Do antioxidants promote longevity?

It is a fact taken for granted that free radicals promote aging and that antioxidants by neutralizing them are a factor in longevity. However, a recent study shows just the opposite, so who to believe?

Short answer

Free radicals, to a limited extent, are useful to the body. In fact they are the result of a defense of cells against the damage they suffered during exercises, themselve good for health.
The body needs antioxidants, they are used to control excessive production of free radicals that accelerate aging, promote cancer and Alzheimer's disease. But food supplement merely disrupt metabolism.
It is found that people who live longer have a diet rich in natural antioxidants.

Long answer

Antioxidants prevent the oxidation of molecules in the body. The loss of electrons in molecules that are transmitted to others and cause a chain reaction causing havoc in cells.
Antioxidants by absorbing free radicals halt these reactions. Therefore they are considered as beneficial and there are even in store food supplement intended to provide antioxidants ... that we can found in fact in sufficient quantities in a balanced diet.

The study to which it is referred was published in PLoS Biology, was led by McGill University in Montreal. It shows on worms that the increase in free radicals with adequate food leads to increased longevity and, conversely, when they did absorb antioxidants, their lifespan is reduced.

But the author of the study, Siegfried Hekimi, did not draw any hasty conclusion. He said it is possible that the correlation between age and free radicals come from that older cells produce more free radicals.
In other words, the activity of the body (physical exercise in humans) tends to destroy the cells and they defend themselves by a reaction of oxidative stress, free radical production. But the exercise is good for the body.

And when antioxidants are administered, they disturb the reaction and affect the metabolism, something that studies on dietary supplements had also demonstrated.

However, a study conducted on worms, made to observe the behavior of mitochondria, is useful to observe it, but the animal's minimalist nervous system is very far from to provide a reference for human consumption.
It is known that excess free radicals promote cancer and Alzheimer's, which do not affect the worms.

A diet low in meat and fat, rich in vitamins and minerals playing the role of antioxidants among others, as practiced in Okinawa and Japan in general, promotes longevity. Natural antioxidants in foods such as vitamin C, E, selenium etc.. hold multiple roles in the metabolism, the antioxidant virtu is probably accessory.