Advanced meditation techniques linked to younger brain age during sleep

People who regularly engage in advanced meditation techniques may possess brains that appear biologically younger than their actual chronological age. By measuring electrical activity in the brain during sleep, researchers found that long-term meditators exhibited brain activity patterns typical of people nearly six years younger. These measurements were published recently in Mindfulness.

As human beings age, their sleep changes in predictable ways. Older adults typically experience shorter, more fragmented rest alongside a reduction in deep sleep stages. At the level of brain electrical activity, aging is associated with fewer slow brain waves and a reduction in sleep spindles, which are short bursts of high-frequency brain activity that help consolidate memories.

Scientists can use these natural age-related changes to calculate a biological brain age. They compare an individual’s sleep brain waves against established age norms. When a person’s biological brain age is higher than the number of years they have been alive, they are at a higher risk for cognitive decline, dementia, and mortality. Lower estimates are associated with better general health.

Previous studies using magnetic resonance imaging have shown that meditation protects the physical structure of the brain against aging. Jayme Banks, a neurology researcher at Massachusetts General Hospital, and a team of colleagues wanted to see if similar protective markers appeared in the brain’s real-time electrical activity. The researchers decided to study brain age in a cohort of advanced meditation practitioners.

The research team recruited 34 individuals scheduled to attend an intensive four-day meditation retreat called Samyama Sadhana. This specific retreat requires participants to complete years of prerequisite meditation courses. In the weeks leading up to the retreat, participants must adhere to a vegan diet and practice specific breathing and seated meditation techniques for several hours every day.

To measure brain activity, the study participants wore specialized headbands while sleeping in their own beds. These at-home devices used electroencephalography, a technology that records electrical signals through sensors resting against the scalp. The meditators wore the headbands for several nights in the week before the retreat and for several nights in the weeks following the event.

The researchers compared the sleep data of the meditators against several large existing databases of sleep records. The comparison groups included healthy individuals who used the same at-home headbands, as well as distinct groups of patients who had visited clinical sleep laboratories. These clinical groups ranged from entirely healthy individuals to patients diagnosed with mild cognitive impairment and severe dementia.

The research team matched the meditators with the control subjects based on age, sex, race, and education levels to ensure equivalent comparisons. The meditators possessed an average chronological age of 38 years. According to the sleep data, the estimated biological brain age of the meditation group was 5.9 years younger than their true age.

In contrast, the healthy control groups showed brain ages that closely matched their true chronological ages. The groups with known age-related pathologies displayed much older brain ages. Individuals with mild cognitive impairment possessed brain ages nearly nine years older than their true age, and patients with dementia scored over ten years older.

The researchers looked closely at the specific sleep stages responsible for the younger brain age in the meditators. The younger estimations were largely driven by high-amplitude bursts of brain activity during periods of light sleep. These bursts suggest a highly active and organized neurological state during rest.

The data also revealed a difference in the overall amount of sleep. The meditating cohort slept an average of 6.0 hours per night, while the healthy control group slept an average of 7.6 hours. The researchers propose that advanced meditation habits improve sleep quality, which allows for restorative rest in a shorter period of time.

Alongside the sleep monitoring, the participants completed a series of standardized emotional and cognitive tests. The results showed that the meditators consistently outperformed national averages on tests of fluid cognition, which measures real-time problem-solving skills. They also scored highly on certain tests of crystallized cognition, which measures accumulated knowledge like reading recall.

Interestingly, the four-day meditation retreat itself did not alter the measured brain ages. Sleep records taken in the weeks following the retreat showed no measurable reduction in brain age compared to the records taken beforehand. The cognitive test scores also remained entirely static across the event.

The retreat did affect emotional health. Participants reported increased feelings of positive affect, emotional support, and friendship after the event concluded. They also reported lowered levels of perceived daily stress. The researchers suggest that brief meditation retreats can rapidly shift emotional well-being, but physiological shifts in brain aging likely require years of sustained practice.

The biological mechanisms that connect meditation to sleep and brain aging are not fully understood. Regular slow-paced breathing exercises might play a role by altering activity in the brain stem. Specific cellular groups in the brain stem supply norepinephrine to the cerebral cortex, and calming these cells through controlled breathing might encourage the brain to produce protective sleep patterns.

The study has several limitations regarding its ability to establish cause and effect. The research team did not have access to baseline sleep data from before the participants originally began their long-term meditation habits. Because of this missing baseline, it is not possible to claim that meditation directly caused the younger brain age.

A phenomenon known as self-selection bias could explain the findings. People who are naturally healthier, or who possess lifestyles and genetics that promote slower brain aging, might be more likely to pursue intensive meditation practices in the first place. The study cohort was also highly educated, with the vast majority holding advanced college degrees, which is another factor known to protect cognitive health.

When the researchers tested whether the sheer number of years a person had been meditating correlated with an even younger brain age, the results were not statistically significant. This absence of a longitudinal correlation adds weight to the possibility that innate predispositions might be at play. Future studies tracking beginners over many years are required to see if meditation actively drives these changes in brain health.

The study, “Sleep-Based Brain Age Is Reduced in Advanced Inner Engineering Meditators,” was authored by Jayme C. Banks, Sepideh Hariri, Kestutis Kveraga, An Ouyang, Kaileigh Gallagher, Syed A. Quadri, Ryan A. Tesh, Preeti Upadhyay Reed, Robert J. Thomas, M. Brandon Westover, Haoqi Sun, and Balachundhar Subramaniam.