France: A recent study in JAMA Neurology investigating the effects of meditation training on brain integrity in older people confirmed the feasibility of the 18-month meditation and non-native language training with very low attrition and high adherence.
The study showed positive behavioral effects of meditation that did not reflect on volume and not remarkably on the perfusion of target brain areas.

"The findings from the Age-Well trial showed that the meditation-based intervention for 18 months did not significantly modify anterior cingulate cortex (ACC) and insula volume in older adults versus a passive or active control, respectively; also, for perfusion, the between-group differences did not reach statistical significance," the researchers wrote in their study.
Considering that no lifestyle-based randomized clinical trial has directly targeted psycho-affective risk factors of dementia and the urgent need for strategies for dementia prevention, meditation practices come into focus. Meditation appears to be an excellent mental training exercise for preserving brain structure, function, and cognition, thus preventing dementia risk by directly targeting psycho-affective factors.
Against the above background, a research team led by Gael Chételat addressed the question, "could meditation, a mental training approach toward attention and emotion regulation, preserve brain function and structure in older adults with unimpaired cognition?" They aimed to investigate the effects of meditation training on brain integrity in the elderly.
Age-Well is a controlled superiority, randomized trial with a blinded end-point assessment. The trial enrolled community-dwelling cognitively unimpaired adults aged 65 and older in France. They were randomly assigned in a ratio of 1:1:1 to receive an 18-month meditation-based training, a structurally matched non-native language (English) training, or no intervention arm.
Meditation and non-native language training comprised of 2-hour weekly group sessions, 1-day intensive practices, and practice of 20 minutes or longer daily at home.
The primary outcomes were the volume and perfusion of the anterior cingulate cortex (ACC) and insula.
Among 137 participants (mean age 69.4 years; 60.6% female and 39.4% male), 45 were assigned to the meditation, 46 to the non-native language training, or 46 to the no-intervention groups; all but 1 completed the trial.
The study led to the following findings:
There were no differences in volume changes of ACC (0.01) or insula (0.01) between meditation and no intervention or non-native language training groups, respectively.
Differences in perfusion changes did not reach statistical significance for meditation compared with no intervention in ACC (0.02) or with non-native language training in the insula (0.02).
Meditation was superior to non-native language training on 18-month changes in a global composite score capturing attention regulation, socioemotional, and self-knowledge capacities (Cohen d, 0.52).
"Future analyses on secondary outcomes will allow for assessing the impact of meditation on perfusion and volume throughout the whole brain and on other measures and examine factors linked with responsiveness to the intervention," the researchers wrote in their conclusion.
Reference:
Chételat G, Lutz A, Klimecki O, et al. Effect of an 18-Month Meditation Training on Regional Brain Volume and Perfusion in Older Adults: The Age-Well Randomized Clinical Trial . JAMA Neurol. Published online October 10, 2022. doi:10.1001/jamaneurol.2022.3185