What causes oxidative stress?

Our bodies naturally produce a range of chemical products called free radicals as a consequence of typical metabolic processes.

To deal with these reactive species, our bodies also produce enzymes with antioxidant properties, like superoxide dismutase.

But our environment can also be a source of free radicals. Absorbing pollutants, including cigarette smoke and toxic metals, can overwhelm our bodies' home-grown defenses and increase oxidative damage.