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To determine whether the glycemic index (GI) and insulinemic index (II) of dates could be altered by Arabic coffee consumption. This randomized cross-over study was conducted at the Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom from November 2009 to February 2010. Healthy subjects (5 males, 5 females) were recruited to the study. They were fed Khulas dates either with water, or with Arabic coffee. Plasma glucose and insulin responses were measured using standardized methods. Responses were compared with a pure glucose solution matched for available carbohydrate. The GI and II were calculated using standardized methods, and results were presented as means and standard error of mean. Glucose and insulin responses were compared using repeated measures analysis of variance. The GI of dates was 55 +/- 6, which increased to 63 +/- 5 for dates consumed with Arabic coffee (p=0.08). No significant difference was observed between the II for dates, and the II of dates consumed with Arabic coffee (p=1.00). Arabic coffee consumption modestly increased the plasma glucose response of dates compared to that of dates consumed with water. Insulin levels were not significantly affected. The modestly higher glycemic response to dates in the presence of Arabic coffee indicates that this custom may be considered detrimental to health.
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Arabic coee increases the glycemic index but not
insulinemic index of dates
Muneera Q. Al-Mssallem, MSc, PhD, Jonathan E. Brown, MSc, PhD.
     
      
 ±
      
6 ± 55 
5 ± 63
p= 0.08
p = 1.00
         
Objectives: To determine whether the glycemic index
(GI) and insulinemic index (II) of dates could be
altered by Arabic coee consumption.
Methods: is randomized cross-over study was
conducted at the Department of Nutritional Sciences,
Faculty of Health and Medical Sciences, University of
Surrey, Guildford, United Kingdom from November
2009 to February 2010. Healthy subjects (5 males,
5 females) were recruited to the study. ey were
fed Khulas dates either with water, or with Arabic
coee. Plasma glucose and insulin responses were
measured using standardized methods. Responses
were compared with a pure glucose solution matched
for available carbohydrate. e GI and II were
calculated using standardized methods, and results
were presented as means and standard error of mean.
Glucose and insulin responses were compared using
repeated measures analysis of variance.
Results: e GI of dates was 55 ± 6, which increased
to 63 ± 5 for dates consumed with Arabic coee
(p=0.08). No signicant dierence was observed
between the II for dates, and the II of dates consumed
with Arabic coee (p=1.00).
Conclusion: Arabic coee consumption modestly
increased the plasma glucose response of dates
compared to that of dates consumed with water.
Insulin levels were not signicantly aected. e
modestly higher glycemic response to dates in the
presence of Arabic coee indicates that this custom
may be considered detrimental to health.
Saudi Med J 2013; Vol. 34 (9): 923-928
From the Department of Food and Nutritional Sciences (Al-Mssallem),
Faculty of Agricultural and Food Sciences, King Faisal University,
Al-Hassa, Kingdom of Saudi Arabia, and the Department of
Nutritional Sciences (Brown), Faculty of Health and Medical Sciences,
University of Surrey, Guildford, United Kingdom.
Received 2nd April 2013. Accepted 14th August 2013.
Address correspondence and reprint request to: Dr. Muneera Q.
Al-Mssallem, Department of Food and Nutritional Sciences, College of
Agricultural and Food Sciences, King Faisal University, PO Box 420,
Al-Hassa 31982, Kingdom of Saudi Arabia. Tel. +966 505959598.
