The body can handle significant changes but balance is the key. If the number of free radicals is too great, the body is overwhelmed. Now the scavenging increases and the body can't cope. Anti-oxidants Rust is nothing but oxidation, the effect of free radicals of oxygen. Anti-oxidants are good.
Free radicals are bad.
It picks up free radicals and makes them inoperable. An advantage of chelation is that it operates on a molecular level. If the body's arteries are diseased, they are diseased down to the smallest vessels. Surgery and angioplasty cannot reach the very smallest. But a chelation molecule can.