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(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.
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