Fax. +966 (3) 5801251. E-mail: Saudi Med J 2013; Vol. 34 (9)
Disclosure. is study was supported by a grant from
King Faisal University, Al-Hassa, Kingdom of Saudi
Glucose and insulin responses of dates with coee ... Al-Mssallem & Brown
Saudi Med J 2013; Vol. 34 (9)
The relationship between coee consumption and
the risk of developing type 2 diabetes mellitus
(T2DM) has been studied in short-term randomized
controlled trials and epidemiologic studies.1-3 ese
studies have shown that high consumption of coee
beverage is associated with better glucose tolerance, and
a substantially lower risk of T2DM.1,3 is may in part,
be related to coee phenolic constituents where coee is
considered the major source of chlorogenic acids (CGA)
in the human diet.4,5 e CGA and other phenolic
compounds in coee may inhibit glucose absorption
via interference with glucose transporters.3,6,7 Also,
CGAs have been shown to aect glucose metabolism by
increasing insulin sensitivity.4,5 Nevertheless, ingestion
of coee has also been shown to increase the area under
the glucose and insulin curves, and to reduce insulin
sensitivity,8-10 in response to high and low glycemic index
(GI) meals. is eect was associated with the presence
of caeine in the coee beverage, which has also been
shown to have important physiological eects.8,9 ere is
evidence that dietary habits and lifestyle play important
roles in developing, or preventing chronic diseases,
such as diabetes.3,11 Saudi populations habitually enjoy
consuming Arabic coee, which is mainly made from
Arabica coee beans which are lightly roasted, and then
mixed with cardamom.12 Arabic coee is traditionally
served along with varieties of dates on a daily basis. e
GI for dierent varieties of dates ranges from 46-57.13-16
Interestingly, the rst documentation of the GI for
dates came from a Saudi Arabian variety known as
Khulas, which had a GI of 57.13 A later study showed
that the GI of dates can be reduced to 36 when they
are consumed with sour milk.17 A typical adult Saudi
may consume between 20 and 120 g of dates with
60-300 mL of Arabic coee at one sitting. However,
although the eects of consuming dates with sour milk
are known, the metabolic impact of consuming dates
with Arabic coee has not been investigated previously.
It is apparent from our knowledge of the constituents
of coee that both benecial and detrimental outcome
could occur in terms of glucose and insulin levels by
consuming coee. e eect of consuming dates and
Arabic coee has not been investigated before, and as
this is a traditional dietary habit in the Arabian Gulf
countries, we were interested on its eect on blood
glucose. erefore, this study aimed to investigate the
glucose and insulin responses to the ingestion of an
equivalent amount of 50 g of available carbohydrate
from dates with water, and dates with Arabic coee.
Methods. Total phenol content determination. e
standardized Folin-Ciocalteu method18 was applied to
determine the level of total phenols in Arabic coee
colorimetrically using the Folin-Ciocalteus reagent
(Sigma Chemical Company Ltd., Poole, UK). Coee
beverage was prepared by dissolving coee particles (4
g) in 100 mL boiled Milli-Q water. Ten mL of coee
beverage was added to a screw-capped tube containing
8 mL of 1.2 M hydrochloric acid in 50% methanol/
water. e samples were then placed in a water bath
at 80ºC for 3 hours. A reagent blank was made using
Folin-Ciocalteus reagent diluted 1 in 9. e calibration
standards were made using epicatechin at a concentration
range of 0.025 - 0.3 mg/mL, in which 100 μL of each of
these solutions were also reacted with Folin-Ciocalteu’s
reagent. For analysis of the coee samples, 100 μL was
used and reacted with the diluted Folin-Ciocalteu’s
reagent. e colorimetric measurement was carried out
at 720 nm.
Liquid chromatography-mass spectrometry (LC-MS)
analysis. Arabic coee (Coea Arabica) was analyzed
for CGA, other components with a similar structure
to CGA, and also other phenolic compounds. Coee
particles (375 g) were dissolved into 20 mL Milli-Q
boiling water and left to stand for 2 minutes. en, 10
mL of this coee solution was transferred to a test tube
containing 0.5 mL of Carrez A and then vortex mixed.
Carrez B reagent (0.5 mL) was added and the sample
was vortex mixed, and then centrifuged at 4000xg for
20 minutes at 4ºC. Peaks were obtained corresponding
to the retention times of a number of phenols and
chlorogenic acids. eir identity was conrmed from
their fragmentation patterns of standard compounds
found within the Arabic coee.
e GI and II determination. Subjects. A randomized
cross-over design carried out in accordance with the
FAO/WHO guidelines for GI testing was used.19 is
study was conducted at the Department of Nutritional
Sciences, Faculty of Health and Medical Sciences,
University of Surrey, Guildford, United Kingdom from
November 2009 to February 2010. e study design
received ethical approval from the University of Surrey
Ethics Committee (EC/2009/95/FHMS) and approved
in accordance with the Helsinki II declaration. Ten
healthy volunteers (5 men and 5 women, aged 30.8±
2.8 years) were recruited from the post-graduate
student and sta population at the University of
Surrey by distribution of both e-mails and posters. All
volunteers gave informed written consent. Weight,
height, fasting blood glucose, and blood pressure
were measured at baseline. e inclusion criteria were
healthy men and women aged between 18-60 years old
and free from medication with the exception of minor
analgesics. Participants were excluded from the study
925 Saudi Med J 2013; Vol. 34 (9)
Glucose and insulin responses of dates with coee ... Al-Mssallem & Brown
when they have had familial or personal history of
psychiatric disorders, epilepsy, sleep disorders, diabetes,
cardiovascular disease, or food allergies, taken any
medication, or were pregnant women.
