A by-product of the body’s cells natural respiration – i.e. chemical reactions within body cells which exchange oxygen for energy. Highly reactive free radical substances are then formed which circulate around the body, and there is a theory that these build up as we age and that they are involved in the ageing process. Anti-oxidant free radical scavengers are sometimes useful to ‘mop up’ (eliminate) free radial accumulation in the body. Some specific vitamins can assist to slow down or mop up free radicals in the body, but they will not stop the ageing process. Avoiding cigarettes, pollution, limiting alcohol consumption and fresh food diets are important lifestyle factors which help to limit free radical accumulation and damage.