Despite a lack of evidence many such products do anything beneficial, Americans love their St. John’s wort, their glucosamine, their black cohosh. According to data released today by the National Center for Health Statistics, a part of the Centers for Disease Control and Prevention, nearly one in five Americans used a non-vitamin, non-mineral dietary supplement in 2012.
The data was assembled as part of the National Health Interview Survey of 34,525 adults.
The percentages were virtually unchanged from the survey taken 10 years earlier when 18.9 percent of American adults said they took a non-vitamin, non-mineral supplement, such as glucosamine for joint pain, Echinacea for colds, and St. John’s wort for depression. Studies of some of the most popular herbal and other non-vitamin or mineral supplements undertaken during the intervening years have often been disappointing, but American enthusiasm for them has not waned much.
Partly, suggested Candy Tsourounis, a professor in the University of California San Francisco School of Pharmacy who studies dietary supplements, that’s because of clever marketing by the supplement industry and vague rules governing it.
While a few herbal remedies may be beneficial for some people in certain cases, she said, very little is actually known about many of them.
“I can say to you categorically that we don’t know how much St. John’s wort is a lethal dose,” she said. “We don’t know what is carcinogenic, what’s immunogenic. We have so much more work to do with botanicals it boggles the mind.”
For example, chaparral was a popular herbal supplement in the 1990s. As more people began taking it, more people also suffered cases of liver toxicity and even failure.
Chaparral was touted as health-giving and anti-aging, though there was no scientific proof for any such claim. Thanks largely to a law called the Dietary Supplement and Health Education Act of 1994, which was written by the industry itself, ingredients can be marketed by implying all sorts of benefits.
“The industry puts fairy dust amounts in beverages, potato chips, hoping that because they’re on the label, the consumer might purchase it,” she said.
The Council for Responsible Nutrition (CRN), a trade group representing dietary supplement manufacturers and ingredient suppliers argues that "when used properly" supplements "help promote overall good health and prevent disease."
The industry is highly regulated, the trade groups says. "Virtually all facets of dietary supplement manufacturing, labeling and marketing are covered by extensive regulations issued and enforced by [Food and Drug Administration] and [Federal Trade Commission]," the groups says on its website. "If dietary supplements were regulated like drugs, there would likely be no dietary supplement industry and the products that did exist would cost what drugs cost."
The group also defends non-vitamin, non-mineral supplement effectiveness. For example, it says that glucosamine is backed by "a strong body of human clinical trials that supports the safe use of glucosamine, chondroitin sulfate, or their combination for significant and long-lasting decreases in joint pain and improvements in mobility." It cites interim results from the largest trial of glucosamine, sponsored by the National Institutes of Health. But longer-term results from that same trial, called GAIT, published in 2010, showed no difference between glucosamine and placebo for knee pain or knee damage.
People who take such remedies should always disclose them to doctors to avoid possible interactions with prescription drugs.
“The take home message should be that people need to use these responsibly and that they are not necessarily cure-alls for whatever ails us,” Tsourounis said.
Such pills and tonics were the most popular “complementary” health tools by far. Only 8.5 percent of Americans went to chiropractors and osteopaths for manipulations in 2012, about the same who practiced yoga for health. Comparing the 2002 survey data does reflect yoga’s growth, however. Back then, only 5.1 percent of Americans said they practiced yoga in the past 12 months. Massage therapy was used by 6.8 percent, 4.1 percent practiced meditation, and 3 percent ate special diets.
The mountain and coastal west regions lived up to their stereotype of seeking out alternative health products. The Rocky Mountain states led the nation in taking non-vitamin or non-mineral supplements at 28.7 percent, followed closely by the coastal west at 23.3 percent. At 13.1 percent, the southern coastal states had fewest people who used such a supplement in 2012.
In the west north central region, the area of the country that includes the Dakotas, Nebraska, Kansas, Minnesota, Iowa and Missouri, 16.4 percent of adults went to see a chiropractor or osteopath for one or more manipulations, almost three times the percentage of people — 5.9 — in the west south central region.
Brian Alexander is a frequent contributor to NBC News and a co-author of “The Chemistry Between Us: Love, Sex, and the Science of Attraction.”