Alkaabi et al.

Nutrition Journal 2011, 10:59

http://www.nutritionj.com/content/10/1/59

RESEARCH Open Access

Glycemic indices of five varieties of dates in

healthy and diabetic subjects
Juma M Alkaabi1*, Bayan Al-Dabbagh1, Shakeel Ahmad2, Hussein F Saadi1, Salah Gariballa1 and Mustafa Al Ghazali2

Abstract
Background: This study was designed to determine the glycemic indices of five commonly used varieties of dates
in healthy subjects and their effects on postprandial glucose excursions in individuals with type 2 diabetes mellitus.
Methods: Composition analysis was carried out for five types of dates (Tamer stage). The weights of the flesh of
the dates equivalent to 50 g of available carbohydrates were calculated. The study subjects were thirteen healthy
volunteers with a mean (± SD) age of 40.2 ± 6.7 years and ten participants with type 2 diabetes mellitus
(controlled on lifestyle measures and/or metformin) with a mean HbA1c (± SD) of 6.6 ± (0.7%) and a mean age (±
SD) of 40.8 ± 5.7 years. Each subject was tested on eight separate days with 50 g of glucose (on 3 occasions) and
50 g equivalent of available carbohydrates from the 5 varieties of date (each on one occasion). Capillary glucose
was measured in the healthy subjects at 0, 15, 30, 45, 60, 90 and 120 min and for the diabetics at 0, 30, 60, 90, 120,
150 and 180 min. The glycemic indices were determined as ratios of the incremental areas under the response
curves for the dates compared to glucose. Statistical analyses were performed using the Mann-Whitney U test and
repeated measures analysis of variance.
Results: Mean glycemic indices ± SEM of the dates for the healthy individuals were 54.0 ± 6.1, 53.5 ± 8.6, 46.3 ±
7.1, 49.1 ± 3.6 and 55.1 ± 7.7 for Fara’d, Lulu, Bo ma’an, Dabbas and Khalas, respectively. Corresponding values for
those with type 2 diabetes were very similar (46.1 ± 6.2, 43.8 ± 7.7, 51.8 ± 6.9, 50.2 ± 3.9 and 53.0 ± 6.0). There
were no statistically significant differences in the GIs between the control and the diabetic groups for the five
types of dates, nor were there statistically significant differences among the dates’ GIs (df = 4, F = 0.365, p = 0.83).
Conclusion: The results show low glycemic indices for the five types of dates included in the study and that their
consumption by diabetic individuals does not result in significant postprandial glucose excursions. These findings
point to the potential benefits of dates for diabetic subjects when used in a healthy balanced diet.
Trial Registration Number: ClinicalTrials.gov NCT01307904

