GINSENG
The ginseng root has been used in Chinese medicine
for thousands of years for a variety of ailments ranging from fatigue and
stress to high blood pressure and
even cancer. Traditionally it is used as a daily tonic. It is available here in the United States in a wide
variety of forms, from teas to the
root (which is chewed). Ginseng comes from several members of the plant family Araliaceae. American, Korean, and
Japanese ginseng are
Does ginseng have real biologic activity? If you
listen to testimonials by happy users, then the answer is yes. The most
biologically active ingredients in ginseng (the ginsenosides) have some
activities in the brain. In some studies, extracts of ginseng improved the
ability of rats to learn amaze. Studies showing effects on human memory are
mixed and sufferfrom small subject numbers and mixed results. Part
of the confusionarises from different approaches to testing
ginseng and many other nutri‑tional supplements: while some studies try to show
effects of a single dosein a highly controlled laboratory setting, others
have used population studies in people who are self-medicating with
supplements. The latter studies may be the best test of the efficacy of
available supplement preparation. Unfortunately, these have been less
successful than the more controlled tests with well-defined doses. One problem
that arises in understanding the
results of such studies is that people who choose to self-medicate with herbal drugs may be, in general,
more health conscious than those who
don't, and may do a lot of other things that improve
their health and maintain good brain
function. Ginseng has a variety of effects in experimental cell systems including effects on cell growth and immune
function. Its ability to lower blood
glucose in animal models of diabetes has
attracted some notice, and studies are underway in humans.
The recommended dose
on preparations sold in a local health-food store come in the same range as doses used in the experimental studies (about 700 milligrams for a normal
adult male). However, the exact content
of these formulations is unknown, so potency can vary widely. In addition, the effectiveness of a single dose is
not clear. Some studies fail to show
significant effects except with repeated dosing. Fortunately, no dangerous side effects of single, high
doses are known. The safety of repeated doses is unknown. Some case reports of uterine bleeding in postmenopausal women indicate that ginseng has effects
resembling those of estrogen. As
with many ancient herbal cures, there is active research ongoing to test the safety and efficacy of ginseng in
treating disease. This is another drug
that might have potential, but we just don't have enough informa‑
tion yet to judge.
GINKGO
An extract of the leaves of the ginkgo biloba tree is a
popular herbal cure that is supposed to improve
circulation in small blood vessels in the brain, and so improve memory and alertness. Like ginseng, it has many advocates. Unfortunately, it has even less in the way
of research to back up the claims of
satisfied users. Numerous studies of memory in healthy adults offer conflicting results—some show benefits,
while others do not. Investigations
of its benefits in treating diseases of memory are sparser. One study in
Alzheimer's patients suggests that ginkgo provided some help, and studies are underway of the effects on
dementia and normal aging. However,
other studies do not support its effectiveness. One potential problem with ginkgo is that it can slow blood
clotting, which can lead to dangerous
hemorrhages if it is used in combination with prescribed anticoagulant medication.
It is often marketed in combination with ginseng
for similar conditions, such as stress.
Its effectiveness as stress cureremains to be proved.
