Review: Can yoga breathing exercises improve glycemic response and insulin sensitivity? - Wilson et al. (2017)
Key Points
Slow breathing lowers blood sugar by reducing the liver’s production of glucose
Slow breathing increases insulin sensitivity
Slow breathing might be a no-cost beneficial intervention for diabetics
The Breathing Diabetic Summary
This is a follow on to the previous Wilson et al. (2013) paper that described how a relaxation breathing exercise improved glycemic response in healthy college-aged humans. Here, the authors review other key evidence showing that breathing can potentially improve glycemic response and insulin sensitivity. This subject is especially important to the diabetic community because breathing is a no-cost intervention that could potentially improve our overall health.
To motivate their review, they cite some numbers on diabetes in the U.S. Can you believe that in 2013, ~9.3% of Americans had diabetes?!? That’s insane. And, pharmacy costs added up to ~$18 billion! Breathing might not cure diabetes, but maybe it can help reduce the costs and negative side effects of diabetics by improving our insulin sensitivity and glycemic control, which is what this paper examined.
One mechanism that might explain why slow, relaxation breathing lowers blood sugar is due to the reduction in sympathetic activity. In short, the liver generates glucose via a process called gluconeogenesis. When the sympathetic nervous system is activated, it increases this process, thus increasing the body’s endogenous production of glucose. Other stress hormones, such as adrenaline, also increase the liver’s production of glucose. By breathing slowly, we shift out of this sympathetic state, thus reducing the amount of glucose produced by the liver and helping reduce our blood sugar. Pretty awesome!
They also describe how slow breathing could potentially restore insulin sensitivity. Most of the studies they cite do not have specific mechanisms explaining how this might be happening. But, several studies have shown improved insulin sensitivity through slow breathing. My speculation is that, because slow breathing will improve tissue oxygenation through the Bohr effect, and because we know chronic tissue hypoxia can cause insulin resistance, this might partially explain these results. Regardless of the exact mechanism, the scientific literature shows that slow breathing exercises can increase insulin sensitivity, which is the key point for us.
Overall, this review showed scientific evidence that breathing exercises can improve glycemic control and increase insulin sensitivity. The glucose-lowering effect of slow breathing is likely due to reduced sympathetic activity and subsequently reduced glucose production by the liver. The improved insulin sensitivity is likely also related to reduced sympathetic output, but might also be due to improved tissue oxygenation. See the overview of Principle 2 for more on the benefits of slow breathing for diabetes.
Abstract from Paper
This is the first review of the literature on the effects of slow breathing on glycemic regulation and insulin sensitivity. While many studies have investigated the effects of yoga on individuals with diabetes, few studies have specifically focusing on the isolation of slow breathing as the principle factor in their intervention. While it is difficult to separate the exercise-related effects of yoga, there is considerable evidence that a breathing intervention is capable of increasing insulin sensitivity and improving glycemic regulation. This appears to be true both acutely and chronically in healthy individuals and those with diabetes. Yoga pranayama and the slow breathing practices that are fundamental to yoga represent a relatively low-cost and under-utilized intervention for individuals with conditions related to altered glycemic regulation and insulin sensitivity. More studies should focus on pranayama and slow breathing maneuvers to better clarify the role of respiratory modulation on glucose metabolism and insulin response.
Journal Reference:
Ted Wilson, Kevin L Kelly and Sarah E Baker, (2017) Review: Can yoga breathing exercises improve glycemic response and insulin sensitivity?, Journal of Yoga & Physical Therapy, 7 (2), DOI: 10.4172/2157-7595.1000270.