The Health Benefits of Fasting
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.'' (Surat
Al Baqarah: 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.
A person goes through five stages while going to 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.
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
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
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
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
Fasting & 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
Fasting, Jet Lag & Shift Work
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
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.
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,
Fasting & 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
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.