Research shows that a diet high in protein and low in carbohydrates can help shed pounds and normalize blood-glucose levels, improvements that lower the risk of diabetes and cardiovascular disease.
研究表明，含有高蛋白、低碳水化合物的饮食有助于减肥并能使血糖水平恢复正常，而血糖水平得到改善能降低糖尿病和心血管疾病的患病风险。
But will you live longer on a high-protein, low-carb diet? Two studies in the current edition of the scientific journal Cell Metabolism suggest the opposite. One involved an experiment conducted on mice, the other an 18-year study of humans who had divulged their dietary habits. Both studies found a strong association between longevity and a low-protein, high-carbohydrate diet, although the human study bore a twist: Beyond age 65, higher protein levels appeared to promote longevity.
但你会因为高蛋白、低碳饮食而活得更久吗？科学期刊《细胞代谢》(Cell Metabolism)本期上的两项研究认为答案是否定的。其中一则研究涉及对老鼠进行的一项试验，另一则项则对那些暴露自己饮食习惯的人进行了长达18年的研究。尽管针对人类进行的研究与最终的结论有些出入，即过了65岁以后，更高的蛋白水平似乎会延年益寿。但前述两项研究均发现：在长寿与高蛋白、低碳水化合物的饮食习惯之间存在着一种强烈的关联。
'Those high-protein diets were developed with a shortsighted vision,' said Valter D. Longo, a University of Southern California professor of gerontology and biological sciences and the lead author of the human study. 'On a high-protein, high-fat diet you can lose weight, but in the long run you may be hurting yourself.'
南加州大学(University of Southern California)老年医学和生物科学教授、上述人类研究的首席作者瓦尔特・D・隆戈(Valter D. Longo)说：“那些高蛋白饮食的发展伴随着一种短视现象。坚持高蛋白、健康高脂的饮食习惯，你是可以减肥，但长远来看，你现在的所在所为可能正在伤害你自己。”
These studies are anything but definitive, showing only associations derived from highly limited evidence. But in gerontology, the influence of protein consumption on longevity is a hot topic. Last year, the American Federation for Aging Research hosted a symposium on 'Optimal Protein Intake for Older Adults,' featuring a panel of scientists from academia and industry. No concrete answers emerged, except perhaps that protein consumption influences health in ways that are complex.
这些研究目前均无定论，仅仅显示出了一些关联性，这些关联性还是从非常有限的证据中提炼出来的。但在老年医学中，蛋白质摄取对寿命的影响是一个热门话题。去年，美国联邦老化研究所(American Federation for Aging Research)举办了一场有关“老年人最佳蛋白摄取量”的研讨会，有一组来自学界和业界的科学家出席了会议。对于前述问题，大家尚未得出具体的答案，或许只有这样一个结论：蛋白质摄取量会通过复杂的方式影响健康。
'High protein diets may be effective to lose weight rapidly,' said Elena Volpi, a professor of geriatrics at the University of Texas Medical Branch in Galveston. 'But very high protein diets may also be harmful.'
德克萨斯大学加尔维斯顿医学分部(University of Texas Medical Branch in Galveston)老年病学教授埃琳娜・沃尔皮(Elena Volpi)说：“高蛋白饮食对快速减肥可能会有效，但特别高的蛋白饮食可能也会有害。”
In the human study, those consuming high levels of plant-based protein had a threefold increase in cancer mortality but no higher rate of overall mortality. That suggests, as other research has shown, that there may be benefits from minimizing consumption of animal-based protein. 'These results indicate that respondents ages 50 to 65 consuming moderate to high levels of animal protein display a major increase in the risks for overall and cancer mortality,' the researchers concluded.
在上述针对人类的研究中，那些摄取高植物蛋白的人群癌症死亡率增加了三倍，但并未出现更高的总体死亡率。那表明──也正如其他研究所示──将动物蛋白摄入量最小化可能会有所裨益。研究人员得出结论称：“这些结果表明，那些食用中到高水平动物蛋白、年龄在50到65岁的受访者在总体死亡率和癌症死亡率方面的风险大幅增加。”
For subjects 66 and older, the opposite proved true: Higher protein consumption was associated with greater survival. Gerontologists say this makes sense, because the ability to absorb protein appears to diminish in the aging body, requiring perhaps greater consumption.
