October 25, 2014 19:41 UTC

As It Is

Air Pollution Linked to Increased Risk of Heart Disease

Air pollution, as seen here in Hong Kong, can increase the risk of heart disease.
Air pollution, as seen here in Hong Kong, can increase the risk of heart disease.

Multimedia

Play or download an MP3 of this story
  • Air Pollution Linked to Increased Risk of Heart Disease


From VOA Learning English, this is As It Is. 
 
I’m Caty Weaver.  Welcome back!
 
Cardiovascular diseases kill about 17 million people around the world every year. Heart attacks and strokes are to blame for a large share of the deaths. And, tobacco use greatly increases the risk of developing the diseases and dying from them.
 
Today on As It Is, we talk about cardiovascular disease: what some new studies are showing, and ways to reduce your risk.

Urban Air and Cardiovascular Disease
 
Have you ever had trouble breathing while outdoors in a busy city with lots of cars and busses rolling down the street? Fine particulate air pollution might be the cause of your trouble. This is the black, dirty gas clouds you see pouring out of the back of buses or the smoke rising from factory chimneys in urban areas.
 
Air pollution is a big problem in cities. It can lead to cardiovascular disease and other health problems. But now scientists say air pollution and its health risks seem to be localized. They say the level of threat people face may depend on which part of the city they live in. Katherine Cole has more.
 
Atherosclerosis, or hardening of the arteries, is a leading cause of death around the world. It can block the flow of blood to the heart or brain.
 
American researchers examined the part that air pollution plays in the development of atherosclerosis. They followed a group of almost 5,400 adults is six major cities. None of the adults were known to have heart disease. They were part of a larger study called the Multi-Ethnic Study of Atherosclerosis and Air Pollution.
 
Between 2000 and 2005, the researchers performed two non-invasive ultrasound tests on every member of the group. The exams were given three years apart, and measured the thickness of carotid artery walls.
 
The carotid artery carries blood to the head, neck and brain. Thickening of an arterial wall can be evidence of atherosclerosis throughout the body, even in patients with no other sign of heart disease.
 
The researchers found a meaningful increase in the thickening among individuals who lived in the neighborhoods with higher pollution levels. The lead researcher was Sara Adar, an epidemiologist at University of Michigan. She says their work confirmed earlier studies of the same group of people.
 
“Based on another study that was done in the same cohort (group) of people, they found that the amount of change that we saw for living in a high-pollution neighborhood versus living in a low pollution neighborhood would correspond to about a two percent increased risk in stroke.”
 
Fine particulate air pollution is widely believed to cause swelling and other conditions that can add to the development of heart disease. Sara Adar notes that medical officials urge people to stay indoors when pollution levels are especially high. But she says doctors should discuss the dangers of air pollution directly with their patients.
 
“So, just as they might ask somebody, ‘do you smoke?’ or think about if someone is obese, how long someone has lived in a highly polluted environment might factor into a physician’s notion of whether or not somebody is at high or low risk for cardiovascular disease, or heart disease.”
 
A report about the study of air pollution and artery hardening can be found in the online journal PLoS Medicine.
 
I’m Katherine Cole.

Physical activity helps prevent heart disease.Physical activity helps prevent heart disease.
x
Physical activity helps prevent heart disease.
Physical activity helps prevent heart disease.
Don't Smoke, Eat Right and Exercise
 
The World Health Organization reports that cardiovascular diseases kill more people every year than any other disease. And the number of deaths is expected to increase from 17 million to over 23 million by the year 2030.

Yet, development of cardiovascular disease is highly preventable. Behavior plays a big part. Major risk factors are tobacco use and drinking too much alcohol, unhealthy diet and physical inactivity. The WHO says these behaviors are responsible for 80 percent of cardiovascular disease cases around the world.
 
So, quit smoking or do not start. Drink alcohol in moderation. Eat foods that are low in fat, sugars and salt and include fruits and vegetables in your daily diet. And, make exercise a usual activity.
 