Background (2.3-5.6%), and fibers (6.4-11.5%) [4-6]. The develop-

The date palm (Phoenix dactylifera L.) is one of man- ment of the fruit is classified into four stages. Stage 1:
kind’s oldest cultivated plants. There are more than ‘Kimiri’ stage, stage 2: ‘Khalal’ stage, stage 3: ‘Rutab’
2000 different varieties of dates [1], which have been stage and stage 4: ‘Tamer’ stage. The tamer stage is the
used as food for over 6000 years. Dates are grown final stage of maturation when the date has dried to a
mostly between latitudes 10°N and 39°N [2] and are the fairly firm consistency with a darker color [4].
most common fruit crop grown in the United Arab The daily consumption of dates is a deeply rooted tra-
Emirates (UAE), occupying about 30% of the cultivated dition in many societies, including those in the UAE. In
land [3]. Oman, which lies immediately adjacent to the UAE, the
Dates are rich in carbohydrates (total sugars, 44-88%), per capita daily consumption of dates is estimated at
salts, minerals, vitamins, fatty acids (0.2-0.5%), proteins 55-164 grams and thus constitutes a vital component of
the daily diet [7]. The UAE has developed rapidly over
* Correspondence: j.kaabi@uaeu.ac.ae the last 40 years from a nomadic and trading economy
1
Department of Internal Medicine, Faculty of Medicine and Health Sciences,
United Arab Emirates University, United Arab Emirates into an emerging industrialized nation with a per-capita
Full list of author information is available at the end of the article gross domestic product ranked seventh in the world
© 2011 Alkaabi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Alkaabi et al. Nutrition Journal 2011, 10:59 Page 2 of 9
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(World Bank 2010). This economic growth has given dates among healthy and diabetic subjects. The results
rise to an abundance of food varieties and a decrease in may help diabetic subjects and their health care provi-
physical activity which, in turn, has lead to a dramatic ders in developing a diet that is both medically and cul-
increase in the prevalence of obesity, metabolic syn- turally appropriate.
drome, dyslipidemia, hypertension, prediabetes and dia-
betes [8-11]. Materials and methods
The prevalence of diabetes mellitus (DM) in the UAE Subjects
is currently the second highest in the world according Study participants were recruited from local poster
to the International Diabetes Federation 2010 [8]. From advertisements (Figure 1). After providing informed
a population-based study in the city of Al Ain in the written consent, all volunteers completed an inter-
UAE, the age-standardized rates for DM (diagnosed and viewer-administered questionnaire covering demo-
undiagnosed) and pre-diabetes among 30-64 year olds graphic data, tobacco and alcohol use, past medical and
were 29% and 24.2% respectively [9]. surgical history, co-morbidities, medications use and
It is well documented that adherence to a healthy diet current health status. In patients known to have dia-
can improve glycemic control [12], may reduce glycosy- betes, information on disease onset, duration, and man-
lated hemoglobin (HbA1c) levels [13-15], and when agement was elicited. Each subject underwent a
used in combination with other components of diabetes complete physical examination including measurements
care, can further improve clinical and metabolic out- of blood pressure, pulse rate, height, weight, body mass
comes [13,14]. These observations have been translated index (BMI), body fat composition analysis using the
into dietary guidelines for individuals with DM which Tanita TBF-410 Body Composition Analyzer (Tanita
include the recommendation that complex carbohy- Corp., Tokyo, Japan) and measurement of waist circum-
drates are preferable to simple carbohydrates [16,17]. ference. Inclusion criteria required that those in the
The glycemic index (GI), first proposed in 1981 [18], healthy group were indeed healthy and in the diabetes
is a system of classifying food items by glycemic group that their diabetes was controlled (HbA1c ≤ 8%)
response. The GI of a food depends upon the rapidity of on diet with or without metformin. Exclusion criteria
digestion and absorption of its carbohydrates, which is for both healthy and diabetic volunteers included mor-
determined largely by its physical and chemical proper- bid obesity (BMI > 40 kg/m2), pre diabetes, pregnancy,
ties. A particular food’s GI is determined by measuring presence of gastroenterological disorders, alimentary
the rise in blood glucose after ingestion of a quantity of tract surgery, a history of gastroenteritis in the prior six
that food containing 50 g carbohydrate equivalent com- months, any alcohol intake, smoking, taking any medica-
pared with the same amount of carbohydrate from a tions (except metformin), poorly controlled diabetes
reference (such as glucose or white bread) taken by the (HbA1c > 8%) and the presence of chronic diseases
same subject [19,20]. Using glucose as the reference, a (such as bronchial asthma or rheumatoid arthritis) or
GI of ≤ 55(i.e. ≤ 55% of the reference) is considered low, acute illness (such as upper respiratory tract or urinary
of 56-69 is considered medium, and of ≥ 70 is consid- tract infection).
ered high [18]. Thirteen healthy subjects (7 females and 6 males) and
In the UAE, the partaking in frequent snacks of dates ten volunteers with type 2 DM (5 females and 5 males)
(as often as four to five times per day) is a tradition. were enrolled for the study (Table 1). These numbers
Our observation from clinical practice is that diabetic were chosen based on the literature where similar
patients tend to receive conflicting messages from health numbers had provided adequate power [19-22,25]. In
educators regarding the advisability of consuming dates, order to reduce within and between-subject variability
with some suggesting restraint or even avoidance as a in GI measurements, subjects were asked to refrain
means to improve glycemic control. However, this from changing their eating and physical activity habits
appears to conflict with findings from previous studies until the study was completed; i.e. subjects were
demonstrating that dates have low to medium GIs advised to take their normal diet and to avoid unusual
[4,21-24]. We hypothesized that different types of com- vigorous activity. In addition, we used capillary blood
monly used dates would have low to medium GIs and for the measurement of GIs instead of using venous
therefore their consumption by diabetic subjects does samples and we also used oral glucose as a reference
not result in significant postprandial glucose excursions. food three times in keeping with recommendations in
The purpose of this study was therefore to evaluate the the literature [26]. Patients on metformin (5 patients)
composition and the GIs of five common types of dates were asked to take their usual dose of the drug before
consumed in the UAE in both healthy and diabetic sub- eating the test meal [19]. Prior to the GI studies, a fast-
jects. To the best of our knowledge, this is the first ana- ing blood sample was obtained from all subjects for
lysis of the composition and GIs of these particular measurements utilizing a Beckman Coulter DXC800
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Composition analysis of the five selected types of dates

