Can Yoga prevent cancer development by reduction in DNA damage?
I asked myself this question after reading through a peer reviewed paper titled “Comparison of lymphocyte apoptotic index and qualitative DNA damage in yoga practitioners and breast cancer patients: A pilot study.” which was published in Jan 2013 by an Indian research group in India. The pilot experiment was small, consisting of only 27 people. There are three groups tested - (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 with no experience of yoga. Peripheral blood lymphocytes were isolated and qualitative DNA damage was measured using comet assays.
The initial findings did suggest that group 2 cohorts with senior yoga practitioners did have a smaller % of DNA damage relative to healthy & cancer patients. However, as chemotherapy increases DNA damage in healthy cells, the data doesn’t mean much. This is a very poorly designed experiment. Also, there are other downstream markets of apoptosis including caspase 3/7 assays which could give a better indication of DNA-damage induced cell death. Furthermore, it would be interesting to look at the breast carcinoma tissues for specific DNA damage rather than a generic blood DNA assay could also yield better insight.
Despite the shortcomings of the experiment and clinical design of this research, what caught my attention is the notion that prevention is better than cure, and it is worthwhile to pursue further research in comparing DNA damage levels between yoga practitioners and non-yoga practitioners with a similar age range & geography, both sets with no known hereditary cancer in the family and monitor at regular time intervals throughout their life time and following up on their incidence of specific cancer incidence rates. Similarly, it would be interesting to conduct further in vitro studies to determine whether yoga can contribute to lower DNA damage in healthy cells based on this preliminary finding, and how? It is through the classical BRAC1/2 genetic pathways or others? So far, the only known physiological effect backed up by clinical study is that yoga can reduce cortisol level, which is related to stress and cancer prognosis outcome. Hence, unravelling other effect on yoga on human biochemical or physiological pathway would help better articulate how the ancient yoga practice can confer health benefits using modern day medical terminologies and studies.