英语听力每日五分钟（短文篇）11

11 《保护心脏的良方》

Many diseases and medical conditions are caused by things out of our control. Yet experts say you can control and even prevent many of the risk factors that increase your chances of dying. Experts note that an unhealthy lifestyle can put you at great risk of heart disease and stroke. Poor diet, having too much body fat and a lack of physical exercise all increase your risk of heart disease - so can using tobacco products and drinking too much alcohol. So doctors urge us to eat healthy foods, get exercise, stop smoking and limit our alcohol intake. But there is something else you can do. And it is free and easy. Smile!Anand Chockalingam is a heart disease specialist at University of Missouri Health Care in Columbia,Missouri. He advises his patients to smile. "When we smile, the brain wiring gets altered. The chemicals that are released are more positive." He says smiling is a first step in fighting physical and emotional stress and its sometimes harmful effects on human health. This is not just New Age advice. Several studies support Dr. Chockaligam's prescription to smile more. When we talk about disorders of the heart and blood vessels, we are talking about cardiovascular diseases, such as coronary heart disease.
And they are the number one cause of death around the world. That information comes from the World Health Organization. The main cause of heart attacks and strokes are blockages in blood vessels. These prevent blood from flowing to the heart or the brain. The most common reason for these blockages is a build-up of fatty deposits on the inner walls of the arteries. When you feel stressed or under pressure, your body releases many natural hormones including adrenaline and cortisol. Adrenaline increases your heart rate and blood pressure. Cortisol is the body's main stress hormone. It increases sugar in the bloodstream.If you are truly in danger, these hormones can help you. They are part of what we call our fight-or-flight response. However, when stressed for a long period, these stress hormones are ever-present in our bodies.And that, medical researchers warn, may lead to health problems. Researchers with the American Heart Association say the connection between stress and heart disease is still unclear. However, they claim that when people are stressed for long periods of time, they may not make the best decisions about what to eat.They may overeat, smoke or drink too much alcohol. They may not get enough exercise or sleep. 
And all of this can lead to health problems. Dr. Chockalingam says a smile may be one way to help.He tells his patients to smile 20 times an hour. To some, that might seem like a lot of smiling. Or some might even feel foolish .. smiling for seemingly no reason. But a smile does not involve drugs. It is not invasive like a surgical operation. It is free and it has no bad side effects. "Once people smile, they are relaxing. This relaxation directly lowers blood pressure, improves sugar levels in the blood. If we are smiling, we are breaking that link between stress and health." And it just may provide a little extra protection to everyone's heart health.