- AnJenette Afridi. MA
Epigenetics
In an era where each day seemingly gives way to another genomic breakthrough, we are often led to accept our DNA as a pre-determined genetic lottery. After all, when genes can explain idiosyncrasies ranging from low metabolism to frequent sneezing, it can be tempting to lose a sense of agency in changing what is apparently fixed. Modern research, however, spanning fields such as neuropsychology, anthropology, and genetics, lends a novel perspective to the age-old puzzle of the genetic code. While post-Darwinian thinkers once scoffed at the Lamarckian notion that environmental influences can modify DNA, to the extent that these modifications can even be passed to offspring, this claim may not be as ludicrous as once believed.
Groundbreaking new evidence has led to the proliferation of epigenetics, a field exploring how chemical modifications to DNA affect gene expression. In other words, epigenetics is the study of environmental changes causing otherwise dormant genes to be “turned on” or modified. Still in its relatively early stages, the field may promise answers to pressing questions, explaining why we collectively hit puberty earlier or grow taller than previous generations.
In fact, an astounding revelation has been observed in the eastern Democratic Republic of the Congo. Known for its war-stricken terrain and grim history of violence towards women, the region is an unfortunately prime location to study the implications of prenatal stress in women. Ultimately, studies have found that harmful psychosocial exposures in pregnant Congolese women can affect their children’s genes, particularly those which regulate stress physiology. This effectively means that children whose mothers experienced immense physical and psychological stressors may have inherent complications, such as difficulty managing extreme stress and greater susceptibility to depression.
To better understand this mechanism and conversely, to learn how epigenetics can be used to improve mental and physical health, it is integral to examine the process behind it. Essentially, various environments can influence gene expression by provoking methylation, in which a methyl group (CH3 molecule) binds to a cytosine-guanine nucleotide (CpG site) on the DNA. In doing so, transcription factors, or DNA-binding proteins that can stimulate or repress certain genes, can no longer bind to their designated DNA sequences. Thus, methylation is associated with less expression of particular genes.
In the case of the aforementioned Congolese newborns, methylation was observed in the promoter of the glucocorticoid receptor gene, which was ultimately found to be correlated with maternal prenatal stress. The study concluded that a mother’s environmental stress can affect DNA methylation, and in doing so, modify her child’s biology (Thayer and Non, 2015).
Findings such as these continue to reinforce the significance epigenetics can bring to a multitude of fields and debates. Rather than accept the genes we are born with as canon, we can now look to epigenetics as a sort of bridge between genotype (our allotted genes) and phenotype (how these genes are expressed physically). Geneticists Landeker and Pandofsky (2013) aptly illustrate this concept with their Molecular Conduit Model, in which external environmental exposures to an organism are subsequently internalized as epigenetic marks through methylation. These marks, in turn, can modify the behavior and biology of the organism, and resultantly, those of the organisms around them.
Everyday applications of epigenetics abound, leading to increasing studies about common health questions and dilemmas. In particular, considerable attention is being directed towards the epigenetic effects of mindfulness and meditation on the body. For millennia, yoga and meditation have been lauded for their abilities to promote lower stress levels and prolong life. Dating back to the Indus-Sarasvati empire, the apparent healing powers of yoga have largely lacked the confirmation of controlled, empirical evidence until recently (Epel et al., 2016).
Studies have shown that psychological stress and irregular metabolism are correlated with accelerated cellular aging; notably, a 2012 research project conducted by the University of California, San Francisco (UCSF) investigates whether mindfulness and meditation can trigger epigenetic mechanisms that combat this. In short, the study is centered around telomeres and telomerase, which are protein-DNA complexes at the ends of chromosomes and enzymes that preserve and regulate telomeres, respectively. Common marks of cellular aging are reduced telomerase activity and shortened telomere length. In a controlled study, the group examined how mindfulness intervention, lower psychological distress, and clean eating were associated with increases in telomerase activity in peripheral blood mononuclear cells (PBMCs), white blood cells that are integral to the immune system by fighting infections, binding to foreign antigens, and removing dead cells. To do so, participants underwent extensive meditation classes, mindfulness seminars, and nutrition advising.
