Coffee is now a staple for millions of people around the world. But before you reach out for that cup of joe, there are a few things you must know.

咖啡现在是全世界数百万人的主食。但在你伸手去拿那杯咖啡之前，有几件事你必须知道。

The golden ingredient in coffee is caffeine. It is what gives the coffee that kick that people seek. But the way it is roasted, ground and even consumed can make all the difference in the world.

咖啡中最重要的成分是咖啡因。正是它给咖啡带来了人们所追求的刺激。但它的烘烤、研磨甚至消费方式都会让世界变得截然不同。

Coffee wakes people up. Many athletes consume this drink to enhance their performance, while the normal man has it in the morning to kickstart his day. But there are nuances to coffee making that can alter the composition of the beverage.

咖啡能提神。许多运动员喝它是为了提高成绩，而普通人早上喝它是为了开始新的一天。但是咖啡制作的细微差别会改变饮料的成分。

“Beans can make a difference – standard robusta beans are higher in caffeine than arabica beans, for example,” Dr. Mike T Nelson, a researcher and performance specialist who recently co-wrote the International Society of Sports Nutrition’s position on coffee, said, according to The Guardian. “But there are other factors – roasting actually breaks down caffeine, so in general darker roasts will have lower caffeine content. But even when outlets try to control for beans, brewing methods, and so on, the variability in caffeine content is still quite high."

据《卫报》报道，研究人员兼性能专家迈克·T·尼尔森博士最近与人合作撰写了国际运动营养学会关于咖啡的立场，他说:“豆的品类不同成分不同——例如，标准的罗布斯塔豆比阿拉比卡豆含有更高的咖啡因。”“但还有其他因素——烘焙实际上会分解咖啡因，所以一般来说，烘焙颜色较深的咖啡咖啡因含量较低。但即使咖啡店试图控制咖啡豆、冲泡方法等，咖啡因含量的可变性仍然相当高。”

“This is why, for athletes, if you’re using it purely for performance-enhancing effects and you want to be very specific with it, I recommend taking caffeine in a pill form, because you can control your intake better,” Nelson added.

纳尔逊补充说：“这就是为什么，对于运动员来说，如果纯粹是为了提高成绩，而且你想对它有非常明确的要求，我建议你以药片的形式服用咖啡因，这样可以更好地控制摄入量。”

As for how quickly the effects of coffee occur, a 2008 study found that the duration is a minimal 10 minutes after gulping down a cup of coffee. The peak caffeine concentration in the blood occurred after 45 minutes in the study.

至于咖啡的作用有多快，2008年的一项研究发现，在喝下一杯咖啡后，作用时间最短为10分钟 。在研究中，血液中咖啡因浓度的峰值出现在45分钟后。

Besides the beans, the way coffee is ground can also have a bearing on the benefits it accords to the drinker. While the time when the beans were ground is irrelevant, how much the beans are ground makes a difference. Generally, a finer grind releases more polyphenols, making the coffee more beneficial.

除了咖啡豆，咖啡的研磨方式也会对饮用者的益处产生影响。虽然咖啡豆被磨碎的时间无关紧要，但咖啡豆被磨碎的程度却有区别。一般来说，更细的研磨会释放更多的多酚，使咖啡更有益。

In addition to the beans, whether the coffee is filtered or unfiltered also has a say. Coffee filtered through paper may be healthier than coffee made with a metal filter or no filter at all. According to a study published in 2020, 500,000 healthy coffee drinkers with two decades of consuming the liquid had lower rates of arterial disease and death compared to those who drank filtered coffee.

除了咖啡豆，咖啡是过滤的还是不过滤的也有发言权。用纸过滤的咖啡可能比用金属过滤器或根本不过滤的咖啡更健康。根据2020年发表的一项研究，50万名喝了20年咖啡的健康咖啡者与喝过滤咖啡的人相比，动脉疾病和死亡率更低。