Why Does Spicy Food Make My Nose Run?

Feel the heat and embrace the burn in this episode! Join us as we dive into the realm of spicy cuisine and the reactions it sparks, including making your nose feel like its running a race. We’ll discuss the science behind this and share tips for handling the heat.  

Shownotes: yournutritionprofs.com

Do you have a nutrition question you'd like us to answer? Let us know! Contact Us on our website or any of the following ways:

yournutritionprofs@gmail.com

YouTube

Instagram

Facebook



 

Transcript

Does the thought of spicy Mexican or Thai food make you smile? Or are you someone who avoids hot chilies because of the side effects like runny nose, watery eyes, sweating… you know the drill. In this episode we will explain why these side effects occur, and why some have a love-hate relationship with these spicy foods. 

M: I’m Professor Megan

S: And I’m Professor Susan, and we’re

Both: Your Nutrition Profs!

M: We are registered dietitians and college professors who have taught more than 10,000 students about health and nutrition. We have answered a LOT of questions about nutrition over the years – 

S: Some questions we get asked every year and some are rarely asked but very interesting.

M: We’re here to share our answers to these common (and uncommon) nutrition questions with you.

S: So bring your curiosity and let’s get started. 

Both: Welcome to our class!

M: Welcome to the podcast everyone. We hope you’re all doing well! Can you believe this is episode #45? 

S: 45 episodes already? I really can’t believe that.

M: It’s hard to believe. But we’re having so much fun.

S: We are! And make sure to rate and review us cuz it really does help!

M: Ok Susan -  what question are we answering today?

S: Well on the menu today is a question that was asked by a listener from San Antonio…and the question is - Why does eating spicy food make my nose run?

M: Well it’s definitely an appropriate question here in Texas where spicy food is very common and I get this question in class too.

S: Yeah me too, and I think spicy food is so tasty! I mean my nose definitely runs when I eat salsa or jalapenos. And some people love the heat of chiles. In fact, as far as we know, humans are the only species that deliberately seek out spicy foods. I mean most animals avoid them.

M: Yeah I’m one those latter animals… heat does not agree with me…  I usually have someone taste test even like salsa if we go to a restaurant. I’m like let me know if it’s going to be too spicy  for me.

S: I often play the “taste test” role for my family and friends. 

M: You’ve definitely done that for me! Ok, well let’s get into it. The sciencey name for this spice induced runny nose is gustatory rhinitis. 

S: Gustatory rhinitis -  I love learning the sciencey names for normal things – like borborygmi for stomach growls, that’s one of my favorites. 

M: I love it! Well gustatory rhinitis is a nonallergic reaction that is triggered by food that causes a watery, runny nose and sometimes postnasal drip which is when that drip runs down the back of your throat.

S: It usually occurs as soon as you eat a trigger food – something that’s spicy or it can be something that’s just temperature hot. 

M: And it often starts with a tingling numbness in your mouth, followed by a burning sensation. And if the burning is strong enough, your eyes will start to water, and your body will become a fluid making machine. 

S: That’s right. You’ll have extra fluids in your eyes, your nose, your mouth, your throat, and even in your stomach and parts of your intestines although you’re probably not going to be able to feel those. 

M: Well these trigger foods can differ from person to person, but common ones are black pepper, curry, hot sauce, chili powder, hot peppers, even horseradish. 

S: Fortunately, for most people the runny nose and the other symptoms are temporary. 

M: But why does this happen? Well here’s the science. There are 12 cranial nerves in your head. The trigeminal nerve is the 5ththand is considered the main sensory nerve of the head. 

S: This nerve transmits information from your forehead, eyelids, cheeks, nose, lips, and gums to the brain about things like touch, pain, temperature, and proprioception which is where your head is in space. It also controls the muscles involved in motor movements like chewing and swallowing.

M: It has other functions too. It helps the ear to dampen loud noises and controls a muscle that helps prevent food from entering the nasopharynx which is the space between your nose and mouth. 

S: If you’ve ever had milk or something shoot out your nose while you were laughing and eating – it had to go through the nasopharynx to get there. And FYI…Stuff from your mouth is not supposed to go out your nose….

M: Ewwww. I’ve seen that happen but I’ve never experienced it! It kind of seems like it might hurt… 

S: Yeah it’s never happened to me before either but yeah I agree - ouch!

M: Yeah - stuff from the nose to the throat – like mucus from the nose – that post nasal drip we mentioned - that’s more appropriate. 

S: Right, right.

M: Not the other direction.

S:  That nasopharynx area also contains the Eustachian tube the connects the throat to the middle ear. And the muscle controlled by the trigeminal nerve keeps the tube open to equalize pressure between the middle ear and outside air. 

M: But back to the trigeminal nerve specifically. When you eat something spicy or hot, you start to experience the symptoms we mentioned because all chile peppers contain plant compounds called capsaicinoids and the most abundant is, perhaps not surprisingly, capsaicin. 

