Antioxidants aren't a magic bullet. Far from.

To pick a popular one, too much beta-carotene will increase your chances of lung cancer. Even if you aren't a smoker- they don't know why, but there are several medium-sized clinical studies to support this. They are all reductants- they can do the as much damage in large quantities as the oxidizers the average person has their shorts in a bunch over.

There are a couple ways to die:
-by annoying people to the point they do something unsocial to you
-cardiovascular issues
-neural issues
-malnutrition/dehydration
-viral/bacterial/fungal infection
-cancer

If you can beat everything else, cancer is going to kill you. Don't worry, you'll be happier.