I grew up in an Italian family, which meant three things:

1. A lot of laughing.
2. A lot of swearing.
3. A lot of food.

All three were on display every Sunday, when our table overfloweth with conversation, mushroom risotto, roasted veal, homemade tiramisu, and onion soup.

That’s right, onion soup. In many Italian families, grandmother’s marinara is the cherished recipe, passed down from generation to generation. In mine, it was onion soup. It wasn’t even an Italian recipe, but my grandfather swore by it his entire life—for very good reason.

When he immigrated to America from Italy right after the turn of the century, my grandfather traveled by boat. It wasn’t exactly Royal Caribbean. He was on an old, rickety ship packed to capacity. There wasn’t enough food, water, fresh air, or room to move. During the journey, dozens of people got sick and many died. At the time, even getting a cold was such a matter of life and death that people started to respond with “God Bless You” whenever someone sneezed.

About halfway across the Atlantic, my grandfather got sick too. He was wheezing, shivering, and burning up all at once. He thought he was a goner.

Then he met one of the onboard chefs, a Frenchman who claimed to have a recipe that would cure my grandfather that day. And it was really simple: Chop a whole white onion, add some water and a dash of salt and pepper, stir in one chicken bouillon cube (a modern addition), and boil. After 15 minutes, throw in a finely chopped clove of garlic and simmer for a few hours. No cheese. No bread. Just plain old onion soup.

The chef gave my grandfather a bowl and told him to wrap himself in a few blankets and sit just outside the engine room, where it was crazy hot. The chef claimed he’d sweat out all the toxins. My grandfather obeyed and, sure enough, his fever disappeared within a few hours.

As a kid, whenever my sister and I were feeling under the weather, my grandfather would tell us this story. When we sneezed, we needed onion soup. When we scraped a knee, onion soup. When we didn’t sleep well, more soup for you. The answer was always onion soup.

At first, I didn’t really believe him. How could a soup made solely of onions and water have some magical power? But sure enough, whenever I felt like garbage, my mother would whip up a pot of grandfather’s famous onion soup. I’d wrap myself as tightly as possible in as many blankets as I could find and wait for the magic to happen. It always worked.

When you think about it, I shouldn’t have been surprised. For years, children have been slurping down chicken soup to fight the common cold. Studies suggest that chicken soup may have anti-inflammatory properties, and the aroma alone may help clear your sinuses.

In Japan, miso soup is a staple. Made from fermented soybeans and grain, miso is packed full of vitamins and is known for improving gut health, which is critical to your overall health and wellbeing.

In Mexico, families stir up pieces of fried tortilla in a soothing broth of onion, tomato, garlic, and chili powder. The heat from the chili powder serves as a natural decongestant, and the garlic can help reduce the length of your cold.

And onions? They’ve been considered a preventative medicine since the dawn of time. Even the Roman emperor Nero was known to eat onions by the handful to fight off colds.

To this day, I still make myself onion soup when I’m feeling under the weather. My grandfather taught me how to be in tune with my body from an early age. He’d always say, “If you listen, your body will tell you when it’s time to break out the soup before it’s too late.”

As for my family, well, they’re still skeptics. My wife claims that the only thing onion soup cures is a nice-smelling home. She won’t even come near me when I’m making it, but that’s probably for the best: I wouldn’t want her to get sick.