Sharply cutting calories in the diets of rhesus monkeys was found to reduce aging-related deaths, according to a study that followed 76 monkeys for two decades.
The findings, published Thursday in Science magazine by researchers at the University of Wisconsin, give new impetus to researchers and companies, including GlaxoSmithKline PLC (GSK), that are searching for a drug to mimic the beneficial effects of a meager diet in humans without the feeling of near-starvation.
For thousands of people who already attempt to sharply restrict their food intake - by as much as 30% below a normal diet of roughly 2,200 calories a day - in an effort to live longer, the findings appear to validate a technique called calorie restriction as a way to live longer.
Scientists have known since the 1930s that the technique lengthens the lives of mice. But until now, no study had shown the technique worked in monkeys, which are more genetically similar to humans. One difficulty: Monkeys live almost 30 years on average, meaning any study to measure a difference in death rates would need to wait a long time.
The Wisconsin study, which began in 1989 with 30 rhesus monkeys and added 46 more in 1994, is the first to yield a definitive finding. Researchers beg an restricting half the monkeys' diets, reducing their calories by 30%, when the monkeys were fully grown, or about 10 years old.
Thursday's findings are 'all consistent with what human practitioners of calorie restriction have always believed,' said Brian Delaney, president of the Calorie Restriction Society, which claims about 3,000 members. 'Any degree of restriction beyond what you're currently eating will confer health benefits and will slow the aging process,' he said.
After almost 20 years, 14 of 38 monkeys in the control group had died of what were considered age-related causes, such as heart disease and cancer. That compares with only five of 38 monkeys in the restricted-diet group, a significant decrease. However, the difference wasn't statistically significant when considering all causes of death, including monkeys who died from injuries and complications from anesthesia.
Calorie restriction also appeared to slow the loss of gray matter in the brain.
'It's a pretty simply story, really,' said Richard Weindruch, a Wisconsin professor who led the study. 'We've been waiting all these years for the monkeys to become old enough to get meaningful data on lifespan and brain aging and diseases.'
He is the co-founder of a Wisconsin company, LifeGen Technologies LLC, that works with drug makers to quantify the effect of possible life-extending drugs.
这份威斯康星大学(University of Wisconsin)研究人员的研究报告刊登在周四的《科学》(Science)杂志上。这些研究发现给诸多研究人员和葛兰素史克(GlaxoSmithKline)等公司带来了新的动力。这些人员和公司一直在寻找一种药物能够模拟节食给人带来的好处，又不用感受到饥饿的痛苦。
美国热量限制学会(Calorie Restriction Society)会长德拉尼(Brian Delaney)表示，周四公布的研究结果和那些身体力行热量限制的人一直坚信的信念完全一致。该学会有大约3,000名会员。他说，限制你当前的进食量，不管程度如何，都能带来健康方面的好处，能够延缓老化过程。
温德鲁奇是当地一家公司LifeGen Technologies LLC的共同创始人。该公司与制药商合作，对可能延长寿命的药物成效进行量化衡量。