|October 30, 2015||
Stress and Immune Function
Guest post courtesy content partners Labrix Clinical Services
Since the dawn of time humans have responded to pressure from the environment such as predation and natural disaster. The ability to withstand these stressors were dependent upon physiological responses that supported survival, such as the increase of oxygen and glucose to the heart and large skeletal muscles to enable the fight or flight response. Stressful situations such as fighting and fleeing carry with it the risk of injury and subsequent infection. Since fleeing usually interferes with proper wound care, stress-induced adaptive changes in the immune system took hold to accelerate wound repair and help prevent infection.
How does stress get “into the body” to affect the immune response? First, sympathetic fibers descend from the brain into both primary and secondary lymph tissue. These fibers release substances that bind to receptors on white blood cells. Second, the adrenal hormones epinephrine, norepinephrine and cortisol bind to specific receptors on white blood cells and have regulatory effects on their distribution and function. Finally, one’s efforts to manage the demands of stress often result in coping strategies that have a secondary negative effect on the immune system – such as alcohol use or changes in sleeping patterns. Thus behavior can be an important pathway linking stress with the immune system.
Fast forward to present day. Human stress responses still reflect the demands that shaped our physiology. Even threats that do not require a physical response (work, marital strife, school, social pressures, public speaking, etc) have physical consequences that affect the immune system. Many studies have been conducted that corroborate the effects of stress on immunity.
In 2004 a meta analysis was conducted on 293 independent studies from 1960-2001. Analysis confirmed that stress alters immune function. The most distinctive finding was that short term stress may enhance immune function as an adaptive response, but chronic stress suppresses immune response as a result of depletion of body resources. Some additional examples: impairments in the immune system including a decrease in immune cells and increased susceptibility to common cold have been reported during periods of stress; fewer T-cells, B-cells and natural killer cells (NK) are reported among individuals experiencing posttraumatic stress disorder; and there is an inverse relationship between natural killer cell activity and psychological distress and anxiety.
And while the detrimental effects of stress on immune function are well-documented, there is a growing body of evidence in support of lifestyle interventions that have an immune enhancing effect. Meditation, psychotherapy, mindfulness, cognitive behavioral therapy (CBT) and relaxation techniques have all been shown to maintain and support healthy immune function.
Want to stay healthy this winter? Check your cortisol levels! Optimizing adrenal health will enable your body to better manage stress, thus enhancing your natural immunity. Getting a baseline on your cortisol levels will force you to take stock of which aspects of your lifestyle are supporting your adrenal health, and which are threatening it.
- Hussain D. (2010). Stress, Immunity, and Health: Research Findings and Implications. International Journal of Psychosocial Rehabilitation. Vol 15(1) 94-100
- Segerstrom SC, Miller GE. Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry. Psychological bulletin. 2004;130(4):601-630. doi:10.1037/0033-2909.130.4.601.