Effects of mindfulness meditation on serum cortisol of medical students

Abstract

Mindfulness meditation is a method to relax the mind that decreases stress, which otherwise would increase serum cortisol. So, mindfulness meditation should decrease serum cortisol.
To study the effect of mindfulness meditation on mental health by using Thai GHQ28 questionaire and study the effect of mindfulness meditation on stress by using serum cortisol.
Volunteer subjects were 30 second year medical students, aged 19.1 +/- 0.55 year olds (range 18-20) from Srinakharinwirot University. They were screened by Thai GHQ28 and blood was drawn to measure cortisol at 8:00 am before and after a four-day mindfulness meditation programme. The comparison of Thai GHQ28 scores and serum cortisol levels before and after meditation were analysed by paired t-test.
The subjects were 66.77% female and 33.33% male. The average score of Thai GHQ28 before and after the mindfulness meditation was 1.50 (SD 2.53) and 0.77 (SD 2.08) respectively. The average serum cortisol levels before mindfulness meditation was 381.93 nmol/L (SD 97.74) becoming significantly lower after mindfulness meditation 306.38 nmol/L (SD 90.95). The difference was statistically significant in cortisol level, but not statistically significant in Thai GHQ28.
Mindfulness meditation lowers the cortisol levels in the blood suggesting that it can lower stress and may decrease the risk of diseases that arise from stress such as psychiatric disorder, peptic ulcer and migraine. Then, mindfulness meditation should be used in combination with standard treatment.

Full text

S90 J Med Assoc Thai Vol. 96 Suppl. 1 2013
Correspondence to:
Turakitwanakan W, Department of Psychiatry, Faculty of Medi-
cine, Srinakharinvirot University, 62 Moo 7, Ongkharak, Nakhon
Nayok 26120, Thailand.
Phone: 037-395-085 ext. 80705
E-mail: wanpen2550@yahoo.com
J Med Assoc Thai 2013; 96 (Suppl. 1): S90-S95
Full text. e-Journal: http://jmat.mat.or.th
Effects of Mindfulness Meditation on Serum Cortisol
of Medical Students
Wanpen Turakitwanakan MD*,
Chantana Mekseepralard PhD**, Panaree Busarakumtragul PhD***
* Department of Psychiatry, Faculty of Medicine, Srinakharinwirot University, Nakhon Nayok, Thailand
** Department of Microbiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand
*** Department of Physiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand
Background: Mindfulness meditation is a method to relax the mind that decreases stress, which otherwise would increase
serum cortisol. So, mindfulness meditation should decrease serum cortisol.
Objective: To study the effect of mindfulness meditation on mental health by using Thai GHQ28 questionaire and study the
effect of mindfulness meditation on stress by using serum cortisol.
Material and Method: Volunteer subjects were 30 second year medical students, aged 19.1 + 0.55 year olds (range 18-20)
from Srinakharinwirot University. They were screened by Thai GHQ28 and blood was drawn to measure cortisol at 8:00 am
before and after a four-day mindfulness meditation programme. The comparison of Thai GHQ28 scores and serum cortisol
levels before and after meditation were analysed by paired t-test.
Results: The subjects were 66.77% female and 33.33% male. The average score of Thai GHQ28 before and after the
mindfulness meditation was 1.50 (SD 2.53) and 0.77 (SD 2.08) respectively. The average serum cortisol levels before
mindfulness meditation was 381.93 nmol/L (SD 97.74) becoming significantly lower after mindfulness meditation 306.38
nmol/L (SD 90.95). The difference was statistically significant in cortisol level, but not statistically significant in Thai GHQ28.
Conclusion: Mindfulness meditation lowers the cortisol levels in the blood suggesting that it can lower stress and may
decrease the risk of diseases that arise from stress such as psychiatric disorder, peptic ulcer and migraine. Then, mindfulness
meditation should be used in combination with standard treatment.
Keywords: Mindfulness meditation, Thai GHQ28, Cortisol
Mindfulness meditation practices have been
examined for their health benefits and used as a
technique to increase longevity(1). Some scientific
attention has focused on the effects of mindfulness
meditation on stress and serum cortisol level which
regulate the stress pathways including hypothalamic-
pituitary-adrenal axis which functions by releasing
corticotrophin-releasing hormone (CRH) from the
hypothalamus to stimulate the pituitary gland to release
adrenocorticotropic hormone (ACTH). Then, ACTH
stimulates the adrenal cortex to release cortisol. The
activation of this stress pathway from psychological
stressors as well as physical stressors(2) stimulates
noradrenalin secretion(3). Both pathways cause several
physiological changes. For example, changes in
cortisol, ACTH and noradrenalin in the blood stream
activate the sympathetic system resulting in an increase
in pulse rate and blood pressure(4,5) which can cause
hypertension. Cortisol is the most prominent
glucocorticoid synthesized from the cholesterol
precursor in the adrenal cortex. Cortisol levels changes
with time according to diurnal variation, having the
highest level in the early morning(6). Plasma cortisol
levels are increased by stress from infection, fever,
prolonged strenuous exercise, and acute anxiety(7).
Previous research have found that persons
who always practice mindfulness meditation have lower
stress(8). So the present study was a before-after with
one comparison group study to investigate whether a
four consecutive day mindfulness meditation course
has any effect on mental health and serum cortisol level
in trainees. Therefore, the authors report the effect of
meditation on mental health by using Thai GHQ28 and
on stress by using serum cortisol.
Material and Method
Study design and participants
The present study was approved by the

