Feb. 14, 2005 -- In any given week, nearly one in five Americans takes a dietary supplement containing herbs or some other natural product. But after a surge in popularity in the 1990s, new research shows that dietary supplement use may be hitting a plateau.
Researchers say the use of alternative medicines, particularly herbal products, has increased dramatically in the past decade, with Americans spending $4.2 billion on herbs and other botanical remedies in 2001 alone.
But the study shows that after hitting a peak in 2001, the number of Americans taking a separate dietary supplement is holding steady while a growing number of Americans are now getting herbal supplements along with their daily multivitamin.
"Although the deliberate use of herbal products may have reached a plateau in the last few years, exposure to individual herbal ingredients may continue to rise as more of them are added to mainstream multivitamin products," write researcher Judith Kelly of the Boston University School of Public Health, and colleagues.
The results also indicate the popularity of certain dietary supplements, such as ginkgo biloba and panax ginseng, is waning, but use of lutein, an antioxidant thought to protect against macular degeneration (a common cause of blindness in adults) is on the rise.
In the study, which appears in the Feb. 14 issue of the Archives of Internal Medicine, researchers examined data gathered from phone interviews conducted from 1998 through 2002 on dietary supplement use. Researchers asked the 8,470 participants to identify all over-the-counter and prescription drugs, along with dietary supplements taken during the preceding seven days.
Researchers found the percentage of people using dietary supplements increased from 14.2% in 1998-1999 to 18.8% in 2002. Dietary supplement use was lowest in 2000 at 12.3% and peaked in 2001 at 19.8%.
Which Supplements Are Popular Today?
Although the 18.8% of Americans who said they used a dietary supplement in 2002 was higher than in 1998-1999, researchers say that increase is explained by a dramatic rise in exposure to lutein in 2001 and 2002. During this time the antioxidant was added to the formulation of several popular multivitamins.
When lutein use was excluded, the study showed that the prevalence of dietary supplement use was unchanged during this period.
For example, researchers say lutein was the most commonly used supplement among both men and women of all ages in 2002, but it was not among the top dietary supplements in any age group in 1998-1999.
Overall, the study showed that dietary supplement users tended to be older, female, and white. Although dietary supplement use did not change among younger people, researchers say the use of dietary supplements doubled among men and women over age 65 from 1998 to 2002.
- Panax ginseng was used by 4% of men aged 18-44 in 1998-1999 but only 2% in 2002.
- Among middle-aged men, use of ginkgo biloba, panax ginseng, and St. John's wort was also lower in 2002 than in 1998-1999.
- Use of chondroitin more than tripled among men over 65 during the study period, while use of saw palmetto and garlic declined in this age group.
- For women, none of the top six supplements used in 1998-1999 were in the top five in 2002.
- A growing proportion of middle-aged women also used chondroitin and glucosamine in 2002, but use of ginkgo biloba, panax ginseng, and garlic fell slightly.
- In older women over 65, use of glucosamine nearly doubled during the study, while use of ginkgo biloba and panax ginseng declined.