Garlic: The Key to a Long Life?

 

From VOA Learning English, this is the Health & Lifestyle report.

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, leeks¹ 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 toxic² and flammable. It smells like rotten eggs. But it does an important job in our bodies. Hydrogen sulfide relaxes blood vessels³.

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 “vascular⁴” 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, affected⁵ 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 relaxation⁶ 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 Physiology⁷.

Older garlic may be even healthier

But let’s leave the laboratory and go to the kitchen. Don’t throw out older garlic that has sprouted⁹. You may have thought that garlic growing light green sprouts¹⁰ was past its prime or old and on its way to the trash bin¹¹.

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 mincing¹² 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 mince¹³ 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 sulfur¹⁴ 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 lettuce¹⁵ after eating garlic cuts down on the strong garlic smell on one’s breath.

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

sprout⁸ – 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

1 leeks   

韭葱( leek的名词复数 )

参考例句：

• Leeks and potatoes go well together in a soup. 汤中放韭菜和土豆尝起来很对味。
• When I was young I grew some leeks in a pot. 小时候我曾在花盆里种了些韭葱。

2 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

3 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

4 vascular   

adj.血管的，脉管的

参考例句：

• The mechanism of this anomalous vascular response is unknown.此种不规则的血管反应的机制尚不清楚。
• The vascular changes interfere with diffusion of nutrients from plasma into adjacent perivascular tissue and cells.这些血管变化干扰了营养物质从血浆中向血管周围邻接的组织和细胞扩散。

5 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

6 relaxation   

n.松弛，放松；休息；消遣；娱乐

参考例句：

• The minister has consistently opposed any relaxation in the law.部长一向反对法律上的任何放宽。
• She listens to classical music for relaxation.她听古典音乐放松。

7 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

8 sprout   

n.芽，萌芽；vt.使发芽，摘去芽；vi.长芽，抽条

参考例句：

• When do deer first sprout horns?鹿在多大的时候开始长出角？
• It takes about a week for the seeds to sprout.这些种子大约要一周后才会发芽。

9 sprouted   

v.发芽( sprout的过去式和过去分词 )；抽芽；出现；（使）涌现出

参考例句：

• We can't use these potatoes; they've all sprouted. 这些土豆儿不能吃了，都出芽了。 来自《简明英汉词典》
• The rice seeds have sprouted. 稻种已经出芽了。 来自《现代汉英综合大词典》

10 sprouts   

n.新芽，嫩枝( sprout的名词复数 )v.发芽( sprout的第三人称单数 )；抽芽；出现；（使）涌现出

参考例句：

• The wheat sprouts grew perceptibly after the rain. 下了一场雨，麦苗立刻见长。 来自《现代汉英综合大词典》
• The sprouts have pushed up the earth. 嫩芽把土顶起来了。 来自《现代汉英综合大词典》

11 bin   

n.箱柜；vt.放入箱内；[计算机] DOS文件名:二进制目标文件

参考例句：

• He emptied several bags of rice into a bin.他把几袋米倒进大箱里。
• He threw the empty bottles in the bin.他把空瓶子扔进垃圾箱。

12 mincing   

adj.矫饰的；v.切碎；切碎

参考例句：

• She came to the park with mincing,and light footsteps.她轻移莲步来到了花园之中。
• There is no use in mincing matters.掩饰事实是没有用的。

13 mince   

n.切碎物；v.切碎，矫揉做作地说

参考例句：

• Would you like me to mince the meat for you?你要我替你把肉切碎吗？
• Don't mince matters,but speak plainly.不要含糊其词，有话就直说吧。

14 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

15 lettuce   

n.莴苣；生菜

参考例句：

• Get some lettuce and tomatoes so I can make a salad.买些莴苣和西红柿，我好做色拉。
• The lettuce is crisp and cold.莴苣松脆爽口。