48 individuals responded to the study advertisements

34 were potentially eligible 23 subjects were selected (11

excluded: 2 prediabetics, 3 HbA1c
> 8%, 1 smoker, 3 declined
participation and 2 unable to start
immediately)

13 healthy subjects 10 Type 2 DM subjects

Visit 1 OGTT (50g glucose)

Visit 2 OGTT (50g glucose)
Visit 3 OGTT (50g glucose)
Visit 4 50g equivalent carbohydrates of Fara’d
Visit 5 50g equivalent carbohydrates of Lulu
Visit 6 50g equivalent carbohydrates of Boma’an
Visit 7 50g equivalent carbohydrates of Dabbas
Visit 8 50g equivalent carbohydrates of Khalas

Capillary glucose measured at Capillary glucose measured at

0, 15, 30, 45, 60, 90 and 120 min 0, 30, 60, 90, 120, 150 and 180 min
each visit each visit

GI determination
Figure 1 Study flow chart.

(Beckman Instruments, Inc., Fullerton, CA, USA) auto- Test foods

analyzer at the central laboratory of Tawam hospital, a Fara’d, Lulu, Bo ma’an, Dabbas and Khalas, five varieties
tertiary referral hospital in Al Ain. These tests included of date, very popular in the UAE, were chosen for this
a complete blood count, glucose and lipids, liver func- study. The same batches of packaged dates (Tamer
tion tests, urea and electrolytes, urine protein and stage) obtained from a local dates processing factory (Al
hemoglobin A1c. Saad date factory, Al Ain, UAE) were used for all tests.

