Effects of Mindfulness and Yoga on Stress

Sara Lazar’s talk at TEDxCambridge in 2011 encapsulated her previous three years of research, highlighting two of her latest studies. The concept of her talk was to discuss how, at a neurobiological level, yoga and meditation are effective in reducing stress, depression, anxiety, pain and insomnia; improving the ability to pay attention; and generally making people happier [1].

In the first study she compared individuals who meditate with those who never meditate. By using MRI brain scanning technology, they were able to determine that among those who mediate, there is a larger amount of gray matter in the areas of the brain associated with working memory and executive decision-making. Their second finding came when they plotted the MRI data against the ages of the participants. They discovered that older participants who meditated did not share the shrinkage of the cortex that people typically experience as they age, and in fact, the size of their cortex was the same as the twenty year olds [1].

Lazar conceded that this does not infer causality and there could be a host of other factors that could confound the relationship of meditation and brain structure. This train of thought lead to her second study, a longitudinal analysis on the effects of meditation. This time they recruited participants who did not have significant mediation or yoga experience, collected their MRI data, placed them in an 8-week mindfulness program and then collected their MRI data again, all while taking measurements of their self-reported levels of stress. They found that various areas of the brain associated with learning, memory, emotion regulation, perspective taking, empathy and compassion, had grown over the 8-week period. The last discovery that Lazar reported in the talk was that the amygdala, associated with fight or flight response, had decreased in size, correlating with a decrease in self-perceived levels of stress [1].

Lazar elaborated on the amygdala’s relationship with stress by comparing it to an animal study, which demonstrated that an increase in stress correlated with an increase in the size of the amygdala. Three weeks after the rats were stimulated by stress and then left alone, they were still exhibiting behaviors of stress and their amygdala still large. Lazar concluded that these finding suggest that the amygdala is not responding to a change in the environment, but rather representing the change in people’s reaction or relationship to their environment [1].

What I found immediately confusing was that Lazar used yoga and mediation almost interchangeably in her talk, which incited doubt to the efficacy of the research. After digging through her studies, I found that the intervention they used was specifically called, Mindfulness Based Stress Reduction program (MBSR) hosted by the Center for Mindfulness at the University of Massachusetts Medical School [2]. What I discovered was that MBSR is a multi-prong approach incorporating aspects of yoga, mindfulness meditation, group dialogue, and home assignments.

At a convention like TEDxCambridge, where there is a time limit of 9 minutes, I can see why an in depth explanation of MBSR might have been forgotten to be included. I believe, however, that it would have been important to note that the research for Lazar’s second study is discussing the effects of the combination of yoga and meditation and that we cannot draw a conclusion from any single intervention.

That being said, the findings are still very interesting and hold a large potential for application. The fundamental concept that I get out of Lazar’s work is that whenever you engage in a behavior over and over again, this leads to changes in brain. Some behaviors can add to mental and physical well being, while others can subtract. It so happens that yoga and mindfulness, in concurrence, are behaviors that promote well being. I believe there is large potential for determining what those individual factors of yoga and mindfulness are, and how those mechanisms are influencing the brain.

If we can fully understand the mechanisms in yoga and mindfulness, like Lazar is currently trying to do [3], we might be able to consistently promote these mechanisms through nudges, and hopefully curate behavior. For example, a computer-based work place could install software on the companies’ computers to remind their employees to get up and stretch, or guide them on a five-minute mindfulness mediation process. A more direct method might be to market it the concept to marketing directors of large companies to implement nudges for these mechanisms in their commercials. Clearly, people are left happier; so long term exposure to a non-stressful, happiness promoting advert might engage users on an intrinsic level. The customer is guided towards healthier behavior and the company potentially receives a loyal customer base.

[1] TEDxTalks. “How Meditation Can Reshape Our Brains: Sara Lazar at TEDxCambridge 2011”. Online video clip. Youtube. January 23, 2012.

[2] Hölzel, Britta K., et al. “Stress reduction correlates with structural changes in the amygdala.” Social cognitive and affective neuroscience 5.1 (2010): 11-17.

[3] Desbordes, Gaëlle, et al. “Moving Beyond Mindfulness: Defining Equanimity as an Outcome Measure in Meditation and Contemplative Research.” Mindfulness (2014): 1-17.