Table 1.
Description of the Studies.
| First Author (Year) | Location; Design | Quality Ratinga | Diagnosis (Total Sample); Group n; Mean Age (SD) | Yoga Type; Components | Control Group | Frequency × Session Length × Intervention Duration = Total Dose in Minutes | Inflammatory Biomarkers | Outcomes on Inflammatory Biomarkers From Baseline to Post Yoga Intervention |
|---|---|---|---|---|---|---|---|---|
| Bower et al. (2014) | USA; RCT | Excellent | Breast cancer Stages 0–II (N = 31); YG (n = 16), CG (n = 15); x̅ age = 54 (5.4) | HY/IY; postures, breathing | HE | 2/week × 90 min × 12 weeks = 2,160 min | NF-κB, GR, sTNF-RII, IL-1, IL-6, CRP, CREB, and salivary cortisol | No changes in CRP, IL-1, IL-6 or diurnal cortisol. Reduced NF-κB, increased activity of the CREB (all p < .05). sTNF-RII plasma levels remained stable in the yoga group compared to the control group (p = .028) after 12 weeks of yoga |
| Cho et al. (2015) | Republic of Korea; non-RCT | Excellent | Premenopausal women with CLBP (N = 25); YG (n = 14), CG (n = 11); x¯ age = 43.3 (7.5) | HY; postures, breathing, meditation | UC | 3/week × 60 min × 12 weeks = 2,160 min | CRP, TNF-α, and cortisol | TNF-α maintained in the yoga group, whereas TNF-α significantly increased in the control group (p < .01). Serum cortisol level significantly decreased in the yoga group (p < .05) after 12 weeks of yoga |
| Harkess et al. (2016) | Australia; subsample of large RCT | Average | Chronically stressed women (N = 26); YG (n = 11), CG (n = 15); x¯ age = 41 (4.3) | HY/Ashtanga; postures, breathing, meditation | WL | 1/weekb × 60 min × 8 weeks = 480 min | Il-6, TNF, CRP, and LINE-1 methylation | No significant findings after 8 weeks of yoga. However, methylation of the TNF region in the yoga group was reduced relative to the waitlist control group, but the change was not statistically significant |
| Kiecolt-Glaser et al. (2014) | USA; RCT | Excellent | Breast cancer Stages 0–III (N = 200); YG (n = 100), CG (n = 100); x¯ age = 51.6 (9.2) | HY; postures, breathing | WL | 2/week × 90 min × 12 weeks = 2,160 min | IL-6, TNF-α, and IL-1B | IL-6 (p = .027), TNF-α (p = .027), and IL-1B (p = .037) were lower for yoga participants compared with the CG at 3 months’ follow-up, but not after 12 weeks of yoga |
| Parma et al. (2015) | USA; non-RCT | Excellent | Breast cancer survivors Stages I–II (N = 94); YG (n = 31), CE (n = 31), C (n = 32); x¯ age = 56.2 (7.9) | HY; not described, postures mentioned in the text | CE (second arm) and any exercise (third arm) | 3/week × 60 min × 24 weeks = 4,320 min | IL-6, IL-8, TNF-α, and CRP | No significant differences among groups after 24 weeks of yoga. Note. YG had attrition of 11 participants |
| Pullen et al. (2008) | USA; RCT | Average | HF (N = 19); YG (n = 9), CG (n = 10); YG x¯ age = 52.1 (3.3), CG x¯ age = 50.5 (12.8) | HY; postures, breathing, meditation | UC | 2/week × 70 min × 8 weeks = 1,120 min | IL-6, hs-CRP, and EC-SOD | Statistically significant reductions in serum levels of IL-6 and hs-CRP and an increase in EC-SOD in the YG group (p < .005) after 8 weeks of yoga |
| Pullen et al. (2010) | USA; RCT | Average | HF (N = 40); YG (n = 21), CG (n =19); YG x¯ age = 55.8 (7.6), CG x¯ age = 52.5 (12.7) | HY; postures, breathing, meditation | UC | 2/week × 60 min × 8 weeks = 1,080 min | IL-6, CRP, and EC-SOD | IL-6 (p = .004) and CRP (p = .016) were reduced, and EC-SOD (p = .012) was increased after 8 weeks of yoga |
| Rajbhoj et al. (2015) | India; RCT | Average | Industrial workers w/chronic stress (N = 48); YG (n = 24), CG (n = 24); YG x¯ age = 40.7 (6.8), CG x¯ age = 40.2 (6.3) | Not identified; postures, breathing, “om” chanting | WL | 6/week × 45 min × 12 weeks = 3,240 min | IL-10 and IL-1B | YG showed a significant decrease in IL-1 β and a significant increase in IL-10 (p < .05 for both) after 12 weeks of yoga |