Table 1 Demographic and other baseline characteristics of the studied subjects1

Parameter Healthy (n = 13) Mean ± SD Type 2 DM (n = 10) Mean ± SD
Age (Yrs) 40.2 ± 6.7 40.8 ± 5.7
Body weight (Kg) 75.4 ± 16.0 83 ± 16.7
Height (cm) 165.9 ± 8.0 163.9 ± 7.8
Body mass index (Kg/m2) 27.4 ± 4.1 30.7 ± 5.2
HbA1c (%) 5.8 ± 0.4 6.6 ± 0.7
Fasting blood glucose (mg/dl) 95.7 ± 6.5 116.1 ± 7.9
Waist circumference (cm) Males: 97.3 ± 9.4 Males: 101.3 ± 10.9
Females: 89.2 ± 12.6 Females: 98.7 ± 9.2
Body fat composition (%) Males: 29.8 ± 8.6 Males: 30.0 ± 7.5
Females: 32.3 ± 8.2 Females: 39.7 ± 6.1
1
Data are presented as mean ± SD.
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Table 2 Chemical compositions of the flesh of studied The dates were weighed using an H110 Sartor analyti-
dates cal scale (Sartorius AG, Goettingen, Germany), and con-
Analysis Fara’d Lulu Bo ma’an Dabbas Khalas sumed by all participants with 250 ml of water. Blood
Moisture (%) 13.20 14.40 14.81 12.89 16.13 glucose was monitored during 2 hrs for the healthy indi-
Crude fiber (%) 2.64 1.84 2.58 2.36 2.50 viduals at 0, 15, 30, 45, 60, 90 and 120 min and over 3
Fat (%) 0.12 0.15 0.06 0.15 0.12 hrs for the diabetics at 0, 30, 60, 90, 120, 150 and 180
Nitrogen (%) 0.186 0.240 0.224 0.259 0.191 min [19]. Areas under the curve (AUC) of blood glucose
Protein (%) 1.162 1.498 1.399 1.622 1.192 concentrations resulting from glucose given orally in a
Fructose (%) 33.25 31.64 32.51 28.55 32.36 dose of 50 g with a corresponding oral carbohydrate
Glucose (%) 35.73 36.25 36.29 37.08 36.47 load of 50 g were compared as previously described
Sucrose (%) 0.91 1.07 0.16 2.26 BLD2 [19]. The 50 g of glucose was used as the reference food
1
TRS (%) 68.98 67.89 68.80 65.63 68.83 (GI = 100) against which all test dates were compared.
1
TRS: total reducing sugars The areas under the incremental glycemic-response
2
BLD: below limit of detection curves for each date type were expressed as a percentage
of the mean area under the three glucose curves for the
The compositions of the dates (Tables 2, 3) were ana- same subject. The resulting values for all subjects were
lyzed using standard methods (Association of Official averaged to calculate the GI for each type of dates. The
Analytical Chemists, 2000) [27]. blood glucose levels used to calculate GIs were mea-
sured in our research laboratory in the Faculty of Medi-
Protocol cine and Health Sciences, United Arab Emirates
Glucose was measured in capillary blood samples using University between March and June 2010.
one of two One Touch II® Lifescan glucometers (Life- The study conformed to the requirements of the
Scan, Inc., Milpitas, CA, USA), which were tested for Declaration of Helsinki and was approved by Al Ain
accuracy and precision with the provided kits and Medical District Human Research Ethics Committee
against a Beckman Synchron CX7 laboratory analyzer (approval reference: 10/06) and was registered in a clini-
(Beckman Instruments, Inc., Fullerton, CA, USA) which cal trials registry (ClinicalTrials.gov Identifier:
uses the glucose oxidase method. The coefficient of var- NCT01307904).
iation was 2.20-2.65% for both glucometers using three
testing samples across the low, mid and high glucose Statistical analysis
ranges. Data were analyzed using Microsoft Excel 2003 and
SPSS version 18 (SPSS Inc., Chicago, IL). For each dates
Measurement of glycemic response meal the GI was measured by calculating the area under
GI testing was carried out after an overnight fast on 8 the curve using the formulae kindly provided by Profes-
occasions in every subject, each test being separated sor Thomas Wolever from the University of Toronto-
from the next by a “washout” day. As shown in Figure Canada. Standard descriptive statistics were used and
1, the first 3 test days utilized 50 g of glucose dissolved results are presented as means and standard deviations
in 250 ml water (Trutol ® 50, Thermo Scientific) fol- (SD) or standard errors of the mean (SEM). In addition,
lowed sequentially by 50g carbohydrate equivalents of for each type of date the GIs were compared between
the five selected dates (Table 4). The reference food (50 DM patients and controls using Mann-Whitney tests.
g of glucose) was tested on 3 alternating days in order Comparisons of GIs of the 5 different dates were carried
to minimize day to day variation of glucose tolerance. out using repeated measures analysis of variance
Subjects were blinded to the type of the dates. (ANOVA) on the combined (DM and controls) data set

Table 3 Trace elements and minerals content of the flesh of the studied dates1
Variety Arsenic Cadmium Lead Calcium Sodium Iron Magnesium Phosphorus Manganese Zinc
μg/kg μg/kg μg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg
Fara’d 36.1 0.7 12.6 1170.5 192.1 2.256 1205.4 445.9 0.797 0.173
Lulu 29.2 2.2 45.5 517.7 93.4 7.94 411.1 338.3 1.268 1.415
Bo 68.8 0.9 24.7 288.6 47.7 7.369 561.0 543.8 2.341 1.172
ma’an
Dabbas 36.4 0.9 25.3 846.5 91.1 3.495 604.9 411.8 4.293 0.820
Khalas 70.9 1.4 19.5 936.3 121.9 3.894 746.9 245.5 0.836 1.329
1
Selenium < 0.14, Cobalt < 0.09 and Copper < 0.01 (mg/kg) for all five types of dates.
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Table 4 Mean glycemic indices of dates in healthy and type 2 DM subjects1

