Antioxidants are molecules that protect cells against damage caused by free radicals, unstable molecules that can cause disease and accelerate aging by damaging cells. They neutralize free radicals to prevent such damage. Antioxidants include vitamins (A, C, E), minerals (selenium, zinc) and plant compounds (carotenoids, flavonoids, phenols). They are found in various foods like fruits, vegetables, nuts and whole grains. Taking them may protect against heart disease, cancer, cataracts, macular degeneration, premature aging, and reduce oxidative stress-related damage while improving overall health.