Antioxidants have become a popular buzzword and depending who you listen to these compounds are credited with everything from curing cancer to reversing the body clock as well as other more outlandish claims.
So what are antioxidants? And in what ways (if any) can they help the human body to heal or strengthen itself?
The theory of how antioxidants work is not hard to understand. However, as we will see their efficacy, especially in the form of dietary supplements is still somewhat controversial.
The human body metabolizes oxygen in order to produce energy and free radicals are a natural by-product of this metabolic process. Free radicals are atoms or groups of atoms with unpaired or unbalanced electrons. These volatile particles steal electrons from cells and other molecules within the body and may cause cell damage in the process. This cell damage manifests itself as aging and disease.
It is quite normal to have free radicals in the body. However, excessive quantities have the potential to do significant harm. Exposure to excessive sunlight, smoking, pollution, alcohol and radiation are all known to exacerbate the effects of free radicals and lead to premature aging and/or serious illness.
Free radical damage has far reaching consequences and is implicated in:
Speeding up the aging process.
Cardiovascular disease including arteriosclerosis (hardening of the arteries) - Free radicals react with Low Density Lipoprotein (LDL) cholesterol causing it to stick to the walls of arteries. LDL or bad cholesterol is a major contributor to Coronary Heart Disease.
Failing eyesight caused by deterioration in the lenses of the eyes.
Diseases such as Parkinson’s and Dementia resulting from breakdown in cells of the nervous system
Certain cancers which are related to changes in cell DNA
Arthritis caused by joint inflammation
Antioxidants are compounds that mop up free radicals and neutralize their impact on cells. Antioxidants are present naturally in the food we eat in varying degrees. Some of the most commonly known antioxidants are Vitamin C, Vitamin E, the mineral Selenium and Beta-carotene which is a precursor of Vitamin A.
There are however countless other compounds which function as antioxidants. Some such as lycopene and anthocyanins are classified as non-nutrient antioxidants which provide little or no nutritional value but are still valuable for their antioxidant properties.
Tests with animals have shown a clear link between antioxidant use and reduction in the incidence of disease. The connection in humans is not quite as clear cut. There is anecdotal evidence that men who eat large quantities of tomatoes which are rich in lycopene have a lower rate of prostate cancer while consumption of tea (high in flavenoids) is hypothesized to be the reason for lower heart disease among Japanese.
However, results of recent clinical studies have been inconsistent and inconclusive. One of the first large studies on antioxidants and cancer found a sharp reduction in gastric and other cancers among Chinese men and women at risk of gastric cancer when treated with a combination of Selenium, Vitamin E and beta carotene.
On the other hand a 1994 study on male Finnish smokers found that beta-carotene significantly increased incidence of lung cancer while vitamin E supplements had no impact. Similarly a 1999 study on cancer and cardiovascular disease among women found no benefit from beta carotene supplements.
The lack of conclusive results from the supplementation studies seems to suggest that antioxidants may be most effective when derived from a healthy and balanced diet rather than in the form of supplements.