Cortisol is released during acute stress to cause a fight or flight response. Cortisol released during stressful situations, affects the immune system by preventing the production of inflammatory mediators. This in turn weakens immune responses against infections (think catching a cold during university exam times). cortisol is also released during exercise and mild exercise can be beneficial with an anti-inflammatory effect. However for professional athletes intense training weakens their immunity making them more susceptible to seasonal infections.
if DEFENSIN LEVELS ARE LOW is INDICATive of a WEAKER immune DEFENCE ability. DEFENSIN IS A NATURAL MUCOSA ANTIBIOTIC WITH ANTI-MICROBIAL EFFECT, IT IS AN IMPORTANT COMPONENT OF THE FIRST DEFENCE LINE AGAINST PATHOGENS. STRESS & AGEING CAN DECREASE DEFENSIN LEVELS leading to a compromised first line of defence.
High levels of IgA antibodies are indicative of a protective intervention by the innate immune system during intestinal damage such as intestinal permeability episodes, food intolerance and elevated microbial lipopolysaccharide (LPS). While low levels of intestinal IgA antibodies is a sign of stress that weakens immunity. Low levels of IgA are prevalent in high pressure jobs, depression and in elite athletes during intensive training.