University of Vermont Extension
Department of Plant and Soil Science
Fall News
Article
THE MANY USES
OF GARLIC
Dr.
Leonard Perry, Extension Professor
University of Vermont
Most
of us are only exposed to one type of garlic in supermarkets, so don't
realize
how many varieties there really are, and the various benefits of garlic
other
than just for cooking. There are
generally 11 types of garlic, all giving similar health benefits, but
with
widely varying flavors.
Garlic
originated in south-central Asia thousands of
years ago. The area of western China, northern
Afganistan and Iran
is called the garlic crescent. It was
valued then, as it is now, for its flavor, long storage, and certain
health
benefits. It especially was important
then, with its antibacterial properties and strong odor, to both
preserve foods
and mask rancid smells.
Nomads likely carried garlic to the Mediterranean, where most associate
it and where it
originally was believed to have come from.
The earliest known record of garlic dates back 6000 years to clay
artifacts resembling garlic bulbs in Egyptian tombs. Other garlic
artifacts have been found in
later tombs as well, including bulbs dating to 1500 B.C. Mummies
were
rubbed with it during
embalming. Other references indicate
garlic was being used 5000 years ago in India, 4500 years ago in
Babylon, and at least
2000 years ago in China.
Garlic
spread through trade around the Mediterranean
and southern Europe, being better adapted to
these warm climates. Garlic was one of
the original antibiotics used by Greeks and Romans. With its long
history of cultivation in this
area, many varieties have come from there. Our original varieties
arrived from there in the
1700's with explorers and early colonists.
Other
varieties originated from early cultivation in the Caucasus
and Eastern Europe. These have led to more
recent introductions to this country with Polish and German immigrants.
Most
recently, the Caucasus region led to a surge
in new varieties (for us) when the USDA in 1989 was finally allowed
into areas
of the Soviet Union previously closed. Story has it that the
plant
explorers were
accompanied by guards, and only allowed to roam at night so not to
compromise
the security of oil fields and secret missile bases. Varieties
often
were named for the villages
where they were found.
All
through this history of garlic, its flavoring and therapeutic uses have
come
mainly from one chemical, allicin. This
chemical can perhaps be remembered from the genus name of garlic, and
their
close relatives the onions (Allium).
It's interesting that
allicin doesn't exist in whole garlic cloves, but is formed quickly
from two
other chemicals that mix when plant cells are crushed. If you've
ever
smelled or eaten whole garlic
cloves, then immediately upon crushing or mincing them, you've seen
just how
quickly this chemical reaction happens.
Another
key point to know is that allicin is destroyed by heat, as in
cooking.
So if you are after the full health benefits
of garlic, you'll need to eat it raw.
Biting, crushing, chopping, or slicing will release allicin.
Cooking
isn't all bad though from a health
perspective, as many other sulfur compounds are released when cloves
are
prepared and aren't destroyed by cooking.
If
you do eat raw garlic, studies suggest "a clove a day keeps the doctor
away." Raw garlic should be
consumed with other food to avoid the possibility of heartburn and
stomach
upset. Eating more may cause these
symptoms, and other side effects. Garlic
may interact with certain medicines, like an anticoagulant, so it is
best to
check with your doctor before beginning a regime of garlic for
health.
There are many garlic supplements you'll find
in vitamin sections of stores, but the research on these and their
effects is
inconclusive. Of course the most common
side effect of raw garlic is the famous "garlic
breath", as well as flatulence in some.
So
why even consider eating raw garlic, or worrying about destroying its
allicin? This sulfur compound, and other
similar ones created from breaking the garlic cloves, is an effective
antibiotic on many organisms. It may
help reduce salmonella that causes some food poisoning, and some
intestinal
infections including diarrhea. Yet don't
store or preserve garlic in oil, as may seem desirable. Oil
provides
the perfect environment for the
botulism bacterium to contaminate this low-acid vegetable, an organism
that
garlic has no effect on.
Heart-related
studies indicate several benefits including possible cholesterol
lowering,
lowering blood pressure, lowering blood glucose, and providing
antioxidant
effects that have become more known recently in other foods. Both
cooked and raw garlic may help reduce
the risk of certain cancers, including gastrointestinal ones.
Increasingly, studies are showing that garlic
enhances the body's immune system.
If
you aren't focused merely on the health effects of garlic, just enjoy
it in
your cooking. Cooking whole, or
roasting, results in a mild, caramelized flavor without the strong
aromas. Chopping releases the flavors, then cooking
in oil serves to enhance these and form the basis for many types of
cuisine
including sauces, stews, curries, and stir-fries. Just make sure
to
not cook too much until
dark brown or burned, or it will taste unpleasant. Cooking in oil
until straw-colored or tan
results in complex and nutty flavors.
Don't merely settle for supermarket garlic, but visit local growers and
farmers markets for more variety. Better
yet, grow your own!
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