Although oxidative stress occurs throughout life, it worsens as we age. It is hypothesized that as we become older normal defense mechanisms preventing oxidation decline, making it more difficult to fight off age related deterioration in physical and mental function. The main source of oxidant formation is believed to be generated by the mitochondria , the part of the cell responsible for energy production. The mitochondria produces energy through a process known as oxidative phosphorylation , and during this process highly reactive oxygen radicals are generated which can subsequently attack cells in our body. Free radicals, also known as reactive oxygen species , are only a minor by-product of cell respiration, but damage to DNA occurring over time can lead to increased free radical production and possibly more mitochondrial DNA mutations.
Oxidative stress can also cause damage to lipids and proteins.
Recent research has shown that long-term caloric restriction promotes longevity and chronic overeating and obesity results in a condition that mimics the aging process, which explains the higher prevalence of inflammation, free radicals, and metabolic diseases in overweight individuals. Recent research on exercise, diet and antioxidant supplementation indicates that such interventions will reduce body weight, oxidative stress, the production of free radicals and resulting inflammation, leaving us thinner and healthier. The role of free radicals and inflammation in oxidative stress. Antioxidant defenses against oxidative stress. Methods of reducing oxidative stress.