Are free radicals really “bad”?
The natural process of cellular respiration generates free radicals that are naturally regulated by the production of antioxidants in our body. Necessary for our body, they can however be harmful to it when they are produced in too large quantities, thus generating a disruption of the physiological balance. This imbalance is called oxidative stress : it is considered the major cause of cellular aging and the diseases associated with it. ( Oxidative stress in image: see the infographic )
Anne-Marie Roussel, Professor Emeritus of Metabolic and Nutritional Biochemistry at the University of Grenoble Alpes, wishes to qualify this approach and rehabilitate them:
"Free radicals are oxidative species produced during cellular respiration. Their uncontrolled production generates oxidative stress. Free radicals aren't the bad oxidants, while antioxidants are said to be the good guys. It is not a question of destroying all the free radicals. They are necessary for metabolism and certain functions. For example, they are essential for phagocytosis and antibacterial defense. However, produced in too large quantities, they lead to a disruption of the necessary physiological balance between their production and their “detoxification” by antioxidants."