We just can’t help it. This epigenetics stuff really floats our boat. The last few weeks we’ve brought you a Dear Mark primer on gene expression as well as news on recent studies examining the role of lifestyle/environment on genetic expression. Diabetes, heart disease, even lung function are impacted by external factors like nutrition, exercise, and pollution exposure. But mental health is part of the epigenetic picture as well: chronic stress and even early emotional experiences, it turns out, may be significant enough to alter our genes’ expression.
Earlier this month at the American Psychiatric Association annual meeting, scientists shared their latest research uncovering the link between epigenetics and depression. According to the scientists, significant stress or primary experiences can influence “supporting structures of DNA” like chromatin.
Depression, because of its duration and slow response to medication, has been an intriguing area for epigenetic research. Eric Nestler, one of the presenting researchers from the University of Texas Southwestern Medical School in Dallas, explains that depression’s “persistence is thought to be influenced by slowly developing but stable adaptations, which might include epigenetic regulation.”
Research conducted by Nestler and colleagues found that chronic social stress can cause chromatin changes in genes in the brain’s nucleus accumbens and hippocampus. ‘In both brain regions, we have been able to directly relate these chromatin changes to some of the behavioral abnormalities observed,’ Nestler said. In animal models of chronic stress, he and his colleagues were able to manipulate these two brain areas in ways that produced antidepressant-like effects.
Another group of scientists from the University of Massachusetts Medical School in Worcester has observed that chemical alterations of DNA “are dynamically regulated from the perinatal period to old age.” In animal studies at McGill University in Montreal, rat pups’ early separation from mothers resulted in chemical modifications to genes found in the hippocampus. These changes coincided with enduring changes in behavior. The care pups receive from their mothers in practices like grooming apparently influence their long term “hormonal and behavioral response to stress.” Michael Meaney, one of the McGill University researchers, says the findings suggest an “experience-dependent adaptability in the chemistry of the DNA and chromatin structure.”
Environment and “experience-dependent adaptability.” That’s the crux of epigenetics. We have more influence on our mental and physical health than we previously thought. While we can’t control every aspect of our environment or our emotional experiences, we have the considerable potential to ameliorate those factors. In terms of physical health, we can eat well, supplement wisely, exercise strategically, sleep adequately, and reduce our exposure to toxins as much as possible. For our mental health, we can do all of the above as well as learn effective ways to cope with the stress in our lives (as well as find overall fulfillment). While physical activity can help us feel less stressed in the short term, a personally beneficial meditation practice (yoga, Tai Chi, Transcendental, etc.) can fundamentally change our response to stress. Over time, our efforts can potentially modify the expression of those genes that are involved in stress response and very likely related areas of mental health like anxiety and depression. While some of us might be more genetically predisposed to certain physical and mental health conditions, epigenetics offers hope that our own choices and practices can play a significant role in their prevention and treatment.