Why do we eat spicy1 food? 我们为什么喜欢吃辣？

虽然辛辣食物会刺激口内黏膜，让人舌头发麻、嘴巴冒火，浑身冒汗，但很多人认为吃辣是 “痛并快乐的”，甚至 “无辣不欢”。辣椒是世界各地许多菜肴中的关键成分。本期节目从科学和历史两方面分析人们热衷吃辣的原因。

词汇：sensation 感受

You know the feeling – your ears start to warm up, your tongue goes numb2, you start sweating and taking deep breaths. You've just eaten something spicy knowing it would be painful, and, yet, you chose to do it anyway. Are humans just masochistic, or is there something else going on? The answer lies in both science and history.

Let's start with the science. Spicy isn't actually a taste like salty, sweet, sour and bitter – it’s a sensation. This sensation is triggered by a chemical compound found in chilli peppers called 'capsaicin'. When we eat foods containing capsaicin, our bodies are tricked into thinking the temperature is actually rising. In trying to temper the burning sensation, our bodies release endorphins which control pain and, at the same time, give a feeling of pleasure – like painkillers3.

This is what is happening chemically, but there is also a conscious side to choosing spicy food. Dr Tamara Rosenbaum, Cognitive4 Neuroscientist at the National Autonomous5 University of Mexico, explains in an interview with the BBC that this is because we are rational beings – we know that the burning sensation of chilli does not physically6 harm us. Furthermore, we derive pleasure from the other ingredients chilli is generally cooked and eaten with – including fat, sugar and salt. So – like skydiving – eating chilli is a form of thrill-seeking or 'benign masochism', where we get pleasure from a seemingly negative sensation.

This masochistic relationship with capsaicin has been a long one, starting in the Andes of South America, where chilli peppers originate. Humans were one of the few mammals on Earth that developed a taste for capsaicin so, archaeological evidence suggests, they started cultivating chilli peppers about six thousand years ago. Human intervention changed the chilli pepper to suit human tastes and needs – including the pepper's colour, size and capsaicin content – helping7 to explain the many different types of chilli peppers now available.

Fast-forward to today, and our love affair with the chilli pepper is going strong. We eat around 57.3 million tons of peppers globally each year, and chilli is a key ingredient in traditional dishes from Mexico to Korea. Maybe we are masochistic after all.

词汇表

go numb 发麻

masochistic 自讨苦吃的，自找罪受的

taste 味道

sour 酸的

bitter 苦的

sensation 感觉

trigger 引发，触发

chemical compound 化合物

capsaicin 辣椒素

contain 含有

trick 使产生错觉

temper 使缓和

release 释放

endorphin 内啡肽

conscious 有意的

rational being 理性的动物

derive 获得，得到

thrill-seeking 寻求刺激的

benign masochism 良性自虐，从不适中得到享受

develop a taste for 养成吃…的习惯

cultivate 种植

intervention 干预

content 含量

going strong 依旧强烈