Fans of yoga have another new study about yoga’s health benefits to crow about. In an article published in the latest issue of Brain Science, researchers at the University of Illinois-Champagna reviewed 11 published studies that compared the effects of yoga and aerobics on brain structure and functionality. They found that both practices were equally beneficial.
The two main areas of the brain highlighted in the 11 studies were the hippocampus, which plays a central role in memory processing and decision-making, and the amygdale, which affects the regulation of the emotions. The hippocampus normally shrinks with age, which contributes to a greater risk of dementia and Alzheimer’s disease.
But researchers found that people practicing yoga and aerobics held the potential to reverse or slow the brain’s aging process. They also found comparable positive influences in the ability of the two practices to reduce stressful emotions, including anger and sadness, and the risk of violent or aggressive behaviors.
Researchers in the 11 studies had arrived at their conclusions through the use of advanced brain-imaging techniques, including MRI, functional MRI, and in some cases, single-photon emission computerized tomography. They also looked at the results of cognitive and emotional tests administered to the study participants.
The aerobic and yoga groups showed marked increases in brain size and achieved higher test scores after completing their respective practices
Researchers admit that the findings of the 11 studies are largely suggestive and not conclusive. In most cases, the study samples were small and not randomly chosen. Most of the study periods were fairly short – just 8-10 weeks — and only one immediate post-test was conducted. Whether the positive effects on the brain detected in the studies would be long-lasting remains unknown.
“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,” study co-director Jessica Damoiseaux, a psychology professor at Wayne State University, says.
This is only the latest in a slew of research studies over the past five years that have compared the health effects of yoga and aerobics. Previous studies have compared the impact of aerobics and yoga on cardiovascular health and found comparable benefits.
But the latest meta-study – a review of previously published studies – is the first to look at the effects of the two practices on the brain.
One of the reasons the meta-study findings are so striking is that aerobics and many forms of yoga are distinct physical practices. Hatha yoga, the kind practiced by the study participants, focuses on breathing, static postures, and meditation, while aerobics involves physical exercise and cardiovascular stimulation.
“Yoga is not aerobic in nature, so there must be other mechanisms leading to these brain changes,” Damoiseaux said. “So far, we don’t have the evidence to identify what those mechanisms are.”
In fact, there are other forms of yoga, including Ashtanga yoga, which are far more strenuous and aerobic in nature. Future studies might vary the kinds of yoga practiced by participants and compare and contrast their effects. Some forms of yoga may exert a greater influence on brain health than others.
Another useful comparison would be to Tai-Chi and Qi-Gong, which have the same strong meditative orientation as yoga but are less physically demanding
Other areas of the brain are also worthy of study. For example, past studies have examined yoga’s impact on the hypothalamus, a portion of the brain that regulates the appetite for food and sex. Yoga has been shown to reduce food cravings while increasing a person’s sex drive. However, the effect of aerobics on the hypothalamus remains unknown
Researchers caution that neuroscience is still in its infancy. The relationships among the different components of the brain and the impact of exercise and fitness practices on them are exceedingly complex.
Moreover, other factors — including diet and nutrition and a person’s age and gender — might also affect their brain health regardless of the fitness regimen chosen.
Overall, the results of these latest studies, while promising, must be considered preliminary and in need of further validation.