Does religious fasting affect cognitive performance?

Abstract

Purpose
– The purpose of this article is to assess the effect of religious fasting on the cognitive performance during the month of Ramadan among healthy fasting individuals.

Design/methodology/approach
– 30 students were recruited prior the month of Ramadan to compare their cognitive performance during and after fasting. The data on cognition score were collected in two phases during and after Ramadan on four occasions (two times in Ramadan and two times after Ramadan) using structured questionnaire. The level of cognition was assessed by using two approaches: mathematical problem solving and memory testing. Five questions of mathematical problem were given to the subjects and were different at each week. However, the level of difficulty was kept constant. The time and score were recorded for each respondent during and after fasting month. For the memory test, ten pictures of items of similar sizes were displayed for 30 seconds, and the subjects were asked to recall/list down the item shown in the pictures. The cognition scores were expressed as mean±SD, and repeated measures analysis test was used for differences in fasting and non‐fasting days.

Findings
– As expected, during Ramadan meal frequency was lower and sleeping (nap) frequency was higher with shorter duration at night. The feeling of tiredness was higher compared to non‐fasting days. The level of cognition score for was not different during Ramadan compared to non‐fasting days. The result shows that the level of cognition is not affected in fasting.

Originality/value
– The research shows that the cognition is not affected in Ramadan fasting.

Full text

Does religious fasting affect
cognitive performance?
Wardah Mohd Yasin, Muhammad Muzaffar Ali Khan Khattak,
Nik Mazlan Mamat and Wan Azdie Mohd Abu Bakar
International Islamic University Malaysia, Selayang, Malaysia
Abstract
Purpose – The purpose of this article is to assess the effect of religious fasting on the cognitive
performance during the month of Ramadan among healthy fasting individuals.
Design/methodology/approach – 30 students were recruited prior the month of Ramadan to
compare their cognitive performance during and after fasting. The data on cognition score were
collected in two phases during and after Ramadan on four occasions (two times in Ramadan and two
times after Ramadan) using structured questionnaire. The level of cognition was assessed by using
two approaches: mathematical problem solving and memory testing. Five questions of mathematical
problem were given to the subjects and were different at each week. However, the level of difficulty
was kept constant. The time and score were recorded for each respondent during and after fasting
month. For the memory test, ten pictures of items of similar sizes were displayed for 30 seconds, and
the subjects were asked to recall/list down the item shown in the pictures. The cognition scores were
expressed as mean ^ SD, and repeated measures analysis test was used for differences in fasting and
non-fasting days.
Findings – As expected, during Ramadan meal frequency was lower and sleeping (nap) frequency
was higher with shorter duration at night. The feeling of tiredness was higher compared to non-fasting
days. The level of cognition score for was not different during Ramadan compared to non-fasting days.
The result shows that the level of cognition is not affected in fasting.
Originality/value – The research shows that the cognition is not affected in Ramadan fasting.
Keywords Performance, Cognition, Fasting, Ramadan, Religious
Paper type Research paper
Introduction
Cognition is pertaining to psychology, the process of knowing, being aware of
something, learning, judging and thinking, etc. In psychology the concept of cognition is
closely related to performance, understanding and interaction with environment during
certain situations. Religious fasting is one of these situations where the level of cognition
is believed to be affected and therefore the performance of an individual might be
affected. During religious fasting major lifestyle changes take place including eating,
sleeping and religious activities. Among Muslim communities Ramadan is considered
as the month of blessing due to which they are more inclined towards the worship of
Allah (the God). There are numerous articles on the interrelationship of fasting and
health or hunger and starvation/deprivation of food. Religious fasting should be
considered different than hunger or starvation since these two conditions are not
involving the religious (rituals) aspects. However, there is limited information on the
interrelationship of fasting and cognitive performances of the fasting individuals.
Fasting reduces nervousness (Khammash and Al-Shouha, 2006) and this effect might be
important from the cognitive point of view. Among children fasting adversely affect
attention and memory processes (Pollitt et al., 1998). Similarly, the dietary manipulations
The current issue and full text archive of this journal is available at
www.emeraldinsight.com/0034-6659.htm
Received 27 June 2012
Revised 27 June 2012
Accepted 29 June 2012
Nutrition & Food Science
Vol. 43 No. 5, 2013
pp. 483-489
q Emerald Group Publishing Limited
0034-6659
DOI 10.1108/NFS-06-2012-0069
Religious fasting
483