The study ultimately found a correlation between psychological wellbeing, clean eating, and increases in telomerase activity. In fact, class attendance was directly proportional to decreased levels of chronic stress, anxiety, and glucose, and correspondingly, greater telomerase activity across treatment groups (Daubenmier et al., 2012). Thus, implementing a more natural diet, mindfulness exercises, and meditation into a daily regimen, touted by wellness enthusiasts and health professionals alike for years, may actually be capable of modifying innate genetic and cellular processes to preserve vitality and delay aging.
In fact, the prospects of the mindfulness and epigenetics relationship has united scientists from across the world, provoking inter-continental research projects that truly explore the bounds of the scientific niche. A recent study published in the scientific journal Psychoneuroendocrinology hones in on the correlation between the “epigenetic clock” and long-term meditation practices. Building on the UCSF study, the research project is based on the notion that epigenetic markers on the genome, or methylation sites, can be predictors of chronological age. In other words, DNA methylation age, deduced from CpG sites, is largely related to chronological age. This concept of age estimation is known as the epigenetic clock.
Thus far, it is understood that fast-running epigenetic clocks are associated with chronic diseases and lower longevity. Applying previous findings that extreme psychological stressors can lead to an accelerated epigenetic clock, scientists examined the of effects lifelong meditation to alleviate epigenetic aging. Using methylation in PBMCs to measure intrinsic epigenetic age acceleration (IEAAs), or the rate of epigenetic aging, in both long-term meditators and non-meditators, researchers found unexpected results. While both meditators and non-meditators were ultimately found to have equal rates of epigenetic age acceleration, the actual trajectory of epigenetic age acceleration was considerably higher in non-meditators. Scientists interpret these findings to mean that non-meditators may experience increasing rates of chronological aging later in life compared to meditators. Additional studies may further explore and reinforce the notion that mindfulness, meditation, and a clean lifestyle can have a positive genetic impact on cellular aging (Chaix et al., 2017).
Though still in its relatively early stages, studies such as this show promise for the future of epigenetics research and its contemporary applicability to improve our own lives. The discipline’s potential to provide greater understanding of the human genome, paired with its capability to extend and modify the abilities of our very DNA, solidify its pertinence to both science and society.
Works Cited Chaix, R., Alvarez-López, M. J., Fagny, M., Lemee, L., Regnault, B., Davidson, R. J., Lutz, A., & Kaliman, P. (2017). Epigenetic clock analysis in long-term meditators Psychoneuroendocrinology, 85(Supplement C), 210–214. Daubenmier J, Lin J, Blackburn E, Hecht FM, Kristeller J, Maninger N, Kuwata M, Bacchetti P, Havel PJ, Epel E. (2012). Changes in stress, eating, and metabolic factors are related to changes in telomerase activity in a randomized mindfulness intervention pilot study. Psychoneuroendocrinology. 37(7):917-28. Epel, E., Puterman, E, Lin, J., Blackburn, E.H., Lum, P.Y., Beckmann, N.D., Zhu, J., Lee, E., Gilbert, A., Rissman, R.A., Tanzi, R.E. & Shadt, E. (2016). Meditation and vacation effectshave an impact on disease-associated molecular phenotypes. Translational Psychitry 6:8. Landecker, Hannah & Pandofsky, Aaron. (2013). From Social Structure to Gene Regulation, and Back: A Critical Introduction to Environmental Epigenetics for Sociology. Annual Review of Sociology, 39:1, 333-357 Thayer, Z. M., & Non, A. L. (2015). Anthropology meets epigenetics: Current and future directions. American Anthropologist, 117, 722–735.
DISCLAIMER: This article is not intended to diagnose, treat, cure, or prevent any medical issue or disease. The author does not in any way guarantee or warrant the accuracy, completeness, or usefulness of this article and will not be held responsible for the content of this article. The information in this article is not intended to replace a personal relationship with a qualified health care professional and is not intended as medical advice. Always consult your personal health care provider for specific medical advice.