One is that an appropriate amount of free radicals is necessary to maintain human health, because free radicals are part of the body's immune system and can kill pathogenic bacteria. Between free radicals and antioxidants, the body maintains a balance so that free radicals can perform beneficial physiological functions without harm. Ingesting a large amount of antioxidants will actually inhibit the body's own antioxidant capacity.
The second is that the correct way to add antioxidants is to make a reasonable diet and eat more fresh fruits and vegetables. The main source of substances with antioxidant properties is various plants. If the diet is not balanced, or some of the essential antioxidants (such as vitamin C, vitamin E, etc.) are obviously inadequate due to illness, you should follow the doctor's recommendation to take an appropriate amount.
The third is to stay away from smoking and UV damage, and avoid lethal free radicals (smoking, strong UV, etc.).