But, as you try to reduce your chances for cardiovascular disease, scientists continue to search for a cure. In the next story we learn how are own immune systems might provide clues to treatment.

Growing New Blood Vessels
 
Researchers at Yale University and University College London have discovered how some heart disease patients are able to grow new blood vessels. The new vessels permit blood to flow around blockages in arteries and continue on its path around the body. The discovery could mean new treatments for cardiac patients in the future.
Kelly Jean Kelly has details.

It is not uncommon for new blood vessels to grow around blocked arteries in people with heart disease. The new blood vessels keep blood flowing through the body, feeding its organs oxygen. But those emergency blood vessels do not grow in everyone who might need them.
 
Researchers have been working for more than ten years to find a way to force new blood vessel formation, called angiogenesis. They used human growth factors in their research. These are enzymes and hormones that support cellular growth.
 
But Yale University cell biologist Michael Simons says that the scientists were not successful. He said they found that growth factors are limited in fueling new blood vessel growth.
 
“They do that in fact, in normal animals and normal people. But they did not work in people with advanced illnesses and we never understood why.”
 
Mr. Simons and his team decided to look at blood vessel formation at a much earlier period in life. They studied blood vessel formation in fetuses to see why that process does not happen in people with severe heart disease.

Mr. Simons says organs that are damaged by decreased blood flow release a repair molecule. It is called VEGFR. Another molecule called NRP1 attaches to VEGFR and transports it and a second repair molecule to the inside of blood vessels. This process causes healing to begin.
 
But, in experiments with mice, researchers found that repair does not happen in mice that have damaged NRP1. Mr. Simons says angiogenesis is held back because molecules cannot enter damaged blood vessels.
 
The scientist says he believes heart patients whose bodies do not repair and grow new blood vessels also have damaged NRP1.
 
“So now that we understand how this works, you can now begin designing therapies that will specifically stimulate this pathway where you need it if you want to grow arteries. On the other hand, if your goal is to inhibit the growth of blood vessels, you could do this of course in reverse.”
 
Reversing blood vessel formation would block arterial blood to cancer tumors. This could destroy tumors which need the blood to grow and spread.
 
Michael Simons and his co-researchers reported about blood vessel formation in the journal Developmental Cell.
 
I’m Kelly Jean Kelly.
 
And that’s As It Is for today. Thanks for tuning in.

To comment on this show, or any Learning English programs send an e-mail to special@voanews.com.
This forum has been closed.
Comment Sorting
Comments
     
by: ck from: VietNam
05/14/2013 3:40 PM
Thanks for your useful infomation, I think beside eat right, dont smoke, do excercise, we need to reduce air pollution around us by any way we can do. Hope that our evironment will be pure in the near future


by: Edgar Guariguata Gil from: Venezuela
05/10/2013 6:54 PM
It's a good report, congratulations.
I ask you, it is possible, that speak about eyeglasses that can be self-adjusted. thanks Edgar


by: BIJU.P.Y. from: SOUTH INDIA
05/10/2013 4:57 PM
Not to pulish. Our pentecostal convention is due on the twelth and thirteenth of this month. So I'm a little more busy.


by: BIJU.P.Y. from: SOUTH INDIA
05/10/2013 4:55 PM
Highly informative. The relation between cardiovascular diseases and air pollution is beautifully drawn. The second photographs given here is all the more attractive. They are shoot out as a brook shooting out of a virgin woods. Automobile pollution add more poison to the air we breathe in. There must be serious measures to control all these. Thank you. GOOD NIGHT DEAR ONES, I am slipping slowly to sleep tonigt. Bye.


by: stella zhang from: Taipei
05/10/2013 2:32 AM
i think the first photo is taken from Hong Kong not Beijing.

Learn with The News

  • Anti-Occupy Central protesters (L) try to remove a barricade from pro-democracy protesters on a main street in Hong Kong's Mongkok shopping district October 4, 2014.