J Med Assoc Thai Vol. 96 Suppl. 1 2013 S91
Human Ethics Committees of the Faculty of Medicine,
Srinakharinwirot University, Bangkok, Thailand. All
subjects signed informed consent prior to the study.
The present study group consisted of 30 male and
female second-year medical students. The inclusion
criteria included absence of psychiatric disease, not
being afraid of taking blood sample and having no
history of endocrine disorder. Subjects unable to take
the complete course or to adjust to living in a temple
were also excluded. Before the meditation practice, the
procedure was explained to the students. Firstly, they
were tested by Thai GHQ28 and blood was drawn
for cortisol measurements at 8:00 am. Then, they
required to practice the mindfulness meditation course
at the Sunanthavanaram temple, which consists of
mindfulness meditation for four hours during three
periods (5:30-6:30, 11:00-12:00, 19:00-21:00) mentored
by experienced monks during four days. The meditation
focussed the attention on the breathing in a state of
mindfulness(9). The method consists in observing the
breath as it enters and leaves the nostrils, and at the
same time, trying to notice any sensations felt at the
points of entry and exit. The sensation may be felt
close to the tip of the nose or lips. After completion of
the course, subjects were tested by Thai GHQ28 and
blood was drawn for cortisol measurements at 8:00 am.
Thai general health questionnaire 28 (Thai GHQ-
28) All subjects were assessed in their mental
health using thai general health questionnaire 28 (Thai
GHQ-28). It is a multiple-choice questionnaire to
examine the mental health of Thai subjects developed
by Dr. Thana Nilchaikovit(10) from the psychiatric
department, Faculty of Medicine, Ramadhibodi
Hospital, Mahidol University. This questionnaire was
developed from GHQ, Goldberg 1972(11). This test
consists of 28 items concerning somatic symptoms,
anxiety and insomnia, social dysfunction and severe
depression. Each item consists of 4 choices involving
the severity of symptoms (0-0-1-1). A score > 6 is
considered abnormal. From the research, The General
Health Questionnaire is a widely used screening
instrument(12). We found that Thai GHQ28 can
discriminate mental distress. In the Thai version, the
reliability coefficient (Alpha) is 0.84, Thai GHQ28 has a
sensitivity of 78.7%, a specificity of 89.7% and accuracy
of 87%.
Blood cortisol determination
The volume of 4 mls of venous blood samples
were drawn from the antecubital vein of subjects. Blood
was collected at 8:00 am for all subjects. Serum cortisol
levels were assayed by Electro chemi luminescense
immuno-assay (ECLIA) following the manufacturer’s
instruction.
The first incubation: 20 μL of sample is
incubated with a cortisol-specific biotinylated antibody
and a ruthenium complex labeled cortisol derivative.
Depending on the concentration of the analyte in the
sample and the formation of the respective immune
complex, the labeled antibody binding site is occupied
in part with sample analyte and in part with ruthenylated
hapten. The second incubation: After addition of
streptavidin-coated microparticles, the complex
becomes bound to the solid phase via interaction of
biotin and streptavidin.
The reaction mixture is aspirated into the
measuring cell where the microparticles are magnetically
captured onto the surface of the electrode. Unbound
substances are then remove with ProCell. Application
of a voltage to the electrode.
Then induce chemiluminescent emission
which is measured by a photomultiplier.
Results are determined via a calibration curve
which is instrument-specifically generated by 2-point
calibration and a master curve provided via the reagent
barcode.
The mindfulness meditation method
Mindfulness has been described as “paying
attention in a particular way: on purpose, in the present
moment, and non-judgementally”. The mindfulness
meditation method in the present study consists of
observing the breath as it enters and leaves the nostrils,
and at the same time, trying to notice any sensations
felt at the points of entry and exit. The sensation
may be felt close to the tip of the nose or lips. The goal
of mindfulness meditation is to reach a state of
thoughtless awareness, during which a person is
passively aware of sensations at the present moment.
In the present study, the subjects meditated under
the mindfulness meditation courses of the
Sunanthavanaram temple in Kanjanaburi, the western
part of Thailand. This temple holds the famous
meditation courses which are taught and mentored by
well known buddhist monks or supervisors.
Statistical analysis
The descriptive statistics were presented with
percentage, mean, and standard deviation. The

