Oxidative stress happens with every breath we take - when we breath we take in oxygen which creates free radicals - these are highly reactive molecules containing oxygen. As the oxygen molecules move around our bodies the free radicals react with other molecules (to try and stabilise themselves) and cause oxidative stress.
Oxidative stress becomes a problem when it overwhelms the body
Our bodies actually need free radicals - they're not always harmful in their own right. In fact, free radicals help to fight infections in the body so are necessary to our survival. Oxidative stress in our bodies occurs when our ability to neutralise the harmful effects of free radicals with antioxidants becomes imbalanced. Our bodies are always under 'attack' from free radicals but these are counteracted and detoxified by antioxidants, when this happens they are not harmful. Oxidative stress happens when the free radicals overwhelm the body's antioxidant defence system.
Have you ever cut open an apple and seen it go brown?
The majority of us have probably cut open or bitten into an apple, got distracted and not eaten it straight away. After just minutes we see it start to turn brown - have you ever asked yourself why? The answer is that it has oxidised after being exposed to oxygen in the air, this has caused a rapid increase in it's ageing process and it has started to rot very quickly. Another example of oxidation is when iron rusts.
In light of this consider what oxidative stress does to the the body - and therefore why excess oxidative stress is believed to cause us to age prematurely.
Environmental influences play a significant role
The number of free radicals in the body never remains stable. Influences such as stress, strenuous exercise, smoking, sunlight and even prescription medicines significantly increase the number of free radicals produced in the body. In modern times it is argued that the effects of oxidative stress has never been greater as we live in increasingly polluted environments, live stressful lifestyles and medicines/prescription drugs are widely used.
The use of antioxidant supplements or a diet high in antioxidants i.e. fruits and vegetables is widely believed to combat the effects of oxidative stress damage to the body by neutralising the free radicals.
Oxidative stress and disease/illness
The effect on oxidative stress on the body is believed to be a factor in many chronic and degenerative diseases and illnesses as it damages DNA, lipids, and proteins in the body.
There is no clinical evidence to prove that antioxidants can cure or prevent any disease or certainly ageing but they are widely believed to support our overall health.