The Institute for Optimum Nutrition

RADICAL MEASURES: Exploring the benefits of antioxidants
by Kerry Torrens BSc (Hons) DipION Nutritional therapist and health writer

As cold and flu viruses abound, many of us choose to enhance our immune defences by increasing our intake of protective nutrients. A diet high in antioxidants, most notably from fruits and vegetables, has been associated
with a reduced incidence of cardiovascular disease and cancer, and is widely touted as the sure-fire way to delay the signs of premature ageing. Despite this, a number of studies suggest an excess of such nutrients can actually be detrimental to health. So how can we be sure we’re doing the right thing?

FREE-RADICAL PRODUCTION

Oxygen is, of course, essential for life, being a critical element in the production of energy. However, what is, on the one hand vital, also has the potential to cause harm and may, some believe, play an instrumental role in
cell damage and dysfunction. Many essential reactions, including the production of energy inside the mitochondria of every cell and the cytochrome P450 detoxification process, lead to the formation of highly reactive oxygen-containing molecules with one or more unpaired electrons. These reactive oxygen species are one of many forms of ’free radical’. Their instability, due to their unpaired electrons, has a direct potential to
damage cells and tissues as they try to balance their electrons by reacting with double-bonds in olyunsaturated fatty acids in cell membranes, nucleotides in DNA or sulphydryl bonds in proteins.

In order to manage this process, we have evolved certain mechanisms that include enzymes and molecules with an antioxidant capability that helps prevent or slow this damage. They do this by giving up their own electron(s) and thus inactivating free radicals and halting the damaging chain reaction that is oxidation. As well as our endogenous (from within) production of free radicals, our bodies also encounter exogenous (external) sources such as tobacco smoke, air pollutants, by-products from solvents, drugs and pesticides as well as exposure to radiation. Antioxidants not only act as a defence mechanism in the body, but are widely utilised throughout the food and supplement industry to extend shelf life and enhance aesthetic appeal.