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Allah
(all glory be to Him) tells us in the Holy Quran about Ramadan that,
“(He wants you) to complete the prescribed period (of fasting),
and to glorify Him in that He has guided you; and perchance ye shall
be grateful.” (2:185)
Many
benefits, in addition to the spiritual, result from completing this
prescribed period of fasting. This article attempts to explain
those related to our biological rhythms.
The
Stages of Sleep
The
background activity of the brain is called the electroencephalogram
(EEG) and can be recorded by the use of scalp electrodes. The
dominant frequency and amplitude characteristic of the surface EEG
varies with states of arousal.
A
person goes through five stages while going to sleep.
Calm
wakefulness is accompanied by alpha waves 8-12 Hz (cycles per
second) and low voltage fast activity of mixed frequency. This
is called stage one. Alpha waves disappear when we open our
eyes.
As
sleep deepens into stage two, bursts of 12-14 Hz (sleep spindles)
and high amplitude slow waves appear.
The
deep sleep of stages three and four is featured by an increasing
proportion of high voltage slow activity. Breathing is regular
in slow-wave sleep or non-REM (Rapid Eye Movements) sleep.
Delta
activity (very slow waves, 0.5-4 Hz, high amplitude) is unusual in a
normal record and accompanies deep sleep i.e. stages three and four
sleep.
After
about 70 minutes or so mostly spent in stages three and four, the
first REM period occurs, usually heralded by an increase in body
movements, and a shift in the EEG pattern from stage four to stage
two. These rapid low-voltage irregular waves resemble those seen in
alert humans; sleep, however, is not interrupted. This is called
stage 5 or REM sleep, when the EEG activity gets desynchronised.
There is marked muscle atonia despite the rapid eye movements in REM
sleep, and the breathing is irregular.
Theta
activity with a pattern of large regular waves occurs in normal
children and is briefly seen in stage one sleep and also in REM
sleep.
Non-REM
(NREM) sleep passes through stages one and two, and spends 60-70
minutes in stages three and four. Sleep then lightens and a REM
period follows. This cycle is repeated three or four times per
night, at intervals of about 90 minutes throughout the night,
depending on the length of sleep. REM sleep occupies 25% of total
sleeping time.
When
the eyes are opened, the alpha rhythm is replaced by fast irregular
low voltage activity with no dominant frequency, called the alpha
block. Any form of sensory stimulation or mental concentration such
as solving arithmetic problems could produce this break-up of the
alpha rhythm. This replacement of the regular alpha rhythm with
irregular low voltage activity is called “desynchronisation”.
Fasting
Positively Affects Sleep
During
the first few hours of an Islamic fast, the EEG is normal.
However, the frequency of the alpha rhythm is decreased by a low
blood glucose level. This may happen at the end of the fasting
day towards evening when the blood sugar is low.
Fasting
improves the quality and intensifies the depth of sleep, a matter of
particular importance to the aged who have much less stage three and
four sleep (deep sleep). The processes of repair of the body
and of the brain take place during sleep. Two hours of sleep
during the month of Ramadan are more satisfying and refreshing than
more hours of sleep otherwise!
REM
sleep and dreaming are closely associated. Dreaming may be
necessary to maintain health, but prolonged REM deprivation has no
adverse psychological effects. Dreaming sleep occupies 50% of
the sleep cycle in infants and decreases with age. Brain
synthetic processes occur in deep sleep; brain protein molecules are
synthesized in the brain during deep sleep or used in REM sleep in
restoring cerebral function. Fasting significantly increases
deep sleep and leads to a fall in REM sleeping time or dreaming
time, and also accelerates synthesis of memory molecules.
Fasting
and the Circadian Rhythm
The
period of the circadian pace-maker in humans is 24 hours 11 minutes.
Hormonal secretion is frequently characterised by rhythmic
fluctuations which may be regular or irregular in periodicity.
The period of regular oscillation may be as short as a few minutes
or as long as a year.
The
body timing system that drives circadian rhythms is exposed to
external factors ranging from the imposed activity-rest cycle, the
natural light-dark cycle, and social activities outside the
workplace.
There
are biological pacemakers or oscillators within the body with
time-keeping capacity which synchronise with the external
environmental cycles such as light. Environmental cues that
synchronize biological pacemakers are called “zeitgebers” (from
the German “time-givers”), and the process of re-setting the
pacemaker is called re-synchronization.
