Our bodies are battlegrounds against infection and diseases. Normal body functions, such as breathing or physical activity, and other lifestyle habits (such as smoking) produce substances called free radicals that attack healthy cells. When these healthy cells are weakened, they are more susceptible to cardiovascular disease and certain types of cancers. Antioxidants — such as vitamins C and E and carotenoids, which include beta-carotene, lycopene and lutein — help protect healthy cells from damage caused by free radicals.