(1) The balance between beneficial effects and damage induced by free radicals is particularly fragile. To stabilise the balance, the body can rely on both an internal defence system and external sources of antioxidants.
(2) The first molecules involved in this fight, primary antioxidants, are enzymes naturally produced by the body.
Three primary antioxidant enzymes, Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione peroxidase (GPx), control the first stages of oxidative stress and keep the anti-/pro-oxidant balance in equilibrium, even before its initiation.
Capable of catalysing millions of reactions without becoming depleted, they provide continuous and lasting antioxidant protection.
(3) Exclusively provided by food, secondary antioxidants (vitamins, minerals, polyphenols, etc.) act much later. They give up electrons to unstable free radicals and neutralise them, but run out quickly, without the possibility of renewal.