Why do we need antioxidants? The biochemistry
When we use oxygen in normal biochemical processes in our body cells, substances called 'free radicals' are produced as by products. These free radicals are very reactive and we need and can deal with a certain amount to function normally, but in excess free radicals can oxidise (damage) other molecules such as DNA, proteins, carbohydrates and lipids (fats) causing so-called 'oxidative damage'.
Free radicals are an unavoidable consequence of depending on oxygen for life and free radicals are normal by-products of our metabolism. Green plants produce antioxidants because they are exposed to oxidative damage from the pure oxygen they make during photosynthesis and this explains why these plants have a range of these substances for their protection against oxidative damage. Free radicals are also produced by external factors such as x-rays, sunlight (ultra-violet radiation), stress, alcohol and pollution that can arise from the environment or from smoking tobacco.
Most plant species contain a wide variety of antioxidants that have evolved as a consequence of dealing with oxidative damage. Also individual species have developed relatively unique antioxidants such as cranberries. When considering the health effects of antioxidants in humans, it seems unlikely that simple dietary supplementation with pure chemical forms of individual antioxidants will be as effective as the consumption of a wide range of plants that provide a wide range of antioxidants. This view has been adopted by scientific consensus.
It is thought that when we eat plants that contain antioxidants these substances can help minimise the oxidative damage to our body cells by absorbing or scavenging excess free radicals.
Why do we need antioxidants? The health effects
In the 1950's scientists discovered that heart disease, strokes, cancer, diabetes, cataracts, arthritis, Parkinson's and Alzheimer's diseases were linked to oxidative damage. It is known from epidemiological studies that people who eat adequate amounts of fruits and vegetables high in antioxidants have a lower incidence of cardiovascular disease, certain cancers and cataracts. Recent research shows the risk of cancer and heart disease is considerably lower in people who eat between 5 and 7 servings of antioxidant-rich fruit and vegetables per day. In addition to diet however, these effects could be enhanced by a generally healthier lifestyle adopted by these individuals.
It appears that the consumption of a balanced diet, with an emphasis on a variety of antioxidant-rich fruits and vegetables together with whole grains and the avoidance of saturated fats, linked to an active lifestyle will help maintain your health.