    Audio US Group Rejects Claims It Incited Hong Kong Protests

    Chinese media have been criticizing the National Endowment for Democracy. They accuse the US-based group of providing money to and advising the “Occupy” street protest movement. The group says it takes part in normal cooperation with civic groups in Hong Kong. But it says it has nothing to hide. More

  • A rocket carrying the SpaceX Dragon ship lifts off from launch complex 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Florida, April 18, 2014.

    Audio You Don't Have to Be a Rocket Scientist to Read This

    "You do not need to be a rocket scientist." Americans hear these words often. People say them in schools, offices and factories. Broadcasters on radio and television use them. How did the expression begin? No one seems to know for sure. But you can find out by reading this Words and Their Stories. More

  • Audio Control of US Senate Depends on North Carolina

    U.S. congressional elections are less than two weeks away. A small number of races will decide if the Democratic party keeps control of the U.S. Senate or if Republicans will have a majority. One of the closest Senate races is in the state of North Carolina between Kay Hagan and Thom Tillis. More

  • Freed Vietnamese dissident Nguyen Van Hai (L) is greeted upon arrival at Los Angeles International Airport on October  21, 2014 in Los Angeles, California.  The Vietnamese blogger, also known by his pen name "Dieu Cay," was handed a 12-year prison sentenc

    Audio Legality of Vietnamese Blogger’s Release Questioned

    Nguyen Van Hai arrived in the United States on Wednesday. Hai is one of Vietnam’s best known political bloggers. He has written about government corruption and the country’s territorial dispute with China. The United States was among several foreign governments to call for his release. More

  • A miner sifts through dirt for gold flakes at the Atunso Cocoase small-scale mine, Atunsu, Ghana, Oct. 16, 2014. (Chris Stein/VOA)

    Audio Gold Mining in Ghana Can Be Dangerous

    Small mining operations are a common sight in central Ghana. Here, mine workers dig deep into the earth in search of bullion. But not everyone returns alive. Earlier this year, six miners were killed when an earthen wall collapsed in Kyekyewere, a village in the Ashanti Region. More

Featured Stories

  • Audio Oscar de la Renta Dressed First Ladies and Movie Stars

    Clothing designer Oscar de la Renta died Monday at his home in the American state of Connecticut. He was 82 years old. His wife said he died of problems related to cancer. Mr. de la Renta dressed American movie stars and first ladies such as Jacqueline Kennedy, Nancy Reagan and Hillary Clinton. More

  • Audio Iron Ships Clash at Sea

    The American Civil War was fought not only on land, but at sea. In 1862, Confederate and Union forces fought a new kind of navy battle in waters off Hampton Roads, Virginia. It was the first battle between iron ships. On the Confederate side was a ship called the Virginia. | The Making of a Nation More

  • Audio San Francisco Radio Stations Ban Lorde's 'Royals'

    The California baseball team, San Francisco Giants, is playing the Kansas City Royals for the 2014 Major League Baseball championship, the World Series. Two radio stations in San Francisco banned the hit song "Royals." In return, another station in Kansas City chose to play the song once every hour. More

  • A neurovascular unit on a chip being developed by Vanderbilt University researchers. (Vanderbilt University Photo/John Wikswo)

    Video Scientists Design Chips to Act Like Human Organs

    Testing new drugs for safety and effectiveness is a costly process in the United States. It also can take a lot of time. Some scientists are now designing silicon computer chips that act like human organs. The scientists think they have found a way to make the process faster and more economical. More

  • Brain Resource Infographic

    Audio Dealing with Distractions and Overreactions

    Five million American children and teenagers have Attention Deficit / Hyperactivity Disorder, commonly known as ADHD. ADHD makes it difficult - if not impossible - to stay with a duty until it is complete. Katherine Ellison knows the problem well. | Health Report More

Practice Your Writing

Confessions of an English Learner BlogConfessions of an English Learner Blog

Tell us About Our Programs