Food test. Khulas dates (Phoenix dactylifera L.)
and Arabic coee (Coea Arabica) were prepared in a
kitchen at the Clinical Investigation Unit (University
of Surrey). A portion of dates (which contained 50 g
of available carbohydrate) was served to subjects with
water, or Arabic coee (no sugar added) on 4 separate
sessions. On a further 3 separate occasions, a solution
containing 50 g pure glucose (Fisher Scientic, UK)
was given. Volunteers were asked to eat the dates and
consume the drink within 10 minutes.
Blood sample collection. Participants arrived at the
Clinical Investigation Unit at the University of Surrey at
0830 hour each study day of testing after an overnight
fast (10-12 hours). Blood samples were obtained by
nger pricks using preset lancets (Accu-chek Softclix
Pro., Brighton, East Sussex, UK) at fasting, and at 15,
30, 45, 60, 90, and 120 minutes after consuming the
dates, dates with Arabic coee (no added sugar), or
standard glucose solution. Blood samples were collected
into 300 μL plastic microvette tubes (SARSTED Ltd.,
Leicester, UK) coated with uoride oxalate, and were
immediately centrifuged at 3000×g for 10 minutes at
4°C. e resultant plasma was transferred into separate
300 μL plastic plain microvette tubes (SARSTED Ltd.,
Leicester, UK). e tubes were then frozen and kept in
the freezer at -20°C until analysis (within 4 weeks).
Glucose measurement. e plasma glucose
concentration was determined using an automatic
analyser (YSI 2300 STAT plus, Yellow Springs,
Analytical Technologies, YSI, UK). It was an enzymatic
method applied to the enzyme glucose oxidase in
aqueous solution to oxidize the glucose and produce
hydrogen peroxide. e hydrogen peroxide was then
oxidized, and the current product was proportional to
the concentration of the glucose. Twenty-four samples
were analyzed in each run along with 3 quality control
(QC) samples. Within each run the coecient of
variation of the QC1 was 2.5%, QC2 - 3.6%, and QC
3 - 1.8 %. e incremental area under the glucose curve
(iAUC) for the reference glucose drink, dates, and dates
with Arabic coee was calculated using the trapezoid
rule. e GI values of dates and dates with Arabic coee
for each subject were calculated as follows:
GI of dates or dates with Arabic coee = iAUC
for dates or dates with Arabic coee / iAUC for
reference × 100
e GI value of dates with water and dates with Arabic
coee was calculated as the average value obtained for
10 subjects.
Insulin determination. Enzyme linked
immunosorbent assay (ELISA) was employed for
measuring plasma insulin concentrations. Samples were
thawed at room temperature and then centrifuged at
3000xg for 5 minutes to remove insoluble debris. e
QCs, standards (Invitron Ltd, Monmouth, UK), and
samples (25 μL per each) were incubated with the
labelled antibody solution (Invitron Ltd, Monmouth,
UK) at 37°C for 2 hours, and unbound labelled
antibodies were removed using the wash buer (Invitron
Ltd, Monmouth, UK) according to the manufacturer’s
instructions. e insulin was then measured using the
microtiter plate luminometer (Luminescent plate reader
Centro LB 960, Berthold, Germany). All readings
obtained from the luminometer were multiplied by 6 to
convert the units (mU/L) into pmol/L. Two QCs (low
and high) were used, and their CVs were 6.6% (low)
and 4.9% (high).
Statistical analysis. Results were checked for
normality using the Kolmogorov-Smirnov test (K-S
test) and expressed as a means ± one standard error of
the mean (SEM). Two factors repeated measures analysis
of variance (ANOVA) was used to analyze dierences in
the mean of glucose and insulin. In addition, a single
factor repeated measures ANOVA was used, as well,
to analyze dierences in the iAUC for glucose and
insulin (Statistical Package for Social Sciences version
16 for Windows [SPSS Inc, Chicago, IL, USA]). If a
signicant interaction was obtained following ANOVA,
a Bonferroni step-wise post hoc test was performed to
determine the location of the variance. All data were
examined using a 2-tailed approach with a level of
p<0.05 considered as signicant.
