Oxidative Stress

Oxidative stress refers to the creation of an increased volume of reactive oxygen species (ROS) because of an inadequate presence of antioxidants.¹³ Also referred to as peroxides and free radicals, ROS cause damage to cells because their radical movement inside cells destroys them, producing “clinkers” (dead cells). The body inhibits ROS production through antioxidant vitamins and minerals. The minerals work to regulate enzyme activity so as to diminish ROS production, while vitamins accept ROS to remove them from the cellular environment, thereby limiting their potential hazards.

Early studies of vitamin E, a fat-soluble antioxidant vitamin found mainly in vegetable oils, initially showed promise in reducing ROS. However, there has been a recent concern that vitamin E supplementation, by itself, may place the pool of antioxidants out of balance, thereby diminishing the overall defenses humans have to prevent ROS. A proposed strategy to avoid this imbalance is to consume a cocktail of antioxidants rather than a single antioxidant vitamin. In doing so, the sensitive balance between the antioxidants can remain intact while there is an increase in antioxidant presence to provide an improved defense against ROS.

Nutrient imbalances can also cause difficulties with immune function. Excess vitamin E can negatively affect the immune system, but inadequate levels of this vitamin, iron, selenium, zinc, calcium, and magnesium can also create immune problems.¹⁴ All this information points to the importance of maintaining a balance of all the nutrients rather than pushing one or two with the hope of inducing a desirable biochemical effect.

Oxidative metabolic processes are constantly working, even during events that are primarily anaerobic. The anaerobic athlete who just completed a 10-second high-intensity sprint has something in common with a gymnast who just completed a 90-second floor routine: the need to breathe a large volume of air (oxygen) to recharge the fuels they will need for the next bout of high-intensity exercise. Iron is a primary element for transporting oxygen to working tissues and carbon dioxide away from working tissues-it is a critical nutrient for athletes. Nevertheless, iron is the most common nutrient deficiency, and athletes may be at even greater risk for iron deficiency than the general public because of the hemolysis and hematuria commonly experienced. Other nutrients are also important to ensure a healthy red blood cell production (vitamin B₁₂ and folate) and to ensure all the oxygen brought into the system will not be damaging (the antioxidant nutrients beta-carotene, selenium, vitamin C, and vitamin E).

Oxygen is sufficiently important for athletic performance that athletes of all sizes, sports, and ages should regularly check their iron status via a blood test that measures hemoglobin, hematocrit, and ferritin. Only with the information from such a test will athletes know if they should alter food intake or consume iron or other supplements to ensure that oxygen will not be a negative factor in performance.