Traditional Chinese Herbs as Dietary
Supplements
Albert Y. Leung, Ph.D.
Phyto-Technologies, Inc., Woodbine, Iowa
www.phyto-tech.com
Current status
During the past decade, Chinese herbs have been increasingly
promoted as dietary supplements, and the public has responded with
increased demand and a desire to learn more about them.
Nevertheless, there exist many misconceptions about Chinese herbal
products.
There are basically three types of Chinese herbs used in dietary
supplements: (1) herbal drugs that traditionally have only been used
for treating diseases, with no prior use history as supplements to
our diet, such as ephedra (mahuang), coptis (huanglian),
and phellodendron (huangbo); (2) herbal foods, teas and
tonics that are seldom used to treat specific acute diseased
conditions (e.g., lycium, schisandra, ginseng and kudzu); and (3)
herbs that overlap the first two categories, yet do not belong in
either in a clear-cut manner, including magnolia (xinyi),
ginkgo leaf, and forsythia (lianqiao).
Herbal drugs, when used as dietary supplements, are essentially
being used out of traditional context, because these herbs are not
meant for long-term continuous use and many of them have documented
toxicities, cautions, and precautions in their traditional usage
(Leung 2006). Hence, the herbs in this group are the most likely to
cause toxic side-effects. The second category of food and tonifying
herbs can be considered as true dietary supplements due to their
long history of safe use, having been well-documented over a period
of more than three thousand years. These herbs are being
increasingly used in herbal drinks and tonic formulas. However,
despite their relative safety compared to herbs of the other two
categories, their identity and quality have been the most difficult
to measure and control.
This fact has impacted the quality of Chinese herbal products on the
market. While therapeutic herbs of the first category have more
easily identifiable active components (e.g., ephedrine in mahuang;
coptisine and related alkaloids in huanglian), the active
ingredients in food and tonic herbs are much more complex and
difficult to pin down. Thus, many chemicals or chemical groups
contribute to the beneficial effects of tonic herbs. For example,
saponins (e.g., astragalosides), polysaccharides, flavonoids, and
polyphenols are all active components of astragalus root (huangqi).
For this reason, while it is possible to standardize mahuang
to ephedrine or huanglian to coptisine and have some sort of
guarantee of pharmacologic activities of these herbal extracts, it
is impossible to standardize food and tonics using the same
techniques. This has created a free-for-all atmosphere in the
quality control and manufacture of TCM products, resulting in
commercial products of widely different quality.
The time is ripe for Chinese tonic herbs in dietary supplements
The appeal and rationale behind the use of Chinese tonics (not their
specific isolated chemicals or marker compounds) as dietary
supplements stem from the fact that these traditional herbs have a
long history of safe use, help normalize body functions, and have
scientific data to indicate their broad spectrum of biological
activities (antioxidant, anti-inflammatory, etc.) that are keenly
sought in supplements by American consumers. As Americans continue
to learn more about Chinese tonic herbs, they will find out that
therein lies a vast resource of true herbal supplements, with health
benefits not found elsewhere. Among the more than 12,500 Chinese
herbs currently used in TCM, less than 200 are common tonics. The
better-known and most commonly used ones include: lycium berry (gouqizi),
schisandra berry (wuweizi), astragalus root (huangqi),
cured fo-ti root (zhiheshouwu), Job’s tears (yimi),
reishi mushroom (Ganoderma lucidum & G. japonicum),
broomrape (roucongrong), epimedium herb (yinyanghuo),
and dong quai (Chinese angelica). When used as traditionally
indicated, these herbs are safe, as documentation over centuries of
use shows, though there are plenty of documented toxicity data on
other well-known Chinese herbal drugs that belong to the first
category as described earlier. Modern scientific investigations over
the past fifty years have found that many of these tonic herbs have
certain biological effects in common, including: antioxidant,
anti-inflammatory, anti-allergenic, antimicrobial (especially
anti-viral), liver-protectant, healing, boosting the immune system,
improving stamina (sexual & general), diuretic, and pain-relieving.
