Why does your mouth feel like it’s on fire when you eat spicy pepper? Why does chilli make your eyes run? Why it makes you sweat and make your nose run? Why these things happen to your body when you eat something spicy?
First we have to know what is spiciness, though we often say something taste spicy but it’s not actually a taste. Spicy food does not act on our taste bud, it acts on our pain receptor. Yes it’s a pain not a taste like sweet, salty or sour. What really happen is that certain chemical compounds are there in spicy foods which activate the type of sensory neurons. You have these receptors all over your body including your mouth and nose and they’re the same receptors that are activated by extreme heat. So your mouth feels like it’s burning when you eat a chilli pepper because your brain actually thinks it’s burning. The opposite happens when you eat something cool with menthol. The cool minty compound activate your cold receptors.
The chemical compounds which we found in spicy food are capsaicin and allyl isothiocyanate. Capsaicin works as a deterrent to stop various animals from harming the plants particularly from mammals like you, me, our pets that would crunch the seeds . Allyl isothiocyanate on the other hand is a colorless oil that can be found in mustard, radish. It also serves as a defense for the plant and also works as an antifungal agent.
When we eat hot and spicy food our heat sensitive receptors get activated. Our body thinks it’s in contact with a dangerous heat source and reacts accordingly and causing flushed face, watering eyes, sweating, irritation in ears and perhaps grosset of all an uncontrollably running nose. The pepper has elicited the same fight or flight response with which our body reacts to most threats.
Why would spicy food make your nose run?
These chemicals end up not only causing a hot sensation on your tongue but also irritate the mucus membrane in your nose. There are tiny hair and a sticky substance which we called mucus. The hair and mucus trap harmful substances when we breath. Thus prohibiting them from entering inside the body and prevents them from reaching our respiratory system. The capsaicin and allyl isothiocyanate reach our nose when we eat spicy food then these heat sensing receptors of our body get activated by these chemicals. Thus causing inflammation and irritation on the mucus. This triggers the membrane to produce extra amount of mucus as a defense mechanism, try to keep out whatever unwanted substance or particle that are causing irritation.
This is the same type of irritation that makes our eyes watery when we eat very spicy foods. Eyes also want to keep this irritant out of the eyes by watering. As some of the tears drain into our sinuses which makes our nose even more runny.
It also irritates various tissues inside our body such as our intestines. This causes body to react by trying to flush the irritant out. This is why after eating spicy food we sometimes have the dreaded liquid fire poop.
So why anyone would want to eat something that causes such high level of pain? One theory says that human started adding spices to food to kill off the bacteria and for some people eating spicy food is like riding roller coaster. It is thrilling to these people even though they found immediate sensation unpleasant. Even some studies have found that people who like to eat hot spicy food are more likely to enjoy other adrenaline rich activities like gambling. Moreover it may be in somebody’s genes to eat spicy food.
According to some studies the burning sensation does not get any better even if we train ourselves hard. In fact the pain to the people who like to eat spicy food is the same that of those who don’t like spicy food. They just seem to look like that the pain is more. So when it comes to spicy food you are going to get burnt.