Rosmann: Stress can lead to brain, genetic changes
A small but growing body of research indicates stress can produce changes not only in brain functioning, but also in genetic proclivities passed along to future generations.
These scientific findings hold important implications for our physical and behavioral health and that of our descendants.
A process called methylation changes the expression of DNA. Chemical structures called methyl enzymes increase in response to stressful events and can silence genes from working properly. Evidence suggests early life stresses may have more impact on heritability than later life stresses.
DNA is the hereditary material in humans and nearly all organisms. The findings are in the early stages of reaching conclusive scientific certainty.
Duke University biochemists Robert Lefkowitz and Makoto Hara demonstrated that increasing amounts of stress can progressively damage DNA expression and increase the risk for developing cancer and turning hair gray.
In a December article for the website, www.ClearYourStress.com, Karl McDonald cited additional evidence that chronic stress is the culprit, causing psychological and physiological distress that triggers a drop in a key tumor suppression antigen, called p53.
A more recent study was reported last month by the New York Association of Psychiatric Rehabilitation Services. The research was conducted by a team of scientists at Johns Hopkins University, led by Richard Lee.
They found that high levels of corticosteroids, which are released into the blood by severe stress, are associated with changes in brain functions that influence our behaviors, and changes in the DNA methylation of the human genome site, Fkbp5. In other words, stress can change brain chemistry and behavior, and the genetic information is passed along to offspring.
Corticosteroid levels are a good indication of exposure to stress: The higher the cortisol, the greater the stress.
Many environmental toxins are known to produce changes in behavior and DNA expression. For example, habitual heavy alcohol ingestion, which is toxic, not only creates a craving for more of the substance and eventually dulls brain functions, but it also increases the likelihood that offspring of the alcohol abuser will develop alcohol addiction.
While exposures to environmental toxins are widely suspected as an increasing cause of death, the new information accumulating about stress opens a further area for scientific exploration: how stress changes brain chemistry and our genetic material. A new field, behavioral epigenetics, examines how our experiences affect our genetic expression.
It is not fully known how DNA changes, even though the research about methylation offers promising direction. It is clear that almost all organic life forms have adaptive capacities and that these capacities can contribute to survival or extinction.
All of us are subjected to stress. Adaptations to stress that contribute to survival can become part of our heritable genetic material, as well as adaptations that detract from survival over multiple generations.
If we didn't have the capacity to incorporate beneficial DNA changes that contribute to survival, humans would have disappeared as a species long ago.
Since stress is a normal part of life and we can adapt, why worry about managing stress? The answer is that chronic stress and severe acute stress, such as a non-fatal but life-threatening event, lessen our capacity to survive.
It is important for agricultural producers to understand available scientific research that helps us figure out how we work and what we can do to enhance our survival.
We need to know what steps to take to reduce exposures to environmental toxins. We can improve our knowledge about beneficial methods of reducing the body chemicals associated with fright and stress - adrenalin and cortisol.
OK, I know this week's column is pretty technical, but it is foundational to knowing why I try to make behavioral health more understandable to those who engage in the wonderfully life-enhancing activities of growing food and fiber, some of our most basic necessities for life.
Over the next few months I will say more about what we can do to manage ourselves and our choices.
I will tackle difficult topics, such as what is known about various threats to agriculturalists' behavioral health and physical well-being. I will draw on research findings and personal observations.
I have several bright behavioral health and epigenetics scientists who have promised to help me with topics that push the borders of my expertise.
Stay tuned and let me know how you feel about what I am trying to accomplish. I always appreciate feedback.
Mike Rosmann is a Harlan, Iowa, psychologist and farmer. To contact him, go to www.agbehavioralhealth.com.