S92 J Med Assoc Thai Vol. 96 Suppl. 1 2013
association between demographic background and
serum cortisol level or Thai GHQ28 scores were
analysed by independent t-test. The comparison of
the Thai GHQ28 scores and serum cortisol level before
and after mindfulness meditation course were analysed
by paired t-test. Value were considered to be statistical
significance when p-value < 0.05.
Results
Subject characteristics
The demographic data of subjects are shown
in Table 1. There are no statistical significance
association between demographic background and
Thai GHQ28 or serum cortical level (data not shown).
Psychological assessment
All subjects had completed Thai GHQ28 test
(100%). The average Thai GHQ 28 score of the 30
students before the meditation practice was 1.50 (SD =
2.53). After the meditation practice, the average score
was 0.77 (SD = 2.08). This showed that the average
Thai GHQ 28 score of the 30 students before the
meditation practice was higher than the average Thai
GHQ 28 score of the 30 students after the meditation
practice but it was not statistical significant.
Cortisol assessment
The average serum cortisol level of the 30
students before the meditation practice was 381.93
nmol/L (SD = 97.94). After the meditation practice, the
average serum cortisol level was 306.38 nmol/L (SD =
90.95) as shown in Fig. 1. This shows that the average
serum cortisol level of the 30 students before the
Fig. 1 Comparison of the serum cortisol before and after
the meditation practice
Factor Number Percent
Gender
Male 10 33.33
Female 20 66.67
Age (year) 19.1 + 0.55 (range 18-20)
Parent status
Couple 26 86.70
Divorce/widow 4 13.30
Income (bath)
< 10,000 6 20.00
10,000-30,000 10 33.30
30,000-50,000 8 26.70
> 50,000 6 20.00
Smoking
No 30 100.00
Yes 0 0.00
Alcohol drinking
No 26 86.70
Yes 4 13.30
Underlying disease
No 28 93.30
Yes 2 6.70
Stressor in previous month
No 6 20.00
Yes 24 80.00
Hobby
No 24 80.00
Yes 6 20.00
Relationship with parent
Very good 18 60.00
Good 10 33.30
Moderate 2 6.70
Relationship with teacher
Very good 6 20.00
Good 17 56.70
Moderate 7 23.30
Relationship with friend
Very good 12 40.00
Good 16 53.30
Moderate 2 6.70
Relationship with sibling
Very good 18 60.00
Good 10 33.30
Moderate 2 6.70
Table 1. Demographic data of all subjects
meditation practice was higher than after the meditation
practice with statistical significant (p < 0.05).
Discussion
The present study found that Thai GHQ28
score of Thai medical students decreased after the four