Although many of these effects have not yet been reproduced using
appropriate modern science, the mere fact that they have been
obtained points to the existence of something of value, which the
traditional Chinese literature has already documented over three
millennia. While this kind of information is not sufficient to
support any particular herb to be used as a modern pharmaceutical,
it can nevertheless serve as additional evidence of the herb’s
well-documented traditional benefits, to be used as a supplement to
our general diet. The problem, however, has been with their identity
and quality.
What you see is not necessarily what you get
Most people tend to judge the quality of an herbal product simply by
its labeled contents. They frequently treat herbs as if they were
pure chemical drugs, which they are not. For example, a tonic herb
like astragalus has varied traditional properties and indications
(healing, improving stamina and resistance to diseases, etc.) which
are due not to a single compound, but to many chemical components,
working together to produce these various effects. The only way to
get a full complement of its beneficial compounds is to extract it
using a well-documented traditional method. The resulting extract is
the desired ingredient, as it carries the active components for the
particular traditional benefits known and sought for astragalus. A
TCM product containing this ingredient will give the intended and
desired well-known and documented effects of this herb.
In contrast, a ‘standardized’ extract of the same astragalus root
with a fixed amount of astragalosides, flavonoids, polysaccharides,
polyphenols, or other arbitrarily chosen marker compounds, may only
carry a small fraction of astragalus’ well-known traditional
beneficial properties, because the rest of its active components may
not be present.
Unfortunately, products containing ‘standardized’ ingredients are
popular because they give people a false sense of quality, since,
like modern drugs, the chemical markers can be readily analyzed
despite the fact these markers may have nothing to do with the
quality of the products. They also offer extract producers and
suppliers a great opportunity for tremendous profits, as they can
make and sell three or four ‘standardized’ extracts instead of just
one single wholesome and total extract out of a single batch of
herb.
Consequently, unlike other dietary supplements containing vitamins
and minerals which are readily analyzable, herbal products
containing Chinese tonic ingredients cannot be easily tested and
hence are of widely different qualities. Thus, it’s obvious that a
product containing the same two ingredients labeled as ‘astragalus
extract’ and ‘ginseng extract,’ manufactured by two companies,
cannot be the same if one manufacturer uses the traditional total
extracts while the other uses extracts standardized only to specific
marker compounds. At present, this is a common occurrence in herbal
supplements that contain Chinese tonic herbs.
Technology now available for differentiating the good from the
bad
Dubious standardized extracts are not new, nor are the people who
produce or supply them. These were at the height of their prevalence
eight years ago even though few people were aware of them. Some
manufacturers continue to use these questionable extracts in their
products, with no intention of changing, due to financial incentive
or expediency, while others want to do the right thing to provide
consumers with the best genuine products, but they don’t know how.
So far, the major obstacle to uniform, good-quality Chinese herbal
supplements has been the lack of appropriate, efficient analytical
methods that can distinguish these partial ‘standardized’ extracts
from genuine wholesome ones. But now, the technology is here,
developed by Phyto-Technologies, Inc. as a by-product of a 3-year
Small Business Research Innovative (SBIR) grant from the National
Center for Complementary and Alternative Medicine (NCCAM) to
characterize and standardize feverfew preparations for clinical
trial in migraine prevention. Using this developed technology, Phyto-Tech
Bio/Physicochemical Profiling™ (Phyto B/P Profiling™), the
comprehensive analytical profiles of any extract, standardized or
not, can be readily obtained using a combination of two or more
relatively simple chromatographic and spectral techniques. These
Phyto B/P Profiles™ (‘fingerprints’) are compared to those of a
Representative Botanical Reference and/or Research Material™ (RBRM™),
and instantly the truth is revealed. There is no more reason to
produce non-traditional Chinese herbal supplements using arbitrarily
standardized extracts containing only marker compounds with few or
none of the other herbal components, as they can now be easily
detected and avoided.
Reference: Leung, AY. Traditional Toxicity Documentation of
Chinese Materia Medica: An Overview (An Invited Review). Toxicol.
Pathology, 34:319-2006.
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