VOA标准英语2010-Study Says Preventable Diseases Reduce US（在线收听）

Carol Pearson 08 April 2010

Life expectancy is rising in much of the world. But doctors are seeing another trend that is disturbing. Some people are choosing lifestyles that contribute to early death. A new U.S. study looks at four lifestyle choices that prevent people from staying healthy and living longer.

It used to be rare for people to live to 100. But babies born in the U.S. today can hope to live that long.

In the 20th century, life expectancy in wealthy nations increased by as much as 30 years. Average life expectancy for Americans is 78.

But doctors are seeing people adopt bad habits that can cut their lives short....like eating too much or eating too much junk food, exercising too little and smoking cigarettes.

These habits increase the risk for cancer, diabetes, heart disease and stroke.

Researchers at Harvard University and the University of Washington wanted to find out how many years are lost with these lifestyle choices.

"What we found was that high blood pressure, smoking, overweight/obesity and high blood glucose account for five years of loss of life expectancy in men and about four years in women at the national level," Goodarz Danaei, one of the principal researchers said.

The researchers broke down the data into race, income and locale and they found even greater differences.

Middle-income whites have the best blood pressure. But Asian-Americans have fewer bad habits and the best health.

"They are not getting heart disease because of low blood pressure, they are not getting cancer because they have low risk factors for cancer, including smoking," Danaei said.

The researchers found a 14-year difference in life expectancy between Asian-American and African-American men who can expect to live an average of 67 years.

"African-American men in the south have the lowest life expectancy, along with African-American men living in high-risk urban areas, places like downtown Los Angeles," Danaei explained. 

African-American women are another group with low life expectancy because of their high rates of obesity.

People battling excess weight have higher rates of disability, diabetes and heart disease - disorders that make them sicker at younger ages and dependent on medications for many years.

The researchers say public health officials could use the study to plan programs that will help people make better lifestyle choices.