单选题 .  Eating a Mediterranean-style diet—packed with fruits, vegetables, legumes (豆类), nuts, olive oil and fish—is good for your heart, many studies have found. Now scientists are suggesting the diet may be good for your mental health, too.
    A study of over 10,000 Spaniards followed for almost four and haft years on average found that those who reported eating a healthy Mediterranean diet at the beginning of the study were about half as likely to develop depression than those who said they did not stick to the diet.
    All of the participants were free of depression when they were recruited to the study, and each filled out a 136-item food frequency questionnaire when they joined. Based on their self-reported dietary habits, they were assigned a score between 0 and 9, with the highest score reflecting the closest sticking to a Mediterranean diet.
    Over time, those who had scored between 5 and 9 on the Mediterranean diet were 42 percent to 51 percent less likely to develop depression, the study found, than those who scored between 0 and 2.
    The study does not prove a cause-and-effect relationship between the Mediterranean diet and a lower risk for depression, only an association between the two. Still, many scientists are convinced that some damaging processes involved in cardiovascular (心脏血管的) disease may also play a role in mental health.
    "Both cardiovascular disease and depression share common mechanisms," said Dr. Miguel Angel Martinez-Gonzalez, professor of preventive medicine at University of Navarra in Pamplona, Spain, and senior author of the paper, published in the October issue of Archives of General Psychiatry.
    "The membranes (细胞膜) of our nerve cell are composed of fat, so the quality of fat that you are eating definitely has an influence on the quality of the neuron membranes, and the body's combination of neurotransmitters is dependent on the vitamins you're eating," Dr. Martinez-Gonzalez added. "We think those least sticking to the Mediterranean dietary plan have a deficiency of essential nutrients."
    The elements of the diet most closely linked to a lower risk of depression were fruits, nuts and legumes, the study found.1.  Scientists have proved that a Mediterranean-style diet ______.
【正确答案】 A
【答案解析】 第1段第1句。
   原文该句末的have found表明该句提到的内容是通过研究得以“证实”的，该句提到地中海风格的饮食习惯“对心脏有好处”，A与此内容对应，故为本题答案。
   本题稍具干扰性的是B，本文第5段第1句明确表明地中海风格的饮食习惯和心理健康之间的因果关系仍未得到“证实”，且文中的研究不能表明两者是“因果关系”(cause-and-effect-relationship)，由此可见，B不符合本题题意。
[参考译文] 很多研究发现，地中海风格的饮食习惯——以果蔬、豆类、坚果、橄榄油和鱼类为主食——对心脏很有好处。最近，科学家们提出这种饮食习惯可能也有益于人的心理健康。
   一项为期近4年半，对10000多名西班牙人的研究发现，那些从调查一开始就坚持采用健康的地中海式饮食方式的人患上抑郁症的几率比那些不能坚持这种饮食方式的人低将近一半。
   所有参与者在研究开始时都无抑郁症的表现，开始时，每个人都会填写一份关于136种食物食用频率的问卷。研究人员根据他们提供的饮食习惯资料给他们打分，分值范围为0到9分，分数越高说明其饮食习惯与地中海式的饮食习惯越接近。
   研究发现，随着时间的推移，在地中海饮食习惯测试中得分为5～9分的人，比那些得0～2分的人患上抑郁症的几率低了42%～51%。
   这项研究并不能证明地中海式饮食习惯和低抑郁症风险之间的因果关系，只是证明了二者的相关性。许多科学家认为心血管疾病对人身体的伤害同样也可能影响心理健康。
   “心血管疾病和抑郁症有相同的机制，”西班牙潘普洛纳纳瓦拉大学预防医学教授、10月在《普通精神病学纪要》发表该研究论文的主要作者米格尔·安吉尔·马丁内斯-冈萨雷斯博士说道。
   “神经细胞的细胞膜由脂肪组成，所以人们饮食中脂肪的质量必定会影响到神经元细胞膜的质量，而机体神经递质的合成也依赖于人们所摄入的维生素，”马丁内斯-冈萨雷斯博士补充道。“我们认为那些饮食习惯与地中海式饮食习惯差别较大的人在一些关键营养物质的摄入上存在缺陷。”
   研究发现，与低抑郁风险关系最密切的食物是水果、坚果和豆类。