2. Yoga and Qigong in Health and Disease
Mind-body therapies (MBTs), such as yoga and qigong, are currently used in the West as alternative/complementary approaches to the management of disease, especially chronic problems for which there is no effective conventional treatment. These two popular systems of self-performed bodily exercises are applied to the maintenance of a healthy state of the body and mind
[2].
2.1. Immune System and Inflammation
Several conditions that are responsive to yoga and qigong practices, such as fatigue, depression, and pain, comprise inflammatory processes
[10], which may explain researchers’ growing interest in the impact of MBTs on inflammatory markers
[11][12]. Overall, the findings of Morgan et al. suggest that MBTs may reduce inflammation, particularly among clinical populations, as evidenced by the significant reductions in C-reactive protein (CRP)
[13].
Vanketesh et al.
[12] observed a downregulation of the inflammatory response in chronic disease through yoga practice. This had been previously reported by Falkenberg et al.
[14], even though the existing evidence is not entirely consistent. In particular, decreases in IL-1 beta, IL-6, and TNF-alpha have been described in RCTs
[14]. The authors hypothesized that longer periods of yoga practice are necessary in order to attain consistent effects on circulating inflammatory markers.
According to Bower and Irwin
[11], the evidence for the effects of MBTs on IL-6 and other inflammatory markers was diverse, with the majority of the studies showing no changes. Of note, the studies with no significant alterations of the inflammatory markers presented beneficial effects on various symptoms, improving the patients’ health status
[11][15].
2.2. Lower Back Pain
Lower back pain (LBP) is a condition affecting most people, and it results in functional limitations due to the lack of an effective treatment
[16].
Yoga is a good therapeutic approach to LBP treatment, with the majority of the RCT studies showing pain reduction, improvement of psychological distress, and increased energy levels
[16]. However, there is limited research on how the practice of yoga relieves back pain
[16]. It is assumed that the mind–body connection in yoga, which is achieved by mentally focusing on breath and movement, may provide benefits to LBP patients
[16]. Through this focus, yoga may modify the perception of pain; it has been shown that yoga practitioners have larger pain thresholds during thermal and pain threshold tasks
[17]. For spine-related conditions, the core point is that yoga postures make use of unusual positioning in which the body weight is supported by the arms, hips, or muscles of the body. By pitting one muscle group against another, such as in forward bends, each group—agonist and antagonist—is equally exerted and, thereby, strengthened.
Concerning qigong, there are very few studies on chronic LBP, so it is not clear if qigong can be useful in LBP treatment
[16]. It was observed that qigong significantly decreased pain intensity, back functional impairment, heart rate, and respiratory rate, and it increased range of motion, core muscle strength, and mental status in office workers with chronic non-specific lower back pain compared to a waiting-list control group
[18]. On the other hand, Park et al. conducted a narrative review of RCTs that included an active control group, reporting that qigong was not more effective than physical exercise or other alternative therapies
[16]. In the only study comparing the effects of yoga and qigong on the reduction of chronic LBP, Teut et al.
[4] showed that neither yoga nor qigong was better than no treatment in reducing pain and increasing quality of life (QoL).
2.3. Mood Disorders, Sleep Disturbance, Cognitive Impairment, and QoL
Depression is excessively common in people with chronic pain; MBTs (including both yoga and qigong) provide small to moderate reductions of depressive symptoms in the chronic pain context
[19]. However, this research area is still underdeveloped
[19].
People come to yoga classes with a wide array of emotional conditions. For those experiencing depression, yoga can be helpful, as yoga classes may create space for healing emotional traumas and for achieving a steadier sense of serenity
[20]. Yoga may serve as an efficacious supplement to pharmacotherapy, psychotherapy, and healthy lifestyle interventions for people with mental disorders
[21].
Stress reduction seems to be one of the most important benefits of qigong, in which the mind is used to guide activation and deactivation patterns through imagination
[22]. According to Saed et al., qigong has shown inconsistent effectiveness as a complementary treatment for depression and anxiety
[23]. On the other hand, according to Yeung et al.
[24], there is preliminary evidence that qigong may be potentially beneficial for the management of depressive and anxiety symptoms in healthy adults and patients with chronic illnesses. Guo et al. found that qigong-based exercises may be effective for alleviating depression symptoms in individuals with major depressive disorder
[25]. In the context of drug abuse, Liu et al.
[26] suggested that qigong may alleviate anxiety symptoms. However, the authors recommended that their results should be interpreted with caution given the limited numbers of RCTs and their methodological weaknesses
[24][25][26].
In comparison with an inactive control, yoga and qigong significantly reduced insomnia symptoms and improved sleep quality
[27]. These practices may also improve cognitive function
[28][29] everyday activities functioning, memory, resilience, and mindfulness in older adults with mild cognitive impairment, but further research evidence is still needed to make a more conclusive statement
[29]. Yoga may improve cognitive functions—particularly attention and verbal memory—in patients with mild cognitive impairment
[30]. This may occur through improved sleep, mood, and neural connectivity
[30]. Additionally, Weber et al.
[31] found that yoga and qigong seem to positively influence QoL, depressive symptoms, fear of falling, and sleep quality in old adults without mental health conditions.
2.4. Cardiovascular, Neurologic, Respiratory, and Metabolic Diseases
The practice of qigong reduces the systolic and diastolic blood pressure in comparison with those of control groups
[6][32][33]. Qigong may be an alternative non-pharmacological strategy for hypertension management, namely, in an elderly population group that usually takes too many medications
[6]. In patients in an early stage of recovery from stroke, qigong showed more changes than conventional respiratory training in the improvement of trunk control ability, respiratory muscle functions, and ability to perform daily life tasks
[34].
