Wednesday, March 31, 2004
Lack of research stymies efforts to standardize herbal supplement
ANDREW BRIDGES, AP Science Writer
(03-31) 00:02 PST ANAHEIM, Calif. (AP) --
Verifying the quality of the thousands of different botanical extracts
sold to U.S. consumers remains difficult because of a lack of basic
research into what active ingredients are contained in the herbal
supplements and what they do, experts said.
The $4 billion herbal supplement industry peddles extracts from an
estimated 3,000 plants, contained in upward of 50,000 products.
Federal law controls how those products are labeled to indicate what
ingredients they contain and in what quantities, but the claims don't
always withstand scientific scrutiny, said Joseph Betz, of the National
Institutes of Health's office of dietary supplements.
"Some of these numbers are wildly inaccurate and some are spot on,
on the money," Betz told reporters Tuesday at the annual meeting of the
American Chemical Society.
The problem, Betz said, lies in the nonstandardized analytic methods
to measure the chemical compounds found in the products.
"We don't know whether the tests being done are accurate," Betz said.
In many cases, the active ingredients in supplements remain unknown,
making it difficult to ensure the consistency -- or legitimacy -- of a
The raw materials, too, vary in origin, harvest method and how they're
mixed with other ingredients.
Testing conducted by scientists at Rutgers University revealed that a
variety of store-bought herbal supplements didn't match the claims their
labels made when subjected to laboratory tests, the university's Mingfu
The tests found products that contained: the wrong part of a plant,
swapping leaf extracts for those taken from the root; a different species
of plant altogether than that listed on the label; detectable levels of
drugs, including caffeine, used to spike the supplements, Wang
"We found a lot of products didn't match the labels' claims," Wang
Analysis of botanical products frequently relies on a single chemical
marker to detect a botanical ingredient and assess in what quantities it
is present, said Navindra Seeram, of the University of California, Los
His laboratory is one of many working to develop a library of chemical
"fingerprints" that would allow manufacturers and regulators alike to
reliably and accurately analyze herbal products.
Already, there are dozens of analytical methods in place for some plant
species. For others, there are none, experts said.
Government efforts to develop new analytical methods is prioritized,
safety concerns about a product vaulting it to the top of the list, Betz
said. But the work can be slow, especially in a market where products fall
in and out of favor relatively quickly -- especially when backed by
regulatory action or headline-grabbing deaths, as happened with
For instance, two novel methods of testing the herbal stimulant are now
being published, just as a federal ban on its sale enters effect, Betz
The supplement was enormously popular for weight loss and body
but drew regulatory scrutiny after it was linked to more than 150 deaths
and dozens of heart attacks and strokes.