研究表明基因或是导致中年发福的原因_公共英语阅读理解

研究表明基因或是导致中年发福的原因

Jay H. Chung是这项研究的主要作者，他是美国心肺血液研究所（该研究所是美国国家卫生研究院的一部分）下属肥胖和衰老研究室主任，他说道：“我们的社会通常认为，中年人（30到60岁）体重增加和缺乏锻炼，是因为不良的生活方式和缺乏意志力的原因，但是这项研究表明也存在着遗传因素--一种过度活跃的酶会使得人们中年时体重增加、丧失运动能力。”

Chung and his associates searched for biochemical changes that occurred in middle-aged animals that are equivalent to 45 years in humans. They found that an enzyme called DNA-dependent protein kinase, or DNA-PK, increases in activity with age.

Chung和他的同事们在中年动物（相当于45岁的人类）的身体上寻找生物学变化。他们发现，随着年龄的增长，一种被称之为DNA依赖性蛋白激酶的物质的活性与日俱增。

Further work showed that DNA-PK promotes conversion of nutrients to fat and decreases the number of mitochondria, tiny organelles in the cells that turn fat into energy to fuel the body.

进一步的研究发现，DNA依赖性蛋白激酶会促进营养物质转化为脂肪，并且减少线粒体的数量--而线粒体是将脂肪转化为能量以供应人体的细胞器。

Mitochondria can be found in abundance among young people, but the numbers drop considerably in older people. Researchers know that decreased mitochondria can promote obesity as well as loss of exercise capacity.