A seven-day intensive meditation retreat produced changes in brain connectivity resembling patterns seen with psychedelic drugs, according to researchers at UC San Diego. The team also recorded shifts in immune signaling, metabolism, and the body's own pain-control system. No drugs were involved.
The finding comes from a preliminary study of just 20 healthy adults, and the authors caution that results will need to be replicated in larger trials before firm conclusions can be drawn. Participants spent roughly 33 hours in guided meditation over the week.
What the scans actually showed
Using fMRI, the researchers saw reduced connectivity within the default mode network, the set of brain regions active during self-referential thinking and mental chatter. They also observed decreased connectivity within the salience network and a broader shift in how brain regions communicated with each other.
Similar patterns have been documented in earlier studies of people given psilocybin, according to reporting on the research. The work was published in Communications Biology and combined brain imaging with blood tests.
Also read: The everyday habits that could raise your dementia risk
Immune, metabolic and pain signals
Blood plasma drawn after the retreat contained higher levels of endogenous opioids, the body's natural painkillers. The samples also showed a simultaneous rise in both inflammatory and anti-inflammatory immune signals, along with a metabolic shift in how cells produce energy.
When laboratory-grown neurons were bathed in post-retreat plasma, they grew longer branches and formed more connections than neurons treated with plasma taken before the retreat. Levels of BDNF, a protein linked to learning and memory, also rose.
What the researchers said
"We're seeing the same mystical experiences and neural connectivity patterns that typically require psilocybin, now achieved through meditation practice alone," said Hemal H. Patel, Ph.D., professor of anesthesiology at UC San Diego and the study's senior author.
First author Alex Jinich-Diamant, a doctoral student at UC San Diego, called the results "an exciting step toward understanding how conscious experience and physical health are intertwined."
Also read: Your cells age faster with these habits - and some of the damage may be reversible
Important caveats
Twenty participants is a very small sample, and everyone in the group knew they were on a retreat led by chiropractor and neuroscience educator Joe Dispenza. Dispenza is a co-author of the paper, and the disclosures note he is employed by the company that ran the program. The other authors reported no competing interests.
The study did not compare the retreat with an active control group doing a different intensive practice, so it cannot separate meditation itself from the broader effects of a week spent in a structured setting. Anyone considering meditation for a specific medical condition should talk with their doctor.
Meditation more broadly has a larger evidence base for benefits including stress reduction and improvements in anxiety symptoms. What this new study adds is a snapshot of the biology, with brain and blood signals moving in the same direction across a single group of participants over a single week.
Also read: The cholesterol marker most doctors don't routinely test may be raising your heart risk
Also read: The diet that may lower your dementia risk, even if it runs in your family