Should You Eat Spicy Foods When You Have the Flu?

If you're a fan of spicy foods, you know they definitely have an effect on your body. You may break out into a sweat after downing a hot pepper or feel like you've set off the smoke alarms in your mouth after a bowl of zesty chili. But do these fiery foods have any effect on bodily invaders like the flu?

Surprisingly, the answer is yes. Spicy foods don't cure or "kill" the flu, but if you're sick, eating them may actually help relieve some of your symptoms.

Here, Kristine Gedroic, MD, medical director of the Gedroic Medical Institute and author of ‌A Nation Unwell: What's Gone Wrong?‌ tells LIVESTRONG.com about the best spicy foods to eat if you have the flu.

Capsaicin, the active compound in chili peppers, can be used to relieve sinus congestion. A study published July 2015 in the ‌Cochrane Database of Systematic Reviews‌ found that a capsaicin-based nasal spray improved the symptoms of non-allergy-related sinus congestion. (Note: Do not try homemade hot pepper nasal sprays.)

Additionally, a small study of 24 patients published January 2015 in ‌Respiratory Medicine‌ found that taking capsaicin powder capsules decreased cough symptoms.

However, larger-scale research is needed to determine the effects of capsaicin. Additionally, directly eating spicy peppers can cause adverse effects in some people, including bloating and nausea, according to a study published February 2016 in the ‌American Journal of Clinical Nutrition‌.

"Horseradish is beneficial for relieving sinus congestion," Dr. Gedroic says.

If you've ever eaten wasabi or horseradish on steak, you may have already experienced these sinus-clearing benefits. Your eyes may have watered and you may have felt your sinuses "burn." But afterward, your sinuses likely felt clearer and you may even have had to blow your nose.

However, horseradish can be intense and isn't for everyone.

Garlic, a relative of the onion, is a common and flavorful spice. The benefits of garlic have been described by many cultures for centuries. Now scientists are studying the underlying health mechanisms, according to a review published April 2015 in the ‌Journal of Immunology Research‌.

The review found that garlic helps boost the immune system by stimulating the function of certain types of cells. The stronger your immune system, the better chance your body has to fight or prevent infection.

Additionally, aged garlic extract may help reduce the severity of cold and flu symptoms. According to a study published June 2012 in ‌Clinical Nutrition‌, study participants who took aged garlic supplements daily (about 2.5 grams per day) had less severe symptoms than those who took a placebo.

It's worth noting that the science into the immune effects of garlic is still very new. Much more research is needed to fully understand the potential benefits.

If you opt to eat raw garlic, Dr. Gedroic notes that, in order to gain the full benefits, you should crush or cut the garlic and let it sit for about 10 to 15 minutes before eating it. This releases a compound called alliinase, which has antioxidant and anti-inflammatory properties, according to Oregon State University's Linus Pauling Institute.

While spicy food may benefit some, these flavors aren't for everyone. If you don't like spicy food or it upsets your stomach, it's best not to eat it, no matter the reported health benefits.

If you have any gastrointestinal symptoms, including nausea, upset stomach or vomiting, spicy foods can actually make these symptoms worse, according to the Mayo Clinic. In this case, stick with clear broths and bland solid foods. (Note: While an illness with these symptoms is often referred to as the "stomach flu," the official name is viral gastroenteritis, which is caused by a different pathogen than influenza, per the Mayo Clinic.)

It also matters what kind of spicy food you eat. If you have the flu, it's better to avoid greasy or fatty foods, according to The Ohio State University Wexner Medical Center. Skip the tacos and opt for healthier options like soup, vegetables and other plant-based foods.

Dr. Gedroic also says it's important to avoid sugary foods, particularly processed sugar. "Sugar depresses the immune system," she says, meaning the immune system can't properly do its job to fight infection. If you're craving something sweet, choose fresh fruit instead.

The seasonal influenza virus isn't the only type of virus that causes flu symptoms. The novel coronavirus is currently responsible for the global COVID-19 pandemic. There are many similar symptoms between the seasonal flu and COVID-19. These include fever, a dry cough, fatigue, body aches, sinus congestion and a runny nose, according to the University of Alabama at Birmingham.

Because the novel coronavirus has only recently affected humans, there is no available data on whether or not spicy food helps to relieve COVID-19 symptoms.