Pamela A. Popper, Ph.D., N.D.

Wellness Forum Health

 In 2009, I reported the results of a study showing that antioxidant supplements are more harmful than helpful for athletes. Not surprisingly, advocates for supplements thought that the study’s conclusions were wrong. But a new analysis performed by one of the researchers involved in the 2009 study shows that the findings were correct.  Antioxidant supplements are not beneficial for athletes.

Dr. Troy Merry and Dr. Michael Ristow reviewed studies that looked at the effect of supplements on reactive oxygen species (ROS) and reactive nitrogen species (NOS). They reported that taking antioxidant supplements such as vitamin C can impede the normal skeletal muscle adaptation process, which is the opposite of the claims that are made about the supplements – that they reduce ROS levels from exercise. They say that while antioxidant supplements can be beneficial for recovery, repairing muscles, and reducing fatigue, these benefits are offset by the negative effects of the supplements on insulin sensitivity, angiogenesis, cellular defenses, and mitochondrial function. This is particularly true for resistance and high-intensity exercise, according to the authors.

In other words, supplements are much like drugs. While there are some benefits for some, there are always side effects. The supplements to be most concerned about are the ones the “work” since we know that it is impossible to manipulate one function in the body without causing changes in others.

The authors state that exercise itself has the same effect on physiology as antioxidants, since exercise regulates the natural antioxidant defense mechanism, and this effect is “likely to be one of the mechanisms underlying the health-promoting benefits of regular exercise,” they said.  By contrast, the authors say that research shows that antioxidant supplements do not decrease the incidence of disease in humans and have been shown in some studies to increase risk.

In conclusion the authors stated that “Antioxidant supplementation has been more consistently reported to have deleterious effects on the response to overload stress and high intensity training … Importantly there is no convincing evidence to suggest that antioxidant supplementation enhances exercise-training adaptations.”

Merry T, Ristow M. “Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training?” J Physiol 2015 Dec 7 doi: 10.1113/JP270654. [Epub ahead of print]

Ristow M. “Unraveling the Truth About Antioxidants: Mithormesis explains ROS-induced health benefits.”  Nature Medicine 2014;20:709-711