VOA听力9篇文章

1. Foods and Health
This is the VOA Special English Health Report.
Experts say the food people eat greatly affects their health. They say that some foods are especially good for preventing disease.
Many foods contain substances that protect against tissue damage. One of these is tomatoes. The substance lycopene is released when tomatoes are cooked. Lycopene helps reduce the risk of developing cancer in the digestive system, which processes food.
The dark green vegetable spinach contains folic acid that prevents problems in developing fetuses. It also lowers blood levels of homocysteine. High homocysteine levels have been linked to heart attacks and strokes. Another vegetable, broccoli, can help protect against cancers of the breast, colon and stomach.
Oats help lower blood pressure and protect against heart disease. They also may improve the levels of sugar in the blood. This reduces the chance of developing the disease, diabetes.
Fish that contain omega three fatty acids help prevent blockages in the arteries. Omega three also lowers bad cholesterol and may protect brain cells from diseases like Alzheimer's. Fish that provide a lot of omega three acids are salmon, herring, mackerel and bluefish.
Garlic may help protect the heart by reducing cholesterol and making the blood less sticky. Health experts also suggest cooking with olive oil because it also has been shown to help prevent cancer and heart disease.
Studies show that drinking green tea may help prevent cancer of the liver and stomach. Green tea also slows the growth of bacteria in the mouth. Blueberries have been shown to help protect against heart disease and cancer. They can also help prevent some infections by preventing the bacteria from attacking the bladder.
Experts say the skins of red grapes contain substances that increase the good kind of cholesterol in the blood. To get this protection, you can drink red wine... but not more than a few glasses a week. Drinking too much alcohol can be dangerous!
Eating too much chocolate can increase weight. But recent studies have shown that substances in chocolate can help prevent heart attacks and cancer. They have also shown that chocolate is not as bad for the teeth as had been thought. The experts say the best chocolate to eat is the dark kind because it contains the most healthful substances.
This VOA Special English Health Report was written by Nancy Steinbach.
2. Study of Cousins Who Marry
This is the VOA Special English Health Report.
Sometimes people who are first cousins get married. Two people are first cousins if their mothers are sisters, or their fathers are brothers, or one's mother and the other's father are brother and sister. American researchers now say it is
not as dangerous as had been thought for first cousins to have children.
Graphic Image
A new study says that first cousins are only a little more likely than others to have a child with a serious physical or mental problem, or a genetic disease. It says the chance that a child of unrelated parents will be born with a serious problem is between three and four percent.
The risk for first cousins is increased by between two and three percent, to as much as seven percent. One researcher says this means about ninety-three percent of the children of first cousins are normal.
The small increase in risk exists because people in the same family may carry the same genes that cause disease. Scientists say at least five-thousand diseases are caused by these genes. If both parents have a harmful gene, it is more likely that the gene will be passed on to their child. People who are not related share fewer genes, so their chance of passing such a sickness on to their children is lower.
A committee from the National Society of Genetic Counselors reported the results of their investigation in "The Journal of Genetic Counseling." The group examined six major studies done between Nineteen-Sixty-Five and Two-Thousand involving thousands of births. The group began the investigation after learning that some genetic counselors gave wrong information to people who wanted to know if first cousins could safely have children.
The group said in its report that no genetic tests are needed before first cousins have a child. Their report also noted that Americans fear such marriages more than people in other parts of the world.
Marriages between first cousins are illegal in at least twenty-four American states. However, no countries in Europe have such laws. And marriages between cousins are desirable in many parts of the Middle East, Africa and Asia. The researchers say their study shows that such laws in the United States should be changed.
This VOA Special English Health Report was written by Nancy Steinbach.
3. Walking
This is the VOA Special English Health Report.
Researchers agree that intense physical exercise is not the only way to gain better health. Studies show that walking several times a week can lower the risk of many diseases. They include heart disease, stroke, diabetes, bone loss, arthritis and depression. Walking also can help you lose weight.
Graphic Image
Fast walking is good for the heart. It lowers the blood pressure. It raises the amount of good cholesterol in the blood. Researchers say walking can reduce the risk of suffering a heart attack by as much as fifty percent.
Studies have shown that walking for thirty minutes a day can delay and possibly prevent the development of Type Two Diabetes. It can prevent diabetes among people who are overweight and at risk for the disease.