Results. Phenol analysis. e amount of total
phenols in Arabic coee was calculated to be 1.2 mmol
epicatechin equivalents/L using the standard curve
presented in Figure 1. Figure 2 shows the compounds
that were identied within the Arabic coee sample.
e LC-MS analysis showed that the Arabic coee
contained CGAs and caeine. e most abundant
derivative was a caeoyl quinic acid. e highest
peak was shown for 5-Caeoyl quinic acid followed
by 3-Caeoyl quinic acid, Caeoyl quinic acid, and
Caeine. However, p-coumaroyl quinic acid, feruloyl
quinic acid, and dicaeoyl quinic acid were also
observed in relatively small amounts. Identication was
based on their retention time compared to that of the
standard, absorbance spectrum, and MS fragmentation
Glucose and insulin responses of dates with coee ... Al-Mssallem & Brown
Saudi Med J 2013; Vol. 34 (9)
Figure 1 - Standard calibration curve for epicatechin.
Figure 2 - Liquid chromatography-mass spectrometry analysis for Arabic
Figure 3 - Plasma glucose responses over 2 hours following consumption
of reference glucose, dates, and dates with Arabic coee.
Results are presented as mean ± standard error of mean.
Glycemic index was measured using standard procedures.19
A 2-factor (treatment and time) repeated measures ANOVA
was used to analyze dierences in the means of glucose levels
within the dates, dates with Arabic coee, and standard
glucose consumed. No signicant dierences were observed
Figure 4 - Plasma insulin responses over 2 hours following consumption
of reference glucose, dates, and dates with Arabic coee.
Results are presented as mean ± standard error of mean.
Insulinemic index was measured using standard procedures.19
A 2-factor (treatment and time) repeated measures ANOVA
was used to analyze dierences in the means of the insulin
levels within the dates, dates with Arabic coee, and standard
glucose consumed. No signicant dierences were observed
Table 1 - Characteristics of subjects included in a study at the University
of Surrey, Guildford, United Kingdom (N=10).
Characteristics Mean ± SEM Range
Age (year) 30.8 ± 2.8 18-48
Weight (kg) 75.0 ± 5.4 60-108
Height (m) 1.73 ± 0.02 1.60-1.87
Body mass index (kg/m2) 24.0 ± 1.2 20.7-31.7
Diastolic blood pressure (mm Hg) 72.5 ± 3.2 54.0-86.5
Systolic blood pressure (mm Hg) 122.1 ± 2.8 105.6-135.0
Fasting blood glucose (mmol/L) 5.2 ± 0.1 4.5-5.8
Determination of GI and II. Subjects’ characteristics
are shown in Table 1. ey had an average age of 30
years, with normal weight, blood pressure, and fasting
blood glucose levels. As shown in Figure 3, peak
glucose levels occurred at 30 minutes for standard
glucose, dates, and dates with Arabic coee. At this
time, the response to the standard glucose solution was
signicantly higher than the response to both dates, and
dates with Arabic coee (p=0.05, t=2.25). Similarly, the
glucose response at 45 and 60 minute time points for
subjects consuming dates with water was signicantly
lower (p=0.017, t=-2.93) than that for subjects
consuming dates with Arabic coee (p=0.041, t=-2.37).
It appeared that Arabic coee ingestion increased the
glucose peak rise by approximately 0.4 mmol/L. e
iAUC for plasma glucose concentrations over 2 hours
postprandial period following consumption of standard
glucose solution was 180 ± 13, for dates - 96 ± 11, and
dates with Arabic coee - 112 ± 11. From this, the
GI for dates with water was found to be 55 ± 6, and
dates with Arabic coee was found to be 63 ± 5. e
mean GI value for dates with water was lower than that
for dates with Arabic coee, however, the dierence
927 Saudi Med J 2013; Vol. 34 (9)
Glucose and insulin responses of dates with coee ... Al-Mssallem & Brown
did not quite reach statistical signicance (p=0.08,
t=-1.9, n=10). Plasma insulin for the standard glucose
solution dates with water and dates with Arabic coee
peaked at 30 minutes after the ingestion of the foods,
and then declined towards the baseline level by 120
minutes (Figure 4). Similar patterns were evident for
all. e iAUC for plasma insulin concentrations was
also calculated, and the II for dates with water was 64
± 7, and for dates with Arabic coee was 62 ± 8. e
iAUC of insulin for dates with water and dates with
Arabic coee was much lower than that observed for
standard glucose solution. is lower iAUC, however,
was not suciently low enough to be signicantly lower
than the iAUC for glucose. ere was no signicant
dierence in the plasma insulin response between dates
and dates with Arabic coee (p=1.00, t=0.16).