Variety Weight consumed (in g)* Healthy subjects (n = 13) Types 2 DM subjects (n = 10)
Mean GI ± SEM Mean GI ± SEM
Fara’d 72.5 54.0 ± 6.1 46.1 ± 6.2
Lulu 73.6 53.5 ± 8.6 43.8 ± 7.7
Bo ma’an 72.7 46.3 ± 7.1 51.8 ± 6.9
Dabbas 76.2 49.1 ± 3.6 50.2 ± 3.9
Khalas 72.6 55.1 ± 7.7 53.0 ± 6.0
1
Values are given as mean ± SEM.
*Weights of dates are equivalent to 50 g of available carbohydrate.

using groups as a between subjects factor. In all cases Discussion

the statistical significance level was set at p ≤ 0.05. Dates are rich in certain nutrients and are widely con-
sumed in many countries, particularly those within the
Results Islamic world. They have been directly referred to in the
The composition of the dates studied is shown in Table Qur’an and in the Hadith (sayings of the Holy Prophet
2. The moisture content was 12-16%. The dates con- Mohammed).
tained a high concentration of sugar, which is consid- Composition analysis of the pulp of the dates in our
ered the main component (total reducing sugars, 65- study was in keeping with the previously published lit-
69%). The highest concentration of available carbohy- erature [1,4,28]. The average water content of the dates
drate was in Fara’d dates and lowest in Dabbas dates. we studied was 14.3%, consistent with the moisture con-
Crude fiber varied between 2-3%, fat 0.06 - 0.15% and tent analysis (average 12.7%) of 13 varieties of dried
protein 1.1-1.6% (Table 2). Thirteen salts and trace ele- dates [4]. Our studied types of dates are rich in carbohy-
ments were also measured (Table 3). drates with two monosaccharides, glucose and fructose,
There were 13 healthy subjects (7 females and 6 as the main reducing sugars. As fructose is twice as
males) with a mean (± SD) age of 40.2 ± 6.7 years and sweet as glucose, it plays an important role in the flavor
BMI (± SD) of 27.4 ± 4.1 kg/m2, and 10 subjects with and desirability of the dates. From a previously reported
type 2 diabetes (F:M = 1:1) with a mean age (± SD) of study carried out in the UAE, the total sugar content of
40.8 ± 5.7 years, BMI (±S D) of 30.7 ± 5.2 kg/m2 and 12 different varieties of dates varied from 44.3 to 64.1 g/
mean HbA1c (± SD) of 6.6 ± 0.7 (Table 3). 100 g [29]. The carbohydrate content of dates depends
Table 4 shows the GI results for the five types of dates on the type of date and the degree of ripeness with the
in healthy and diabetics subjects. The measured mean ± highest concentration at the tamer stage.
SEM GIs of the dates among healthy individuals were The dietary fiber content varies depending on the type
54.0 ± 6.1, 53.5 ± 8.6, 46.3 ± 7.1, 49.1 ± 3.6 and 55.1 ± and degree of ripeness [4-6]. The percentage of dietary
7.7 for Fara’d, Lulu, Bo ma’an, Dabbas and Khalas dates, fiber decreases throughout the stages of maturation with
respectively. The mean ± SEM GIs among individuals the lowest percentage at the tamer stage [4,29]. Our
with type 2 diabetes were very similar (46.1 ± 6.2, 43.8 measurement of the percentage of dietary fibers (2-3%)
± 7.7, 51.8 ± 6.9, 50.2 ± 3.9 and 53.0 ± 6.0, respectively). was similar to that previously reported [21,22]. The diet-
There were no statistically significant differences in ary fiber of dates at the tamer stage is mostly indigesti-
the GIs between the DM and control groups (M-W ble. The reported insoluble and soluble fiber
tests), for any of the 5 dates, with p-values of 0.457, components contribute 84-94% and 6-16% of total fiber
0.495, 0.352, 0.951 and 0.901 for Farad, Lulu, Bo ma’an, respectively [28]. Higher ranges of total dietary fiber
Dabbas, and Khalas respectively. Nor was there signifi- contents (7.2-14.9%) in 13 pre-packed date varieties
cant heterogeneity in GIs among the 5 types of dates from various countries have also been reported [30].
tested in GIs, ANOVA; (df = 4, F = 0.365, p = 0.83) This variability in the reported dietary fiber content
within and between healthy and diabetic subjects. Given might be explained primarily by the different date vari-
the absence of any evidence for heterogeneity in GIs eties and the methods of measurement used. The con-
among dates, no further post-hoc pairwise comparison sumption of 100g dates can provide 50 - 100% of the
were carried out. Figures 2 and 3 are graphic presenta- recommended daily amount of fiber [31].
tions of the GI changes in the healthy and diabetic sub- The tested dates contain a higher percentage of pro-
jects, respectively. The consumption of the five varieties tein than common fruits such as apples, oranges, bana-
of dates did not result in significant postprandial glucose nas and grapes which contain 0.3%, 0.7%, 1.0% and 1.0%
excursions. protein, respectively [32]. Our dates were also rich in
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200 200
Glucose Glucose
Fara'd Lulu
175 175
Blood glucose (mg/dl)

