For more than 40 years, the prevailing explanation of why we get old has been tied to what is called oxidative stress. This theory postulates that when molecules like free radicals, oxygen ions and peroxides build up in cells, they overwhelm the cells’ ability to repair the damage they cause, and the cells age.

An industry of “alternative” antioxidant therapies -- such as Vitamin E or CoQ10 supplements in megadose format --has sprung up as the result of this theory. However, clinical trials have not shown that these treatments have statistically significant effects.