Without calcium, the changes in the antioxidant system of D. thapsi were observed.

"We've found from studies in rats that if you load the animals up on vitamin E, other antioxidant systems shut down," says Cutler.

He thinks the only people likely to benefit from vitamin supplements are those whose inherent antioxidant systems are sluggish or defective.

In general, antioxidant systems either prevent these reactive species from being formed, or remove them before they can damage vital components of the cell.

Thus, the function of antioxidant systems is not to remove oxidants entirely, but instead to keep them at an optimum level.

The action of one antioxidant may therefore depend on the proper function of other members of the antioxidant system.

Indeed, a 2009 review of experiments in mice concluded that almost all manipulations of antioxidant systems had no effect on aging.

Animals are exposed to the same oxidants, and they have evolved endogenous enzymatic antioxidant systems.

Metabolic imbalances associated with temperature extremes result in the build-up of reactive oxygen species, which can be countered by antioxidant systems.

Lack of either nutrient, which in these cases may be substantial, leaves the body's antioxidant system unable to put out the fires of inflammation.