Garlic is one of the most common cooking
ingredients around the world. Many dishes in Europe, Africa, Asia and the
Americas use this strong-flavored vegetable.
Garlic is similar to other bulb-shaped plants,
including onions, chives, leeks and scallions. But garlic is special. For
centuries, people have used garlic not only for cooking, but also for medicine.
Medicinal
garlic throughout time
Researchers at the Memorial Sloan-Kettering
Cancer Center and Cornell University studied the medicinal use of garlic
throughout history. They found references to garlic in ancient texts from
Egypt, Greece, Rome, China and India.
For example, in ancient Greece and Rome,
people considered garlic an aid to strength and endurance.
The original Olympic athletes in Greece ate
garlic to improve their performance. The ancient Romans fed garlic to the
soldiers and sailors.
Workers who built the pyramids in Egypt ate
garlic. In fact, this is a theme throughout early history -- workers eating
garlic to increase their strength.
But why is
garlic such a healthy food?
The short answer is that garlic creates a gas
called hydrogen sulfide.
At first, hydrogen sulfide does not seem very
healthy. In fact, it is toxic and flammable. It smells like rotten eggs. But it
does an important job in our bodies. Hydrogen sulfide relaxes blood vessels.
Relaxing blood vessels, in turn, allows more
oxygen to travel to the body’s organs. It lowers high blood pressure and
protects the body against cardiovascular disease.
“Cardio” relates to the heart and “vascular”
relates to blood vessels.
Some researchers in China have gone so far as
to call hydrogen sulfide the key to a longer life.
So many studies
on garlic!
In a 2007
study, researchers at the University of Alabama at Birmingham studied how garlic increased hydrogen sulfide and
how that, in turn, affected red blood cells.
David Kraus led that study. At the time, he
was an associate professor in the university’s Departments of Environmental
Health Sciences and Biology. He and his team performed their study on rats.
They found that when garlic compounds changed into hydrogen sulfide in the
vascular system, the gas caused the muscles to relax.
In their report, the researchers wrote, “This
relaxation is the first step in lowering high blood pressure and gaining
heart-protective effects.” They found that these healthy effects are closely
linked to the hydrogen sulfide produced from garlic compounds interacting with
red blood cells.
In 2013, scientists were finally able to see
this process happen. Chemists Alexander Lippert of Southern Methodist
University in Dallas and Vivian S. Lin discovered how to observe this process
in living human cells.
In a Science Daily news release, Lippert
explains that they “made a chemical probe that
reacts and lights up when live human cells generate hydrogen sulfide.”
Lippert’s real-time video features live human cells making hydrogen sulfide.
Their discovery has opened the door to more
research into the health benefits of garlic and the production of hydrogen
sulfide in the body.
In a 2015
experiment at Penn State University,
researchers injected a solution that would create hydrogen sulfide in the arms
of healthy young adults. They wanted to see what hydrogen sulfide would do to a
small area of blood vessels.
The initial findings
are that hydrogen sulfide widened blood vessels, which then increased the flow
of blood. These researchers plan to continue their research. They published
their findings in The Journal of Physiology.
But let’s leave the laboratory and go to the
kitchen. Don’t throw out older garlic that has sprouted. You may have thought that garlic growing light green
sprouts was past its prime or
old and on its way to the trash bin.
But not so fast.
Scientists have reported in the Journal of
Agricultural and Food Chemistry that this older garlic has even more properties
that are good for our bodies than fresh garlic. When researchers tested garlic
that had sprouted for five days, they found it had higher antioxidant activity than fresher bulbs of
garlic.
Also, to get the full effect of garlic’s
health benefits, do not add it to food or cook with it immediately. Cutting,
crushing or mincing garlic releases the healthy compound found in the
vegetable. But heating the garlic or adding it to other ingredients prevents
the release of this healthy compound. So cut or crush or mince the garlic, and let it rest by
itself for a couple minutes.
So, are there any downsides to garlic? Well, the same reason garlic is
good for us and good in dishes -- that strong sulfur odor -- is the same reason
it gives us bad breath.
But there might be a cure for that, too. Yet
another study found that eating an apple or lettuce after eating garlic cuts
down on the strong garlic smell on one’s breath.
And that’s the Health & Lifestyle report.
I’m Anna Matteo. In the Comments Section,
share how you use garlic in your cooking.
Anna Matteo
wrote this story for VOA Learning English. Kelly Jean Kelly was the editor.
- Words in This Story
-
endurance – n. the ability to continue an activity for a long period
toxic – adj. containing or being poisonous material
flammable – adj. capable of being easily lit and of burning quickly
cardiovascular – adj. of, relating to, or involving the heart and blood vessels
probe – n. an usually small object that is inserted into something so as to test conditions at a given point
initial – adj. of or relating to the beginning
sprout – n. to send out new growth
past its prime – figure of speech beyond the most useful or productive period
antioxidant – n. a substance that limits oxidation or chemical reactions caused by oxygen, peroxides, or free radicals
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