NEW DELHI: A study, conducted by researchers at the Washington State University, has found that the immunity system of breast cancer survivors improved significantly after practising the Iyengar form of yoga.

Created by B K S Iyengar, based on the traditional eight limbs of yoga as expounded by Patanjali in his Yoga Sutras, this yoga form emphasises the development of strength, stamina, flexibility and balance, as well as concentration and meditation.

Considered to be a more active form of yoga, researchers reported on Monday at the American Physiological Society meeting in Washington DC that in breast cancer survivors, the Iyengar method not only promoted psychological well-being but also benefited the patients' immune system.

According to lead researcher Pamela E Schultz, practising the yoga form resulted in decreased activation of an important immune system protein called NF-kB in patients, which is a marker of stress in the body.

"So it's possible," Schultz said, "that decreased activation of NF-kB indicates decreased stress in the body. NF-kB is activated in the body by physical or mental stress."

Schultz randomly assigned 19 women, average age 61 years, diagnosed with stage I-III breast cancer and receiving antiestrogen or aromatase inhibitor hormonal therapy, to eight weeks of Iyengar yoga. Beginning level Iyengar yoga classes were conducted two times per week for eight weeks and included the following yoga poses: standing poses, chest and shoulder openers and inversions.

Blood sample to determine lymphocyte NF-kB activation were collected prior to and following the intervention.

"Psychosocial tests showed that the demands of illness, which reflects the burden of hardship of being a breast cancer survivor, lowered in the yoga participants. The survivors showed changes in the way their immune cells respond to activation signals. The function of genes in immune cells can be regulated by proteins called transcription factors. Transcription factor nuclear factor-kappa B (NF-kB) is linked to immune cell activation and to the stress response," Schultz said.

Speaking to TOI, 89-year-old Iyengar said, "Similar studies in Mumbai found that certain asanas improve the quality of blood and results in better blood circulation. It also improved the production of proteins in the immune system called T-cell receptors that actually direct the immune system to attack specific targets. Immune cells that contain the engineered T-cell receptor better display targeted immunity with a few asanas."

Cancer and its treatments are associated with considerable distress, impaired quality of life and reduced physical function, especially for women with breast cancer who receive multi-modality treatment over an extended period of time. "Yoga greatly helps to relieve and improve quality of life among cancer patients over time," Iyengar said.

Dr Chidanand Murthy, director of Central Council for Research in Yoga, said, "A similar study conducted in AIIMS on 30 patients in 2006 found that Sudarshan Kriya and Pranayama greatly helped cut down the growth of breast cancer cells within the body. Through release of stress, adverse effects of chemotherapy were also avoided."

Indian Council of Medical Research data shows that the incidence of breast cancer is high among Indians and is estimated that one in 22 Indian females is likely to develop breast cancer during her lifetime in contrast to one in eight in America.

According to Delhi's latest cancer registry, breast cancer among women is rising by about 2% every year. It now affects 30 per 100,000 females.