The surge in herbal supplement use in the U.S. may reached a plateau, but the love affair is not over, according to a new study.

Indeed, researchers say, the trend toward adding herbs to standard multivitamins means that more Americans may be getting a regular dose of botanicals in the future.

Their survey of nearly 8,500 U.S. adults found that more people were taking herbs or other dietary supplements in 2002 versus three years earlier.

However, the increase came from a spike in the use of lutein; in 2002, more than 8 percent of survey respondents took lutein in any given week, up from just 0.3 percent in 1998-1999.

Lutein, an antioxidant plant compound, has been added to many multivitamins in recent years because research suggests it can lower the risk of age-related eye diseases.

The study found that when lutein use was excluded, the number of supplement users in 2002 was virtually identical to that in 1998-1999. Roughly 14 percent of survey respondents in both periods reported taking supplements, according to findings published in the Archives of Internal Medicine.

The fact that lutein is cropping up in traditional multivitamins is neither a clearly positive nor negative thing, according to study co-author Dr. David W. Kaufman of Boston University.

“There’s really no evidence that lutein is harmful, so I don’t think that’s an issue,” he told Reuters Health.

The main thing, said Kaufman, is that people just be aware of what they’re ingesting. Because lutein intake has jumped due to its addition to multivitamins, there are likely to be “unintentional users” out there, he noted.

According to Kaufman, the findings also underscore a new trend toward marketing standard multivitamins as a weapon against disease, rather than simply a safeguard against vitamin and mineral deficiencies.

Another antioxidant, lycopene, is also showing up in many multivitamins. Like lutein, lycopene is a pigment that colors certain fruits and vegetables. Tomatoes are the top source of lycopene, while lutein is found in foods such as leafy greens, broccoli, peas, oranges and eggs.

While lutein use may be surging, Kaufman and his colleagues found that some of the most popular supplements in 1998-1999 - such as St. John’s wort, ginseng and garlic - had fallen out of favor by 2002, at least in certain age groups.

For example, ginseng was number one among 18- to 44-year-old men in 1998-1999, while St. John’s wort was the top seller among women in that age bracket. By 2002, St. John’s wort - which is marketed as an antidepressant - had fallen off the charts among women, and men’s ginseng use was about half what it was three years earlier.

Such “waxing and waning” in individual supplements’ popularity is not surprising, Kaufman said, given that people self-prescribe them-trying them for a time, then moving on to something else.

“Things are in fashion for a time, then fall out of favor,” he said, noting that because many supplements have not been well researched, the effectiveness of some products in unclear.

“What is constant,” Kaufman added, “is that lots of people are taking dietary supplements.”

That appeared especially true of older adults in the survey, who were the biggest supplement consumers. While supplement use held steady among young and middle-aged men and women, it had doubled by 2002 among adults age 65 and up.

Again, Kaufman said, that jump is related to lutein use, though more older adults were also taking chondroitin and glucosamine, which are marketed for arthritis.

SOURCE: Archives of Internal Medicine, February 14, 2005.