You are what you eat, or so the saying goes. But a new generation of molecular¹ biologists is starting to give that old adage² a decidedly high-tech³ twist.

俗话说：“吃什么像什么”。新一代分子生物学家正着手给这句话作一明白无误的高科技解读。

By combining the latest discoveries in human genetics with a deeper understanding of the hundreds of compounds found in food, investigators⁵ have begun to tease apart some of the more complex interactions between your diet and your DNA⁶. In the process, they hope eventually to give consumers more personalized advice about what to eat and drink to stave off heart disease, cancer and other chronic⁷ conditions of aging.

结合人类遗传学的最新发现和对食物中数百种化合物的进一步了解，研究者已经开始解析人们的日常饮食和DNA之间更为复杂的相互作用。通过这一研究，他们希望最终能为消费者提供一些更个性化的建议，即应如何健康饮食以避免和延缓心脏疾病、癌症和其他老年慢性病。

"We are trying to put more science behind the nutrition," says Jose Ordovas, a geneticist at the Friedman School of Nutrition at Tufts. "We want to finally understand why nutrients⁸ do what they do and to whom--why a low-fat diet may not work for some but works for others."

塔夫茨大学弗里德曼营养学院的基因学家乔斯·奥多维斯说，“我们想让饮食更科学，想彻底弄明白营养成分为什么起作用，对谁起作用——为什么低脂饮食只对一部分人有效。”

Do you drink three cups or more of coffee a day? Genetic⁴ tests can now determine whether you--like approximately 10% to 20% of the population--have a specific genetic variation that makes it harder for your body to absorb calcium⁹ in the presence of caffeine, thus increasing your rate of bone loss.

你是否每天要喝三杯以上的咖啡？现在遗传学测试能够确定你这样的人——约占人口的10%到20%——体内是否有某种基因变体，导致你的身体在有咖啡因时更难吸收钙质，从而加速骨质流失。

Are you getting enough folic acid, found in beans, peas and fortified¹⁰ grains? Researchers have learned that many people have a genetic predisposition that puts them at greater risk of developing heart disease because they need more folic acid than the average person to maintain normal blood chemistry.

你是否摄取了足够的叶酸？叶酸存在于蚕豆、豌豆和强化谷物里。研究者们已经意识到许多人都有一种遗传性易患病体质，使他们更易患心脏疾病，因为他们需要比正常人摄入更多的叶酸来维持正常的血液化学作用。

Would a high-fat diet be particularly damaging to your health, given your genetic makeup¹¹? About 15% of folks are born with a form of a liver enzyme¹² that causes their HDL, or good cholesterol¹³, level to go down in response to dietary fat. In most people the HDL level goes up, counterbalancing some of the bad effects of dietary fat on LDL--the dangerous cholesterol.

从基因构成的角度来看，高脂饮食对你的健康造成严重损害吗？大约15%的人生来就带来某种形式的肝脏酶，这种酶在食物脂肪的作用下会导致高密度脂蛋白——或“好”胆固醇——的水平下降。而大多数人体内的高密度脂蛋白水平会上升，以部分抵消食物脂肪通过低密度脂蛋白——或有害胆固醇——所造成的不良影响。

None of those genetic variations are immediately life threatening. In fact, most of them have no apparent effect. The variants¹⁴ are not like the mutations most of us learned about in school--alterations that cause entire genes¹⁵ or series of genes to malfunction¹⁶ and that result in diseases like sickle-cell anemia¹⁷ and cystic fibrosis.

这些基因变异都不会直接危及生命。事实上，它们中的大多数变异甚至不会产生明显的影响。这些变异不同于我们大多数人从学校里了解到的基因突变——一种引起全部基因或者几种基因机能的失常，并导致像镰形血球贫血症和囊性纤维变性之类疾病的变化。

Instead the changes nutritional¹⁸ geneticists are looking for are more like normal variations in the correct spelling of a word--say, theatre or theater, depending on whether you speak the Queen's English or American. "We all have these variants in our genes," says Ray Rodriguez, a geneticist at the University of California at Davis. "And they affect how we absorb, utilize¹⁹ and store various nutrients."

相反，营养基因学家正在寻找的变异更像是一个单词的不同的、但都正确的拼写方式，例如theatre或theater，取决于你说的是英式英语还是美式英语。加利福尼亚大学戴维斯分校的基因学家雷·罗德里格斯说：“我们的基因中都有这样的变异，它们影响着我们吸收、利用以及储存各种营养成分的方式。”

Researchers now have a good reference guide for the 25,000 or so genes of the human genome and the more than 3 million common variants that lurk²⁰ within those genes. They still need to figure out how all those genetic variables relate to health and disease.

研究者目前已详细了解了人类基因组中大约25,000个基因以及潜伏在这些基因中的300多万个常见变 异。他们还需要弄清楚所有这些基因变异是如何与健康和疾病相关联的。

Add the fact that food is full of hundreds of bioactive compounds, each of which varies depending on where plants are grown or animals are raised, and you've got quite a lot of information to puzzle out. In the end, you'll probably find out you still need to eat your broccoli²¹. But at least you'll have a better understanding of why.

再加上食物中含有成百上千种具有生物活性的化合物，而每种化合物又因植物产地或者动物饲养地不同而变化，那你就有大量的信息需要破解了。到最后，你也许会发现你仍需要吃西蓝花，但至少更清楚地知道为什么要吃了。