CHAMPAIGN, Illinois — There’s no shortage of scientific evidence that aerobic exercise is good for the brain. Imaging studies have shown that getting the heart pumping from a strong jog or bike ride strengthens connections in many brain networks and helps new neurons grow. Not nearly as many studies have investigated the benefits of yoga exercise, but scientists from the University of Illinois at Urbana-Champaign say research shows that yoga strengthens many of the same brain networks as aerobic exercise.
The research team conducted a review of 11 peer-reviewed studies that combine brain imaging with yoga practices. Yoga, of course, combines physical postures, rhythmic breathing and meditative exercises, but it is not aerobic in nature.
The review included five studies that trained non-practitioners in at least one yoga session a week for 10-24 weeks. Researchers used various brain imaging techniques in these studies to compare the brain health of participants before and after the yoga intervention. In the other six studies, researchers analyzed the brain scans of regular yoga practitioners and people who don’t practice to identify differences in their scans. Researchers note that many of the studies are exploratory and not driven by hypothesis.
“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,” says University of Illinois kinesiology and community health professor Neha Gothe, in a release. She led the research with Wayne State University psychology professor Jessica Damoiseaux.
The review identifies four brain regions and several brain networks that benefit from yoga practice.
The hippocampus — the seahorse-shaped brain structure that plays a huge role in memory — is shown to grow larger with yoga practice. “It is also the structure that is first affected in dementia and Alzheimer’s disease,” adds Gothe. She suggests that yoga practice can mitigate the onset of these neurodegenerative diseases, just like aerobic exercise has been shown to do.
Two brain structures that contribute to emotional regulation, the amygdala and the cingulate cortex, are also shown to benefit from yoga exercise. The amygdalae of people who practice yoga regularly are larger than those of people that don’t practice at all. This contributes to increased circuit function between the amygdala and the cingulate cortex, and in-turn this leads to improved emotional regulation.
The prefrontal cortex is also shown to be bigger in the brains of people who regularly practice yoga. “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,” says Damoiseaux.
Lastly, the brain’s “default mode network” has been shown to function more efficiently as a result of practicing yoga. The default mode network is a big circuit of brain regions across the entire brain that helps in planning, memory, and self-reflection. They are some of the most active brain networks when people aren’t engaged in anything in particular.
These combined changes in brain structure and function are linked to improved performance on cognitive tests and better measures of emotional regulation in yogis.
The researchers add that we are just scratching the surface of the yoga research. We have a long way to go before we understand the mechanisms behind these brain enhancements. Gothe hypothesizes that improved emotional regulation leads to a lower stress response, and this is one of the leading causes of these improvements.
“In one of my previous studies, we were looking at how yoga changes the cortisol stress response,” she says. “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.”
This review is a good start, but many more research studies need to be conducted to hone in on the mechanisms that yoga exercise uses to cause these improvements. Since many of the studies included in this review are exploratory, they give a good direction for hypothesis-driven research studies in the future. These studies will give us a clearer picture of how yoga benefits the brain.
“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,” Damoiseaux concludes
The study is published in Brain Plasticity.