in terms of macro-nutrients have been shown to influence the level of learning among
children as well ( Jyoti et al., 2005). During the month of fasting daily dietary intakes are
markedly altered where typically, two meals are daily consumed; one before dawn
known as Sahur and one just after sunset known as Iftar (Rahman et al., 2004; Kadri et al.,
2000). There are no restrictions on the foods consumption during the night in the month
of Ramadan. The duration of fasting time varies with the geographical position of the
country and the season in which the Ramadan month falls (Hourani and Atoum, 2007).
Generally, the length of the fast may vary from 12 to 19 hours per day (Adlouni et al.,
1997) which means it is associated with prolonged period of foods and fluids restriction
(Sakr, 1975). Therefore, eating habits during Ramadan are significantly different than
non-fasting days. Food and fluid intakes frequency is reduced which may reduce the
energy intakes (Ziaee et al., 2006; Husain et al., 1987) and this is not necessarily true
(Khattak et al., 2012; Hourani and Atoum, 2007). As mentioned earlier, cognitive
performance can be affected by several factors including dietary intakes. Mental and
psychomotor abilities are deteriorated during progressive voluntary dehydration
(Petri et al., 2006). It is believed that the duration of fluid intake deprivation is a useful
indicator of mental and psychomotor deterioration. The fasting only happened during
the day, thus, there is no dramatic effect on the hydration status of the Muslims
(Roky et al., 2004) since fluid intake pattern is changed only. The hydration status is less
likely to be affected both in normal and obese subjects (Khattak et al., 2012).
In non-Ramadan type fasting (calorie deprivation) is not associated with adverse effect
on cognitive performance, i.e. activity, sleep and mood (Lieberman et al., 2008) whereas
in Ramadan-type fasting 12-19 hours food and fluids deprivation is involved. Similarly,
impairment of cognitive performance is associated with dieting and extreme dietary
restraint (Green et al., 1994). Since glucose is an important factor for brain and it is
always made available for it through gluconeogenesis (Rochmyaningsih, 2009, 2010).
However, this still remains open for investigation whether or not fasting alters cognitive
performance of the fasting subjects. Therefore, this study was designed to assess the
effect of Ramadan fasting on cognitive performance in the healthy university students.
Methodology
30 students were recruited prior the month of Ramadan from the campus of International
Islamic University Malaysia (IIUM), Kuantan Campus. Questionnaires based on meals
frequency, sleeping pattern, napping habits, tiredness and cognitive tests (mathematical
problem solving and memory test) were given to the volunteers four times (two times in
Ramadan and two times after Ramadan) to assess the cognitive performance during
Ramadan and after Ramadan). The questionnaire was developed to assess cognitive
performance of the university students using the idea of Pollitt et al. (1998) and Morris et al.
(1994) as bases in the development of thisparticular questionnaire. Thisquestionnaire was
entirely different than the Morris et al. (1994) scale however; the inspiration was gained
from the said scale. The assessments were performed during the second (W1) and third
week (W2) of Ramadan and second (W3) and third week (W4) after Ramadan. The timing
for assessment was fixed at 2-6 pm for each week which allow assessing the effects of
8-12 hours of foods and fluids restriction on cognitive performance. At the end of the data
collected were compiled; descriptive statistic was performed and expressed as mean and
standard deviation of the mean the significance of the difference was ascertained by
repeated-measures ANOVA analysis using SPSS software Version 16.0.
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Results
The data collected on the on various aspects of performance of the fasting students are
presented in the following sections and discussed in the light of available literature.
The result shows that two to three meals were taken during Ramadan (W1 and W2)
whereas after Ramadan one to four meals were taken per day. There was a difference in
meal frequency between W1 and W2 compared to W3 and W4 (Table I). In Malaysia,
some of the Muslim takes extra meal which is locally known as “moreh” after performing
Taraweeh prayer (long prayers). Furthermore, most of the students were having nap
regardless of the fasting month and there was a difference of napping habit on W1 and
W3 (Table I). The number of students who felt tired was higher than after Ramadan
month and some of the students reported to be very tired during Ramadan (Table I).
The mean duration of sleep at night during Ramadan month (W1 and W2) was
shorter than after Ramadan month (W3 and W4). The total duration of sleep at night
decreased and it is apparent to be related to awakening for the Sahur and staying
awake to perform night prayer (qiamullail) as shown in Figure 1.
As mentioned earlier, the cognitive performance assessment involved two
approaches, i.e. mathematical problem solving and memory test (recalling of
pictures displayed). For mathematical problem solving, the test was assessed in terms
of score and time spent on solving the given problems. The score achieved during
Ramadan was not different what the students achieved after Ramadan (Figure 2).
Furthermore, the time consumed for mathematical test was not different as well. In
contrast, the time consumed after Ramadan was more than Ramadan. Thus, the result
shows that the subjects took shorter time in finishing the test during Ramadan. Hence, it is
indication of improvement in the cognitive performance of the students during Ramadan
(Figure 3).
As mentioned, that the memory score was recorded by displaying ten pictures of
similar sizes for 30 seconds and the respondents were asked to enlist the name of the
pictures. For the memory test, repeated-measures ANOVA analysis revealed that there
was no difference in the mean score for memory test during and after Ramadan (Figure 4).
During Ramadan After Ramadan
WI W2 W3 W4
n % n % n % n %
Meal frequencies
One – – – – 12 40.0 11 36.7
Two 5 16.7 8 26.7 10 33.3 16 53.3
Three 25 83.3 22 73.3 7 23.3 2 6.7
Four – – – – 1 3.3 1 3.3
Napping habits
Yes 29 96.7 27 90.0 21 70.0 26 86.7
No 1 3.3 3 10.0 9 30.0 4 13.7
Self reported level of tiredness
Energetic 3 10.0 4 13.3 4 13.3 4 13.3
Normal 18 60.0 12 40.0 21 70.0 22 73.3
Tired 9 30.0 10 33.3 4 13.3 3 10.0
Very tired – – 4 13.3 1 3.3 1 3.3
Notes: W – week; n – number of students
Table I.
Changes in meal
frequency, napping
habit and tiredness
during Ramadan
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485

