Antioxidants occur naturally in plant-based foods such as fruits, vegetables, coffee, tea, wine, and chocolate. There are thousands of antioxidant compounds. The most common are flavanols (found in chocolate), resveratrol (found in wine), and lycopene (found in tomatoes). Other antioxidants include vitamins A (beta-carotene), C, E, and catechins. However, you probably aren't getting enough.
Antioxidants help prevent or stop cell damage caused by oxidants. “Oxidants are free radicals that you find in the environment, but they're also produced naturally in your body,” says Diane McKay, Ph.D., an assistant professor and researcher at Tufts University’s Antioxidants Research Laboratory.
Your body creates them to help fend off viruses and microbes. You also get hit with oxidants daily from things like air pollution, cigarette smoke, and alcohol.