Medical scientists have known for decades that aerobic exercise strengthens the brain
and contributes to the growth of new neurons, but few studies have examined how yoga
affects the brain. A recent review of the science finds evidence that yoga enhances
many of the same brain
structures and functions that benefit from aerobic exercise.
The detailed review, published in the journal Brain
Plasticity, focused on 11 studies of the relationship between yoga
practice and brain health
. Five of the studies engaged individuals with no background in yoga
practice in one or more yoga
sessions per week over a period of 10-24 weeks, comparing brain health
at the beginning and end of the intervention. The other studies measured brain
differences between individuals who regularly practice yoga
and those who don't.
For each of the studies, brain-imaging techniques such as MRI, functional MRI or single-photon emission computerized tomography were utilized. All involved Hatha yoga
, which includes body movements, meditation and breathing exercises.
Dr Neha Gothe, a University of Illinois kinesiology and community health professor who led the research along with Wayne State University psychology professor, Dr Jessica Damoiseaux told Thailand Medical
News, "From these 11 studies, we identified some brain regions that consistently come up, and they are surprisingly not very different from what we see with exercise research. For example, we see increases in the volume of the hippocampus with yoga
practice. Many studies looking at the brain
effects of aerobic exercise have shown a similar increase in hippocampus size over time.
The hippocampus is involved in memory processing and is known to shrink with age, Dr Gothe said. "It is also the structure that is first affected in dementia and Alzheimer's disease."
Although many of the studies are exploratory and not conclusive, the research points to other important brain
changes associated with regular yoga
practice, Dr Damoiseaux said. The amygdala, a brain
structure that contributes to emotional regulation, tends to be larger in yoga
practitioners than in their peers who do not practice yoga
. The prefrontal cortex, cingulate cortex and brain
networks such as the default mode network also tend to be larger or more efficient in those who regularly practice yoga
Dr Damoiseaux added, "The prefrontal cortex, a brain region just behind the forehead, is essential to planning, decision-making, multitasking, thinking about your options and picking the right option. The default mode network is a set of brain
regions involved in thinking about the self, planning and memory."
Similar to the amygdala, the cingulate cortex is part of the limbic system, a circuit of structures that plays a key role in emotional regulation, learning and memory, she said.
The new studies also find that the brain changes seen in individuals practicing yoga
are associated with better performance on cognitive tests or measures of emotional regulation.
The new discovery that yoga
may have similar effects on the brain to aerobic exercise is intriguing and warrants more study, Dr Gothe said.
Dr Gothe added, "Yoga is not aerobic in nature, so there must be other mechanisms leading to these brain
changes. So far, we don't have the evidence to identify what those mechanisms are."
Dr Gothe suspects that enhancing emotional regulation is a key to yoga
's positive effects on the brain
. Studies link stress in humans and animals to shrinkage of the hippocampus and poorer performance on tests of memory, for example, she said.
She added, "In one of my previous studies, we were looking at how yoga
changes the cortisol stress response. We found that those who had done yoga
for eight weeks had an attenuated cortisol response to stress that was associated with better performance on tests of decision-making, task-switching and attention."
Dr Gothe said that Yoga
helps people with or without anxiety disorders manage their stress. "The practice of yoga
helps improve emotional regulation to reduce stress, anxiety and depression," she said. "And that seems to improve brain
The medical researchers say there is a need for more rigorous -research into yoga
's effects on the brain
. They recommend large intervention studies that engage participants in yoga
for months, match yoga
groups with active control groups, and measure changes in the brain and performance on cognitive tests using standard approaches that allow for easy comparisons with other types of exercise.
Dr Damoiseaux concluded, "The science is pointing to yoga
being beneficial for healthy brain function, but we need more rigorous and well-controlled intervention studies to confirm these initial findings."
Reference: Gothe, N. P., Khan, I., Hayes, J., Erlenbach, E., & Damoiseaux, J. S. (2019). Yoga Effects on Brain Health: A Systematic Review of the Current Literature. Brain Plasticity, Preprint(Preprint), 1–17. https://doi.org/10.3233/BPL-190084