Meditation, yoga, tai chi and other practices
often are mentioned in passing as being
good for health. However, it is surprising
how little medical research has been devoted
to testing such claims. Perhaps equally
surprising is that until recently little work
had been undertaken to quantify the impact of stress on aging.
Of course, people often talk about reducing stress and note that
too much stress is not good for us, but how much is too much
and what, exactly, is the impact on the length of life? It took
the interest of a Nobel Prize Winner finally to direct research at
medical schools towards these questions. A paper by Epel and
Blackburn on the impact of stress on the length of telomeres, a
direct cellular measure of successful aging, only appeared in the
Proceedings of the National Academy of Sciences in December
2004.1 More than a decade later, meditation has begun to be
accepted as a low cost /no cost approach to health benefits.
Stress and Adrenal Fatigue
In medical circles, two syndromes often are discussed with regard
to what laymen consider to be the consequences of stress. The
first is adrenal insufficiency. Adrenal insufficiency is a condition
in which the adrenal glands do not produce adequate amounts
of steroid hormones, primarily cortisol; it also may include
impaired production of aldosterone (a mineralocorticoid),
which regulates sodium conservation, potassium secretion,
and water retention. Craving for salt or salty foods due to the
urinary losses of sodium is common. Adrenal insufficiency is
a medical condition that requires intervention beyond dietary
Adrenal fatigue occupies a bit of a nether world in many medical
circles, meaning that allopathic medicine is not quite sure that
it is real. According to the Mayo Clinic, adrenal fatigue is a term
often applied to a collection of nonspecific symptoms, such
as body aches, fatigue, nervousness, sleep disturbances and
digestive problems. However, it also is used as a catch-all for
the exhaustion caused by placing demands upon the body that
are beyond its normal recovery capacity. Very important in this
picture is cortisol, a hormone manufactured in the adrenals, but
also exhibits a metabolism that is regulated strongly in various
peripheral tissues, such as in fat stores.
The counter-regulatory or "stress" hormone cortisol plays
crucial everyday roles in the regulation of blood sugar levels,
inflammation and the circadian rhythm. Cortisol should be
relatively low late in the day as we unwind and prepare for sleep
and should rise quite significantly starting an hour or two before
waking. The circadian pattern of cortisol release generally is
considerably more important than is its total 24-hour level.
Acute demands outside the normal range and chronic stress
alter this picture. Recurrent increases in stress levels, both from
psychological and physiological sources, can result in excess
cortisol production or alterations in cortisol release timing
leading to a disrupted homeostasis and directly affecting the
hypothalamic-pituitary-adrenal (HPA) axis, the nervous system,
and an array of other body systems.
Immediate responses to stress
Typical acute phase reactions to stress are increases in heart
and respiratory rates, elevations in blood pressure and
blood sugar, and a general increase in cellular metabolism.
Those in good health, especially younger individuals,
quickly recovery equilibrium. However, stress in excess
of immediate recovery capacity can lead to bouts of
hyperglycemia, fatigue, insomnia, irritability, anxiety, etc.
Poor recovery from stress
Chronic stress disrupts the normal equilibrium of the body.
Chronic elevations of cortisol and the neurotransmitters
epinephrine and norepinephrine initially cause people to
feel energetic, yet unable to rest. Indeed, there is increasing
dysregulation of an array of hormonal systems, including
growth hormone, glucocorticoids, adrenocorticotropic
hormone (ACTH), mineral corticoids, angiotensin, and
others. Ultimately a number of vicious cycles can be set
in motion. These include set points involving mineral
corticoids and insulin. One example of this is a cycle
involving blood sugar, insulin and cortisol:
chronic ↑ blood sugar => ↑ insulin + ↑ leptin => insulin resistance + leptin resistance => ↑ cortisol => ↑ blood sugar
Depending on the individual's starting constitution and
habits, this can lead to elevations of blood sugar and
lipids, water retention, mood swings, a loss of lean tissue
followed by a gain in fat tissue, generalized fatigue and
The goal of any program aimed at controlling stress and
reducing adrenal fatigue is to promote adaptation. One classic
way of thinking about this issue is to consider the medical
concept of allostasis, the process of achieving stability, or
homeostasis, through physiological or behavioral changes.
