Antioxidants and arnica

Introductory comments

Until recently we have considered free oxygen radical production in the body to be a solely “negative” occurrence that might be countered by supplementation with antioxidant nutrients. The supposed benefits included improved health and mortality, and for athletes, the extra advantages of enhanced performance through a reduction in exercise-induced damage. In fact, as discussed below, The Cochrane Review1 found little or no difference in the normal population between antioxidant administration and those taking a placebo. Mortality was, in fact, slightly higher in the antioxidant group. The following review focuses on antioxidant supplementation in athletes and includes the possibility that some oxidative species play a positive role in the adaptation to exercise. In addition to this topic, there is a brief but comprehensive review on arnica.

Antioxidants

S K Powers4, A N Kavazis4, W B Nelson44Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA

It is well established that physical exercise results in increased free-radical production in active skeletal muscles. Importantly, numerous reports indicate that exercise-induced free-radical production is responsible for oxidative damage to cells and contributes to muscular fatigue during prolonged exercise.5 The fact that working skeletal muscles produce radicals has motivated many athletes to begin using antioxidant supplements in hopes of preventing exercise-induced free-radical damage and/or muscular fatigue. However, whether or not antioxidant supplements are helpful or harmful to the athlete remains a highly debated topic. The purpose of this brief review is to summarise the arguments for and against antioxidant supplementation in athletes and other physically active individuals. The review begins with an overview of key terms related to free-radical biology and antioxidants.

Free-radical biology and antioxidants: key terms

Free radicals (hereafter referred to as radicals) are molecules or any chemical species that contain one or more unpaired electrons in their outer orbital.3 In cells, radicals can be formed by either losing a single electron or gaining an electron.3 An unpaired electron results in molecular instability, and therefore …