What are antioxidants?
Everyone knows that oxygen is necessary for life, but did you know that it can also produce harmful molecules called oxidants?
These can be produced by our bodies internally (as part of the process of oxidation, which leads to the production of chemicals called free radicals), as well as found in the atmosphere. In fact, levels have increased drastically over the years due to pollution, contributing to ill health and disease.
Antioxidants are natural compounds, found in certain foods, that can help to neutralise free radicals.
What are free radicals and how do antioxidants work?
The processes by which we take in nutrients and energy from food is complex. For the most part, with trillions of cells working synergistically in our bodies, things work as they should. However, like everything else, the human body can falter, especially as we grow older.
One biological process that is not yet fully understood, is the interaction between free radicals and antioxidants. The body uses oxygen as it breaks down food and creates energy for cells; oxidant generation is part of the normal metabolism of many types of cells. This process releases free radical particles that can damage DNA and cell structure.
In fact, free radicals are produced from many of the body's everyday stresses, such as inflammation, illness, poor diet, smoking and alcohol intake. There are also external sources, which (other than pollution, already mentioned above) include exercise and ultraviolet light.
Free radicals are unstable molecules that try to "steal" electrons from nearby molecules in an attempt to stabilise. This renders those molecules unstable themselves, which in turn causes them to seek out electrons from others - and so a vicious cycle is created whereby more and more free radicals are created.
Antioxidants are thought to be able to re-balance things, because they are stable with or without the extra electron. In this way, they can stop the cycle caused by free agents and help to prevent cellular damage.
Antioxidants are not created by our bodies, so they must be sourced from the diet on a regular basis, from antioxidant-rich foods and/or antioxidant supplements.
Antioxidants are found in abundance in natural whole foods, such as plants, fruits, grains, pulses, vegetables and even some animal products. They can take the form of vitamins, minerals, enzymes, carotenoids and polyphenols, among others, and tend to contain highly coloured natural pigments, which give them a bright appearance.
For example, food plants rich in anthocyanins - a type of antioxidant pigment - include blueberries, raspberries, black rice and black soybean. There's also the deep red of cherries and of tomatoes; the orange of carrots; the yellow of corn, mangos, and saffron; and the blue-purple of blackberries and grapes.
Some of nature's most potent vitamin antioxidants include:
- vitamin C, perhaps most notorious for being present in citrus fruits, but also found in other foods such as rosehips, blackcurrants, parsley and cherries.
- vitamin E, found in nuts and whole grains (oatmeal, rye and barley for example).
- vitamin A (including its precursor beta carotene), found in foods like carrots, liver and fish oils.