This can be carried out by means of alterations in HPA axis
hormones, the autonomic nervous system, cytokines, or a
number of other systems, and is generally adaptive in the short
term. This adaptation calls upon mediators such as adrenalin,
cortisol and other chemical messengers with the obvious
corollary of increasing demands on precursor substrates and
the production of downstream metabolites.
Repeated episodes of allostasis increase allostatic load.
This means that repeated episodes of stress increase the
demands that are placed on the body. Even the body's attempts
at rebalancing can lead to cumulative damaging effects. The
burden of the level of responses required either repeatedly or
chronically itself becomes an insult (stressor) in its own right.2,3
Meditation, Stress and Telomeres
The pioneering work of Epel and Blackburn linked perceived
stress to shorter telomeres in healthy women as well as in
Alzheimerfs caregivers, victims of domestic abuse and earlylife
trauma, and people with major depression and posttraumatic
stress disorder. Telomeres are a repeating DNA
(deoxyribonucleic acid) sequence that "caps" or shields the ends
of the chromosomes each time that cells divide and the DNA
is copied. With successive cell divisions, the protective caps
wear down. Blackburn received a Nobel Prize for discovering an
enzyme called telomerase that can protect and rebuild telomeres.
This enzyme slows the slide towards telomeres becoming
too short to protect the chromosomes and leading to a loss
of the ability of cells to divide. The length of telomeres thus is one measure of how many cycles the cells have left, a
measure of aging. The key finding regarding stress and aging
is that stress and our ability to cope with stress strongly affect
telomere length. Subsequent work in other labs revealed that
the stress hormone cortisol reduces the activity of telomerase.
Oxidative stress and inflammation—the physiological fallout of
stress—appear to erode telomeres directly.4,5
There are various ways of attempting to control stress its
negative effects, including exercise, social support groups,
eating advice, and so forth. One of the most successful in trials
is meditation. As reported in an excellent 2104 BBC review,6
In one ambitious project, Blackburn and her colleagues
sent participants to meditate at the Shambhala mountain
retreat in northern Colorado. Those who completed a
three-month-long course had 30 percent higher levels of
telomerase than a similar group on a waiting list. A pilot
study of dementia caregivers, carried out with UCLA's Irwin
and published in 2013, found that volunteers who did an
ancient chanting meditation called Kirtan Kriya, 12 minutes
a day for eight weeks, had significantly higher telomerase
activity than a control group who listened to relaxing music.
And a collaboration with UCSF physician and self-help guru
Dean Ornish, also published in 2013, found that men with
low-risk prostate cancer who undertook comprehensive
lifestyle changes, including meditation, kept their
telomerase activity higher than similar men in a control
group and had slightly longer telomeres after five years.
Western style research thus increasingly is validating meditation
as a tool for combatting known markers for aging. The next
issue is whether meditation improves individual conditions,
such as high blood pressure and high blood sugar.
Meditation and Specific Conditions
Telomere length and the production of telomerase to regenerate
telomeres are indirect measurements of health. Impacts on
these markers can suggest anti-aging benefits, but true clinical
findings involve endpoints, not markers, i.e., were subjects
followed long enough to demonstrate an actual increase in
longevity? With long-lived animals such as human beings, this
type of follow-through is difficult. However, meditation has
been tested in regard to specific medical conditions, including
blood pressure, blood sugar and mental aging. Results have
been positive in all three.
