Sunday, April 8, 2012

New study shows how stress influences disease

Stress has been linked with a greater risk of depression, diabetes, autoimmune diseases, cardiovascular disease, upper respiratory infections, poor wound healing and other physical maladies. A new study reported in the Proceedings of the National Academy of Sciences (PNAS) may now reveal a biochemical mechanism through which stress affects the body.

A team led by Dr. Sheldon Cohen, Psychology Professor at Carnegie Mellon University in Pittsburgh, has found that the body loses its ability to regulate inflammatory response when undergoing chronic psychological stress. "Inflammation is partly regulated by the hormone cortisol and when cortisol is not allowed to serve this function, inflammation can get out of control," stated Cohen. Immune cells normally protect the body from disease. Cortisol regulates the inflammatory response. Prolonged stress alters the effectiveness of cortisol to perform this regulatory function, decreasing sensitivity to the hormone. Immune cells then become insensitive to cortisol’s regulatory effect. This in turn leads to increased and persistent inflammation, which promotes the development and progression of disease. The problem is not simply higher cortisone levels, but target tissue’s response to it. [1]

Cohen’s team conducted two studies with a total of 355 healthy adult subjects by exposing them to two rhinoviruses following an intensive measurement of stress in their lives. The team proposed a model in which chronic stress results in glucocorticoid receptor resistance (GCR) that leads to a failure in the inflammatory response, thus tending to make a person more susceptible to illness. After controlling variables, those with recent long-term threatening stressful experiences demonstrated GCR and were at a higher risk of developing a cold. (Leaving the house on a cold day without a jacket was not studied.) In the second study, greater GCR predicted production of more local proinflammatory cytokines (regulatory proteins that are produced by immune system cells and act as intercellular mediators in the modulation of immune response) among infected subjects. The researchers noted that “these data provide support for a model suggesting that prolonged stressors result in GCR, which, in turn, interferes with appropriate regulation of inflammation. Inflammation plays an important role in the onset and progression of a wide range of diseases.” [2]

So, how can we reduce stress, which is primarily a psychological and cognitive phenomenon? Aside from giving up the car to avoid driving stress and quitting the job, there are a number of practical and effective methods, some of which include:
• Exercise
• Laugh
• Listen to music
• Get enough sleep
• Eat healthy
• Count our blessings
• Take a walk
• Work in the garden
• Do some charitable work
• Learn to say no
• Don’t procrastinate

Then, there is a method for achieving long-term continual stress reduction. The answer to enduring peace is found in a book written nearly two millennia ago:
“Be anxious for nothing, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.” (Phil. 4:6)
Jesus promises: “My peace I give to you ... Do not let your heart be troubled” (John 14:27).

And, an old song provides some wise advice:
“What a privilege to carry everything to God in prayer!
O what peace we often forfeit, O what needless pain we bear,
all because we do not carry everything to God in prayer.”
(Text: Joseph M. Scriven, 1820-1886
Music: Charles C. Converse, 1832-1918)

[1] Carnegie Mellon University, “How stress influences disease: Study reveals inflammation as the culprit.” Science Daily, posted 2 Apr 2012, accessed 5 Apr 2012.
[2] “Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk”, Sheldon Cohen, Denise Janicki-Deverts, William J. Doyle, Gregory E. Miller, Ellen Frank, Bruce S. Rabin, and Ronald B. Turner, Proceedings of the National Academy of Sciences, April 2, 2012, doi:10.1073/pnas.11183551.

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