Medical literature is rife with articles on oxidative stress and the value of anti oxidants. Oxidative stress is being blamed for various lifestyle diseases such as thickening of arteries, high blood pressure, diabetes, cancer and heart diseases.
Basically, the oxygen-free radicals formed in this reaction attacks fats, proteins and DNA. This stress is fought by antioxidants, and when the oxygen-free radicals exceed the antioxidants in the system, the body suffers damage.
How can we ascertain if our bodies are undergoing oxidative stress? There are a number of markers -lipid hydroperoxides, 4 hydroxynonenal, 4 ubiquinol and a host of other tongue-twisters.
The object of this somewhat complicated preamble is to judge if use of vitamins and supplements can we really prevent this attack on the human body. I don’t think a clear-cut answer to this question exists, but it is worthwhile looking at the medical evidence at hand.
Alarge study in the American Journal of Epidemiology examines the contention that antioxidant vitamins taken orally boost the efforts of the body’s inbuilt antioxidant system. It is a landmark in the sense that it addresses the issue in 14,000 men and women and goes through 32 years of follow-up.
In a study like this, collection of data is difficult. The authors relied on questionnaires directly addressing the intake of vitamins A, C and E, the so-called antioxidant vitamins. Dosage for each was established and participants were asked to check the containers for printed information on the type of vitamins and dosage.
Dietary intake of these substances in the natural form is even more difficult to document. They were asked about 56 food groups and the frequency of their intake. This was then translated into estimated average dietary intakes of vitamins.
A summary of other factors affecting mortality was also taken into account, like smoking, alcohol and caffeine intake, exercise weight, history of high blood pressure, heart attack, stroke, diabetes and cancer. These factors can independently af fect mortality, and the study would hardly be valid without accounting for them, and making statistical adjustments.
Though the study did show that risk of death was decreased with the intake of dietary or supplemental antioxidants, it did not show any beneficial effects of such antioxidant intake when the factors stated above were taken into consideration.
Several other large studies in the UK, USA, Europe and Japan have, however, shown significantly lowered death rates with supplementation of vitamins A, C and E. In many, variables such as high blood pressure, heart disease, alcohol intake and smoking were not taken into consideration.
Arecent analysis has also suggested a small but definitive increase in death rate with vitamin supplementation, and the article’s authors did not find any justification to prescribe intake of vitamins A, C or E to increase longevity.
With evidence of antioxidant and vitamin use seesawing though several studies, a clear-cut recommendation is difficult to make. The answer given by most doctors is that it cannot hurt.
This may hold true for vitamin C, but not for fat-soluble vitamins like A. Side-effects of vitamin A intoxication are well-documented, including blurred vision, dizziness, increased pressure in the brain and hair loss.
In this city I still have to find a prescription written without some sort of supplementation, and despite the evidences, doctors still rely on their own experiences while prescribing such intake.