Although statistical reviews typically have found that clinically
meaningful changes in health related to blood pressure usually
take place only when systolic blood pressure (SBP, the upper
figure) exceeds 140 and diastolic blood pressure (DBP) exceeds
90, in recent years increasing attention has been paid to the
category of prehypertension. Nearly 60 million Americans have
blood pressure (BP) in the prehypertensive range (SBP of 120–
139 and/or DBP of 80–89). These numbers do not yet warrant
medication, yet may signal that changes in diet, exercise and
other habits should be undertaken to prevent the emergence of
the clinical condition that does require treatment.
Mindfulness-based stress reduction (MBSR) is a change
in habits that has been tested under controlled conditions. In
a trial published in 2013, it involved body scanning exercises,
sitting meditation and yoga exercises performed in eight
supervised group sessions totaling 2½ hours per week. Subjects
also were encouraged to practice at home. The trial examined
56 men and women averaging 50.3 years of age with BP in the
prehypertensive range randomized to eight weeks of either
MBSR or active control conditioning consisting of progressive
muscle relaxation training (PMR) (the control arm).7
Patients in the MBSR group exhibited significant reductions
in blood pressure measurements; systolic blood pressure
decreased by an average of 4.8 millimeters of mercury (mm Hg)
compared to 0.7 mm Hg with the control group, which did not
receive the mindfulness intervention. Diastolic blood pressure
also was lower in the mindfulness-based intervention group
with a reduction of 1.9 mm Hg compared to an increase of 1.2
mm Hg in the control group.
As is true of blood pressure, in free-living populations
meditation and other mind-body practices long have been
associated with better body mass index and blood sugar
regulation.8 Nevertheless, without prospective clinical trials,
such benefits cannot be definitively claimed to be due to any
given factor. Over the last handful of years, studies have gone
some way towards remedying this issue.
In 2015, the Endocrine Society presented information on
the effects of MBSR on fasting blood glucose in overweight and
obese women. The NIH National Center for Complementary and
Alternative Medicine (NCCAM) and the NIH National Center
for Research Resources and the National Center for Advancing
Translational Sciences funded the study.9 A pilot randomized
controlled trial of 86 overweight or obese women (similar in age
and body mass index) tracked eight weeks of either MBSR or
health education control (HEC) with tests of fasting blood work
and completed questionnaires at baseline, eight weeks and then
at 16 weeks. The MBSR group's mindfulness scores significantly
increased and its perceived stress scores significantly decreased
compared to the HEC group's scores. Fasting glucose dropped
significantly and quality of life improved significantly in the
MBSR group, but not in the HEC group. Other measures were
similar between the two groups.
Results with the MBSR intervention were good with
regard to blood sugar just as with blood pressure. A different
form of meditation may be even more successful. Traditional
Buddhist walking meditation in a 2016 trial improved not only
fasting blood glucose and blood pressure, but also glycosylated
hemoglobin (HbA1c, a measure of long term blood sugar
control) and other factors above the results found with walking
alone in diabetic test groups.10 Twenty-three type 2 diabetics
were split into two groups that performed a 12-week exercise
program that consisted of walking on the treadmill at an
exercise intensity of 50–70 percent maximum heart rate for 30
min/session, 3 times/week. In the Buddhism-based walking
meditation exercise (WM) training program, the participants
performed walking on the treadmill while concentrating on foot
stepping by voiced "Budd" and "Dha" with each footstep that
contacted the floor to practice mindfulness while walking.
Both arms in this trial improved. After 12 weeks, maximal
oxygen consumption increased and fasting blood glucose level
decreased significantly in both groups. In contrast, walking
meditation exceeded simple treadmill exercise in other areas.
There were significant decreases in HbA1c and both systolic and diastolic blood pressure only in the WM group. Again, arterial
stiffness was improved only in the WM group and blood cortisol
levels were reduced only in the WM group.
Another area, one that concerns all of us who are getting a
bit older, is brain aging. Observational studies and a number
of studies have indicated that meditation can exert a positive
influence, yet the question of "how" remains poorly determined.
Does it involve telomeres, inflammation, stress regulation,
macroscopic brain anatomy or other mechanisms? Answers
suitable to the Western allopathic medical model only now are
beginning to be uncovered.