Walking strengthens the muscles and builds up the bones to which they are attached. Studies show that women who walked and took calcium decreased their risk of developing osteoporosis or thinning of the bones. Walking also helps ease the pain of arthritis in areas where bones are joined by strengthening the muscles around the bones.
Walking several times a week is a good way to control your weight and even lose body fat. Studies show it also helps ease depression, feelings of extreme sadness. Experts say walking is one of the safest ways to exercise. There is a low risk of injuries. So it is good for people who are starting an exercise program for the first time and for older people.
A walking program is easy to start. You should wear loose clothes and good shoes. Shoes designed for walking are best.
You should stretch the muscles in your arms, legs, and back before and after you walk. Stretching is an important part of any exercise program. It helps prevent injury and muscle pain.
How fast should you walk? You should be breathing hard while you are walking. Yet, you should be able to talk. Let your arms move back and forward at your sides while you walk.
There are no rules to starting a walking program. You may walk short distances. Or you may walk up hills to strengthen your leg muscles. Health experts say you can gain the most from a walking program if you walk about five kilometers an hour for thirty minutes a day. You should do this about five times a week.
This VOA Special English Health Report was written by Lawan Davis.
4. Tobacco and Cancer
This is the VOA Special English Health Report.
Graphic Image
A recent report by the International Agency for Research on Cancer says the dangers of tobacco smoke are greater than had been thought.
The International Agency for Research on Cancer is part of the World Health Organization. It is based in Lyon, France. The agency researches the causes of cancer. It identifies the number of people who develop cancer around the world. And it develops programs aimed at finding ways to prevent the disease. The new report is part of a series written by independent international experts on the dangers of different chemicals.
A committee of twenty-nine experts from twelve countries developed the report. These scientists examined more than fifty medical studies concerning tobacco smoking. The group says that tobacco use is the largest cause of preventable cancers around the world. Experts say that more than one-thousand-million people around the world smoke tobacco.
The report says that one-half of all people who smoke cigarettes will die from diseases caused by smoking tobacco. These include cancers of the lung, stomach, liver, kidney and blood. The report also says tobacco use causes an even greater number of deaths from lung diseases, heart disease and stroke.
The report says other kinds of tobacco use also increase the chances of developing cancers of the lung, head and neck. These include smoking cigars, pipes and bidis -- tobacco rolled in a leaf that is popular in South Asia.
The report also says that people who smoke endanger the health of non-smokers who breathe in tobacco smoke. These non-smokers are breathing in a smaller amount of cancer-causing chemicals than active smokers get. But it is still enough to cause deadly lung cancer.
However, the scientists found no increased risk of cancer among children who breathe in this second-hand smoke. But they say they do not know the long-term effect of tobacco smoke on children as they grow older. The scientists also say their research found that smoking tobacco does not cause some kinds of cancer. There is clear evidence that smoking has little or no effect on developing breast cancer or prostate cancer.
This VOA Special English Health Report was written by Nancy Steinbach.
5. Addiction and Girls
This is the VOA Special English Health Report.
A study in the United States finds that girls and young women use tobacco, drugs and alcohol for different reasons than boys. It says young males generally use alcohol or drugs for excitement. Or they think it will make them more popular.
Young females, however, may hope to feel happier or reduce tension or lose weight. The National Center on Addiction and Substance Abuse at Columbia University in New York released the findings. The center chairman, Joseph Califano, says prevention programs are often developed more for males. He called for programs designed for girls and young women.
There are physical, psychological and social effects from smoking, drinking and using drugs. The report says some of these may happen more quickly and severely in females. For example, it says they are more likely to become dependent on tobacco than males who smoke just as many cigarettes. And it says females have a greater risk of brain damage from too much alcohol.
The report notes general reductions in substance use by young Americans. But it says girls in many cases have caught up with boys in rates of use.
Here are some other findings:
Girls and young women who drink coffee are much likelier to smoke and drink alcohol -- and to start sooner -- than those who do not drink coffee. The report calls caffeine a "little known" warning sign.
Girls who do unhealthy things to lose weight drink more alcohol than those who do not diet -- even though alcohol can cause weight gain. Also, even girls who do healthy things to lose weight smoke more than those not on diets.
