Background: Yoga is found to be effective in reducing stress levels and radiation-induced DNA damage, and improving the quality of life, in breast cancer patients. The present study was aimed at comparing the apoptotic index (AI) and DNA damage of advanced yoga practitioners with those of breast cancer patients.
Materials and methods: This cross-sectional pilot study compared three groups (n = 9 each) of age-matched subjects viz. (1) Carcinoma breast patients in stage II or III undergoing radiation therapy after completing three cycles of chemotherapy; (2) Senior yoga practitioners who were practicing asanas, pranayama and meditation daily for more than 10 years; and (3) Normal healthy volunteers. Peripheral blood lymphocytes were isolated, and qualitative DNA damage (QDD) and AI were evaluated by single-cell gel electrophoresis assay. Approximately 500 cells were counted in each case. Number of cells that were normal, undergoing apoptosis, and with DNA damage were categorized and percentages were calculated.
Results: Data being normally distributed, one-way analysis of variance (ANOVA) showed significant interaction between groups in AI (P = 0.016) and QDD (P = 0.045). On post-hoc analysis using Scheffe test, AI was significantly lower in non-yoga volunteers as compared with the breast cancer group (P = 0.019) and QDD was significantly lower in yoga practitioners when compared with non-yoga volunteers (P = 0.047).
Conclusion: Cellular dysfunction (QDD) requires restorative mechanisms (AI) to restore the system to a balance. The results of this pilot study show trends, which indicate that in ill-health, there is inadequate restorative mechanisms (AI) although dysfunction (QDD) is high. Through regular practice of yoga, cellular dysfunction can be lowered, thus necessitating reduced restorative mechanisms. AI and QDD could also be useful indicators for predicting the three zones of health viz. disease, health, and positive health.
Keywords: Apoptotic index; DNA damage; breast cancer; comet assay; yoga.