Hypertension and Cardiovascular Health

What do 69 percent of people who have a first heart attack, 77 percent of people who have a first stroke, and 74 percent of people with chronic heart failure all have in common? They all have hypertension, or chronically high blood pressure (Roger et al, 2012). In fact, as many as one in three American adults have high blood pressure (CDC, 2012). Cardiovascular disease is the leading cause of death worldwide and hypertension is the leading risk factor. High blood pressure is also a major risk factor for other serious illnesses such as kidney disease.

High blood pressure, and the resulting cardiovascular damage, typically develops over many years. But fortunately, hypertension is detectable, measurable, and usually manageable. In the modern age of high-tech medicine, is it possible to treat cardiovascular problems such as hypertension with ancient techniques of meditation? Yes. And here’s why…

First, meditation automatically influences the autonomic nervous system (ANS), in part, by inducing the “relaxation response. In fact, ANS regulation is a characteristic, automatic feature of most all forms of meditation. The ANS itself is involuntary or automatic, responsible for bodily functions not under our conscious control, such as breathing, heartbeat, body temperature and digestive processes. The ANS includes the sympathetic and parasympathetic nervous systems, which counterbalance each other.

In general, meditation influences cardiovascular health by decreasing certain activity in the sympathetic nervous system and increasing certain activity in the parasympathetic nervous system.  While the roles of these two complex systems both during meditation and during normal everyday life are not quite so black and white, in general:

• the sympathetic nervous system (SNS) is our high-energy system, responsible for producing the fight-or-flight response that mobilizes the body for action, including increased heart rate, respiration rate and blood glucose, halt of digestive functions, and increased blood flow to muscles. Sympathetic nerves arising from the spinal cord supply our organs, blood vessels, and glands. When the SNS response kicks in, blood vessels are constricted, while force, or blood pressure, is increased.
• the parasympathetic nervous system (PNS) controls restorative and resting functions, sometimes referred to as “rest and digest” functions. The PNS slows heart and breathing rates, dilates blood vessels (improving blood flow), and increases the flow of digestive juices.

Meditation directly influences autonomic activity through respiration control.

Respiration is one of the few autonomic functions over which we have some degree of voluntary, direct control, and respiration control ultimately influences other autonomic functions. For example, slower respiration rate during meditation triggers restorative, parasympathetic cardiovascular changes, such as reduced heart rate and blood pressure, and increased synchronization (known as respiratory sinus arrhythmia or RSA) between heartbeats (Cysarz, Bussing 2005; Ditto et al., 2006). RSA is the naturally occurring variability in heart rate during a breathing cycle; for example, heart rate is faster during inhalation and slower during exhalation.

Meditation heavily influences the Hypothalamus-Pituitary-Adrenal (HPA) Axis

The HPA is a brain-body circuit which plays a critical role in the body’s stress response. Inhibition of the sympathetic nervous system during meditation has many calming, anti-anxiety affects on the body; for example, by partially inhibiting the hypothalamus, a substation of the limbic system that integrates complex mind-body responses throughout our autonomic and somatic (motor and sensory) nervous systems. (The hypothalamus regulates metabolic processes such as glandular activity, blood pressure, body temperature, appetite, energy balance, and other autonomic functions.)

Inhibiting the hypothalamus inhibits the pituitary gland’s release of adrenocorticoids (steroid hormones produced by the adrenal glands), decreases blood pressure, blood lactate, and urinary vanillylmandelic acid (indicators of the body’s epinephrine and norepinephrine levels) (Newberg, A., Iverson, J., 2003). Through it’s connection to the reticular activating system (RAS) in the brainstem, the hypothalamus influences the flow of incoming sensory stimuli. During meditation, the RAS is partially inhibited, which inhibits the incoming flow of irrelevant, distracting sensory information and allows brain cells to emit the alpha waves commonly associated with meditation and a relaxed mind-body.

Neurochemicals

Meditation can also influence neurotransmitters and neurohormones that are involved in autonomic nervous system activity and help us cope with stress. For more, see Evidence of Meditation’s Impact on Neurotransmitters & Neurohormones.

Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure, which means your heart must work harder than normal to circulate blood through the vessels. Blood pressure is summarized by two measurements, systolic and diastolic, depending on whether the heart muscle is contracted (systole) or relaxed between beats (diastole). The top number, systolic pressure, represents the pressure in the arteries as the heart contracts and pumps blood from its chambers into the arteries. The bottom number, diastolic pressure, reflects the pressure in the arteries as heart muscle relaxes after contraction and allows its chambers to fill with blood. The diastolic pressure reflects the lowest pressure to which vessels are exposed.

Normal blood pressure at rest is within the range of 100-140mmHg systolic (top reading) and 60-90mmHg diastolic (bottom reading). High blood pressure is considered to be a reading that is persistently at or above 140/90 mmHg. Many physicians consider a blood pressure reading between 120/80 and 139/89 to be “pre-hypertensive.”

We used to believe that diastolic elevation was a more significant risk factor than systolic elevation. But systolic BP increases steadily with age in Western societies, whereas diastolic BP increases until about age 55, then declines (Burt et al, 1995); thus in people 55 or older, systolic BP may be the more precise risk indicator. These age-related changes in BP are related to increasing arterial stiffness (or decreasing compliance) results from collagen replacing elastin in artery walls (O’Rourke, 1990).

Different forms of meditation can impact systolic or diastolic pressure differently, or have more impact on one than the other. And of course, meditation-induced changes may vary with age.

Emotional Reactivity and Blood Pressure

For every emotional reaction, there is a corresponding physiological reaction. The heart, fittingly, always reacts to strong emotions. While the capacity to modify heart rate, blood flow, respiration, etc. is required to meet the metabolic needs of a stressful situation (such as in the fight‐flight reflex), we must also have the ability to return to “normal” quickly — to homeostasis — in order to relieve stress on organs and tissues. When the body is chronically unable to return to balance, it becomes vulnerable to any number of diseases and disorders.

It takes the heart longer to recover from negative emotions than from positive emotions. Negative emotions and rumination have been found to prolong cardiovascular recovery and lead to higher, prolonged levels of the stress hormone cortisol, which can have damaging effects on the body (Brosschot, Thayer, 2003; Glynn LM, Christenfeld, Gerin, 2002).  (For an in-depth look at meditation’s emotional regulation benefits, see: Meditation as Emotional Regulator.

Anger

Several studies have documented the relationship between anger and cardiovascular disease. Anger typically triggers sympathetic activation. As the “fight” component in the fight‐flight reflex, the psychophysiology of anger overlaps with that of stress and has a similar impact on the body. For example, chronic anger, and angry rumination, in particular, slows blood pressure recovery, which can eventually lead to hypertension. People who have a tendency to ruminate or repeatedly “chew on” past anger-provoking events are at greater risk for target organ damage as a result of sustained blood pressure elevations, especially when there are no distractions to interrupt or modulate the ruminative process. (For an in-depth look at how Sahaja helps us eliminate or manage anger, see How Sahaja meditation helps resolve Anger.

The Impact of Stress on Blood Pressure

Stress-related thoughts and emotions are, of course, not limited to those moments when a stressor is physically present. We may spend relatively little time “in the heat of the moment,” yet spend an entire lifetime recovering from a past stressor or anxiously anticipating future stressors. Often, the most damaging effects of a stressor occur long after the stressor itself has ended.

Sustained blood pressure elevations can occur any time we use emotional or thought processes that sustain arousal, such as rumination. Rumination focuses one’s attention on a negative mood (e.g.. depression) and, often, negative self-evaluations. Rumination is different from structured problem-solving. People who ruminate tend to repeatedly and lengthily think about the causes and consequences of their anger, guilt or other negative emotions but don’t actually act to change the situation. In fact, ruminators are significantly less likely to engage in active, structured problem-solving.

It’s not often clear to what extent the blood pressure peaks and troughs that occur during acute stress contribute to cardiovascular damage, but sustained blood pressure elevations have certainly been linked to target organ damage, such as vessels, kidneys, brain, or heart (Liu et al, 1999). So, even a small 2 mm Hg blood pressure increase that lasts several hours might produce a far greater cardiovascular load than a large blood pressure spike that lasts only a few minutes. In fact, it’s been estimated that a 2-mm Hg reduction in diastolic blood pressure could prevent 6 percent risk of coronary heart disease and 15 percent risk of stroke or transient ischemic attack (Cook, et al, 1995).