Blood glucose (mg/dl)

150 150

125 125

100 100

75 75
0 15 30 45 60 75 90 105 120 0 15 30 45 60 75 90 105 120
Time (min) Time (min)
200
200 Glucose
Glucose
Bo ma’an Dabbas
175

Blood glucose (mg/dl)

175
Blood glucose (mg/dl)

150 150

125 125

100 100

75 75
0 15 30 45 60 75 90 105 120 0 15 30 45 60 75 90 105 120
Time (min) Time (min)
200
Glucose
Khalas
175
Blood glucose (mg/dl)

150

125

100

75
0 15 30 45 60 75 90 105 120
Time (min)
Figure 2 Mean capillary glucose concentrations following ingestion of dates in healthy subjects. Data are expressed as the changes in
capillary glucose concentration from the fasting baseline concentration. Each data point represents the mean value for all the healthy subjects
and the standard error of the mean.

salts, minerals and trace elements consistent with pre- 57.7 [34]. Lock et al reported one date GI result of 61.6.
vious reports [4-6,28]. The trace elements are indispen- However, that study was performed in pregnant women
sable for proper functioning of a myriad of biochemical [23]. From international tables, the mean GI ± SEM for
reactions, more particularly as enzyme cofactors in glu- dates is 42 ± 4 [35]. In summary, the reported GI for
cose metabolism, the organic derivatives yielded much dates classifies them as low to medium food items
better results than inorganic forms, likely because of (mostly low GI food items). The low GI of dates can be
better absorption [33]. attributed to their high fructose and dietary fiber con-
The range of GIs of the five types of dates assessed in tent. In our study, the glucose: fructose ratio is approxi-
our study was 46 to 55 for healthy subjects and 43 to 53 mately 1:1 consistent with previous publications
for the type 2 diabetic patients. All of these date vari- [26,29,36]. A mean GI for fructose from 4 studies has
eties, therefore, are low GI food items. In healthy sub- been reported as 23 [37].
jects, the mean GIs reported by Miller et al for Khalas A diet low in GI may decrease the risk of coronary
and Bo ma’an were 35.5 and 30.5 respectively [21] and heart disease, gallbladder disease and breast cancer.
the mean GI for Khalas with yoghurt mixed meal was Furthermore, a low GI diet demonstrably improves
35.5 [22]. The GIs of three varieties of dates collected HbA1c levels, body weight and the lipid profile
from various regions of Oman ranged between 47.6 and [38,39,15,40-43].
Alkaabi et al. Nutrition Journal 2011, 10:59 Page 7 of 9
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320 320
Glucose Glucose
280 Fara'd Lulu
280
Blood glucose (mg/dl)

Blood glucose (mg/dl)

240 240

200 200

160 160

120 120

80 80
0 30 60 90 120 150 180 0 30 60 90 120 150 180
Time (min) Time (min)
320 320
Glucose Glucose
280 Bo ma’an 280 Dabbas
Blood glucose (mg/dl)

Blood glucose (mg/dl)

240 240

200 200

160 160

120 120

80 80
0 30 60 90 120 150 180 0 30 60 90 120 150 180
Time (min) Time (min)
320
Glucose
280 Khalas
Blood glucose (mg/dl)

240

200

160

120

80
0 30 60 90 120 150 180
Time (min)

Figure 3 Mean capillary glucose concentrations following ingestion of dates in subjects with type 2 diabetes. Data are expressed as
changes in capillary glucose concentration from the fasting baseline concentration. Each data point represents the mean value for all the
healthy subjects and the standard error of the mean.