Puberty is a time of higher risk of substance use by girls, especially those whose bodies change early. Other times are when girls rise from elementary to middle school, from middle to high school, and from high school to college. And, girls who move often from one home or community to another are at greater risk than boys.
The report lists a number of warning signs to watch for. These include depression and too much concern about appearance. The study also reminds parents and other adults that they set examples -- good or bad -- by their own actions.
More than one-thousand-two-hundred girls and young women answered questions as part of the study. Most who talk with their parents about substance use said these talks made them less likely to smoke, drink or use drugs.
This VOA Special English Health Report was written by Jerilyn Watson.
6. Explaining the Placebo Effect
I'm Katherine Cole with the VOA Special English Health Report.
Studies of new drugs traditionally involve at least two groups of people. The people in one of those groups are given only what they think is the drug. Really they get a placebo -- an inactive substance. The drug is proven effective if it performs better than the placebo.
Some researchers do not think drug studies should use placebos. They say it makes more sense to compare new medicines to drugs already on the market. Then people would know if a new drug is any better.
"Placebo" is Latin for "I shall please." It may contain nothing more than sugar. Yet some people who are given a placebo experience improvements in their health. This is called the placebo effect.
Some doctors use the placebo effect in their treatments. An influential study published in nineteen fifty-five said placebo treatments made patients feel better thirty-five percent of the time.
But in two thousand one, Danish researchers reported that they had examined more than one hundred studies. They found little evidence of healing as a result of placebos.
Still, there is continued belief in the placebo effect.
A Swedish study published last year suggested that a placebo can reduce the emotional effects of unpleasant experiences. The study involved people who looked at images of dead bodies and other unpleasant pictures. The findings appeared in the journal Neuron.
The researchers said the effects in the brain were similar to those seen when placebos have been used as a pain treatment. In both cases, they said, expectations of improvement are a major influence.
But more than expectations might explain why placebos appear effective sometimes. Researchers led by Scot Simpson at the University of Alberta, in Canada, just had a report published in the British Medical Journal. They examined twenty-one studies. These compared death rates between patients who always took their medicine and those who did not.
Even patients who took placebos had better results than those who did not follow doctor's orders. The researchers see this finding as support for the idea of a so-called healthy adherer effect. That is, a person who takes a drug treatment as directed may also do other things to live a healthy life.
And that is the VOA Special English Health Report. You can download free transcripts and MP3 files of our weekly reports at .voaspecialenglish.. I'm Katherine Cole.
7. Staying Healthy by Washing Your Hands
This is the VOA Special English Health Report.
Hand washing is a powerful way to prevent the spread of disease.
The World Bank, the United Nations and the London School of Hygiene and Tropical
Washing hands with soap
Medicine did a study to urge hand washing around the world. They found that one million lives could be saved each year if people washed their hands with soap often. They said that programs to increase hand washing with soap could be among the most effective ways to reduce infectious disease.
Doctors say many diseases can be prevented from spreading by hand washing. These include pinworms, influenza, the common cold, hepatitis A, meningitis and infectious diarrhea.
Hand washing destroys germs from other people, animals or objects a person has touched. When people get bacteria on their hands, they can infect themselves by touching their eyes, nose or mouth. Then these people can infect other people. The experts say the easiest way to catch a cold is to touch your nose or eyes after someone nearby has sneezed or coughed. Another way to become sick is to eat food prepared by someone whose hands were not clean.
The experts say that hand washing is especially important before and after preparing food, before eating and after using the toilet. People should wash their hands after handling animals or animal waste, and after cleaning a baby. The experts say it is also a good idea to wash your hands after handling money and after sneezing or coughing. And it is important to wash your hands often when someone in your home is sick.
The experts say the most effective way to wash your hands is to rub them together while using soap and warm water. They say you do not have to use special antibacterial soap. Be sure to rub all areas of the hands for about ten to fifteen seconds. The rubbing action helps remove germs. Then rinse the hands with water and dry them.
Alcohol-based hand sanitizers are rubbed into the hands and do not require soap and water. Experts say these products must contain at least sixty percent alcohol to be effective in killing most bacteria and viruses.
Experts also say that people who use public bathrooms and dry their hands with a paper towel should use the towel to turn off the water. Then, before throwing it away, use the same paper to open the bathroom door.
And that's the VOA Special English Health Report, written by Nancy Steinbach. For more news and information about health, go to .voaspecialenglish.. I'm Steve
Ember.
