阅读材料，回答题： Eat to LiveA meager diet may give you health and long life, hut it&39;s

阅读材料，回答题：

Eat to Live

A meager diet may give you health and long life, hut it&39;s not much fun--and it might not e-yen be necessary. We may be aB．le to hang on to most of that youthful vigor even if we don&39;t start todiet until old age.

Stephen Spindler and his colleagues from the University of Californiaat Riverside have found that some of an elderly mouse&39;s liver genes can be made to behave as they did when the mouse wasyoung simply by limiting its food for four weeks. The geneticrejuvenation won&39;t reverse other dam- age causedby time for the mouse, B．ut could help its liver metabolize drugs or get rid of toxins.

Spindler&39;s team fed three mice anormal diet for their whole lives, and fed another three onhalf-rations. Three more mice were switched from the normal diet to half-feed for amonth whenthey were 34 months old--equivalent to about 70 human years.

The researchers checked the activity of 11,000 genes from the mouse livers, and found that46 changed with age in the normally fed mice. The changes were associated with things like in-flammation and free radical production--probably bad news for mouse health. In the mice that haddieted all their lives, 27 of those 46 genes continued to behave like young genes. but the most sur-prising finding was that the mice that only started dieting in old age alsobenefited from 70 percentof these gene changes.

"This is the first indication that these effects kick in pretty quickly," says HuB．er Warnerfrom the National Institute on Aging near Washington D. C.

No one yet knows if calorie restriction works in people as it does in mice, B．ut Spindler ishopeful. "There&39;s attracting and tempting evidence out there that it will work," he says.

If it does work in people, there might be good reasons for rejuvenating the liver. As we get ol-der, our bodies are less efficient at metabolizing drugs, for example. A．brief period of time of die-ting, says Spindler, could be enough to make sure adrug is effective.

but Spindler isn&39;t sure the trade-off is worth it. "The mice get less disease,they live longer,but they&39;re hungry," he says. "Even seeing what adiet does, it&39;s still hard to go to arestaurantand say: &39; I can only eat half of that. &39;"

Spindler hopes we soon won&39;t need to diet at all. His company, Lifespan Genetics in Califor-nia, is looking for drugs that have the effects of calorie restriction.

According to the passage， which of the following is NOT true？ 查看材料

A.Eating less than usual might make us live longer

B.If we go on adiet when old， we may keep healthy

C.Dieting might not be needed

D.We have to begin dieting since childhood