Antioxidants play vital roles in relation to DNA damage and repair. ROS can cause oxidative damage to DNA by attacking its bases and sugar-phosphate backbone. Antioxidants are substances that counteract the harmful effects of free radicals by interacting with them and neutralizing their damaging properties. They are also known as “free radical scavengers”. Cells utilize antioxidant enzymes to remove ROS before they can harm DNA. Antioxidant enzymes protect the roughly 3 billion nucleotides in DNA from harmful mutations.