Stress, Aging, and Psychological Wellbeing

I came across an interesting article that was recently published in the journal Health Psychology ("Cumulative Stress and Epigenetic Aging: Examining the Role of Psychological Moderators").  The study used epigenetics to determine whether life stressors are associated with aging.  Epigenetics is the study of how the changes in how different genes are expressed ("turned on" or "turned off") are passed down from generation to generation.  

Gene expression is regulated through slight chemical modifications in the genetic material (called deoxyribonucleic acid, or DNA) itself or of the proteins that are tightly bound to the genetic material (called histones).  For example, a small chemical group called a methyl group can be added to specific sites (usually the cytosine base) on the DNA molecule (called DNA methylation).  DNA methylation usually turns genes off or reduces their activity.  Factors like diet, stress, physical activity, and exposure to toxins can influence these epigenetic patterns, potentially across generations.  

Importantly, as we grow older, the number of epigenetic modifications to our genetic material increases, such that we all have an epigenetic age, so to speak.  Individuals who are exposed to chronic environmental stress accumulate more of these epigenetic changes, and when their DNA is examined closely, they appear older (from an epigenetic standpoint) than their chronologic age, a phenomenon that is called epigenetic age acceleration (EAA).  

The present study involved over 2,000 subjects in which sociodemographic data, cumulative life stressors, and measures of psychological wellbeing were collected, along with blood samples to measure the levels of DNA methylation to determine the epigenetic age.  As expected, higher levels of cumulative life stressors was associated with EAA.  In other words, lifelong stress causes us to age faster.  However, this was only true for individuals with lower levels of psychological wellbeing.  In other words, individuals who scored higher on validated measures of purpose in life, environmental mastery, self-acceptance, autonomy, positive relations with others, and personal growth did not age faster (as shown by EAA), even when they have significant and cumulative life stressors.  

Psychological wellbeing refers to that state of mental health where an individual experiences positive emotions, life satisfaction, and a sense of purpose. It involves feeling good emotionally and functioning effectively in daily life.  I've posted about psychological wellbeing in the past - see in particular "Languishing and Flourishing", "The Three Dimensions of a Complete Life", and "The Five Pillars of Happiness".  As it turns out, having a positive attitude, being satisfied and content with life, and having a sense of purpose can be incredibly powerful when it comes to our physical, mental, and spiritual health.