Whereas our estimates of the GIs among healthy in individuals with type 2 diabetics on different medica-
volunteers are similar to previously reported values tion regimens, and in patients with type 1 diabetes.
[21,22,34], we are not aware of similar studies on the
effect of these dates on postprandial glucose excursions Limitations of the study
among diabetic subjects. Our results show that the con- The test meals were not randomized and, ideally, the
sumption of the five varieties of dates did not result in glucose meals should have been taken before, halfway
significant postprandial glucose excursions, suggesting and at the end of the test meals. We used only five vari-
that such patients can consume dates in similar quanti- eties of dates (Tamer stage) hence the conclusions from
ties to those used in this study without the risk of indu- this study may not be generalizable to all types of dates.
cing undesirable postprandial excursions in blood The volunteers with type 2 DM were controlled on diet
glucose. The equivalent of 7-10 dates was used in each or metformin only. Thus, the results of this study can-
of our studies, which is similar to what is maximally not be extended to all patients with type 2 DM espe-
eaten at a single sitting by UAE subjects. The caloric cially at advanced stages of the disease, i.e. those
content, however, should be accounted for in any meal receiving multiple oral hypoglycemic agents or insulin.
plan, as dates are rich in energy i.e. 100 g of flesh can
provide approximately 314 kcal i.e. 11-15% of the total Conclusions
energy requirement per day for adults [36]. Further stu- We have determined the composition of five common
dies are needed to examine the GIs of dates at different types of dates (Fara’d, Lulu, Bo ma’an, Dabbas and Kha-
stages of maturation and to measure the glycemic and las) and calculated their glycemic indices. Our results
metabolic profile responses to the consumption of dates support the study hypothesis that the tested varieties of
Alkaabi et al. Nutrition Journal 2011, 10:59 Page 8 of 9
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dates would have low GIs in healthy subjects and that 8. International Diabetes Federation (IDF) Atlas website:[http://www.eatlas.idf.
org/Complications/].
their consumption by diabetic individuals does not 9. Saadi H, Carruthers SG, Nagelkerke N, Al-Maskari F, Afandi B, Reed R,
result in significant postprandial glucose excursions. Lukic M, Nicholls MG, Kazam E, Algawi K, Al-Kaabi J, Leduc C, Sabri S, El-
Future prospective studies are needed to evaluate the Sadig M, Elkhumaidi S, Agarwal M, Benedict S: Prevalence of diabetes
mellitus and its complications in a population-based sample in Al Ain,
effects of long-term consumption of these dates on pre- United Arab Emirates. Diabetes Res Clin Pract 2007, 78(3):369-377.
vention of diabetes and other chronic diseases in the 10. Malik M, Bakir A, Abi Saab B, Roglic G, King H: Glucose intolerance and
UAE, and on the control of hyperglycemia in subjects associated factors in the multi-ethnic population of the United Arab
Emirates: results of a national survey. Diabetes Res Clin Pract 2005,
with diabetes. 69:188-195.
11. Al-Maskari F, El-Sadig M, Nagelkerke N: Assessment of the direct medical
costs of diabetes mellitus and its complications in the United Arab
Abbreviations Emirates. BMC Public Health 2010, 10:679.
GI: Glycemic Index; HbA1c: Glycated hemoglobin A1c; OGTT: Oral glucose 12. Pastors JG, Warshaw H, Daly A, Franz M, Kulkarni K: The evidence for the
tolerance test. effectiveness of medical nutrition therapy in diabetes management.
Diabetes Care 2002, 25(3):608-613.
Acknowledgements 13. Pi-Sunyer FX, Maggio CA, McCarron DA, Reusser ME, Stern JS, Haynes RB,
We would like to thank the Abu Dhabi Food Control Authority (ADFCA) for Oparil S, Kris-Etherton P, Resnick LM, Chait A, Morris CD, Hatton DC,
the financial grant to support this research project. Professor T. Wolever, Metz JA, Snyder GW, Clark S, McMahon M: Multicenter randomized trial of
University of Toronto, has kindly provided the Excel GI calculator and Al a comprehensive prepared meal program in type 2 diabetes. Diabetes
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doi:10.1186/1475-2891-10-59
Cite this article as: Alkaabi et al.: Glycemic indices of five varieties of
dates in healthy and diabetic subjects. Nutrition Journal 2011 10:59.

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