You can see how an intervention like mediation can, even in small increments, systematically improve blood pressure. Let’s look at the scientific evidence of how meditation impacts blood pressure and other aspects of cardiovascular health…

One key underlying cause of coronary artery disease is endothelial dysfunction, which some physicians fail to address. The endothelium, a thin layer of flat cells lining interior surfaces of the circulatory system (such as blood and lymphatic vessels and the heart), is responsible for maintaining circulation. One of the endothelium’s primary jobs is releasing nitric oxide, which signals the arteries to relax and dilate, providing healthy blood flow throughout the body. Oxidative stress, common in people with hypertension, deactivates nitric oxide, which contributes to endothelial dysfunction. Endothelial dysfunction, in turn, contributes to building blockages in arteries, which elevates the risk for heart attacks and strokes.

A pair of studies suggest that Sahaja meditation can help.

A large, randomized 2013 study of long-term Sahaja meditators found that Sahaja meditation had a significant effect on endothelial function, oxidative stress, serum cortisol, perceived stress levels and heart rate variability (HRV).

HRV and endothelial function improved and blood cortisol levels significantly decreased, which decreased oxidative stress and perceived stress levels in meditators, compared to the non-meditating control population (Rai et al, 2013).

The results were corroborated in a second study of people with diabetes, many of who also had hypertension or other cardiac dysfunction.

Researchers found that just 20 minutes per day of Sahaja meditation has an immediate and marked effect on HRV by switching off the “stress button.” Compared to the non-meditating diabetic group, the Sahaja diabetic group showed: marked reductions in systolic blood pressure and the stress hormone cortisol; increased levels of the vasodilator nitric oxide, which improved blood flow; marked reduction in bad cholesterol (LDL) and triglycerides; significant improvement in good cholesterol (HDL) levels; and a  significant reduction in fasting blood glucose.

Stress and illness can arise when the body’s physiological systems are not integrated with the holistic “inner intelligence” of the body. One result is a loss of homeostasis in the cardiovascular system that might be expressed as higher blood pressure or increased atherosclerosis (arterial plaque buildup).

The practice of Sahaja meditation may trigger a set of adaptive responses at the cortical, autonomic, neuroendocrine, and cardiovascular levels that restore homeostatic and self-repair mechanisms.

Neuroimaging studies of Sahaja meditation, for example, have demonstrated that the meditative experience of thoughtless awareness involves a communication loop between the brain’s frontal lobes (responsible for rational thought, behavior, learning, personality, and voluntary movement) and the limbic system, which is responsible for emotional processing (Aftanas, Golosheykin, 2001, 2002, 2005). Thus, meditation may actually intervene and mediate between our thoughts and emotions and ultimately help us become better self-regulators.

Several studies have shown that Sahaja meditation significantly reduces autonomic activity in both short- and long-term practitioners by activating parasympathetic-limbic pathways (e.g., Rai et al., 1988). The autonomic impact includes: reduced heart, respiratory and pulse rates, lower systolic blood pressure and oxygen metabolism, and reduced levels of the stress marker urinary vanillylmandelic acid (VMA).

Some studies have found that Sahaja meditation reduces distress, fear and anxiety, increases psychosocial coping abilities, and helps build long-term resilience. Thoughtless awareness has been found to trigger positive changes in psychological, neurological and autonomic functioning by modulating limbic (emotional) system activity, which can, in turn, act on the hypothalamus to modulate sympathetic nervous activity and regulate neurotransmitter and hormonal functioning (Rai et al, 2010). One study found that conditioning these brain systems through a Sahaja meditative practice can help balance or restore normal functioning of homeostatic mechanisms (Aftanas, Golosheykin, 2005).

One 2012 2-week trial of Sahaja meditation found that hypertensive participants who received meditation treatment significantly improved both systolic (9.4 mm Hg decrease) and diastolic (12.32 mm Hg decrease) blood pressure and had better blood pressure control than control hypertensives who received only conventional Western medical treatment.

