In the cytoplasm of the 60 trillion cells in your body, there are in each cell hundreds of mitochondria, organelles that take the food you eat and the oxygen you breath and produce the energy your body must have (ATP).  Mitochondria have their own DNA distinct from nuclear DNA, and damage to mitochondrial DNA may be a major cause of aging.  As oxidative phosphorylation and glycolysis produce ATP, the mitochondria use an electron transport chain.  This process is imperfect and results in charged particles, atoms or molecules that have an unpaired electron in the outer ring.  These dangerous free radicals include reactive oxygen species, such as hydrogen peroxide, hydroxyl and superoxide, as well as reactive nitrogen species.  Because they are charged they are highly reactive and can damage lipids and cell membranes, proteins and enzymes and DNA.  The great majority of free radicals are generated in the mitochondria but there are many other processes that can generate them.

    To defuse these dangerous free radicals, the body has built in defense mechanisms, including endogenous anti-oxidants superoxide dismutase, catalase and glutathione.  In addition our diet is an important source of antioxidants to counter free radicals.  There are thousands of antioxidants, and fruits and vegetable are loaded with them (Diet: CRON).  Most of the time our endogenous and dietary antioxidants combined can control the free radicals and minimize any damage. 

    Oxidative stress, however, occurs when there is an imbalance between the body's production of free radicals and it's ability to detoxify them and repair the damage, and this contributes to many diseases.  Oxidative stress and inflammation are intimately related and each can contribute to the other.  Oxidative stress plays a key role in atherosclerosis, hypertension, stroke, diabetes and heart failure.  In Alzheimer's disease, oxidative stress is a major factor early, before the appearance of beta-amyloid plaques or neurofibrillary tangles.  Oxidative stress contributes to cancer and many other diseases.     Specific laboratory tests are available to assess your oxidative stress levels. 

Prevention

     Long-term regular exercise is protective by increasing your endogenous antioxidants and reducing oxidant production.  Diet is critical;  fruits and vegetables are loaded with many different antioxidants; a diet rich in a variety of fruits and vegetables should help reduce oxidative stress.  Caloric restriction reduces free radical production by decreasing the load on the mitochondrial energy production mechanism.  There are a very large number of antioxidant compounds available as supplements. 

    All diet changes, exercise and drugs and supplements have risks so please consult your health care provider before following any ideas from this website; no specific medical advice is given to any individual.