The association between sleep quality and telomere length: A systematic literature review

Several sleep parameters present an elevated risk for processes that contribute to cellular aging. Short sleep duration, sleep apnoea, and insomnia are significantly associated with shorter telomeres, a biological marker of cellular aging. However, there has been no review or analysis of studies that have examined the association between the psychological construct of sleep quality and telomere length. The present study aimed to provide a systematic review of the association between sleep quality and telomere length. A systematic review of English articles was conducted using MEDLINE/PubMed, PsycINFO, Google Scholar, and Web of Science electronic databases, with the final search conducted on 3rd September 2021. Search terms included sleep quality, poor sleep, insomnia, sleep difficulties, sleep issue*, non-restorative sleep, telomere*, cellular aging, and immune cell telomere length. Study eligibility criteria included human participants aged 18 years or older and a reproducible methodology. Study appraisal and synthesis were completed using a systematic search in line with a PICOS approach (P = Patient, problem, or population; I = Intervention, prognostic factor, exposure; C = Comparison, control, or comparator; O = Outcomes; S = Study designs). Twenty-two studies met review inclusion criteria. Qualitative synthesis of the literature indicated insufficient evidence overall to support a significant association between sleep quality and telomere length. Limitations across studies were addressed, such as the assessment of examined constructs. Findings highlight important targets for future research, including the standardised operationalisation of the sleep quality construct and experimental study designs. Research in this area has clinical significance by identifying possible mechanisms that increase the risk for age-related disease and mortality. PROSPERO Registration No.: CRD 42021233139

EcoMeditation Modifies Brain Resting State Network Activity

BACKGROUND: The tendency of the mind to wander, a characteristic of the brain’s default mode network (DMN), correlates with increased unhappiness and self-referential processing and is a deterrent to establishing a consistent meditation practice. The objective of this study was to test the impact of a secular physiological method of meditation. We hypothesized that EcoMeditation would produce increases in neural communication in brain regions associated with compassion and prosociality and decreases in self-referencing networks, such as the DMN, and that these changes would be found in the experimental group, but not the control group. METHODS: Participants (n=38) were randomized into two groups, and the final sample consisted of 25 participants. One group listened daily to a 22-minute EcoMeditation audio track, while the other used an active control. Functional magnetic resonance imaging (fMRI) was used to assess brain function before and after four weeks of practice. Mystical experiences, as well as psychological conditions, such as anxiety and depression, were measured. RESULTS: Participants in the EcoMeditation group showed significantly increased connectivity between the bilateral hippocampus and the bilateral insula, compared to pre-intervention. In addition, significant decreases of connectivity between the bilateral hippocampus and the midprefrontal and left dorsolateral prefrontal cortices occurred. EcoMeditation participants also scored significantly higher for mystical experiences than the control group. The results for emotional states were mixed, with one assessment finding increased positive mood, but another finding increased negative affect. CONCLUSION: After only four weeks, participants using EcoMeditation demonstrated brain states similar to meditation adepts with thousands of hours of traditional practice