What is Redox and Oxidative Stress?

The technical answer:

"Redox" is a scientific term that describes chemical reactions that involve the addition or reduction of electrons to molecules, thus altering oxidation numbers or "oxidation states".  Redox is shorthand for the reduction/oxidation reaction involved.  Disturbances in this normal redox state in the body can cause toxic effects due to the production of peroxides (yes, the same stuff in your medicine cabinet!) and free radicals that inflict molecular damage to proteins, DNA, and lipid membranes, in a process called "oxidative stress."

The real-world answer:

The process by which our cells extract energy from food involves chemical reactions that leave some molecules missing an electron, making them unstable and very reactive.  This unstable molecule is called a free radical.  In the free radical's effort to restore its natural energy balance it will “steal” an electron from the first available source.  In the absence of adequate anti-oxidants, the free radical will steal an electron from healthy tissue such as DNA, your cellular membranes, or a host of other tissues you would prefer left intact.

Also, oxygen itself is an exceedingly reactive element when unbound, and is capable of forming various dangerous free radicals.

The bottom line:

Cellular redox balance is maintained by varous complex chemical and enzymatic antioxidant defenses to free radicals.  When the body's redox balance is lost, harmful oxidative stress is caused.  Minimizing oxidative stress means minimizing cell degeneration and cellular aging.