Vadiraja, H.S., Raghavendra, R.M., Nagarathna, R., Nagendra, H.R., Rekha, M., Vanitha, N., . . . Kumar, V. (2009). Effects of a yoga program on cortisol rhythm and mood states in early breast cancer patients undergoing adjuvant radiotherapy: A randomized controlled trial. Integrative Cancer Therapies, 8, 37–46.
To compare effects of an integrated yoga intervention with those of a brief supportive intervention on salivary cortisol levels and mood in patients with early breast cancer undergoing adjuvant radiotherapy
Patients were randomly assigned to a six-week yoga intervention or a control group. The yoga intervention included a set of asanas (postures), breathing exercises, meditation, and yogic relaxation techniques with imagery. Individual hour-long sessions were to be attended at least three times per week for six weeks during radiation treatments. These were administered by a trained yoga therapist. The control intervention was brief supportive therapy with education that was routinely offered to all patients. Control patients and caretakers underwent counseling sessions for 15 minutes every 10 days with a social worker as well. Study data were collected at baseline and at the end of the study period. Patients were asked to provide saliva samples three times per day for three consecutive days before and after radiotherapy. Specific procedures for saliva collection, storage, and immunoassay were followed.
Patients were undergoing the active treatment phase of care.
A randomized controlled trial design was used.
There were no significant effects of the yoga intervention on cortisol results overall; however, the mean pooled diurnal cortisol and 6 am cortisol levels were lower in the yoga group (p < 0.05). There were significant declines in anxiety levels in both groups. ANCOVA showed a significant decrease in reported anxiety in the yoga group compared to controls (p < 0.001). Depression declined in both groups over time. ANCOVA showed a significant decrease in reported depression in the yoga group compared to controls (p = 0.002). There was a significant decrease in perceived stress in the yoga group (p < 0.001), but not in the control group. Effect sizes seen were 0.31 for anxiety and depression scores and 0.36 for perceived stress.
Results suggest decreases in anxiety, depression, perceived stress, and 6 am and pooled mean cortisol levels with the yoga intervention used here.
Findings show that anxiety and depressive symptoms decline over time among patients in active treatment with adjuvant radiation therapy in women with breast cancer. Participation in stress reduction interventions, such as yoga, may augment this decline. Changes in cortisol findings seen here with yoga suggest that effects may be attributed to stress reduction, rather than attention, social support, and education alone. Further research in this area is warranted to determine efficacy of yoga in other patient groups, and association with other patient symptoms and problems associated with anxiety and depression.