We all know that regularly practicing yoga makes us limber, improves cognitive abilities, releases tension and anxiety, reduces brain fog and energy slumps, and improves overall wellness.
And yoga has also been shown in published research to support healthy immunity.
Immunity is a complex system, perhaps the most complicated and nuanced in the body. In general, there are three types.
Innate immunity: This immune function is “innate” meaning that we are born with it, and it is a primary defense system, the first to detect invasive organisms such as viruses, bacteria, fungi and parasites as well as toxins that are foreign and potentially harmful. Once an “evildoer” is detected, the innate immune system calls forth cells to arrest and destroy it.
Adaptive immunity: The adaptive immune system charges into action if any of the above foreign matter successfully passes through the innate system, which sends out SOS signals to adaptive cells. Therefore, the adaptive immune system is the second line of defense and is also critical in function. At this point, the adaptive immune cells kick into action when they recognize the destructive agent, then launch an appropriate response attack. As described by one source, “By adapting to a particular bacteria or virus, and remembering them, our bodies can become immune to future invasions. These cells are pretty aggressive. They check the protein markers of all cell membranes, like a ticket inspector, making sure they are meant to be there. If they are not, it goes into terminator mode.”
Yoga is an increasingly popular practice that combines mind-body exercises. Human clinical research continues to evaluate how it affects health. One systematic review summarized the results of 15 randomized control trials that looked at the effects of yoga on immune system function. The study authors found a general pattern that practicing yoga potentially downregulates pro-inflammatory markers, such as a reduction in interleukin 1beta, interleukin 6 and TNF-alpha. They also noted that yoga may also enhance cell-mediated and mucosal immunity.
In people with hyper-sensitive immune function, stressors can provoke even more vigilant action, which expresses itself as a variety of discomforts. An inappropriate immune response can galvanize an inflammatory cascade, which reduces wellness. One study evaluated how eight weeks of yoga affected psycho-neuro-immune markers and quality of life in 66 individuals with immune-aggravated joint discomfort.
The participants were assessed for a panel of inflammatory cytokines (IL-6, IL-17A, TNF-alpha, and TGF-beta), mind-body communicative markers (BDNF, DHEAS, beta-endorphin, and sirtuin) and transcript levels of various genes (IL-6, TNF-alpha, NFKB1, TGF-beta, and CTLA4). At the study’s conclusion, the yoga group exhibited significant improvements in the levels of markers, which influenced the psycho-neuro-immune axis with an estimated effect size from small to medium range. The yoga group showed downregulation of IL-6, TNF-alpha, and CTLA4 and upregulation of TGF-beta. “Thus the adoption of YBLI decreases systemic inflammation by its beneficial effects on psycho-neuro-immune axis and normalization of dysregulated transcripts,” they concluded.
Another study compared practicing yoga breathing exercises to a control group who read their choice of material, for 20 minutes each group of 10 participants. Using a tool called Cytokine Multiplex at various intervals in the time allotted, the authors found that salivary samples showed significant reduction of interleukin 8 in the yoga group over the control group. The authors concluded, “These data are the first to demonstrate the feasibility of detecting salivary cytokines using multiplex assay in response to a yoga practice.”
Yoga was also found to help the body resist autonomic changes and immune impairment during times of extreme examination stress. In this study on 60 students randomly assigned to perform yoga or a control group, found that 12 weeks of practicing yoga had immune-protective benefits. In the yoga group, according to the researchers, “no significant difference was observed in physiological parameters during the examination stress, whereas in the control group, a significant increase was observed. Likewise, the indicators of psychological stress showed highly significant difference in control group compared with significant difference in yoga group.”
Yoga and Metabolic Health
Yoga has also been clinically studied for a range of other specific health benefits. For example, it can promote heart health and modulate related factors of metabolic syndrome. One systematic review of 37 randomized controlled trials and random-effects meta-analysis of 32 RCTs comprehensively compared risk factors of cardiovascular disease and metabolic syndrome between a group practicing yoga and those who did not exercise. Analysis showed that those who practiced yoga regularly showed statistically significant improvements in body mass index, systolic and diastolic blood pressure, total cholesterol, low-density lipoprotein cholesterol levels, and high-density lipoprotein cholesterol levels, triglycerides and heart rate. Here, the authors declared that their study showed “promising evidence of yoga on improving cardio-metabolic health.”
Yet another systematic review and meta-analysis looked at the effects of yoga on cardiovascular risk factors in the general population; this study analyzed data from 44 RCTs totaling 3,168 participants. Similar to the outcomes of the aforementioned work, there were marked improvements in blood pressure (systolic and diastolic), heart rate, respiratory weight, waist circumference, total cholesterol and triglycerides. This data analysis also found improvements in HbA1C levels and insulin resistance.
Yet another large-scale data analysis project – a systematic review and meta-analysis of 12 RCTs and 2 non-randomized controlled trials lasting between 4 and 52 weeks found benefit of yoga on metabolic and cardiovascular factors. According to the researchers, compared to the controls, “yoga intervention improved fasting blood glucose, low-density lipoprotein, triglycerides, total cholesterol, and systolic blood pressure. This meta-analysis uncovered clinically improved effects of yoga intervention on glycemic control, lipid profiles and other parameters of blood sugar management a prediabetic population.”
The aim of another systematic review and meta-analysis was to investigate and quantify the effects of yoga on weight. Analyzing the results of 30 trials with 2,173 participants, the authors concluded that practicing yoga can be a safe way to reduce body mass index in overweight and obese individuals.
Yoga, once it was rediscovered in the past 50 years, has grown exponentially and resonates with younger generations – with each new younger generation. Beyond clinically shown health benefits, the increased sense of well-being generates a higher sense of improved quality of life. Benefits can be had for anyone at any age, weight or condition.