For decades, health-conscious people have been popping multi-vitamin tablets to stay healthy and prevent their body from rusting. But it may not be such a good idea, scientists now say, as the pills may actually make you prone to diabetes. In a major blow to the multi-billion dollar vitamin industry, researchers in Australia have gathered enough scientific evidence to show that synthetic antioxidants contained in multi-vitamin pills stunt the bodys ability to release insulin, an important hormone required to maintain healthy blood glucose levels.
Antioxidants, which are primarily multi-vitamin supplements, help the body maintain good health and vitality by mopping up what scientists call reactive oxygen species or ROS, a natural by-product of metabolism. Extremely reactive, the latter are capable of damaging cell structures and DNA, if not continuously removed from the system. Normally, a healthy body is capable of scavenging these harmful compounds on its own. But when one is chronically ill, this ability is severely compromised, thus creating a need for an external supply of antioxidants.
Whether antioxidants really help depends on the users state of health, says Tony Tiganis, associate professor of biochemistry and molecular biology at the Cellular Signalling and Human Disease Laboratory, Monash University, Australia, and leader of the study team.
The study, which appeared in the latest issue of the journal Cell Metabolism, suggests that mopping up the entire quantity of ROS from the body is not a good idea. That is because a low level of ROS can promote insulin response and attenuate insulin resistance in the early stages of type 2 diabetes. Insulin response can be best described as the bodys ability to release insulin — which removes sugar (or glucose) from blood, storing it away in muscles and fat cells.
This is the first ever study to show that ROS can promote insulin sensitivity in vivo to prevent the development of insulin resistance, Tiganis told KnowHow.
Experimenting with laboratory mice, Tiganis and his colleagues showed that the animals which lacked the ability to eliminate normal levels of ROS do not become insulin resistant even when put on a high-fat diet as they otherwise would have. These health benefits could be attributed to the increased release of insulin and uptake of ROS in their muscles, say the researchers.
It is a pathbreaking study, the conclusions of which go against the prevailing scientific opinion that increase in oxidation (release of ROS) inhibits insulin action and predisposes one to diabetes, says Anoop Misra, internal medicine specialist at Fortis Hospital, New Delhi.
However, one must be careful in embracing the findings, cautions Misra. The authors themselves say that only a subtle increase (and not gross) in oxidation can enhance sensitivity to insulin and that too in the early phase of the onset of diabetes.
In practical terms, the general use of antioxidants (which are available in India in a wide variety, as vitamins and strength giving and anti-ageing pills) is best avoided, he observes.
It is not for the first time that the growing multi-vitamin industry is getting a bad press. Early last year, a study by Danish researchers — which appeared in the Journal of American Medical Association — showed that certain antioxidants could cut short the lifespan of an individual.
The study, which was an analysis of 67 random studies covering 2,00,000 people on antioxidant supplements, showed that some supplements — including vitamin A, beta-carotene and vitamin E — were capable of increasing mortality. Yet another suggested that an overdose of antioxidants could make men vulnerable to prostrate cancer.
In May this year, a team of researchers from Germany and the US showed that vitamin supplements could negate the health-promoting benefits of physical exercise. Published in the Proceedings of National Academy of Sciences, the study said supplements might lower the activity of several genes that are responsible for the bodys natural ROS scavenging mechanism.
Tiganis and other scientists, however, argue that they are not totally against intake of antioxidants. The body requires them and there are several natural sources of antioxidants such as fruits and vegetables. There is a delicate balance; too much of a good thing… might be bad, he says.
I think healthy individuals should not take antioxidant supplements, but exercise and follow a healthy diet. It is possible that antioxidants may improve insulin sensitivity in obese diabetics, he observes.
As a next step, the scientists are planning to work out at what stage ROS change from being beneficial to harmful.
So think again before you pop those pills in the morning.