New research suggests taking vitamins after exercise may undo some of the beneficial effects of your workout.
Some advocate taking antioxidants like vitamin C and E to help protect your body from harmful chemical by-products it creates in breaking into a sweat. But some scientists now believe these “free radicals” may actually be good for you and even buffer against diabetes — which means that mopping them up with antioxidants may do more harm than good.
It is thought that antioxidant vitamins prevent oxidative stress damage to your body’s tissues by eliminating the free radicals that cause it. Oxidative stress has been implicated in several major diseases, including cancer and heart disease.
But a research team has claimed that free radicals may have a positive effect on your body by increasing its sensitivity to insulin, something that is lost in type 2 diabetes; this effect is blocked by antioxidant vitamins.
Reacting to the study, antioxidant expert Dr. Alexander Schauss said that the title of the study (Antioxidants prevent health-promoting effects of physical exercise in humans) was misleading. He said:
“The primary objective of this study was to study the effect of a 4-week intensive 5-days a week exercise program on insulin sensitivity. Yet the title of the paper leads one to believe otherwise.
This is a small gender-biased study of 40 male subjects, 25 to 35 years of age. When I read through the study for the first time I had to wonder, how could the authors have come up with such a title for their paper?”
In addition to questioning the study design, particularly with respect to both trained and untrained people being assigned to an intensive exercise program, Dr. Schauss also questioned the conclusions drawn from the data. Dr. Schauss said:
“Skeletal muscle biopsies were obtained from the right vastus lateralis muscle of study subjects. But some of the data is missing for a number of subjects, and reported as such by the authors.”
Dr. Schauss also noted that the authors presented no evidence of adverse effects by any of the individuals from vitamin C and E supplementation.
Proceedings of the National Academy of Sciences of the United States May 11, 2009