S: Capsaicin was first isolated from paprika and cayenne in the late 1800s. It’s a small molecule produced in high quantities in the placenta of the pepper where the seeds and those white internal membranes are. It can also be found in the fleshy part of the pepper, but in much smaller amounts.

M: It’s protection for the plants. They don’t want to be eaten so they’ve evolved to produce this irritant. 

S: So that’s why if you don’t want a lot of heat in your salsa you take out the seeds and the ribs before you slice up the pepper. 

M: But the capsaicin doesn’t directly cause the problem. 

S: Right. The capsaicin binds to a pain receptor in the mouth called (get ready) Transient Receptor Potential cation channel subfamily V member 1.

M: Wow.

S: Yeah. or as we’re going to call it - TRPV1.  It’s not only found in the mouth, but it’s also found  in the skin. 

M: And normally TRPV1 gets activated when you touch something hotter than 107.6 degrees Fahrenheit –

S: That seems freakishly specific!

M: Yes! Well touching something that hot or hotter sends a message to your brain that “you’re about to be burned!”

S: So capsaicin also activates the TRPV1 receptor – and that same “burning” message gets sent to your brain. The message also initiates the release of neurotransmitters in the brain called endorphins, and the release of a brain protein called Substance P. 

M: Substance P? What is it P for… pain?

S: I guess so. I couldn’t find…it makes sense to me - right? So anyway, when capsaicin activates TRPV1 it tricks the brain into thinking that you’re really really hot, so you start to sweat, blood vessels in the skin dilate, and you may turn red. And substance P tells your body to make more mucus to flush out whatever is causing the burn. 

M: So your eyes water, your nose runs, and your mouth fills with saliva.

S: And this is why chile peppers are often used in home remedies to treat allergies or cold or flu symptoms. To get those fluids to flow and that helps to flush out the allergen or the cold or the  flu bug. 

M: And one other thing – the TRPV1 receptor is super sensitive for capsaicin – it really doesn’t take much to trigger the response. 

S: Every pepper has a “hotness” rating based on the Scoville scale that was first developed in 1912 by an American pharmacist named, of course, Wilbur Scoville. The first scale was really subjective – like how hot did Scoville think that pepper was when he ate it.  

M: But in the 1980s they started using a more objective and precise measure using High Performance Liquid Chromatography to determine the level of heat in a particular pepper. 

S: The mildest peppers are bell, Anaheim, and Poblano and they have between 0-2000 Scoville heat units or SHU. The hottest known pepper so far is the Carolina Reaper at 2 million SHU.

M: Absolutely not for me. No thank you. I can handle bell peppers, I love bell peppers

S: Yeah.

M: But, uh huh. 

S: I don’t think I can do the Carolina reaper either. 

S: Well what can cool your mouth and stop this process? Water won’t help – capsaicin is hydrophobic – this is a sciency word that means it does not like water. So capsaicin won’t dissolve or go away if you drink water.  

M: You’re going to need something with high fat and protein – so something like whole milk. The casein protein in milk coats the fatty capsaicin and keeps it from touching the pain receptor directly, thus stopping the burning and reducing the reaction. 

S: And if you don’t have milk available some people say that you could try cooking oil, but most say it doesn’t seem to work much better than water.

M: Eventually, even without milk, the pain will subside. And the good news is that capsaicin doesn’t cause any long term damage.

S: Even though it might feel that way…

M: Yes. But the bigger question for me is why do people actually seek out hot peppers? I mean some actually seem to enjoy the pain and burning associated with eating spicy food. But why?

S: Yeah. That’s a good question. The answer? No one really knows. 

M: Of course!

S: I mean psychologists have actually studied this and they, some of them say that maybe it's about pushing our limits, like riding roller coasters or watching scary movies. 

M: And the pain receptors can provoke a release of endorphins and dopamine which can give some people a sense of pleasure or heightened well-being.

S: Or maybe it’s so that we can enjoy eating healthy sources of nutrients like peppers that would otherwise be inedible. Peppers, they’re very low in calories but are rich in several vitamins like vitamins A, C, B6, K, and minerals like potassium and copper. 

M: They also contain phytochemicals that have antioxidant and anti-inflammatory properties. But we tend not to eat a lot at a time – especially the really hot ones. 

S: Right. I mean usually just a tablespoon or two will do it in a dish. I mean you don’t need much. So they do contribute a lot of flavor and of course heat, but not many calories.

M: I always wonder how people can eat so many chilies in those contests! 

S: Oh my god it looks so painful! 

M: I know!

S: Not for me, no. But I did read you can build up a tolerance to the reaction. The TRPV1 receptors become desensitized to the heat, so that allows you to consume more and hotter peppers.  And of course the endorphins that we mentioned are natural pain killers and they can give you  a sense of “well-being” – so maybe you’re kind of tricking yourself into believing you’re OK.