Yoga might be considered as an effective adjuvant for patients with various neurological disorders, such as stroke, Parkinson’s disease, multiple sclerosis, epilepsy, Alzheimer’s disease, dementia, headache, myelopathy, and neuropathies
[35].
Reychler et al.
[36] found that qigong and yoga improve the main symptoms of chronic obstructive pulmonary disease. Both therapies produced an effect that was slow but increased with time, with a good rate of adherence and long-lasting effects. Yoga (including
pranayama) has been suggested as an adjuvant therapy in the treatment of childhood asthma, although it cannot yet be recommended as a standard of care due to the insufficiency of data on its efficacy
[37]. A Cochrane review on this pathology showed moderate-quality evidence that yoga may provide small improvements in asthma patients’ symptomatology
[38]. In patients with respiratory diseases, namely, asthma,
pranayama has physiological and psychological benefits, although more high-quality RCTs are required to obtain definitive evidence
[39].
Yoga may promote significant improvements in the management of type 2 diabetes (DM2), as shown by the glycemic control (including HbA1c)
[40][41], lipid levels
[40][41], and body composition
[41]. More limited data suggest that yoga may also lower oxidative stress and blood pressure, enhance pulmonary and autonomic function, mood, sleep, and QoL, and reduce medication use in adults with DM2
[41]. Qigong was not found to have any advantages in reducing fasting blood glucose or postprandial blood glucose in patients with DM2, but demonstrated better control of HbA1c than that of other aerobic exercises
[42].
Cramer et al.
[43], who based their meta-analysis on the use of yoga for the management of metabolic syndrome, stated that no recommendation could be made for or against yoga’s effects on the parameters of metabolic syndrome. However, they also stated that, in spite of the methodological problems found in the evaluated studies, yoga could be preliminarily considered an effective intervention for reducing waist circumference and systolic blood pressure in people with metabolic syndrome who do not want to practice conventional forms of exercise
[43]. Regarding qigong, Zou et al.
[33] suggested that it might be an effective intervention for improving the risk factors for cardiovascular disease in the metabolic syndrome.
2.5. Cancer
Yoga and qigong have been shown to improve the anxiety and mood changes that are commonly associated with pain in cancer patients, even though these MBTs were not able to reduce the pain
[44]. Evidence supports recommending yoga for the improvement of psychological outcomes and, probably, physical symptoms in adult cancer patients undergoing treatment
[45]. For childhood patients, the evidence is insufficient
[45].
Gentle hatha and restorative yoga are effective practices for treating sleep disruption, cancer-related fatigue, cognitive impairment, psychosocial distress
[45][46], and musculoskeletal symptoms in cancer survivors and cancer patients under treatment
[46].
As an adjuvant therapy, yoga seems effective for QoL improvement in women with breast cancer, with better results with increasing intervention time
[47]. Specifically, it seems to increase the psychological and social wellbeing of breast cancer survivors by helping to restore their body image and self-esteem and easing the return to their previous daily lives
[47]. Future directions for yoga research in oncology should comprise: enrollment of participants with various cancer types, standardization of self-reported assessments, general use of active control groups and objective measures, and addressing yoga interventions’ heterogeneity
[48].
Concerning qigong, and according to some authors, evidence on QoL improvement has not yet been established
[47][49], but according to other authors, qigong seems to be a good strategy for cancer-related symptoms and QoL in cancer survivors
[50], at least in women with breast cancer
[51].
As described for yoga, statistically significant and clinically meaningful effects of qigong interventions were observed for symptoms of fatigue
[52][53], sleep quality
[53], and immune function
[52] in cancer patients. Additionally, Carlson et al.
[54] reported that both qigong and yoga might improve QoL in these patients.
2.6. Menopause Symptoms
Shepherd-Banigan et al. reviewed studies on the efficacy of yoga and qigong on the improvement of symptoms of peri- or post-menopausal women, namely, vasomotor symptoms, psychological symptoms, and QoL
[55]. The authors did not identify any systematic reviews or RCTs using qigong in this context
[55]. Concerning yoga, small to moderate benefits in the reduction of hot flash severity and psychological symptoms were observed, without an impact on QoL
[55]. On the contrary, Cramer et al. reported that yoga can reduce psychological, somatic, vasomotor, and urogenital menopausal symptoms
[56]. A more recent meta-analysis on menopause symptoms found that yoga significantly improved physical QoL, but its effects on the general, psychological, sexual, and vasomotor symptom QoL scores were not significant
[57].
3. Conclusions
Summing up, yoga and qigong have resulted from thousands of years of experience in using mind–body practices to treat diseases, promote health and longevity, improve fighting skills, and achieve different levels of development of awareness and spirituality.
Yoga and qigong seem to have similar effects; this may be expected, since both are comparable mind–body approaches. There are many similarities between them, and their overall purpose is the same, even though the way in which they achieve it may be slightly different. In general, they have been used for similar health conditions, even though more research has been conducted on yoga in comparison with qigong. Moreover, for yoga, most trials have been conducted on relatively younger healthy participants across India and the United States, while for qigong, most trials have been conducted with relatively older ill people in China and the United States [20].
Participants’ preferences between yoga and qigong apparently differ, but this is probably due to the lower availability of qigong classes and the comparative lack of knowledge about qigong.
Studies comparing yoga and qigong (such as those proposed in the previous section) are warranted in order to assess differences/similarities between the two approaches in the health context. As far as we know, such studies have not been published to date, but are certainly needed.