苹果比咖啡含有更多的咖啡因吗?

根据《古德曼和吉尔曼药理学和治疗手册》，咖啡因是一种存在于许多食物中的兴奋剂，是世界上使用最广泛的精神活性药物。虽然咖啡的咖啡因含量很高，但苹果不是。因此，一杯咖啡里的咖啡因比一个苹果里的还要多。苹果里的糖比咖啡里的多;然而，这种糖的升糖指数相对较低，因此不会像你加在咖啡里的糖那样迅速起作用。

咖啡因存在于许多常见的食物和饮料中，包括咖啡、茶、巧克力、苏打水和能量饮料。它也存在于大多数减肥药中。人们摄入咖啡因是因为它会刺激体内一种特殊的分子，即腺苷受体，从而使他们感觉更加警觉。

一个标准的16盎司。一杯自家煮的咖啡大约含有266毫克咖啡因。相比之下，一杯典型的茶大约含有50到100毫克咖啡因，而一瓶典型的瓶装软饮料大约含有100到200毫克咖啡因。虽然很难过量摄入咖啡因，但它可能是致命的，据报道，超过每公斤体重150到200毫克咖啡因就会死亡。一公斤约等于2.2磅。,so that would be about 70 cups of coffee for a average-sized American man.

苹果是许多营养物质的良好来源。例如，一个典型的小苹果含有你每日建议摄入量的12%的纤维，10%每日建议摄入量的维生素C，以及微量的矿物质，如钙，钾，锰。然而，苹果不含任何咖啡因。

用谷歌搜索“苹果咖啡因咖啡”，会出现几个网页的链接，人们会在这些网站上问这样一个问题:“一个苹果是否比咖啡含有更多的咖啡因?”The misconception seems to stem from the fact that apples have sugar in them -- an average small apple has about 13 g of it -- and that people are equating the energy boost they get from a cup of coffee with the energy boost they presumably get from eating an apple.

基于以上的讨论，一个更合适的问题可能是“一个苹果比一杯普通的咖啡含糖量多吗?”Presuming you put one to two sugar packets in your typical cup of coffee, and that each sugar packet contains -- as most do -- about 4 g of sugar, the answer is yes, a typical apple contains more sugar than a typical cup of coffee. However, if you compare the glycemic index of apples and typical table sugar -- the glycemic index being a measurement of how quickly an ingested glucose load finds its way into your bloodstream, and hence a measure of how quickly you feel the effects of ingestion -- you'll see that apples, at 38 out of 100, are about half as strong as table sugar, at 68. So if you're looking for a quick energy kick, a cup of coffee is likely to get you there faster. However, an apple is probably your healthiest option.