Antioxidants are compounds that inhibit oxidation, protecting cells by neutralising free radicals. Vitamins such as vitamin C are antioxidants. They also serve as important food additives for preservation.

A free radical can be defined as any molecular species capable of independent existence that contains an unpaired electron in an atomic orbital*.

  • Given their high reactivity, free radicals can damage important chemical structures such as proteins, DNA, lipids, etc. When your DNA is damaged and fails to be repaired, that can potentially lead to cancer.
  • Free radicals have some utility in the body, such as in fighting pathogens, so a balance between free radicals and antioxidants exist.
  • Oxidative stress is when the amount of free radicals exceeds the amount of antioxidants. This disequilibrium, when prolonged, is linked to serious health risks for cancer and other diseases. Increasing antioxidants by too much is similarly damaging.

One prominent theory in medicine is that aging is really just the result of the cellular damage caused by free radicals. Antioxidants, therefore, can slow down this process.

Which foods are rich in antioxidants? From Dr. Michael Greger’s observations:

Here’s the simple rule: On average, plant foods contain 64 times more antioxidants than animal foods. As the researchers put it, “Antioxidant rich foods originate from the plant kingdom while meat, fish and other foods from the animal kingdom are low in antioxidants.”