Discussion. is study examined the impact of
Saudi Arabian Khulas dates on glucose and insulin,
with and without simultaneous consumption of Arabic
coee. e Khulas dates variety was chosen as it is the
most famous variety consumed in Saudi Arabia.20 Also,
the GI of this variety has been reported previously,
which can be used for comparison with our data.13,15
In this study, the GI value of 55 was obtained for
Khulas dates and this compared well with previous
studies.13,15 It is well known that coee contains many
phenolic compounds such as CGA, which may have
a potential eect on glucose and insulin levels.3,6,7 e
possible role of CGA in glucose metabolism could be
due to the inhibition of glucose transporters (Na+-
dependent glucose transporter) or digestive enzymes
(α-amylase and α-glucosidase), which could potentially
inuence the amount of glucose absorbed and reduce
glucose release.3 Also, consumption of coee (400 mL
containing 350 mg CGA) may aect the secretion
of gastrointestinal peptides (glucose-dependent
insulinotropic polypeptide (GIP) and glucagon-like
peptide-1 (GLP-1) by decreasing GIP and increasing
GLP-1, leading to slow intestinal glucose absorption.7,21
In addition, the CGA may reduce plasma glucose output
from the liver by inhibiting glucose-6-phosphatase
activity.3,6,21 e benecial eects of CGA may appear at
high concentrations of the coee beverage, or for long
periods of frequent coee consumption. is might be
the reason why we have not seen an eect in our study
because it was a study examining the acute eects of
coee, or because the concentration of the Arabic coee
beverage was too low. is ndings is similar to that of
Louie et al.22 ey observed that there was no dierence
between the postprandial glucose and insulin levels of
decaeinated coee versus water owing to a lower CGA
content that was in the decaeinated coee beverage
consumed. Nevertheless, it must be emphasized that
the aim of this study was to study the eect of Arabic
coee as it is normally consumed rather than as a more
concentrated beverage.
It is evident from other studies that the phenols, which
are poorly absorbed from the human small intestine
and are likely metabolized to their metabolites.23 For
example, approximately 33% of CGA is only absorbed
and approximately two-thirds of it reach the colon, and
may be metabolized to caeic acid and quinic acid.6 It
has reported that the level of CGA that seems to have
health benets would range from 0.5-2.5 g/day.1-5 Our
LC-MS results for Arabic coee have shown that the
coee used in this study certainly contained an array
of CGA (Figure 2), but its total phenols’ concentration
was just 1.2 mmol/L. is concentration may have been
too low to elicit a signicant eect on plasma glucose
and insulin levels. Our study has indicated that the
consumption of coee with dates exacerbates the plasma
glucose response in healthy volunteers compared to the
consumption of dates with water. In a similar way, an
increase in the area under glucose and insulin curves and
reduction in the insulin sensitivity has been observed
with the ingestion of coee with meals.7-9 All these
eects were proposed to be associated with the presence
of caeine in the coee, which increases AUC of glucose
and insulin.8,9 Caeine is a phosphodiesterase inhibitor
which can increase the concentration of cyclic adenosine
monophosphate (cAMP). Increased concentrations of
cAMP have been associated with an impaired glucose
tolerance after the consumption caeinated coee
beverage.7 Caeine can also inhibit muscle glucose
uptake as it acts as adenosine receptor antagonist.6,24 It
is clear that the consumption of Arabic coee with dates
had a modest eect bordering on a signicant eect.
In contrast to these short-term controlled trials, which
have shown the eects of caeine, this eect might be
modied during long periods of coee consumption
among heavy and chronic coee consumers.3 Indeed,
better glucose tolerance and a substantially lower risk
of T2DM was associated with the high consumption
of coee.2,3
ere are some limitations to this study. Clearly,
this was an assessment of only one variety of dates and
as such, it is quite a small study. However, the results
provide useful information on a famous variety of dates
consumed with Arabic coee, which has not been
reported previously. It is unfortunate that there are
no insulinemic data on dates, or dates consumed with
coee in order to create comparison with our ndings.