Discussion
In fasting month the dietary pattern changes significantly and also the skipping of
Sahour meal is common in the university students due to various factors. Among the
factors, sleep, being lazy, awakening early in the morning, availability of food, or the
food stall is located away from the residing places. In the present study, three things
were dominating among the fasting students:
Figure 3.
Comparison of the effect
fasting during and after
Ramadan on the students
means time consumed on
mathematical tests
10
8
6
4
2
0
During Ramadan After Ramadan
W1 W2
Mean mathematics (time taken)
Minutes
W3 W4
Figure 2.
Comparison of the effect
fasting during and after
Ramadan on the students
means score in
mathematical tests
1
2
4
8
During Ramadan After Ramadan
W1
Mean mathematics (score)
W2 W1 W2
Figure 1.
Comparison of sleeping
duration of the subjects
during and after Ramadan
0
2
4
6
8
During Ramadan After Ramadan
W1
Mean sleep duration
(Hours)
W2
W3 W4
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(1) skipping of Sahour meal;
(2) napping and longer duration of sleep; and
(3) no effect on mathematical problem solving or memory test (recalling displayed
pictures).
These three finding or associations are important for the understanding of cognition or
level of performance of the fasting individuals. Furthermore, these indications are
important for the studies to be performed on the alertness and cognitive performances of
the fasting communities. During Ramadan, there is a possibility of abstention from food
and fluids for 13-18 hours depending upon the geographical location/season. However,
in Malaysia, the average duration is about 13-14 hours which is just comfortable for the
fasting individuals. In longer fasting duration, there are chances of hypoglycemia which
causes fatigue, headache, forgetfulness, mental idleness and confusion (Hamilton et al.,
1991). Therefore, there are chances of poor performances in different situations,
e.g. work, sports, alertness and learning, etc. According to Roky et al. (2000), Ramadan
fasting is accompanied by impairment in alertness and this happens in the beginning of
Ramadan and not towards the end of Ramadan (Lagarde et al., 1996). These observations
suggest that there is adaptation mechanism to fasting. Previous studies on sleep and
vigilance during the fasting month, has shown that the decrease in sleep time have a
negative effect on cognitive functions, such as a decrease in vigilance during the first
week of fasting (Ain, 1989). However, this was not so, in our study which indicates that
there was no difference in the score of problem solving and memory test score. In the
present study, the students were having longer sleeping duration in fasting compared
to after fasting. In a study performed by Hakkou et al.(1988) reports that altered sleep,
activity and eating schedule does not affect physical performance during Ramadan in
athletes but memory is affected in certain instances. According to Doniger et al. (2006)
a 12-16 hour Jewish religious fast, adversely affect memory, problem solving and verbal
naming, in time dependant manner. However, this is not always the case and is related to
the perception of the fasting individuals. Singh et al. (2011) suggested that due to the
differences in athlete’s perception of changes in their training, sleep and dietary patterns
during Ramadan fast probably represent differences in their adaptability during fasting.
Zerguini et al. (2008) reports that subjective well-being and performance variables are
Figure 4.
Comparison of the effect
fasting during and after
Ramadan on the students
means memory score
9
6
3
0
During Ramadan After Ramadan
W1 W2
Mean memory (score)
W3 W4
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487

not adversely affected in football players in Ramadan fasting. The disagreements may
be due to the differences in methods of assessing memory functions and other
performances. Our study suggest that the students performance in terms of memory and
problem solving is not affected by Ramadan fasting.
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Further reading
Tian, H.H., Aziz, A.R., Png, W., Wahid, M.F., Yeo, D. and Png, A.L.C. (2011), “Effects of fasting
during Ramadan month on cognitive function in Muslim athletes”, Asian J. Sports Med.,
Vol. 2 No. 3, pp. 145-153.
Corresponding author
Muhammad Muzaffar Ali Khan Khattak can be contacted at: muzaffar@iium.edu.my
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