Posted 12.19.2019 | by AMRA
The human genome is the sum total of genes encoded in our DNA. Epigenetics is the study of how these genes get turned on and off to produce physiological effects. For example, epigenetic changes in the immune system play a central role in disease onset and aging.
We may be able to alter our epigenetic activity through behavioral changes in exercise, diet, and stress reduction. While stress reduction practices have previously been found to down-regulate the immune system and inflammation, little is known about how such practices affect immune system epigenetics.
DNA strands are wrapped around protein complexes called histones. Genes can be turned on or off through methylation (the addition of carbon atoms bonded to four hydrogen atoms) of the histones adjacent to DNA gene segments.
Chaix et al. [Brain, Behavior and Immunity] studied the effect of intensive mindfulness meditation on the methylation of immune cell (lymphocyte and monocyte) genes in experienced meditators after one day of intensive meditation.
The researchers recruited 19 experienced meditators (average age = 50; 58% female; 84% Caucasian) and 21 meditation-naïve controls (average age = 50; 57% female; 84% Caucasian). Meditators had a minimum of 3 years of meditating at least 30 minutes a day and attended at least 3 intensive meditation retreats.
The meditators had their blood drawn before and after an 8-hour period of intensive mindfulness meditation similar to a Mindfulness-Based Stress Reduction all-day retreat. Controls had their blood drawn before and after 8 hours of leisure activities such as reading, playing computer games, watching documentaries, and walking.
Blood draw immune (mononuclear) cell DNA was analyzed for methylation levels at over 400,000 separate DNA sites. After quality filtering, usable data were obtained for 17 meditators and 17 controls.
Meditators and controls had similar methylation levels at baseline. After the 8-hour intervention period, meditators had 61 DNA sites with significantly changed methylation levels, while DNA sites of leisure activity controls showed no significant changes.
Of the 61 altered sites in the meditators, 57 sites showed increased methylation levels. Sites were mainly associated with genes regulating fatty acid metabolism, DNA repair, RNA metabolism, protein translation, telomerase regulation, telomere maintenance, and cell adhesion. These genes also affect immune and inflammatory response by regulating vascular inflammation, the anti-inflammatory cytokine IL-10, and the pro-inflammatory COX-2 molecule.
The study demonstrates that a single 8-hour mindfulness meditation retreat can rapidly alter methylation levels that affect epigenetic expression in genes among experienced meditators. Involved genes include those that regulate inflammation, immune cell metabolism, DNA repair, cellular aging, RNA metabolism, protein translation, cell adhesion, and neurotransmission. These findings align with other studies showing that mindfulness meditation practice has immune system benefits relevant to health and aging.
The study is limited by its small sample size and variability in the control group leisure activities. Moreover, the analysis cannot decipher whether individual genes were turned off or on by methylation, whether these changes up-regulated or down-regulated immune function, or whether epigenetic expression was also altered by biochemical pathways other than methylation.
Chaix, R., Fagny, M., Cosin-Tomás, M., Alvarez-López, M., Lemee, L., Regnault, B., . . . Kaliman, P. (2019). Differential DNA methylation in experienced meditators after an intensive day of mindfulness-based practice: Implications for immune-related pathways. Brain, Behavior, and Immunity.