| Rao et al. (2017) | India; RCT | Excellent | Metastatic breast cancer, Stage IV (N = 91); YG (n = 45), CG (n = 46); YG x¯ age = 48.9 (9.1), CG x¯ age = 50.2 (9.2) | Not identified; postures, breathing, meditation, relaxation w/imagery, philosophical concepts of yoga | Ed and STS | 2/week × 60 min × 12 weeks = 1,440 min | Salivary cortisol, and NK cells | Significant decrease in morning waking cortisol (p < .05) and improvement in NK cell % (p = .03) in YG compared to CG after 12 weeks of yoga |
| Sarvottam et al. (2013) | India; one-group pre–post | Fair | Overweight or obese men (N = 51); x¯ age = 39 (12.2) | Not identified; postures, breathing, nutrition counseling, yoga theory | N/A | 1/day × 120 min × 10 days = 1,200 min | IL-6, adiponectin, and ET-1 | Plasma levels of IL-6 decreased significantly (p = .012) and adiponectin increased significantly (p = .014) following 10 days of yoga compared with baseline. There was no significant change in the levels of plasma ET-1 |
| Shete et al. (2017) | India; RCT | Excellent | Industrial workers with prolonged stress (N = 48); YG (n = 24), CG (n = 24); x¯ age 41.5 (5.2) | Classical yoga; postures, breathing | WL | 6/week × 60 min × 12 weeks = 4,320 min | IL-6, TNF-α, and hs-CRP | Hs-CRP (p < .01), IL-6 (p < .001), and TNF-α (p < .001) significantly reduced in the YG after 12 weeks of yoga |
| Singh et al. (2011) | India; RCT | Average | Rheumatoid arthritis (N = 80); YG (n = 40), CG (n = 40); YG x¯ age = 35.1 (7.3), CG x¯ age = 34.7 (7.3) | Not identified; postures, cleansing practices, healthy yoga diet, breathing, meditation | WL | 6/week × 90 min × 7 weeks = 4,410 min | Lymphocyte count, CRP, and uric acid | CRP, uric acid levels, and lymphocyte count all significantly reduced (p < .01 for all three) in the YG after 7 weeks of yoga |
| Sohl et al. (2016) | USA; RCT-pilot | Excellent | Colorectal cancer Stages 0–IV (N = 15); YG (n = 6), CG (n = 5); median age = 61 | Not identified; movement, breathing, awareness meditation, and relaxation | AC | 3 every 2 weeks × 15 min × 8 weeks = 180 min | IL-6, IL-1, soluble TNF receptor 1, TNF-α, and CRP | No significant differences after 8 weeks of yoga due to underpowered sample |
| Wolff et al. (2015) | Sweden; three-group matched participants design | Average | Adults with diagnosed HTN (N = 83); YG1 (n = 28) YG2 (n = 28), CG (n = 27); YG1 x¯ age = 66.2 (7.7), YG2 x¯ age = 65 (10.3), CG x¯ age = 60.8 (11) | Kundalini; postures, breathing, meditation | Yoga at home (2nd arm) and UC (3rd arm) | 1/week × 60 min × 12 weeks = 720 min | hs-CRP and IL-6 | No significant group differences after 12 weeks of yoga |
| Yadav et al. (2012) | India; one-group, pre–post | Fair | Patients with chronic inflammatory diseases (N = 86); x¯ age = 40.1 (13.9) | Not identified; postures, breathing, nutrition counseling, yoga theory | N/A | 1/day × 120 min × 10 days = 1,200 min | IL-6, TNF-α, cortisol, and β-endorphins | Mean cortisol (p = .001), IL-6 (p = .036) and TNF-α (p = .002) levels decreased and mean β-endorphin levels increased (p = .024) from baseline to after 10 days of yoga |
Note. AC = attention control; C = comparison exercise; CE = comprehensive exercise; CG = control group; CLBP = chronic lower back pain; CREB = cAMP response element-binding protein; CRP = C-reactive protein; EC-SOD = extracellular superoxide dismutase; Ed = education; ET-1 = endothelin-1; GR = glucocorticoid receptor; HE = health education; HF = heart failure; hs-CRP = high-sensitivity C-reactive protein; HTN = hypertension; HY = hatha yoga; IL = interleukin; IY = Iyengar yoga; LINE-1 = long interspersed nuclear element 1; N/A= not applicable; NF-κB = transcription factor nuclear factor kappa B; NK = natural killer; RCT = randomized controlled trial; STS = supportive therapy sessions; sTNF-RII = soluble tumor necrosis factor receptor Type II; TNF-α = tumor necrosis factor-α; UC = usual care; WL = waitlist control; YG = yoga group.
a Yates, Morley, Eccleston, and Williams (2005) and NIH: National Heart, Lung, and Blood Institute (2018).
b Yoga intervention was offered 2 times per week, but only 1 time per week was counted as completion.