Whether a cup of java will leave you craving more could be chalked up to your genes。

　　一杯咖啡是否会使你上瘾也许是由你的基因决定的。

　　People with a newly identified genetic variant in their DNA， called PDSS2， may be inclined to drink fewer cups of coffee than others， according to a small study published in the journal Scientific Reports on Thursday。

　　根据上周四在《科学报告杂志》上的一篇小研究显示：基因里有这种新发现的遗传变异PDSS2的人，可能倾向于比其他人喝更少的咖啡。

　　I actually was very surprised to find a new gene for coffee consumption， said Nicola Pirastu， a chancellor’s research fellow at the University of Edinburgh’s Usher Institute of Population Health Sciences and Informatics， and lead author of the study。

　　尼古拉·皮拉斯图说：“能找到关于咖啡消费的新的基因真的使我非常惊讶。” 尼古拉是爱丁堡大学厄舍学院人口健康科学和信息学的校长研究成员，同时他也是这篇研究的主撰写人。

　　We believe that this PDSS2 genetic variant is impacting coffee drinking through the regulation of the speed at which caffeine is metabolized， he said。 “It has been observed before that higher levels of PDSS2 inhibits the expression of the genes metabolizing caffeine and thus the speed at which caffeine is degraded。”

　　他说“我们认为这种PDSS2的基因变量通过咖啡因的常规新陈代谢速度来影响咖啡的饮用量，我们观察到这种现象是产生在在人体产生释放更多的PDSS2来抑制咖啡因的代谢之前，因此咖啡因的代谢由此减慢。”

　　The findings add to existing research suggesting that our espresso habits may be embedded in our genes， Pirastu said。

　　皮拉斯图说，基于现有的研究基础上，这些新发现表明我们对于浓咖啡的爱好是藏在我们的基因中的。

　　About 64% of American adults drink at least one cup of coffee a day， according to a 2015 Gallup poll。

　　根据2015年的盖洛普民意测试，约有64%的美国成年人每天要喝至少一杯咖啡。

　　For the new study， researchers analyzed medical and genetic data on 370 people from a small village in southern Italy， and 843 people from six villages in northeast Italy。 The study participants also self-reported their daily coffee-drinking habits。

　　在这项新的研究中，研究者们分析了人们的医学和遗传数据，其中370人来自意大利南部的一个小村庄，843人来自意大利北部六个不同的村庄。研究对象们也会报告自己每天喝咖啡的情况。

　　The researchers discovered that people with the PDSS2 variant reported consuming fewer cups of coffee than people without the variant。

　　研究者发现，体内带有PDSS2变量的人会比没有这种变量的人少喝很多咖啡。

　　When the researchers replicated the study with a group of 1，731 study participants from the Netherlands， they noticed similar results。

　　当研究者们在荷兰对1731名研究对象重复这项研究的时候，他们得出了相似的结果。

　　This variant is very common， and around 50% of the European population has either one or two copies of it， Pirastu said。 More research is needed to determine the variant’s prevalence in other populations as well as to clarify its biological link with caffeine。

　　皮拉斯图说：“这种基因变体很常见，欧洲人口中大约有50%的人有一或两种PDSS2的基因副本。”我们需要更多的研究来判定这种记忆变体在其他人口中的广泛性、同时弄清楚这种变体与咖啡因在生物学上的联系。

　　Although different statistical models were used， the previous research tested a few of the same genetic variations included in the new study。 However， an association with coffee consumption was not found， said Marilyn Cornelis， assistant professor of preventive medicine at Northwestern University who led the 2014 study。

　　尽管运用了不同的统计模式，但是之前的研究也测试了几种新研究中所提到的基因变体。然而并没有发现有任何和饮用咖啡的行为的关联，玛丽莲·康奈利说。玛丽莲·康奈利预防医学的副教授，同时她也是2014研究的负责人。

　　Therefore， it seems that the newfound variant’s impact on coffee consumption may be minor compared with the previously identified genetic variants， said Cornelis， who was not involved in the new research。

　　康奈利说，因此和之前研究中已被识别的基因变量相比，可能新发现的变量对于咖啡消耗的影响是比较弱的。康奈利没有参与新的研究。

　　The [new] study is small relative to the previous genome-wide association studies of coffee consumption， Cornelis said。

　　康奈利说：“新的研究和之前的全组基因与咖啡消费行为的研究相关甚微。”

　　Genes can exist in different forms from one person to the next。 We can have ’fast’ and ’slow’ acting forms， and depending on what we’ve inherited， it can impact how our body processes or metabolizes nutrients or food constituents like caffeine， said Ahmed El-Sohemy， professor of nutritional sciences at the University of Toronto， who was not involved in the new research。

　　艾哈迈德教授说，每个人的基因组成都不相同。我们会有“快”和“慢”的作用形式，而且根据我们已经继承的基因的不同，这些基因组会影响我们身体的工作或者代谢营养物质及类似咖啡因这样的食物成分。他是多伦多大学营养科学教授，也没有参与这次新的研究。

　　People generally tend to self-regulate how much coffee they consume based on a balance of how caffeine in the beverage has positive benefits， such as mood-enhancing effects， and negative outcomes， such as anxiety or “jitters，” he added。

　　艾哈迈德补充道，通常人们倾向于通过判断咖啡因在积极作用和消极作用的平衡来自我调节咖啡的摄入量。比如饮料中的咖啡因有多大的提高情绪的积极作用，还是有引发焦虑或神经过敏这样的消极作用。

（编辑：何莹莹）