In fact, hypertensive participants in this particular control group actually showed no improvement in blood pressure after conventional treatment (Chung et al, 2012).

While similar anxiety levels were observed in both the meditation and control groups at baseline, participants in the control group actually reported greater anxiety and a small but significant decline in quality of life during the 2-week trial. This study found that the therapeutic effect of Sahaja meditation was achieved during the state of thoughtless awareness where participants were better able to introspect, address, and resolve the distress caused by negative thoughts and emotions. The study found that just one week of Sahaja meditation practice also produced significant improvements in anxiety reduction and betterment over an extensive spectrum of quality of life.

A small clinical trial conducted at Lady Harding Medical College, New Delhi, India and Sucheta Kripalani Hospital explored the effects of Sahaja Yoga Meditation on hypertensive 35- to 50-year-olds. Some were taking blood pressure medication, but as the practice of Sahaja progressed, blood pressure medications were gradually discontinued. Over a 12-week period, diastolic blood pressure dropped from 100 to 80. None of the meditators had previous yoga/meditation training or experience, suggesting that one need not already have a lifetime of meditative practice to benefit.

There is growing body of cardiovascular literature to support the effects of various forms of meditation on cardiovascular health. Here are just a few studies showing how meditation helps manage cardiovascular disease and control risk factors…

Reduction of cholesterol and drug, alcohol and tobacco consumption in addition to blood pressure and blood flow improvement.

• A review of 600 meditation studies (Walton et al, 2004) found that meditation reduced blood pressure (11 mm Hg systolic and 6 mm Hg diastolic), atherosclerosis, tobacco, drug and alcohol usage, fasting serum cholesterol levels and lipid oxidation (a marker of exposure to free radicals) after 11 months of practice. Eight months to one year of meditative practice was also found to improve blood flow in people with myocardial ischemia (inadequate blood flow).

• A 9-month clinical trial of hypertensive African American adults found that the stress reduction associated with meditation practice, compared to conventional health education, reduced carotid artery atherosclerosis or buildup of plaque or fatty deposits in coronary arteries. (The meditation group showed a significant decrease of −0.098 mm compared with an increase of 0.054 mm in the control group (Castillo-Richmond et al, 2000). Even a small reduction could reduce the risk of heart attack by 11 percent and reduce the risk of stroke by 15 percent.

• Several studies comparing complementary and alternative therapies found that meditation was the most effective stress relief component of rehabilitation (e.g., Arthur et al, 2006). Since cardiac rehabilitation patients often suffer from distress, anxiety and depression, all of which can lead to a poor prognosis and worsening of cardiac symptoms, several studies have demonstrated that meditation can help improve cardiac recovery, in part, by relieving mood and anxiety symptoms (Griffiths et al, 2009).
• A meta-analysis of 23 clinical trials (3180 patients) found that adding meditation to cardiac rehabilitation programs, especially during the first 2 years, reduces mortality rates (as much as 41 percent during the first two years), reduces recurrence rates of coronary artery disease by up to 46 percent, and reduces distress and some biological risk factors, such as systolic blood pressure, heart rate, cholesterol level and blood glucose) (Linden, 1996).

• A 6-month study conducted at the University of Pennsylvania School of Medicine showed that meditation, compared to health education, significantly reduced the severity of congestive heart failure (CHF) in CHF patients and improved their quality of life and functional capacity (Jayadevappa, 2007). Researchers believed that the results were due to meditation’s ability to reduce the stress-related sympathetic nervous system activation that’s known to contribute to a failing heart.
• A small study of severely ill elderly patients with congestive heart failure participated in weekly mindfulness meditation sessions and listened to a meditation tape at home for 30 minutes, twice daily for 12 weeks, compared to a control group that only attended weekly meetings (Curiati, Bocchi, 2005). The meditation group had lower levels of norepinephrine, better cardiopulmonary performance on exercise testing, and showed significantly greater improvements in quality of life.

It is increasingly clear that meditating for just a few minutes per day has positive, measurable effects on cardiovascular health and that a regular meditative practice may play an important role in eliminating or controlling risk factors for cardiovascular disease.