with Raghuram Nagarathna MD and Kaushik Chattopadhyay MD
Adopting a regular yoga practice has been proposed for use in managing everything from depression to heart disease and diabetes. Two meta-analyses by Jayawardena et al (1) and Thind, et al (2) describe the benefit of yoga for people with type 2 diabetes. Both found improvements in free blood glucose, postprandial blood glucose, A1c and BMI. Several studies (3-5) have also revealed various benefits of yoga practice in participants with prediabetes, such as improved fasting blood glucose, triglycerides and low-density lipoproteins, total cholesterol and systolic blood pressure.
Yoga for diabetes?
A recent presentation at the 81st Scientific Session of the American Diabetes Association (ADA2021) explored how yoga might be working to reduce the risk of diabetes (6). The trial included participants randomly assigned to doing yoga or walking five times a week for 45 minutes for 3 months. All of the participants were diagnosed with prediabetes, with fasting glucose of 100-125 mg/dL.
Study outcomes measured changes in insulin and c-peptide release after oral glucose dosing at baseline and after 3 months of intervention. Investigators also measured fasting glucose, beta-cell activity (HOMA%), GLP-1, free triiodothyronine, perceived stress and heart rate variability.
How yoga helps in diabetes
The authors found a significant increase in the acute phase of insulin release which was paralleled by increases in c-peptide levels in the yoga group as compared to the control group after 3 months of intervention. Increases in GLP-1 and beta-cell function were also recorded, as were improvements in insulin resistance and measures of heart rate variation in those in the yoga protocol group. Perceived stress levels in the yoga group shifted from severe at the start of the study to moderate at the end, whereas the walking controls had no change. Lastly, the authors found that stress levels were positively correlated to beta-cell function.
Presenting author Raghuram Nagarathna MD (Division of Yoga and Life Sciences, Swami Vivekananda Yoga Research Foundation, Bangalore, India) concluded that “the shift to normoglycemia, due to an increase in acute phase insulin release, was associated with improved autonomic balance and reduced stress after yoga.”
Is it yoga or a lifestyle that improves diabetic health?
“Yoga has multiple components – including a healthy lifestyle. Yoga tells us what to do and what not to do. In the West, and more generally, people think that yoga means postures, breathing exercises, and/or meditation and relaxation practices,” explains independent researcher Kaushik Chattopadhyay MD, (Evidence Based Healthcare, University of Nottingham, UK). The studies by Chattopadhyay et al used the following in a yoga-based program: loosening exercises, sun salutation, yogic poses, breathing practices and meditation (4,5).
Dr. Chattopadhyay indicated that there is also some evidence that meditation, for example, works to potentially reduce blood sugar levels (7), but it does not contain the multifaceted holistic approach that true yoga does. There is also some evidence that Tai Chi can impact blood sugar positively (8). What differs is the healthy lifestyle component promoted in these yoga programs – healthy diet, smoking cessation, no alcohol consumption.
A “relevant package” of diabetic interventions is required to be effective, says Dr. Chattopadhyay. He also notes that those practices need to be developed, implemented widely, and most importantly, evaluated with a randomized controlled trial.
For now, Dr. Chattopadhyay thinks it is too early to draw hard conclusions about preventing diabetes with yoga practice. However, if a number of high-quality studies find it to be beneficial, “yoga will be another evidence-based choice available to people to prevent type 2 diabetes.” It might also be one that many would appreciate as a gentle, holistic method of improving their health.