While attending training camp in the summer of 2012, NFL star Adrian Peterson was taken down so hard that he had to call his athletic trainer for help. But it wasn’t a 300-pound linebacker that almost took out the then 27-year-old, it was a bowl of seafood gumbo. Peterson has a shellfish allergy that he did not know about at the time, according to U.S. News.

“I had a couple bowls of seafood gumbo at lunch that day, and 30 minutes after eating I went back to my room to rest up for afternoon practice,” Peterson told U.S. News. “At the time, I didn't necessarily know what I was experiencing, but my throat and eyes were very itchy. I remember lying there and rubbing my eyes — just rubbing and rubbing. So I got up and looked in the mirror and everything was swollen.”

Peterson then called his athletic trainer who had an EpiPen on-hand and was able to inject him with epinephrine, which slowly reversed his symptoms. Peterson was immediately rushed to the hospital where testing found that he’s allergic to shrimp, scallops, and lobster. What he was experiencing was anaphylaxis, a severe allergic reaction that typically occurs within minutes of exposure to something you’re allergic to. According to the Mayo Clinic, symptoms of anaphylaxis include a swollen tongue or throat, nausea, itching, and dizziness. Most commonly, medications, foods, and insect stings cause anaphylactic reactions in those who are allergic to them. Epinephrine, which reversed Peterson’s symptoms, is usually the most effective treatment in reducing the body’s allergic response.

As for Peterson, he is now the face of an anaphylaxis preparedness campaign. He says that he carries his epinephrine autoinjectors with him everywhere. The NFL’s 2012 MVP says he wants to raise awareness because at 27, he didn’t believe he was at risk. Now, he realizes that there are a lot of unsuspecting people who need to be conscious of the sometimes subtle symptoms.

“My favorite food was seafood, and that's all I used to eat,” he said. “And then there I was, 27 years old, and bam, I have this allergic reaction — and it's life-threatening. So it's very important to spread the word and spread awareness so people can be better prepared in case anaphylaxis occurs in their life. Having this platform I have, a lot of adults respect me and a lot of kids look up to me. And you know, who better to help spread the word to America?”

And while Peterson has taken on the role of advocate, there are plenty of other celebs who cope with severe food allergies. Here are five that you may not have known about:

1. Clay Aiken is allergic to coffee, mints, chocolate, almonds, cashews, walnuts, and pistachios.

2. Serena Williams is allergic to peanuts, which is the most common food allergen among children.

3. Martha Stewart is allergic to lobster.

4. Drew Barrymore is allergic to garlic, coffee, bee stings, and perfume.

5. Jessica Simpson is allergic to cheese, wheat, tomatoes, hot peppers, coffee, corn, and chocolate.