Yoga practitioners have thicker brain regions associated with attention and memory

MRI scans show that the prefrontal cortexes of elderly women who practice hatha yoga are thicker than those of non-practitioners.

By Karina Toledo  |  Agência FAPESP – The regular practice of yoga can help preserve those brain regions associated with functions such as attention and working memory during the natural aging process according to a new study conducted at the Brain Institute of the Albert Einstein Jewish Hospital (HIAE) in the city of São Paulo, Brazil.

Researchers came to this conclusion after analyzing the brains of 42 older women using magnetic resonance imaging (MRI). The women were all similar in terms of their health, age, years of formal education and levels of physical activity, but only half were yoga practitioners. 

“The MRI scans showed that, in women who had practiced hatha yoga for at least eight years, the prefrontal cortex was thicker than in non-practitioners. This finding suggests exercise is neuroprotective and delays the brain degeneration that occurs with aging, just as it retards the loss of muscle mass,” said Rui Afonso, first author of an article with the results of the study that was published in the journal Frontiers in Aging Neuroscience.

The investigation was performed as part of Afonso’s PhD research with a scholarship from FAPESP and was supervised by Elisa Harumi Kozasa. Scientists from the Federal University of the ABC (UFABC) in Brazil and Harvard Medical School in the United States also collaborated.

“We were inspired by a previous study by one of the co-authors [Sara Lazar of Harvard Medical School], according to which certain areas of the prefrontal cortex and insula were thicker in people who practiced meditation for at least ten years than they were in non-practitioners,” said Kozasa, principal investigator for the research project “Effects of yoga practice in multiple sclerosis patients: a multidimensional approach”.

The Harvard study included individuals of different ages, but the differences in cortical thicknesses were most significant in older people. “So, we decided to do the study only with seniors,” Kozasa said. “We chose hatha yoga because it’s easier to find long-term practitioners and also because it involves meditation as well as exercise.”

Originally from India, hatha yoga is one of the most widely practiced forms of yoga in the West, comprising body poses (asanas), breathing techniques (pranayamas), gestures (mudras), and voluntary muscle contractions (bandhas).

Therefore, in addition to balance and muscular strength, yoga exercises require attention, concentration, and working memory to perform specific tasks, such as reproducing some of the hundreds of different asanas.

“There are several studies that prove the benefits of yoga, particularly with regard to stretching and balance, but also for memory and attention. Our data matches this evidence from the scientific literature,” Kozasa said.

She added a reservation, however: to be absolutely certain that the increased cortical thickness observed results from yoga, it would be necessary to start measuring brain functions in a group of volunteers before they become yoga practitioners.

“For this reason, we plan to start a new longitudinal study with other volunteers who don’t yet practice yoga but intend to do so,” she said. A longitudinal study involves repeated observations of the same variables over a long period of time, often a decade or more.

The article “Greater cortical thickness in elderly female yoga practitioners – a cross-sectional study” (doi: https://doi.org/10.3389/fnagi.2017.00201) by Rui F. Afonso, Joana B. Balardin, Sara Lazar, João R. Sato, Nadja Igarashi, Danilo F. Santaella, Shirley S. Lacerda, Edson Amaro Jr. and Elisa H. Kozasa can be read at frontiersin.org/articles/10.3389/fnagi.2017.00201/full.