Yoga - Evidence Based

  • THE SCIENCE BEHIND YOGA

    Biological Understanding of Yoga and Meditation

    Today, there is a paradigm shift around the concepts of health, illness, and treatment options. We are living in a time where medical physicians largely rely on technology and drugs to treat illnesses and diseases. Yet in the midst of the best health care system that western medicine has to offer, millions of people are seeking alternative health care (Barnes, 2004). In the recent past, efficacy and therapeutic effects of yoga have been reported in various medical journals using latest technology, suggesting that yoga has scientific basis. Moreover, millions of people are exploring and paying for such complementary treatment primarily out of their own pocket, which again emphasizes and acknowledges the positive and healing effect of yoga.

    What causes diseases? What is the role of oxygen?

    Disease arises when there is an imbalance in the body due to negative thoughts and energy. Oxygen is vital for life and life is about the breaths. A person who maintains the synchronization of breathing leads a healthy and disease free life.

    Oxygen is vital for life and life is about the breaths

    Scientist have concluded that the chemical basis of energy production in the body is a chemical called ATP (Adenosine Triphosphate). If the production of this ATP is disrupted in some way or the other, the result is lowered vitality, disease and premature ageing. Oxygen is considered critical for the production of this ATP and pranayam allows us to tap into this vital component.

    The effects of yoga

    In the last two decades research into meditation suggests that meditation can improve the immune response and the response of the sympathetic nervous system to modify cardiac symptoms, reduce pain, reverse heart symptoms and slow down the ageing process. These are some of the mechanisms by which these effects arise.

    • Response to reduced oxygen(hypoxia): Individuals practicing yoga have generalised reduction in chemical reflex to reduced oxygen (hypoxia) in laboratory conditions.
    • Muscle relaxation: stretching of muscles, which produce sensory stimulation thereby helps in relaxing muscle tension and restoring optimal muscle tone and posture. Localized relaxation of the head and neck areas again are the areas of propioceptive stimulation, which not only improves respiration, but also stabilizes emotion.
    • Brain blood flow: alteration of blood flow (particularly by inverted head posture when large volume of blood surges the head and brain to provide increased distribution of blood to relatively starved part of the human body). In Pranayama, the elimination of CO2 and increased O2 uptake creates a stage of Kevela-Kumbhaka (apnoea-like condition), which helps concentration capability and voluntary control over respiratory centre. This oxygenates areas in the brain (frontal, temporal, parietal and anterior cingulate gyrus) which have significant role in mental balance and concentration.
    • Blood pressure: practicing voluntarily controlled abdominal breathing reduces the raised blood pressure.
    • Consciousness: breathing and relaxation produces a sedative effect while deeper relaxation can produce temporary loss of ego. The ecstatic vibration temporarily leads to phenomenological unity by merging the awareness of environment and self in one through fixed attention. This unity phase produces the stage of egoizing, which forms a buffer against anxiety provoking stimuli.
    • Yogic meditation influences the reticular-activating system and cortex to produce the most beneficial state of sub cortical alpha-regulated activity as confirmed by various electroencephalograph studies. This altered state of consciousness causes TROPHOTROPIC activity that can be used with a high degree of success in the treatment of psychosomatic disorder.
    • Emotions: meditation helps in relaxation and uplifts a person spiritually. Meditation like Kundalini yoga regulates the neurotransmitters, hormones and enhances coherence between the two brain hemispheres. Chanting of mantras, meditation, rhythmic movements have a positive effect on our emotions and helps in activation of the parasympathetic system which facilitates relaxation (Aftanas,2002; Kjaer, 2002).

    Brain waves and Yoga

    We can record the waves of electrical activity in the brain using the electroencephalogram (EEG).

    • Alpha waves: these represent a pleasant, calm, and positive resting state that appears to act as a bridge and increase awareness of the deeper states of consciousness. Along with the pleasant feelings, training alpha waves provides enhanced performance for athletes, golfers, singers, martial artists or anyone who requires speed and accuracy with their hands or body. Many meditation systems train Alpha waves through visualisations or mantra repetitions (Tassi and Muzet, 2001; Young and Taylor,1998; Tetsuya et al. 2004).
    • Beta waves: with its constant mind-chatter has proven to be the most difficult area to master for most meditators, particularly those raised in our information overload age. Many people who try meditation give up in frustration at this seemingly impossible challenge.
    • Delta waves: these can provide a profound calming and deep meditation experience and appears to be related to the capacity for empathy and reaching out beyond oneself. Meditators who have a conscious experience of Delta waves report that the state is both profound and psychologically healing. However, very few meditation systems have been successful in training.
    • Theta waves: these are at the brainwave frequency that we are producing in dreaming sleep and has been the goal of many meditation systems. It is recognised as the storehouse of emotions and the subconscious memories. Theta, as in our dreams, is very creative and intuitive. However, it also carries the potential for terrifying images and emotions. Based on the Neuro observations, one can develop an approach to access Theta safely and use its wonderful creativity.

    Neurobiology of yoga

    In the continuing endeavour to unravel the neurobiological mysteries of yoga, latest imaging technologies are constantly being used, like functional magnetic resonance imaging (fMRI) (Baerentsen et al, 2001), positron emission tomography (PET) of regional cerebral metabolic rate & regional cerebral blood flow, radio-ligand binding to receptors of neurotransmitters (Kjaer,2002, Roggia,2001), diffusion tensor imaging (DTI), magneto encephalography, conventional electroencephalography (EEG), quantitative electroencephalography (qEEG) and event-related potentials (ERP).

    Especially, qEEG is a non-invasive tool that is capable of assessing quantitatively the resting and evoked activity of the brain, having a high sensitivity and a temporal resolution superior to those of any other imaging method.

    In the past 20 years, research in EEG has made significant contributions to the understanding of brain-electrophysiology. Recently, digital electroencephalography has come into widespread use and has become an established alternative to conventional EEG (Nuwer, 1997). EEG records the action potentials of electrical energy generated by cortical neurons, by a non-invasive method through electrodes placed on the scalp. An extension to this is the electrocorticograms, an invasive procedure that records electrical potentials over the human cortex.

    The EEG rhythms recorded on the scalp are the result of the summation effect of many excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) produced in the pyramidal layer of the cerebral cortex. In humans, the thalamus is thought to be the main site of origin of EEG activities (alpha and beta bands). Thalamic oscillations activate the firing of the cortical neurons. The depolarisation (mainly in layer IV) creates a dipole with negativity at layer IV and positivity at more superficial layers. The scalp electrodes will detect a small but perceptible far-field potential that represents the summed potential fluctuations. Scalp electrodes cannot detect charges outside six square centimetres of the cortical surface area, and the effective recording depth is several millimetres (Thakor and Shanbao, 2004).