The high number of spice-loving foodies in the world led to the increasing popularity of spicy food. Unfortunately, there are plenty of health conditions that can limit a person’s tolerance to spicy foods. One such case is acid reflux that prohibits people from consuming spicy or acidic foods.
Spicy foods are not inherently acidic. While acidic spicy foods certainly exist, the acidity of a food does not determine its spiciness. Different components contribute to the spiciness or acidity of foods.
Are you curious about what makes some foods spicy, some foods acidic, and some foods both? Read on to learn a little bit more about the science of spice and acidity.
The Differences Between Spicy Food and Acidic Food
There are plenty of foods out there that are both spicy and acidic. However, spice does not equal acidity, and acidity does not equal spice. For instance, plenty of citrus fruits are acidic but not spicy at all.
The mechanisms that cause a food to be spicy or acidic are separate, so the two don’t correlate.
What Makes Food Spicy?
Capsaicin is the element that makes spicy food spicy. It has the ability to bind to protein receptors in human cells that send signals to the brain that something is hot or spicy.
Capsaicin is a compound produced by plants in the genus Capsicum within the nightshade family. There are five domesticated species of Capsicum, and these include the peppers most of us are familiar with, like chili peppers, bell peppers, poblano peppers, and jalapeño peppers.
The Scoville Scale measures how spicy a pepper is based on how much capsaicin it contains.
For example, a bell pepper contains almost no capsaicin. On the Scoville Heat Scale, it has zero Scoville Heat Units and a Scoville Heat Level of zero.
Meanwhile, the current hottest pepper, the Carolina Reaper, has a Scoville Heat Level of 10+++ with 1,500,000 – 2,200,000 Scoville Heat Units.
Capsaicin has other uses aside from making food spicy. Topical pain relievers sometimes contain a small amount, and you can often find capsaicin in pepper spray and some pest repellents.
What Makes Food Acidic?
Most of us learned about bases and acids and the pH scale in school. We learned that vinegar and baking soda erupt out of a paper mache volcano because baking soda is a base and vinegar is an acid. But what makes something an acid or a base?
A high number of hydrogen ions makes food acidic. To put it in simple terms, something with more positively charged hydrogen (H+) ions is acidic, while something with more negatively charged hydroxide (OH-) ions is basic.
The pH scale runs from 0-14, with 0 being the most acidic, 14 being the most basic, and 7 being neutral. Battery acid is a 0 on the pH scale, while drain cleaner is a 14. Because both acids and bases are caustic, the further away from neutral you go on either side, the more dangerous a substance can be, especially to your skin.
You might be surprised to learn the pH values of ingredients we use every day. While milk and dairy are pretty close to neutral, eggs have a pH of 8, and baking soda is a 9.
As for acids, we humans really like our acidic foods. Almost all fruits are acidic to some degree. Bananas have a pH of around 5, while strawberries and oranges are somewhere between 3-4. Lemons and limes generally fall closer to a 2, as does vinegar.
As for capsaicin, it’s a weak base. It’s not acidic at all.
What Makes Foods Both Spicy and Acidic?
By now, you may be starting to put two and two together. While capsaicin, the ingredient that makes things spicy, isn’t acidic, some spicy foods can be acidic.
Foods can be both spicy and acidic if they contain capsaicin and an acidic ingredient. Capsaicin is a weak base that cannot cancel out the acidity of the rest of the fruit. Some popular spicy fruits like jalapeño peppers and habanero peppers both tend to fall in the pH range of 5-6.
Consider, for example, hot sauce. We know hot sauce is, well, hot and spicy. It has capsaicin in it. But what’s one of the key ingredients in hot sauce? If your answer was vinegar, you’re spot on. And as we learned above, vinegar is super acidic, with a pH of around 2.
Often, we add spices and condiments to season meat, and meat is acidic. Beef is usually at a pH near 5.5, and chicken is typically close to 5.9. The peppers you’re using can affect how acidic your meal is as well.
Why Spicy Foods Cause Heartburn
Many people assume that spicy foods are also acidic because they cause heartburn or acid reflux the same way acidic foods do. While it’s true that spicy foods can cause discomfort, it’s not necessarily because the food is acidic.
Heartburn from spicy food can be caused by the way your body reacts to the capsaicin. Capsaicin slows down digestion, meaning the food you eat sits in your stomach longer, making heartburn more likely.
Capsaicin can also be very irritating to your throat. If you’ve ever seen someone sprayed with pepper spray, you know it’s highly irritating to the skin and eyes. The same thing can happen with your throat. When your throat is irritated, it can also increase the likelihood of heartburn.
As we mentioned above, capsaicin is also often paired with acidic foods, like how it’s paired with vinegar to make hot sauce. The combination of capsaicin and acids, or even just the acid itself, could be causing your heartburn.
Of course, if you’re a spice lover, the answer could simply be that the food is so delicious you eat more than you should, leading to heartburn.
Why Spice Makes You Feel Hot
We often call spicy food “hot” because it can literally make us feel hot. But why? The science behind this phenomenon is actually pretty cool.
Capsaicin activates a protein within our cells called TRVP1. The job of this protein is to sense pain and send a message to the brain alerting it of danger. If you accidentally set your hand down on a hot stove burner, that TRVP1 protein sends alarm bells to your brain, causing you to yank your hand away. It does the same thing when it comes into contact with something spicy-hot.
This likely was used as a defense mechanism by the Capsicum plants. The problem is, now humans have learned that eating something spicy is fun and won’t cause lasting damage, so we eat them anyway.
What To Do if Something Is Too Spicy?
Maybe you’re trying a new pepper or hot sauce for the first time, and you discover it’s way hotter than you expected. Do you reach for water? Soda? Beer?
The answer is actually milk. You may have heard this before, or you may have seen images of pepper-sprayed protesters applying milk to their eyes. Milk is the antithesis of capsaicin because the casein in milk breaks down the capsaicin and washes it away. Foods like ice cream and yogurt can work here as well, and the higher the fat content, the better.
Capsaicin, the thing that makes spicy food spicy, is not acidic. However, it is not at all uncommon for it to be combined with or added to acidic foods. If you experience reflux or feel ill after eating spicy food, it could be due to a number of things like the capsaicin irritating your throat or the acidity of the other foods you ate.
Many of us enjoy eating spicy foods, and knowing how to do so safely and avoid discomfort will make the experience even better.
- NPR: What Made Chili Peppers So Spicy?
- Scoville Scale: The Scoville Scale for Chili Peppers
- WebMD: What Is Capsaicin?
- Scientific American: What makes things acid: The pH scale
- US Geological Survey: pH Scale
- Austin Gastroenterology: Foods That Cause Heartburn
- Science News for Students: The Cool Science of Hot Peppers
- Food Network: Mouth-on-Fire Myths: What Really Cools Your Palate
- Pick Your Own: pH of Beef, Chicken, Fish, and Pork