Why does your mouth feel like it's on fire when you eat a spicy pepper?
为什么吃辣椒时嘴里像是着了火一样？
And how do you soothe the burn?
怎样才能缓解这种灼烧感？
Why does wasabi make your eyes water?
为什么芥末酱能让人流泪？
And how spicy is the spiciest spice?
最辣的辛香料究竟有多辣？
Let's back up a bit. First, what is spiciness?
让我们从头说起。首先想一个问题：什么是辣味？
Even though we often say that something tastes spicy, it's not actually a taste, like sweet or salty or sour.
我们常说一些食物很辣但实际上辣并不是一种味道它不同于甜、咸、酸这些可以尝到的味道。
Instead, what's really happening is that certain compounds in spicy foods activate the type of sensory neurons called polymodal nociceptors.
之所以会感到辣是因为辛辣食物中的一些复合物激活了人体中一种叫“伤害性感受器”的感觉神经元。
You have these all over your body, including your mouth and nose, and they're the same receptors that are activated by extreme heat.
这种神经元遍布全身，包括嘴巴和鼻子，值得一提的是，当身体接触到热烫物体时也能激活这种神经元。
So, when you eat a chili pepper, your mouth feels like it's burning because your brain actually thinks it's burning.
当你吃辣椒时，嘴里之所以像是着了火是因为大脑的确认为嘴里起火了。
The opposite happens when you eat something with menthol in it.
而如果这时再吃一些含薄荷醇的食物，嘴里就会有相反的感觉，灼烧感会缓解很多。
The cool, minty compound is activating your cold receptors.
这是因为凉凉的薄荷味复合物激活了你的冷觉感受器。
When these heat-sensitive receptors are activated, your body thinks it's in contact with a dangerous heat source and reacts accordingly.
当热敏感受器被激活，会认为你贴近了危险的热源，身体会做出一定的反应。
This is why you start to sweat, and your heart starts beating faster.
因此这时你会开始流汗心跳加速。
The peppers have elicited the same fight-or-flight response with which your body reacts to most threats.
吃辣椒引起的身体本能反应跟身体应对危险状况的本能反应是一样的。
But you may have noticed that not all spicy foods are spicy in the same way.
你可能已经发现不同辣食的辣味各有不同。
And the difference lies in the types of compounds involved.
食物中的不同复合物形成了不同的辣味。
The capsaicin and piperine, found in black pepper and chili peppers, are made up of larger,
比如，黑胡椒和红辣椒中含有的辣椒素和胡椒碱是由一种叫“烷基胺”的分子组成的，
heavier molecules called alkylamides, and those mostly stay in your mouth.
这种分子较大、较重能滞留在嘴中。
Mustard, horseradish, and wasabi are made up of smaller molecules, called isothiocyanates, that easily float up into your sinuses.
而芥末酱、辣根酱、芥末酱中含有一种叫“异硫氰酸盐”的分子这种分子较小能轻松扩散到鼻窦处。
This is why chili peppers burn your mouth, and wasabi burns your nose.
所以，吃红辣椒时，嘴里会有灼烧感而吃芥末酱时，鼻子里会有灼烧感。