M: As you sweat and cry and drool….no thank you. 

S:  Well you have to be careful when handling foods with capsaicin. 

M: Oh yeah. 

S: Mm huh. I mean you may want to wear gloves when you slice or prepare them. At the very least, wash your hands immediately after touching peppers – with soap, not just water. The soap can pull the fatty capsaicin away from your hands. 

M: If you don’t use gloves or wash your hands – and you touch your face, your eyes, or your genitals – yikes! You will be sorry!!

S: You will be! But it’s not all doom and gloom, capsaicin can actually trigger positive effects. Some arthritis and muscle pain creams and lotions actually contain it on purpose.  

M: And that, that may seem counterintuitive – like why would I want to feel that pain sensation and how exactly is that going to relieve my muscle or joint pain? Well, once the initial activation dies down, the affected TRPV1 receptors start to become desensitized as Susan mentioned,  which means pain relief – at least in a small area for a short period of time. 

S: They also make a higher dose patch that you can wear, and that makes the nerve endings pull away from wherever the patch is located. So in some people this can lead to several weeks of pain relief in a particular area. 

M: And here’s a fun fact – David Julius and Ardem Patapoutian were awarded the Nobel Prize in Medicine in 2021 for their discovery of TRPV1! Of course not for the spicy food angle, but for the pain-relieving aspects. And, and probably there’s more drugs to come!

S: You know there have also been several studies over the past decade that show a definite benefit to liver function, 

M: Interesting.

S: Yeah with both oral and topical capsaicin – at least in mice. 

M: Mmm.

S:  I read one study where obese mice were treated with a daily cream of capsaicin on their shaved abdomens for 8 weeks. And after the 8 weeks the amount of fat in their liver was reduced. 

M: That’s pretty amazing for a topical cream! But I want to know who was rubbing capsaicin on, on these adorable little mice bellies!

S: Grad students. 

M: I didn’t get to do that when I was a grad student!

S: It does seem kind of amazing right.

M: Yeah.

S: that you’d rub on a lotion and fat in your liver goes down. 

M: Magic!

S: I know! Well the scientists theorized that the activation of the TRPV-1 receptor stimulated the use of fats in the liver and blocked some enzymes that help produce and store fats.

M: That’s amazing. And it might be really good for people who may have non-alcoholic fatty liver disease or non-alcoholic steatohepatitis or NASH. This is the fastest growing chronic disease in the nation. You know, we should do an episode about NASH. 

S: I think we should! We will. So capsaicin lotion helped the liver – but so did oral capsaicin. So in a couple of other studies oral capsaicin helped improve liver function and heal liver tissue damage that was caused by either alcohol or obesity.

M: That is so cool! But dear listeners, keep in mind these studies have been in mice. We’ll have to see if the same is true in human trials.

S: I mean it would be cool if it was.

M: Amazing.

S: That capsaicin seems to be really powerful stuff. And NIH is sponsoring quite a few research studies on this topic because - maybe it could work for NASH or NAFLD? All good. 

M: Definitely, So what’s the bottom line on spicy foods and your runny nose? 

S: OK, bottom line. The reason you get a runny nose, or sciencey word gustatory rhinitis, after eating hot peppers is that the capsaicin in these peppers activates pain receptors, and your body reacts by creating a whole bunch of fluids like mucus to try to get rid of the irritant. 

M: But capsaicin may also have some beneficial effects – antioxidant, anti-inflammatory, pain relief, and improved liver function if it’s impaired, again at least in mice. 

S: Capsaicin is found in several foods, but we most commonly think of it as being in chile peppers. And of course the amount in chile peppers varies widely  – from mild to super, super  hot. And the chiles are quite nutritious. So go out and enjoy some spicy Thai or Mexican food – but be sure to have a handkerchief handy!

M: Or maybe some milk!

S: Good idea…and as your nose runs, and you sweat, and your eyes water – remember, that capsaicin is not causing any long term damage and may actually be doing you some good so enjoy!

M: Thank you so much for the question! Join us next time for a snackisode all about kohlrabi.

Both: Class dismissed!

S: We hope you enjoyed this episode. You can find the show notes and a list of sources on our website, yournutritionprofs.com. 

M: Your homework is to follow us at your nutrition profs on Instagram and to listen to our next episode. You can listen on Amazon Prime, Apple Podcasts, Spotify, YouTube, or anywhere podcasts are found. We’d appreciate it if you’d “like” us, write a review, subscribe, and invite your family and friends to join us too. 

S: If you have a nutrition or health question you’d like answered, let us know! We may even do a show about it! Send an email to yournutritionprofs@gmail.com or click on the “Contact Us” page on our website.

M: Thanks to Brian Pittman for creating our artwork. You can find him on instagram @BrianPittman77

Both: See you next time!