J Med Assoc Thai Vol. 96 Suppl. 1 2013 S93
consecutive days of mindfulness meditation practice
in agreement with previous studies(13-15). The reason
explaining the beneficial effect of mindfulness
meditation is known and is believed to make the mind
peaceful and relaxed(16), and stop all thinking activated
by external stimuli that cause nervous, anxiety, exciting,
stress, and discomfort. However, the paired t-test
indicated that there was no significant difference of
Thai GHQ28 score between pre-and post-meditation.
The post-meditation levels of serum cortisol were
significantly lower as revealed by the paired t-test
(p < 0.05) in agreement with previous studies(17,18). A
recent research(19) concluded that there is accumulating
evidence that plasma and salivary cortisol can be
reduced by mindfulness meditation. Several studies
have looked at immune parameters. In patients with
cancer, mindfulness meditation tended to restore
cytokine levels and natural killer cell activities toward
normal levels(20,21). In healthy people, meditation
increased the antibody titer to influenza vaccine(22),
lowered the stress-induced increase in interleukin-6(23)
and decreased C-reactive protein(24). In addition, a
person who practice meditation has a lower rise in
cortisol levels compared to whom that does not
practice(23,25). In other words, any causes which are out
of our control and not related to our intervention may
be occurred in place, such as relaxation by listening
the flavorite song, drinking black tea(26) or coffee(27),
exercise, sleep deprivation(28), and diet restriction(29).
More rigorous designs should be used to establish a
cause-effect relationship and a randomized controlled
trial in which the control group receives some other
form of mind-body training may suit the purpose. Further
research with rigorous design including long-term
follow-up periods are needed to address the questions
about the role of the mindfulness meditation in clinical
practice.
Conclusion
Mindfulness meditation lowers the cortisol
levels in the blood suggesting that it can lower stress
and may decrease risk of diseases that arise from stress,
such as psychiatric disorder, peptic ulcer and
migrainous headache. Then, meditation should be used
in combi-nation with standard treatment.
Acknowledgement
The present study was funded by HRH
Princess Maha Chakri Sirindhorn Medical Center,
Ongkharak campus, Faculty of Medicine, Srinakharin-
wirot University, Nakhon Nayok, Thailand. The authors
wish to thank the abbot and monks of the forest temple
Sunanthavanaram, and the second year medical
students that participated in this project.
Potential conflicts of interest
None.
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ผลของการนั่งสมาธิต่อระดับคอร์ติซอลในเลือดของนักศึกษาแพทย์
วันเพ็ญ ธุรกิตต์วัณณการ, จันทนา เมฆสีประหลาด, ภนารี บุษราคัมตระกูล
ภูมิหลัง: การนั่งสมาธิเป็นวิธีผ่อนคลายและลดความเครียด ความเครียดทำให้ระดับคอร์ติซอลในเลือดเพิ่มขึ้น
ดังนั้นการนั่งสมาธิช่วยลดความเครียด จึงช่วยลดระดับคอร์ติซอลในเลือด
วัตถุประสงค์: เพื่อศึกษาผลของการนั่งสมาธิต่อสุขภาพจิตโดยใช้ Thai GHQ28 และเพื่อศึกษาผลของการนั่งสมาธิ
ต่อความเครียดโดยใช้ระดับคอร์ติซอลในเลือด
วัสดุและวิธีการ: กลุ่มตัวอย่างเป็นนักศึกษาแพทย์ ชั้นปีที่ 2 จำนวน 30 คน อายุ 19.1 + 0.55 ปี (18-20 ปี)
จากคณะแพทยศาสตร์ มหาวิทยาลัยศรีนครินทรวิโรฒ ทำแบบทดสอบสุขภาพจิต Thai GHQ28 และเจาะเลือด
เพื่อดูระดับคอร์ติซอลเวลา 8.00 น. ก่อนและหลังนั่งสมาธิตามโปรแกรมของวัดครบ 4 วัน วิเคราะห์ทางสถิติด้วยวิธี
paired t-test
ผลการศึกษา: กลุ่มตัวอย่างเป็นเพศหญิง 66.77% และเพศชาย 33.33% คะแนน Thai GHQ28 ก่อนนั่งสมาธิ เท่ากับ
1.50 (SD 2.53) และหลังนั่งสมาธิครบ 4 วันเท่ากับ 0.77 (SD 2.08) เมื่อนำมาวิเคราะห์ทางสถิติด้วยวิธี paired t-
test พบว่าไม่มีนัยสำคัญทางสถิติ ระดับคอร์ติซอลในเลือดก่อนนั่งสมาธิเท่ากับ 381.93 nmol/L (SD 97.74)
หลังนั่งสมาธิครบ 4 วัน เท่ากับ 306.38 nmol/L (SD 90.95) เมื่อนำมาวิเคราะห์ค่าทางสถิติด้วยวิธี paired t-test
พบว่ามีนัยสำคัญทางสถิติ (p < 0.05)
สรุป: การนั่งสมาธิช่วยลดระดับคอร์ติซอลในเลือด แสดงว่าการนั่งสมาธิช่วยลดความเครียด ซึ่งเป็นสาเหตุให้เกิดโรค
หลายโรค ได้แก่ โรคทางจิตเวช, โรคกระเพาะอาหาร, โรคปวดศีรษะไมเกรน จึงควรใช้การทำสมาธิ เป็นวิธีเสริมเพิ่ม
จากการรักษาตามมาตรฐาน