reason cited by the survey's respondents. Yet, for 11 of 13 herbs, less than 60 percent of the respondents rated the herb as effective or very effective.
The survey's results provide key information about herbal product use that can be helpful to physicians, the authors write.
"Because herbs are being used frequently to treat or prevent an array of health conditions, physicians must become educated about herbs so they can identify potentially unsafe herbal use practices," said Lisa J. Harnack, Doctor of Public Health, of the Division of Epidemiology at the University of Minnesota School of Public Health, the principal author. "Becoming more knowledgeable will prepare physicians for discussing herbal remedies with patients who, at present, are relying predominantly on family and friends for information."
And, Harnack writes, physicians should begin asking patients about herb use when they obtain a medical history. Physicians may be able to identify possible herbal-pharmaceutical and herb-herb interactions and use of herbs with known toxic effects. Physician understanding of patient self-treatment may open a dialogue about patient health concerns and the use of herbs.
The survey respondents who reported using an herbal product were significantly more likely to be women and to have reported using a multivitamin or individual nutritional supplement during the past 12 months compared with those who did not report using an herbal product.
Prevalence of use of specific herbs during the past 12 months ranged from 30.9 percent for ginseng to 3.0 percent for milk thistle. Herbs reported to have been used by 10 percent of more of the respondents included ginseng, echinacea, garlic, ginkgo, St. John's wort, ginger, ephedra and goldenseal.
The survey found 61 percent of the respondents reported using an herbal product in the past 12 months. The authors noted that the survey may have slightly inflated estimates of the usage rates because a higher proportion of women and a lower proportion of non-high school graduates occurred in the sampling compared to census bureau statistics.
The survey was conducted by using data tapes from the Minnesota Department of Public Safety Driver and Vehicle Service Division to randomly selected 752 adults age 18 or older to receive a mail survey between June and August 1999. Of the original sample, 580 people were eligible and 376 of them returned a completed survey for a response rate of 65 percent.