The observations in the study showed a manifold drop in stress, obesity, blood pressure, free radicals, bad cholesterol and an increase in antioxidants, markers of good cardio-respiratory function, breathing regulation and more. All of these show promise in fighting heart disease and stress related problems. Of the 51 studies, the following data was collated.
The research by Dr Innes identified a core set of 42 studies that investigated yoga in relation to cardio-vagal response; specifically, the vagus nerve and its ability to lower the heart rate. These studies showed that those who practiced yoga for a long period time had significant reduction in cortisol concentrations and respiratory and heart rates. Cortisol is a chemical that the body produces in response to anxiety and stress, amongst a set of other ‘stress’ related chemicals, and is believed to suppress immune response and cause an increase in both blood pressure and blood sugar levels.
Skin conductance was reduced and cardiovascular response to stress in general was far more favorable. Renin, an enzyme that controls blood pressure, was reduced as well.
Changes were also noted in adrenal gland secretions, which in turn lead to a drop in blood pressure as these ‘fight or flight’ chemicals were reduced. Overall, the heart and respiratory rate at rest and after exercise were more favorable in all groups involved in these studies, whether healthy or hypertensive, adult or child.
Out of 37 studies, 28 reported improvement in blood pressure. Specifically, healthy adults and those with hypertension who practiced Raja yoga meditation exhibited reduced diastolic pressure.
Mental and physical well being and the chemicals associated with them were increased, as was the body’s production of antioxidants, which eliminate free radicals in the body and protect the skin.
Sleep, posture and energy levels also improved, which in the chronically ill or disabled is a good sign, as yoga is a fairly inclusive exercise regimen – anyone can take part, with supervision, and join in at one of the levels. Yoga creates a feeling of well being that counters the effects of stress, which in turn supports the lowering of blood pressure. Increased and appropriate sleep also supports a better stress response as you are less likely to feel overwhelmed or under pressure if you are clear headed, and this by itself lowers stress.
All of these elements feed from the positive changes in the cardio-vagal system to your mental and physical responses, which in turn supports the lowering and mitigation of risk factors associated with cardiovascular disease. But it doesn’t end there.