Neurofluids, including cerebrospinal fluid (CSF) and interstitial fluid, circulate through regulated central nervous system pathways to clear cerebral waste and support brain health, with elevated CSF flow hyperdynamicity and regurgitation through the cerebral aqueduct associating with aging and neurodegeneration. Sleep exerts state-dependent effects on neurofluid circulation, yet similar modulation during unique waking states, such as meditation, remains underexplored. Notably, mindfulness meditation shares several regulatory features with sleep, with core meditation practices representing distinct arousal states. We investigated whether the focused attention (FA) style of mindfulness meditation modulates neurofluid dynamics directionally opposite to aging and consistent with sleep. Using phase-contrast MRI, we assessed absolute CSF flow and velocity through the aqueduct, and using blood-oxygenation-level-dependent (BOLD) MRI, we assessed CSF fluctuations near the cervicomedullary junction together with total supratentorial gray matter fluctuations. Assessments were repeated in meditation-naïve adults during mind wandering (MW) without (n=13; repeatability controls) and with (n=14; breath controls) respiration rate modulation, and in adept meditators (n=23) during MW and FA meditation. No aqueduct CSF flow changes were observed in control groups. In meditators, absolute aqueduct absolute CSF flow decreased from MW to FA meditation (4.60±2.27 mL/min to 4.17±2.10 mL/min, p=0.005) owing to reduced regurgitant cranially-directed CSF velocity. On BOLD, this paralleled increased low frequency (0.0614-0.0887 Hz) CSF fluctuations (p=0.0138), which were inversely correlated with gray matter fluctuations during FA. Findings suggest that mindfulness meditation may represent a non-pharmacological, waking state capable of modulating neurofluid dynamics in a directionally similar manner to sleep and opposite to aging and neurodegeneration.

Significance statement Mindfulness meditation is widely recognized for its self-reported mental and physical health benefits, yet its effects on core physiological systems that support brain health remain incompletely understood. This study provides the first evidence that a focused attention (FA) style of mindfulness meditation can modulate cerebrospinal fluid (CSF) dynamics in humans. Using neuroimaging, we demonstrate that FA meditation reduces regurgitant CSF flow through the aqueduct, directionally opposite to patterns seen in aging and neurodegeneration; additionally, meditation-induced CSF changes near the skull base are similar to those reported during sleep, an enhancer of neurofluid circulation. Findings suggest that mindfulness may offer a novel, non-pharmacological, waking model for augmenting neurofluid circulation and provide a potential physiological mechanism linking meditation to brain health.

The authors have declared no competing interest.

This study was funded by the National Institutes of Health: Grant NIH/NCCIH 5R01AT011456

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Participants provided informed, prospective consent for this Institutional Review Board (IRB) approved study. IRB approval was obtained through the Vanderbilt University Medical Center IRB. Title: Quantitation of Glymphatic Functioning in Sleep and Meditative States IRB Approval: 202527

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