The
light/dark cycle is a potent zeitgeber for circadian rhythm but
daily cycles in temperature, food availability, social interaction
(such as congregational prayers) and even electro-magnetic field
strength synchronize circadian rhythm in certain species.
Because of recurring cycles of light, temperature and food
availability, organisms evolved endogeous rhythms of metabolism and
behavior providing response to specific environmental cycles.
Many biological rhythms reflect the period of one of four
environmental cycles: cycles of the tide, of day and night, of moon
phase and of seasons.
Muslims
who have been fasting regularly since childhood, have been exposed
to different sleep/wake and light/darkness cycles on a daily basis
in one annual lunar month. Hence, it may be easier for such
persons to synchronize their circadian, circalunar and circannual
biological rhythms under difficult conditions.
Fasting,
Jet Lag and Shift Work
International
travel across time zones produces symptoms of jet lag such as sleep
disturbances, gastro-intestinal disorders, decreased alterness,
fatigue and lack of concentration and motivation.
Factors
contributing to symptoms of jet lag are (1) external
desynchronisaion due to immediate differences between body time and
local time at the end of the flight. (2) internal
desynchronisation due to the fact that different circadian rhythms
in the body re-synchronise at different rates, and during the
re-synchronisation period, these rhythms will be out of phase with
one another.
General
symptoms arising from desynchronisation include tiredness during the
day and disturbed sleep and reaction time. The severity of
these adverse effects and therefore the time required for
re-synchronisation depends on the ability to pre-set the bodily
rhythms prior to flying, the number of time zones crossed, the
direction of flight, age, social interaction and activity.
NASA estimates that it takes one day for every time zone crossed to
regain normal rhythm and energy levels. A 6-hour
time-difference thus needs 6 days to get back to normal.
Rapid
adaptation to a new zone can be facilitated by maximising exposure
to zeitgebers for the new cycle e.g. changing to meal times and
sleep times appropriate to the new time zone. Maximising
social contact and exposure to natural lgihting will result in
faster resynchronisation than staying at home in a hotel and eating
and sleeping without regard to local time. There are
widesperead individual viariations in the rapidity of
resynchronisation.
Muslims
who fast regularly and who have experienced disturbed
wakefulness/sleep cycles on a daily lunar annual basis, can adapt
themselves much faster to different time zones during international
travel and do not suffer from the ill effects of jet lag.
Moreover, the social contact during the Tarawih congregational
prayer and the other social-cum–spiritual activities act as
zeitgebers which regulate any desynchronised biological rhythm.
Shift
workers also experience similar symptoms as jet lag, especially
gastro-intestinal, cardiovascular, and sleep disorders and also
reproductive dysfunctions in women. The inverted schedule of
sleeping and waking also results in diminshed alterness and
performance during night-time work with attendant increase in the
number of fatigue-related accidents during night time shift hours.
Normally, a period of three weeks is required for re-synchronisation
among shift workers, and as the fasting Muslim atunes himself to
resynchronization processes during the space of just over four weeks
in Ramadan, his health problems as a shift worker would be
negligible, as his synchronization processes would be more rapid,
whether during Ramadan or at any other time.
It
is also a common observation that as soon as Ramadan is over, normal
circadian rhythms are established in the fasted Muslims with such
great rapidity as to be at par with pre-Ramadan levels on the first
day of Shawwal, i.e. Eid-ul-Fitr.
Fasting
and Encephalins
During
fasting, certain endogenous, narcotic-like substances known as
opioids (or endorphins) are released into the body. They have
a tranquilizing effect as well as an elating effect on the mind.
These are also probably responsible for prevention of psychosomatic
diseases. The opioids have several effects, including slowing
down metabolism to conserve energy. Another effect of opioids
may be that, although they produce elation as well as intense
hunger, they do not drive the person to eat with sheer gluttony.
Muslims
in Ramadan experience an ability to intensely focus their minds on
meditation, Quranic recitation and prayers. This spiritual
gain during the Holy Month is despite the fact that normal
sleep/waking cycles are somewhat disturbed and despite a long day of
fasting. Perhaps now we have a closer idea as to the science
of this miraculous process.
Dr.
Ebrahim Kazim is a medical doctor and the founder and
director of the Islamic Academy in Trinidad. The above article
was excerpted with permission of the author from his book “Further
Essays on Islamic Topics”.
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