Yoga for Type 2 Diabetes: Scientific Rationale and Clinical Research Evidence

By Nikhil Ramburn and Sat Bir Singh Khalsa, Ph.D.

Type 2 Diabetes Mellitus (DM2), also called adult-onset diabetes, is a metabolic disease that was formerly only diagnosed in midlife but is now impacting younger adults and even children. This disorder is characterized by defects in insulin production and action, resulting in elevated blood glucose levels, which can lead to serious medical consequences. Long-term complications from diabetes account for more adult cases of vision loss, end-stage kidney disease, and amputations than any other disease. In addition, diabetes significantly increases the risk of cardiovascular disease and may be linked to cancer. DM2 is largely a lifestyle disease caused by inadequate physical activity, diets rich in highly-processed foods and refined sugars, and elevated levels of life-stress. Twenty-eight million people in the United States have DM2, and more than 80 million are considered to be at high risk of developing it, a state called prediabetes or metabolic syndrome. Worldwide, more than 350 million people are estimated to have DM2, a disease affecting many developing countries with limited resources.

The high cost and relatively low effectiveness of conventional treatment has resulted in an economic burden estimated to total $322 billion annually in the United States. Conventional treatment aims at controlling glucose levels through medications, education, and behavior change schemes. However, behavior change is notoriously hard to enact because the same environmental and social conditions that gave rise to the disease-causing behavior are still in place. Pharmaceutical treatment drawbacks include dependency, resistance, and adverse long-term effects. Consequently, there has been a concentrated search for non-pharmaceutical treatment and preventative measures. Behavioral treatments such as lifestyle interventions addressing the risk factors of obesity and sedentary activity reduce the development of diabetes by as much as 58% and decrease the need for medications. However, current conventional behavioral lifestyle interventions have limited effectiveness; this is a factor that may likely be improved with yoga.

Yoga interventions address several DM2 risk factors and bring a much-needed holistic approach to DM2 treatment. In yoga, physical exercises are linked to lifestyle and behavioral changes that include diet, relaxation, and stress management. A lesser-known aspect of yoga is the social support that a yoga class or community provides and social support is strongly linked to improved diabetes self-care and clinical outcomes. Yoga is better known for increasing fitness and physical function, thereby improving both glucose metabolism, and psychological health. At the same time, yoga promotes and supports weight loss and thereby addresses obesity which is a major cause of DM2 onset and complications. Finally, the two most beneficial and consistent outcomes of yoga are an increase in mind body awareness and stress-coping ability. This leads to a host of positive downstream effects including improvements in healthy behaviors, avoidance of unhealthy behaviors, better sleep cycles, balanced neuroendocrine status, improved metabolic function, and reduced inflammatory responses. There is convincing research that shows that yoga improves mindfulness and mind body awareness, and this may well encourage individuals to gravitate to healthy behaviors such as exercise and healthy food choices, and away from unhealthy habits such as consuming junk food. This is all due to their enhanced experience of the positive effects of these behaviors. Evidence suggests that stress may play a major role in the development of diabetes, which is why relaxation techniques, such as are found in yoga, could serve as a very effective complement to other lifestyle modifications. Therefore, there is every reason to believe that yoga should be efficacious in preventing and treating DM2.

Metabolic Regulation
Studies evaluating yoga interventions in patients with DM2 found that yoga normalized metabolic functions which resulted in increased insulin sensitivity, glucose tolerance, and improved lipid profiles. These beneficial effects of yoga on glycemic control are well documented. A recent review in the International Journal of Yoga Therapy looked at the evidence for the benefits of yoga in adults with DM2. Peer-reviewed studies published between 1970 and 2006 looked at the effects of yoga on diabetes and diabetes risk factors in a broad range of outcomes, such as insulin resistance, glucose intolerance, elevated blood pressure, and excess body weight. Each of these factors is strongly implicated in the development and progression of DM2. Despite considerable variability in design, clinical measures, and target populations, most trials reported positive changes in at least one of the outcomes related to DM2 and in clinical outcomes as well. The most recent review of research on yoga therapy for DM2 was published this year by Kim Innes of West Virginia University in the Journal of Diabetes Research. Researchers found 33 papers reporting findings from 25 controlled trials (12 of them RCTs) representing 2170 participating research subjects, and concluded that “collectively, the findings suggest that yogic practices may promote significant improvements in several indices of importance in DM2 management, including glycemic control, lipid levels, and body composition. More limited data suggest that yoga may also lower oxidative stress and blood pressure; enhance pulmonary and autonomic function, mood, sleep, and quality of life; and reduce medication use in adults with DM2.”

Improved Sense of Well-Being
In a pilot study conducted by Shanti Shanti Kaur Khalsa and Guru Parkash Kaur of the Guru Ram Das Center for Medicine and Humanology (founded by Yogi Bhajan in Espanola, New Mexico to apply the practices of Kundalini Yoga for therapeutic populations), they applied 3 questionnaires to evaluate the effectiveness of an 8-week Kundalini Yoga and lifestyle intervention program in diabetic patients. One of these was the Audit of Diabetes Dependent Quality of Life, which measures individuals’ perception of the impact of diabetes on their quality of life. Improvement in quality of life was measured in 9 of 11 participants. The second scale was the Profile of Mood States which consists of subscales measuring the following moods: anger, confusion, depression, fatigue, anxiety, and vigor. There was statistically significant improvement in all of the above mood states following participation in the diabetes program. The third measure was the Functional Assessment of Chronic Illness Therapy – Spiritual Well-Being, which measures a faith factor as well as a meaning-and-peace factor. There was a statistically significant improvement in spiritual well-being following participation in the diabetes program as measured by this scale. The evaluation showed that most participants found the components of the program extremely helpful especially in the areas of mood, stress management, quality of life, and ability to relax. Although such findings support the efficacy of yoga as a therapeutic intervention to improve quality of life and stress management, larger randomized control trials are required to substantiate the results.

Assist Controlling Glucose Levels
There is now a growing number of studies with larger sample sizes showing that yoga can have positive impact on diabetes. For example, a recent Indian study from 2015 highlights the efficacy of yoga in controlling blood glucose levels in patients with DM2. The study was conducted at the Department of Physiology and Diabetic clinic of a teaching hospital over a period of two years. The subjects were 30 middle-age male diabetic patients and an equal number of non-diabetic volunteers made up the control group. The significant decrease in blood glucose levels after yoga in both the experimental and control groups indicates the potential role of yoga as preventive and treatment strategies for DM2. In addition, there is some reason to believe that yoga may rejuvenate or regenerate beta cells of the pancreas which can normalize insulin production.

Given its positive effects on metabolic regulation, physical well-being, and mental health, yoga can be considered as a cost-effective and non-invasive adjunct therapy for treating DM2. With few exceptions, the studies document beneficial changes in yoga program participants and suggest improvements in several risk indices mentioned previously such as glucose tolerance, insulin sensitivity, lipid profiles, blood pressure, oxidative stress, and pulmonary function. However, several of the current studies have small sample sizes which prevent the generalization of findings. The therapeutic potential of yoga in the face of a worldwide epidemic of diabetes warrants additional research, which will require more funding from our public health institutions. This would likely prove to be a valuable investment given that conventional pharmaceutical treatment comes with a number of side effects and limited efficacy. Yoga is potentially a highly cost-effective protocol to treat and prevent DM2 since it addresses the underlying causes along with symptoms.