VOA健康报道2022--研究人员称运动是防止衰老的最佳工具

Researchers: Exercise Best Tool Against Aging

More scientists are exploring cellular¹ senescence – a state in which cells no longer divide.

Senescent cells, which build up in older bodies, have a link to age-related conditions such as dementia and cardiovascular disease.

Scientists are exploring drugs that target senescent cells. But the most promising² tool against the negative effects of senescent cells, experts say, is exercise.

"A very hot topic"

Viviana Perez Montes of the National Institutes of Health described cellular senescence as "a very hot topic." The Associated Press reports that about 11,500 projects involving cellular senescence have begun since 1985. The AP report was based on its study of an NIH research database. A large number of the projects began in recent years, the report said.

Such research is built upon the idea that cells stop dividing and enter a "senescent" state in reaction to damage. The body expels most of these cells.

But others remain in the body. They can harm nearby cells, says Mayo Clinic's Nathan LeBrasseur. He compared it to the way one bad fruit can ruin a container full of fruit.

But scientists wonder: Can the unhealthy buildup of senescent cells be stopped?

"The ability to understand aging ....is truly the greatest opportunity we have had, maybe in history, to transform human health," LeBrasseur says. Extending the healthy years affects "quality of life" and "public health," he said.

The number of people 65 or older is expected to double around the world by 2050.

Although no one thinks senescence holds the key to extremely long life, Tufts University researcher Christopher Wiley hopes for a day when fewer people suffer like his grandfather did before death. He had Alzheimer's disease.

"I'm not looking for the fountain of youth," Wiley says. "I'm looking for the fountain of not being sick when I'm older."

Drugs

About 100 companies, plus academic groups, are exploring drugs to target senescent cells.

Scientists are careful to note that cell senescence can be useful. The process probably developed at least in part to suppress the development of cancer. Cell senescence happens throughout our lives, caused by things like DNA³ damage and the shortening of telomeres, structures that protect the ends of chromosomes⁴. Senescent cells play a role in wound healing, embryonic⁵ development and childbirth.

But problems can come up when senescent cells build up.

"When you're young, your immune system is able to recognize these senescent cells and eliminate them," says Perez, who studies cell biology and aging. But, when we start getting old, in Perez's words, "the activity of our immune system also gets diminished, so we're losing the capacity to eliminate them."

Experimental drugs designed to clear senescent cells have been called "senolytics." In mice, they have been shown to be effective at delaying, preventing or easing several age-related disorders⁶.

At least 12 clinical trials with senolytics are now testing whether the drugs can help control Alzheimer's, improve skeletal health and more.

There is still much to learn.

Exercise

Today, LeBrasseur, who directs a center on aging at Mayo, says exercise is "the most promising tool that we have" for good health in late life, and its power extends to our cells.

Research suggests exercise counters the buildup of senescent cells, helping⁷ the immune system clear them and fight the molecular⁸ damage that can affect the senescence process.

Last year, LeBrasseur led a study that provided the first evidence in humans that exercise substantially affected⁹ the process. It reduced signs in the bloodstream of the effects of senescent cells in the body.

After a 12-week exercise program, researchers found that older adults had decreased signs of senescence and improved muscle strength, physical ability and reported health. A recently-published research review collects even more evidence — in animals and humans — for exercise as a senescence-targeting therapy.

While such studies are not well-known outside scientific circles, many older adults connect exercise with youthfulness.

Rancher Mike Gale¹⁰, 81, put in a track and field throwing circle on his large property in California. He and some of his friends throw the discus and use other exercise equipment.

"I'd like to be competing in my 90s," Gale says. "Why not?"

95-year-old Richard Soller says exercise keeps him fit enough to deal with what comes his way – including the discovery that his wife of 62 years had developed Alzheimer's. The two sometimes walk the streets of their neighborhood together, holding hands.

"Do as much as you can," he says. "That should be the goal for anyone to stay healthy."

Words in This Story

topic – n. someone or something that people talk or write about

opportunity – n. an amount of time or a situation in which something can be done

transform – v. to change (something) completely and usually in a good way

fountain of youth – expression a legendary¹¹ fountain that is supposed to give eternal youth to anyone who drinks from it

diminish – v. to become or to cause (something) to become less in size, importance, etc.

capacity – n. the ability to do something : a mental, emotional, or physical ability

clinical – adj. relating to or based on work done with real patients : of or relating to the medical treatment that is given to patients in hospitals, clinics, etc.

1 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

2 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

3 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

4 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

5 embryonic   

adj.胚胎的

参考例句：

• It is still in an embryonic stage.它还处于萌芽阶段。
• The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

6 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

7 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

8 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

9 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。

10 gale   

n.大风，强风，一阵闹声（尤指笑声等）

参考例句：

• We got our roof blown off in the gale last night.昨夜的大风把我们的房顶给掀掉了。
• According to the weather forecast,there will be a gale tomorrow.据气象台预报，明天有大风。

11 legendary   

adj.传奇（中）的，闻名遐迩的；n.传奇（文学）

参考例句：

• Legendary stories are passed down from parents to children.传奇故事是由父母传给孩子们的。
• Odysseus was a legendary Greek hero.奥狄修斯是传说中的希腊英雄。