科学美国人60秒 SSS 高糖饮食加速老化（在线收听）

High-Sugar Diet Makes Flies Drop Like...Flies 高糖饮食加速老化

I don’t believe, in all my years, I have ever seen a fruit fly I would consider obese. But, thanks to the wonders of modern science, that’s all about to change. Because a team of researchers from Cold Spring Harbor laboratory has produced the first flies that are genetically engineered to overeat.

这么多年来，我从不觉得自己见到一只果蝇会觉得它胖。但是，有了现代科学的奇迹，这一切即将改变。来自冷泉港实验室的一组研究人员创造了第一批会暴饮暴食的转基因果蝇。

\If you are wondering…why…it’s not as silly as it might sound. A big part of weight control has to do with making healthy dietary choices and knowing when to step away from the snack cabinet. But what controls those behaviors?

如果你也好奇他们为什么要这么做……事实可能没它听起来那么傻。体重控制的一个重要部分，就是要做出健康的饮食选择，并且知道于何时远离零食柜。但是这些行为由什么控制呢?

Well, we humans have a hormone called leptin that tells us that we’re full. After eating, leptin is released from our fat cells. And it travels to our brains to signal that we’ve had enough. Indeed, people who don’t produce leptin…or who lack the molecular machinery to detect it…really pack on the pounds.

人类有一种会通知自身我们已经吃饱了的荷尔蒙——瘦素。吃完东西后，脂肪细胞会释放出瘦素。它会传播到我们的大脑，发出信号表明我们已经吃饱了。事实上，那些不产生瘦素或缺少检测瘦素的分子机构的人…体重会着实增加。

In the new study, researchers discovered a hormone that acts the same way in flies. And when they deleted the gene that encodes it, the hormonally deficient insects just kept eating. And when presented with the fly equivalent of a high-fat or high-sugar diet, they gained three times more weight than did their hormonally competent peers. The findings appear in the journal Cell Metabolism.

在这项新的研究中，研究人员发现一种在果蝇中起着同样作用的荷尔蒙。当他们删除了编码它的基因时，荷尔蒙缺失的果蝇就会一直进食。当给荷尔蒙缺失的果蝇和正常果蝇提供同等的高脂肪或高糖食物时，荷尔蒙缺失的果蝇的体重比正常果蝇的体重多长了三倍。这项研究结果发表在《细胞代谢》杂志上。

Interestingly, giving human leptin to these tubby bugs eliminates their tendency to binge. That suggests that by studying these flies, scientists might learn something that’s relevant to us.

有趣的是，将人类的瘦素用到这些果蝇身上，也可以消除它们大吃大喝的倾向。这表明，通过研究这些果蝇，科学家可能会发现一些与人类自身相关的东西。

In the meantime, researchers from the U.K. and Australia have also been plying flies with sweet treats. And they found that consuming large amounts of sugar may lead to fewer birthday cakes.

与此同时，来自英国和澳大利亚的研究人员也在对果蝇进行甜食研究。他们发现摄入大量的糖会缩短其寿命。

In this study, researchers compared the life spans of flies that ate a healthy diet, with 5 percent sugar…to those that went on a three-week bender of 40 percent sucrose. That’s the equivalent, the researchers note, of a person who really took Marie Antoinette’s advice to heart and ate only cake for two decades.

在这项研究中，研究者将只吃5%糖的保持健康饮食的果蝇与连续三周狂吃40%蔗糖的果蝇做了对比。研究人员指出，这相当于一个人真的听从了玛丽·安托瓦内特(法国一位奢靡王后)的建议，20年只吃蛋糕。

The results? The sugar-fed flies lost about 7 percent of their already brief 90-day life span. And that was even if they reverted to the healthy diet after their three weeks on sweets. These results appear in the journal Cell Reports.

结果呢？高糖饮食的果蝇失去了7%的它们本就短暂的90天寿命。这还是基于它们进行了三周高糖饮食后，恢复了健康饮食习惯所得的结果。这些结果发表在《细胞报告》杂志上。

The sugar overload apparently triggered long-term changes in gene activity…which accelerated aging and had the sugar-buzzed flies dropping like, well, like flies.

过量饮食糖显然引发了基因活动的长期变化……这加速了老化，还使沉溺于糖的果蝇像……苍蝇一样快速坠亡。

The findings suggest that you can have your cake and eat it, too. But not for long.

研究结果表明，你可以享受吃蛋糕的乐趣。但不能长期食用。