Sniffing Out the Truth About Garlic
For: Wellness Made Easy,
January 2003
We get a lot of queries about garlic—that pungent, delicious (to some people) member of the onion family. Garlic has been in humanity’s medicine chest for centuries, and modern investigators have taken it seriously, too.
What healthful compounds does garlic
contain?
It’s hard to say. Like all members of the onion family, garlic contains
a sulfur compound called allicin, released only when the clove is crushed
or cut and allowed to stand for 10 minutes. This (and the compounds it
converts into) is what gives these vegetables their strong taste and smell,
and is what’s thought to be beneficial. It’s a now-you-see-it,
now-you-don’t situation, however. The enzyme that forms allicin (and
other sulfur compounds) is destroyed by heating; and allicin converts
quickly to other compounds. But maybe the heat turns some of these compounds
into beneficial substances. Then again, none of these may be the healthful
component, if there is one.
Does cooked garlic have the same health
benefits as raw?
A tough question, since garlic in any form may or may not have health
benefits. Most studies have not distinguished between cooked and raw garlic.
Heat does change the chemical composition of garlic, as we’ve said.
Do garlic supplements lower blood
cholesterol?
No. Garlic supplements are a waste of money. The leading claim for garlic
supplements is that they lower blood cholesterol. But according to several
well-designed studies, neither garlic supplements nor garlic itself has
any effect on blood cholesterol. Heart attack rates are lower in Mediterranean
countries where lots of garlic is consumed, but that doesn’t mean
the garlic is responsible. It might be the olive oil, the emphasis on
fruits and vegetables, genetics, physical activity, or other factors.
It’s true that both garlic and onions contain a substance that might
lower blood cholesterol or interfere with the formation of clots—but
this has not been shown to occur in the human body.
Does garlic, in any form, prevent cancer or boost immunity?
Probably not, but no one knows for sure. You shouldn’t look to garlic
as a cancer fighter.
Is elephant garlic the same as regular?
It’s really not garlic, but a close relative of the leek, another
member of the onion family. It has the same compounds as garlic, but less
of them by weight. Use it if you want something milder.
Can garlic-in-oil combinations cause
food poisoning?
Yes, it’s possible. If the garlic has picked up any botulism spores
from the soil, immersing them in oil can give them the airless environment
they need to grow. If you use these combinations, keep them well refrigerated.
What good is garlic, if its health
benefits are so hard to verify?
If you enjoy it, garlic makes other good foods savory. It is a wonderful
addition to cooked meats and vegetables. Many people like it raw in salads,
salad dressings, and other foods, but raw garlic is likely to irritate
the mouth and stomach lining. The odor is pungent and long-lasting—and
may limit your social contacts if you’re among people who haven’t
also eaten raw garlic.
UC Berkeley Wellness Letter, September 2002
