A Journey Into Yin Yoga

SCIENCE OF YIN YOGA 83

As important as addressing inflammation is, when it comes to heart disease
and many other autoimmune disorders, there is another culprit. Dr. Thomas
Cowan, who has spent many years researching heart disease and its causes,
has found that the primary cause of heart disease and heart attack is the
decreased functioning of the parasympathetic nervous system (2014). Dr.
Cowan’s message is a game changer and a potential life saver.
Dr. Cowan has been joined by a wave of other doctors and scientists who also
affirm this belief. The idea that a diminished parasympathetic nervous system
plays a significant factor in heart disease was written about in the well-respected
medical journals Circulation and American Journal of Cardiology. An article
in Circulation stated, “Abundant evidence links sympathetic nervous system
activation to outcomes of patients with heart failure (HF). In contrast, parasym-
pathetic activation has complex cardiovascular effects that are only beginning
to be recognized” (2008, 863-871). The authors summarized their findings:

Autonomic regulation of the heart has an important influence on the

progression of HF. Although elevated sympathetic activity is associ-

ated with an adverse prognosis, a high level of parasympathetic ac-

tivation confers cardio protection by several potential mechanisms.

These parasympathetic actions on the heart are mediated not only

by the direct consequences of cardiac muscarinic receptor stimula-

tion, but also by a multitude of indirect mechanisms.

Dr. Galitzer and Trivieri explain, “Muscarinic receptors help produce par-
asympathetic effects, such as a slowed heart rate and increased activity of
smooth muscle tissue lining the arteries” (2015, 110). An article published in
the Journal of Cardiology stated the following (2012, 117-122):

In heart failure, it has been recognized that the sympathetic nervous

system (SNS) is activated and the imbalance of the activity of the

SNS and vagal activity interaction occurs. The abnormal activation of

the SNS leads to further worsening of heart failure... In conclusion,

we must recognize that heart failure is a complex syndrome with an

autonomic nervous system dysfunction, and that the autonomic im-

balance with the activation of the SNS and the reduction of vagal

activity should be treated.

In the article, “What’s the Real Cause of Heart Attacks?,” Dr. Cowan explains
the chain of events that leads to a heart attack (2014):

First comes a decrease in the tonic, healing activity of the parasym-

pathetic nervous system—in the vast majority of cases the pathology

for heart attack will not proceed unless this condition is met... Then

comes an increase in the sympathetic nervous system activity, usually

a physical or emotional stressor. This increase in sympathetic activity

cannot be balanced because of chronic parasympathetic suppression.