A review published in 2017 attempts to survey the relevant
issues.11 It judges that "preliminary evidence for possible age-defying
effects of meditation mostly stems from cross-sectional
studies and/or from using indirect markers associated with
aging. In contrast, controlled longitudinal studies between
meditation and diminished brain aging are still missing."
Nevertheless, "[w]ithout a doubt, the accumulating scientific
evidence is very encouraging, especially given that meditation
is relatively easy to integrate in everyone's every-day life."
A philosophical person—a lover of wisdom—indulges
his appetites neither too much nor too little, but just
enough to lay them to sleep and prevent them from
interfering with higher activities. He collects himself in
meditation to pursue spiritual investigations, seeking
and discovering unrealized realities of the past, present,
and future. Through identifying with his Higher Self in
meditation he avoids being the victim of fantastic and
uncivilized vagaries and most effectively attains Truth.
Plato, Commonwealth 9, 571d12
We tend to think of meditation as an "Eastern" tradition, but,
in fact, very similar practices existed in the ancient Greco-Roman world until the closure of the Platonic Academy in 529
AD by Justinian I. A major goal of meditation is to attain inner
balance neither by indulging the passions nor by stifling them.
Many different techniques exist. Overall, the goal of classic
meditation exercises was and remains spiritual benefit. Modern
research has discovered that even those not directly interested
in religious or philosophical paths can obtain quite real and
tangible benefits from meditative practices. These benefits
include stress reduction, a balancing of blood pressure and
blood sugar and, perhaps, greater longevity.
- Epel ES, Blackburn EH, Lin J, Dhabhar FS, Adler NE, Morrow JD, Cawthon RM. Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci USA. 2004 Dec 7;101(49):17312–5.
- McEwen BS, Seeman T. Protective and damaging effects of mediators of stress. Elaborating and testing the concepts of allostasis and allostatic load. Ann N Y Acad Sci. 1999;896:30–47.
- McEwen BS. Central effects of stress hormones in health and disease: Understanding the protective and damaging effects of stress and stress mediators. Eur J Pharmacol. 2008 Apr 7;583(2–3):174–85.
- Marchant J. Can Meditation Help Prevent the Effects of Aging? July 1, 2014. http://www.bbc.com/future/story/20140701-canmeditation- delay-ageing
- Epel E, Daubenmier J, Moskowitz JT, Folkman S, Blackburn E. Can meditation slow rate of cellular aging? Cognitive stress, mindfulness, and telomeres. Ann N Y Acad Sci. 2009 Aug;1172:34–53.
- Marchant (op. cit.)
- Hughes JW, Fresco DM, Myerscough R, van Dulmen MH, Carlson LE, Josephson R. Randomized controlled trial of mindfulness-based stress reduction for prehypertension. Psychosom Med. 2013 Oct;75(8):721–8.
- Younge JO, Leening MJ, Tiemeier H, Franco OH, Kiefte-de Jong J, Hofman A, Roos-Hesselink JW, Hunink MG. Association Between Mind-Body Practice and Cardiometabolic Risk Factors: The Rotterdam Study. Psychosom Med. 2015 Sep;77(7):775–83.
- The Endocrine Society. "Stress reduction may reduce fasting glucose in overweight and obese women." ScienceDaily, 6 March 2015. www.sciencedaily.com/releases/2015/03/150306181815.htm
- Gainey A, Himathongkam T, Tanaka H, Suksom D. Effects of Buddhist walking meditation on glycemic control and vascular function in patients with type 2 diabetes. Complement Ther Med. 2016 Jun;26:92–7.
- Kurth F, Cherbuin N, Luders E. Promising Links between Meditation and Reduced (Brain) Aging: An Attempt to Bridge Some Gaps between the Alleged Fountain of Youth and the Youth of the Field. Front Psychol. 2017 May 30;8:860.
- An admittedly idiosyncratic, yet helpful translation found at http://www.hermes-press.com/meditation0.htm