Antioxidants are substances capable of counteracting the damaging effects of oxidisation in our body tissue. Oxidisation is a normal physiological process, it causes the production of free radicals (harmful molecules), the effects of which are combatted by our bodies antioxidant defence systems. These systems aren't 100% effective so it's impossible to avoid the damage caused by free radicals but we can do a lot to minimise it.
Here are some examples of sources of free radicals inside and outside the body:
Oxidants sources from inside the body:
- aerobic respiration
Oxidant sources from environmental factors:
- strenuous exercise
Oxidative stress occurs when the production of free radicals is greater than our bodies protective antioxidant defences can deal with (see our article on what are free radicals for more details) - we can help our natural defence systems by not smoking and moderating alcohol intake for example and boost them by eating good food sources which are high in vitamins and minerals. We can also take supplements to help maintain antioxidant levels. Smokers, drinkers and heavy exercisers will need more antioxidants than other people as their bodies will be put under higher oxidant stress than others so a supplement for these groups of people may be more necessary.