Free radicals are unstable molecules that have unpaired electrons, making them highly reactive. They can be formed naturally in the body during processes like metabolism or can be introduced through external sources such as pollution, radiation, and cigarette smoke. Because of their reactivity, free radicals can damage cells, proteins, and DNA, potentially leading to various health issues. Antioxidants are substances that can neutralize free radicals, helping to protect the body from their harmful effects. Foods rich in vitamins C and E, as well as minerals like selenium, are known to contain antioxidants. A balanced diet can help maintain a healthy level of free radicals and antioxidants in the body.