Antioxidants neutralize free radicals and that helps us fight inflammation and disease. However, stimulation from free radicals also extends life by activating cellular repair genes! Antioxidants inhibit this response. Some antioxidants, such as beta carotene and retinol can actually shorten life in certain settings. A retrospective review of 68 studies showed that there was an increase in the rate of early death by 5%.
When free radical stress is increased in round worms their life expectancy up to nearly 60%. When these worms were fed antioxidants to neutralize these free radicals that increase in life expectancy disappeared. The amount of oxidative damage caused by the increased levels of free radicals had no bearing on how long they lived. An article in PLoS Biology in 2010 when worms were bred to overproduce superoxide free radicals, they did not develop high levels of oxidative damage and on the average lived 32% longer. Vitamin C prevented this increase in life span.
Is it a good idea to take antioxidants? The answer to this question lies in the situation. Antioxidants can be lifesaving by quenching free radicals, but they do not extend life, and they may shorten it...smile... Mother Nature is a bit too complex for our simple minds!