As yoga becomes increasingly popular in the west, scientific interest and research on its benefits is growing.
We have heard the claims, what are the facts?
Research shows that regular practice of yoga promotes characteristics of friendliness, compassion, and greater self-control, while cultivating a sense of calmness and well-being. So it is not just hippy hype after all. Yoga has been found to be more effective in reducing stress and improving mood than other more traditional types of sport. In fact, a Swedish study in 2006 found yoga practice to be as effective as cognitive behaviour therapy (CBT) for stress management.
The parasympathetic nervous system
Numerous studies show that practicing yoga results in an immediate balancing of automatic control section of the brain known as the autonomic nervous system. It does so by shifting the balance from the sympathetic nervous system (fight or flight), to the parasympathetic system (rest and digest). The latter is calming and restorative; lowering breathing, heart rate, blood pressure and levels of cortisol, a hormone released by the adrenal gland, in response to stress.
Yoga and depression
Consistent yoga practice has also been shown to cause significant increases in serotonin levels coupled with decreases in the levels of monamine oxidase, an enzyme that breaks down neurotransmitters and cortisol. This results in reducing depression levels.
How does yoga affect the brain
Yogic practice inhibits the areas responsible for fear, aggression and anger, and stimulates the reward and pleasure centres in brain, leading to a state of bliss and pleasure. Two fascinating Magnetic Resonance Spectroscopy studies demonstrate that regular practice of gentle yoga releases a chemical called GABA in the thalamus. GABA is sort of the “grand inhibitor” in the brain, and plays a central role in suppressing over-activity such as anxiety. Classical anti-anxiety medications, such as benzodiazepines, work by encouraging the release of GABA in the central nervous system. GABA is what alcohol mimics, by temporarily binding to the same chemical receptors in the brain. You can thank GABA receptor binding for those feelings of relaxation and decreased anxiety that come with enjoying an adult beverage. In the study, GABA was shown to be significantly higher in the brains of those subjects who had been doing yoga.
Long term changes
These findings suggest that yoga practice signals the brain to release chemicals which calm the mind and effect mood in the hours following a session of yoga. Though research remains very preliminary regarding the specifics of how this works, we do know that the strength and configuration of connections in the brain is also controlled by chemical signals. Therefore, it may be that the GABA released over a period of regular yoga practice can help boost baseline levels of this calmative chemical. This could help the brain rewire itself to have a more relaxed, less anxious response in the long run.
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