而在那些年龄为66岁及以上的受访者身上，事实证明情况正好相反：更高的蛋白质摄取量与更大的生存机会息息相关。老年病学者称，这个完全说得通，因为在衰老的身体内，吸收蛋白的能力似乎会减弱，这就可能需要更高的摄取量。
Even then, though, the takeaway is somewhat complicated. Americans tend to consume the bulk of their protein at dinner, and the body isn't always able to process an entire day's worth in one sitting, said Dr. Volpi, who wasn't involved in either study. 'It appears you can better use the protein you need if you distribute it across three meals, especially if you are a senior,' she said.
然而即便如此，有关蛋白质的摄取问题还是有些复杂。沃尔皮博士说，美国人倾向于在晚餐时进食他们一天中的大部分蛋白质，而人体并非总能一口气消化掉一整天的营养。她还说：“如果你能将蛋白质的摄取任务分配到一日三餐中，你似乎就能更好地利用所需的蛋白质，尤其当你是位老年人时，情况更是如此。”沃尔皮并未参与到上述的任何研究中。
In one study, 858 mice were fed one of 25 diets with differing ratios of protein to carbohydrates. Those that ate higher ratios of protein were leaner. But they didn't live as long. 'Median life span increased (by about 30%) from about 95 weeks to 125 weeks as the protein-to-carbohydrate ratio decreased,' said the study, conducted by researchers in Australia. 'Our results show that healthy aging is not achieved in mice fed high protein diets.'
在其中一项研究中，有25种包含了不同蛋白质和碳水化合物比例的饮食，858只老鼠则会被喂食25种饮食当中的某一种。那些吃了更高比例蛋白质的老鼠更为精瘦，但它们活得并不长。该研究称：“随着蛋白质比例相对碳水化合物比例的减少，老鼠的平均寿命长度也从大约95周增至125周（增幅约为30%）。我们的结果显示，健康老龄化并未体现在那些喂食了高蛋白饮食的老鼠身上。”这项研究是由澳大利亚的科研人员完成的。
Of course, mice aren't human. Indeed, the Australian researchers acknowledge that the same results may not be achieved in a different strain of mice.
当然，老鼠并非人类。的确，澳大利亚研究人员们承认，即便是不同品种的老鼠，实验结果也会不一样。
The second study followed 6,381 adult humans for 18 years after they completed a nationally administered survey on their food consumption over a 24-hour period. It divided the subjects into three groups: high-protein consumption (20% or more of calories from protein), moderate-protein consumption (10% to 19% from protein) and low-protein consumption (less than 10%).
第二项研究则在18年的时间里对6,381位成年人进行了追踪调查，在此之前所有受访者都完成了一项有关他们在24小时时间段内食物摄取的全国性问卷调查。该研究将受访者划分为三类：高蛋白摄取（有20%或以上的卡路里来自蛋白质）者，中等蛋白摄取（有10% 到 19%的卡路里来自蛋白质）者以及低蛋白摄取（不到10%的卡路里来自蛋白质）者。
In the 50-to-65 age range, 'subjects in the high protein group had a 74% increase in their relative risk of all-cause mortality, and were more than four times as likely to die of cancer when compared with those in the low-protein group,' the researchers reported.
在50岁到65岁的年龄段人群中，研究人员报告称：“高蛋白摄取组的受访者全因死亡率的相对风险增加了74%。而当与低蛋白摄取组的同龄人相比时，高蛋白组死于癌症的可能性是前者的四倍多。”
One prominent diet expert and high-protein opponent, physician Ron Rosedale, saw the studies as vindicating his longtime warning about the risks of excessive protein. But Dr. Rosedale, who advocates a diet high in so-called healthy fats such as those found in avocados, argues that high levels of carbohydrate consumption are no less dangerous. 'If people take these studies as a thumbs up for high carbohydrates, that's missing the point,' he said.
著名饮食专家及高蛋白反对论者、医师罗恩・罗斯代尔(Ron Rosedale)长期以来就对蛋白质摄取量过多发出了警告，他认为上述研究正好证明了他的警告是对的。罗斯代尔博士提倡一种含有高健康脂肪的饮食，这种所谓的健康脂肪常见于诸如鳄梨这样的食物中。罗斯代尔声称，高水平的碳水化合物摄取量所带来的风险跟高蛋白饮食不相上下。他说：“如果人们将这些研究当成是对高碳水化合物饮食的赞许，那就是没有抓住要旨。”