8. The ABCs of Allergies
This is the VOA Special English Health Report.
An allergy is an unusually strong reaction to a substance. Many things can cause allergies. The most common cause is pollen. Trees usually produce pollen in the spring, grasses in the summer and weeds in the fall as part of their reproductive process.
Seasonal allergies are the
most common kind
Other causes include organisms such as dust mites and molds. Chemicals, plants and dead skin particles from dogs and cats can also cause allergic reactions. So can insect stings and some foods.
The most common kind of allergic reaction is itchy, watery eyes and a blocked or watery nose. Allergies can also cause red, itchy skin. Some reactions can be life-threatening -- for example, when breathing passages become blocked. Avoiding whatever causes an allergy may not always be easy. Antihistamine drugs may offer an effective treatment. Another treatment used in some cases is called immunotherapy. A patient is injected with small amounts of the allergy-causing substance. The idea is that larger and larger amounts are given over time until the patient develops a resistance to the allergen.
In the United States, experts estimate that up to four percent of adults and up to eight percent of young children have food allergies. Every year these allergies cause about thirty thousand cases of anaphylaxis, a severe reaction that requires immediate treatment.
It can result in trouble breathing and in some cases death. The National Institute of Allergy and Infectious Diseases says one hundred to two hundred people die. It says most of the reactions are caused by peanuts and tree nuts such as walnuts. People can also be allergic to medicines. The American Academy of Allergy, Asthma and Immunology says about five to ten percent of bad reactions to commonly used medicines are allergic. In other words, a person's immune system overreacts and produces an allergic reaction. The most common reactions include skin rashes, itching, breathing problems and swelling in areas such as the face.
But the academy estimates that allergic reactions to drugs cause one hundred six thousand deaths each year in the United States alone. It says antibiotics such as penicillin are among the drugs more likely than others to produce allergic reactions. So are anticonvulsants and hormones such as insulin. Other kinds include some anesthesia medicines, vaccines and biotechnology-produced proteins. And that's the VOA Special English Health Report, written by Mario Ritter and Caty Weaver. I'm Steve Ember.
9. Drug Shown to Cut HIV Risk in Breastfed Babies
This is the VOA Special English Health Report.
We talked last week about the value of breastfeeding for a baby's development. But getting the milk into the baby can seem difficult, at least at first. So here is some advice.
A baby breastfeeds
Breastfeeding should begin right after a baby is born. There may be experts at a hospital or other health center who can show a new mother several different positions for breastfeeding.
A mother can get a painful back or neck if she leans over to feed her baby. Better to bring the baby to the breast instead. The baby's mouth should be open as wide as possible so that all of the nipple and area around it fit inside.
A baby should be fed often at the beginning, usually about every two hours. The Mayo Clinic in the United States also notes it is best to feed before a baby gets too hungry. Experts say that when a mother breastfeeds often, it helps increase her milk production.
Women can learn more about breastfeeding from books or support groups or the Internet. But some mothers face difficult decisions.
In developing countries, breastfeeding remains a leading way for babies to become infected with the AIDS virus. Yet formula mixed with dirty water can make a baby sick.
Earlier this week, at a conference in Boston, AIDS experts reported good news. They said a study of about two thousand babies showed that the drug nevirapine can cut the risk of HIV infection through breastfeeding.
Nevirapine is widely used in developing countries to prevent infected mothers from passing the virus to their babies during childbirth. The babies are currently given nevirapine just once, at birth.
But this is what the study found: Babies given nevirapine daily for six weeks had about half the rate of HIV infections as those given only a single dose. By
six months of age, they still had almost one-third less risk of infection or death.
Scientists reported that six weeks of nevirapine appeared to be as safe as the single dose given under current guidelines. Teams from Johns Hopkins University in Maryland led the study with investigators from Ethiopia, India and Uganda.
In two thousand six the United Nations changed its policies on breastfeeding by HIV-infected mothers. The new advice supports breastfeeding for six months if mothers do not have money for basic foods or baby formula. The idea is that the benefits of breastfeeding are greater than the risks.
Experts say newborns who are not breastfed have five to seven times the risk of dying from pneumonia or diarrhea compared to breastfed babies.
And that's the VOA Special English Health Report, written by Caty Weaver. I'm Faith Lapidus.。