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Some
Herbs Rate a Spot in
Medicine Cabinet
Heather
Boon
Good
cooks love herbs for the variety of flavours they impart to food.
An increasing number of Canadians, however, are discovering herbs
may also enhance their well-being. As the use of complementary
or alternative medicine grows, healthcare practitioners and consumers
alike are demanding better and more objective information about
the herbal preparations currently sold in Canada.
Here's
a look at four commonly used herbs and the kind of information
about them that should be available to all consumers:
- Evening
Primose
(Oenothera biennis) contains gamma linolenic acid (GLA), an
omega 6 fatty acid the body uses in a variety of biochemical
reactions. It appears the body’s ability to make GLA decreases
with age. Individuals with specific medical conditions such
as asthma, diabetes and eczema may have an increased risk for
GLA deficiency. It's thus argued evening primrose oil may alleviate
the symptoms of people with these conditions.
Unfortunately,
many of the claims made are not currently supported by scientific
evidence--- even the use of evening primrose oil by people with
eczema or other skin conditions remains controversial.
It's also
widely advertised as a treatment for the symptoms associated with
menopause - despite the fact that research indicates it's not
very good at treating hot flushing or sweating.
On a positive
note, essential fatty acids such as those found in evening primrose
oil may be good for promoting cardiovascular health.
Overall, evening
primrose oil appears very safe, but it's recommended patients
diagnosed with mania or epilepsy use it with caution. Although
there are no reports of drug interactions with the herb, people
taking beta-blockers, lithium carbonate or anticoagulants should
talk to their doctor or pharmacist before taking it.
- Garlic
(Allium sativum) has been used medicinally for centuries. Today,
it's best known for its cardiovascular effects. There's scientific
evidence garlic may help lower cholesterol levels, but claims
that it can lower blood pressure are not supported by research
to date. Studies of the diets of several large groups of people
suggest increased ingestion of garlic may be associated with
a decreased incidence of some types of cancer (especially stomach
and colon cancer).
But it's not
all good news. Stomach upset and heartburn have been described
following high doses of garlic (the equivalent of five or more
cloves daily). Garlic may also be associated with bleeding problems
in rare cases. It's recommended that all garlic supplements be
discontinued at least one week before any elective surgical procedures
and that you inform your physician if you're taking garlic.
There’s a
wide variety of garlic products on the Canadian market. A dose
equivalent to one to eight cloves (400-1200 mg of garlic powder)
taken daily in divided doses appears to be effective. Questions
about different dosage forms of garlic should be directed to your
pharmacist.
- The Ginkgo
Biloba tree is the oldest known tree species on earth, which
has led some to conclude that taking ginkgo products will increase
one's life span. Unfortunately there's no scientific evidence
to support these claims.
Ginkgo has
been extensively studied and found to cause a slight, but noticeable,
improvement in the memory of patients with Alzheimer disease and
other types of dementia. Currently there's no evidence that ginkgo
will improve the memory of people who do not have any memory problems
to start with.
A typical
dose is 40 mg of ginkgo extract (standardized to 24 per cent ginkgo-flavone
glycosides) taken three times daily. Ginkgo may also help to improve
the symptoms of people with a variety of circulatory disorders
such as intermittent claudication (partial obstruction of blood
flow to the legs). Research is continuing in this area.
The most common
side effect of ginkgo is a headache, which can occur if you take
too large a dose too quickly. There's also some evidence that
in rare cases, ginkgo can cause bleeding problems. Anyone taking
anticoagulant drugs should check with their physician or pharmacist
before taking ginkgo.
- Saw
palmetto (Serenoa repens Small) is best known for its use
as a treatment of benign prostatic hyperplasia (BPH). This is
good scientific evidence that 160 mg. of liposterlic extract
taken twice daily can decrease the size of the prostate and
improve urinary flow rate.
Saw palmetto
has been shown to be as effective as some conventional treatments
for BPH. However, it’s important this treatment option be discussed
with your physician and that you continue to be monitored by a
physician during your treatment with saw palmetto.
Important
notes
There are
several important things to remember about herbal medicines:
-
They are
medicines and you should let your pharmacist and physicians
know if you are taking any herbs;
-
There
are a lot of claims made about herbs which are not supported
by scientific evidence;
-
Some herbs
can be very helpful if used appropriately.
Heather
Boon is an assistant professor in the Faculty of Pharmacy, University
of Toronto, and author of The Botanical Pharmacy. © July 2000
Fifty-Plus.net
http://www.fifty-plus.net/
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