Slow breathing improves blood sugar by reducing body’s endogenous production of glucose

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

Breathing Blueprint 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.  In this review, the authors examine key evidence showing that breathing can potentially improve glycemic response and insulin sensitivity.  

Let’s start with some statistics. 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 it might help reduce the costs and negative side effects of diabetics by improving our insulin sensitivity and glycemic control. Which is exactly what this paper examined.

One mechanism they found that explains why slow, relaxation breathing lowers blood sugar is reduction in sympathetic nervous system activity.  In short, the liver generates glucose via a process called gluconeogenesis.  When the sympathetic nervous system is activated, it increases this process, 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, reducing the amount of glucose produced by the liver and helping reduce our blood sugar.

They also examined several studies showing that slow breathing can restore insulin sensitivity.  There were no clear mechanisms as to how slow breathing improved insulin sensitivity, but the take-home point was that it does. We will have to wait on future studies to identify exactly what’s going on “under the hood.”

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 reduced glucose production by the liver.  The improved insulin sensitivity might also be related to this, but the precise mechanism is unknown.

In any case, I think it’s safe to say that practicing Principle 1 and Principle 2 is a good idea, especially for diabetics, to improve glycemic control and insulin sensitivity.

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:

Wilson T, Kelly KL, Baker SE. Review: Can yoga breathing exercises improve glycemic response and insulin sensitivity?. J Yoga Phys Ther. 2017;7(2). DOI: 10.4172/2157-7595.1000270.

Hypoxia has positive impacts on insulin and blood glucose levels while also increasing energy expenditure

Key Points

• Hypoxia positively impacts insulin and blood glucose while also increasing energy use

• Hypoxia and exercise combined reduce weight and blood pressure in obese patients

• The positive effects of hypoxia are dose-dependent

Breathing Blueprint Summary

I love review studies because they save us a lot of time.  Researchers go through all of the literature on a specific topic and consolidate everything into one place for us to read. I like to think of The Breathing Diabetic as a big review of all of the research on breathing, health, and well-being…

This paper reviewed the literature on the potential therapeutic benefits of hypoxia for obese individuals.  We know from other papers we have reviewed on hypoxia that there are many benefits for diabetics as well.  And, since diabetes and obesity often occur simultaneously, this review study is relevant for us.

One important point they make, which bears repeating, is that it is not feasible for us all to have access to high altitude.  We cannot simply move to the mountains, or somewhere close enough, to periodically expose ourselves to high altitude.  But, there are ways to experience some of the effects of altitude while at sea level.  The authors specifically mention masks and tents that can reduce the amount of inspired oxygen to simulate high altitude.  However, we cannot forget that breath holds also simulate high altitude and are available to us anytime, for free!

One of the key findings was that fasting blood glucose and insulin levels were reduced in animals following intermittent hypoxia.  Additionally, energy expenditure was increased in animals following hypoxic exposure.  Finally, hypoxia combined with exercise (what they called “active hypoxia”) decreased body weight and blood pressure in obese humans.

They also found contradictory results in some studies, which appeared to be due to the severity of the hypoxia protocol used (something we have reviewed previously). Thus, again we see that the benefits of hypoxia are dose-dependent.

Overall, the authors conclude that hypoxia could be beneficial for obese populations. However, the improvements in insulin, blood glucose, weight, and blood pressure shown here are further evidence that intermittent hypoxia (Principle 3) can benefit anyone looking to improve overall health and well-being.

Abstract From Paper

Normobaric hypoxic conditioning (HC) is defined as exposure to systemic and/or local hypoxia at rest (passive) or combined with exercise training (active). HC has been previously used by healthy and athletic populations to enhance their physical capacity and improve performance in the lead up to competition. Recently, HC has also been applied acutely (single exposure) and chronically (repeated exposure over several weeks) to overweight and obese populations with the intention of managing and potentially increasing cardio-metabolic health and weight loss. At present, it is unclear what the cardio-metabolic health and weight loss responses of obese populations are in response to passive and active HC. Exploration of potential benefits of exposure to both passive and active HC may provide pivotal findings for improving health and well being in these individuals. A systematic literature search for articles published between 2000 and 2017 was carried out. Studies investigating the effects of normobaric HC as a novel therapeutic approach to elicit improvements in the cardio-metabolic health and weight loss of obese populations were included. Studies investigated passive (n = 7; 5 animals, 2 humans), active (n = 4; all humans) and a combination of passive and active (n = 4; 3 animals, 1 human) HC to an inspired oxygen fraction (FIO2) between 4.8 and 15.0%, ranging between a single session and daily sessions per week, lasting from 5 days up to 8 mo. Passive HC led to reduced insulin concentrations (-37 to -22%) in obese animals and increased energy expenditure (+12 to +16%) in obese humans, whereas active HC lead to reductions in body weight (-4 to -2%) in obese animals and humans, and blood pressure (-8 to -3%) in obese humans compared with a matched workload in normoxic conditions. Inconclusive findings, however, exist in determining the impact of acute and chronic HC on markers such as triglycerides, cholesterol levels, and fitness capacity. Importantly, most of the studies that included animal models involved exposure to severe levels of hypoxia (FIO2 = 5.0%; simulated altitude >10,000 m) that are not suitable for human populations. Overall, normobaric HC demonstrated observable positive findings in relation to insulin and energy expenditure (passive), and body weight and blood pressure (active), which may improve the cardio-metabolic health and body weight management of obese populations. However, further evidence on responses of circulating biomarkers to both passive and active HC in humans is warranted.

Journal Reference:

Hobbins L, Hunter S, Gaoua N, Girard O. Normobaric hypoxic conditioning to maximize weight loss and ameliorate cardio-metabolic health in obese populations: a systematic review. Am J Physiol Regul Integr Comp Physiol. 2017;313:R251-R264.