Glucose and insulin responses of dates with coee ... Al-Mssallem & Brown
Saudi Med J 2013; Vol. 34 (9)
In conclusion, consumption of dates with Arabic
coee is a traditional practice in Saudi Arabia. We
found that this habit of ingestion dates, at the same time
with drinking Arabic coee, increased slightly glucose
response (p=0.08) in healthy people. is eect may
due to the presence of caeine, which has been found to
impair glucose tolerance and decreases insulin sensitivity
in previous clinical trials. As such, these ndings could
be applied on people with diabetes, and we would
assume that consumption of dates would have an eect
on plasma glucose levels in diabetic individuals similar
to that eect seen in healthy people. e inuence of
the coee beverage indicates that some detrimental
eects can occur, and consumption of a decaeinated
coee may be wise. Further research, particularly long
term studies, may be required to ascertain the clear
detrimental eect of dates with Arabic coee on blood
glucose, insulin, and triglycerides levels. In addition,
as our coee was caeinated coee, it is useful to
investigate the eect of decaeinated Arabic coee on
blood glucose and insulin levels.
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... A study was done in Saudi Arabia to find the possible relationship between cholesterol levels and Arabic coffee intake, and it found that cholesterol level is high in coffee drinkers [12]. Another study was performed by Al-Mssallem among 10 healthy subjects who ate Khulas dates with water or Arabic coffee for four months, resulting in increased plasma glucose among those who drink Arabic coffee than those who drink water [13]. In addition, a cross-sectional study conducted among 384 females in Madinah, Kingdom of Saudi Arabia (KSA), found that those who drink too much Arabic coffee have an increased risk of obesity [1]. ...
... There are limited data concerning the relationship between Arabic coffee consumption and the risk of obesity between men and women in the population of the Eastern Province, Saudi Arabia. To date, the previous studies investigated the prevalence of Arabic coffee consumption [10], the effect of Arabic coffee on insulin sensitivity [13], and the Arabic coffee-induced risk of obesity among females only [1]. To our knowledge, there is no study on the effect of coffee consumption on the risk of obesity for both genders among the population in the Eastern Province of Saudi Arabia. ...
... This belief is not based on scientific evidence; however, it is probably based on extrapolation from the chemical composition since dates mainly consist of simple sugar (Ahmed and Ahmed 1995;Ali et al. 2009;Khan et al. 2008). Most date varieties have a low glycemic index (GI) value, and their reported postprandial effect on blood glucose levels in both healthy participants and those with diabetes vary from low to moderate (AlGeffari et al. 2016;Ali et al. 2009;Alkaabi et al. 2011;Al-Mssallem and Brown 2013;Gourchala et al. 2016;Miller et al. 2003). Moreover, the consumption of date fruits has not been shown to have deleterious effects on serum glucose levels (Rock et al. 2009). ...
... Indeed, most date fruit varieties have low GI values (AlGeffari et al. 2016; Ali et al. Alkaabi et al. 2011;Al-Mssallem and Brown 2013;Miller et al. 2003). The low glycamic response to date fruits is not only found in healthy individuals, but is rather low when measured in patients with T2DM (Alkaabi et al. 2011). ...
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AimAssess the relationship between date palm fruit consumption and diabetic control among Saudi patients with type 2 diabetes mellitus.Subjects and methodsSaudi patients with type 2 diabetes (n = 404, aged 55.3 ± 9.7 years) were included in this study. Height, weight and blood pressure were initially measured. Blood glucose levels (fasting and random), glycated hemoglobin HbA1c, total cholesterol, high-density lipoprotein, low-density lipoprotein and triglycerides were retrieved from the patient’s medical records. The amount and frequency of habitual consumption of date fruits were obtained from patients using a validated dietary questionnaire.ResultsThe results revealed that high consumption of date fruits was statistically significantly correlated with lower HbA1c and fasting blood glucose (p < 0.01).Conclusion This cross-sectional study found an association between high date fruit consumption by patients with type 2 diabetes mellitus and lower HbA1c and fasting blood glucose levels. Further studies are required to verify this interesting finding
... It has reported that a typical adult Saudi may consume between 20 and 120 g of dates at one sitting (Al-Mssallem and Brown, 2013). Recently, there is a fluctuation in date's consumption among Saudi populations due to major changes in dietary habit and availability of other fresh fruits and sweets (Al-Mssallem, 2014;Al-Eid et al., 2015). ...
... In this study, the weighted average of dates consumption for the 3 age groups was 80 g/day. It was reported that a typical adult Saudi may consume between 20 and 120 g of dates at one sitting (Al-Mssallem and Brown, 2013). However, it was mentioned that the average per capita consumption of Saudi dates reached about 95 g/day (Al-Eid et al., 2015). ...
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Date palm (Phoenix dactylifera L.) is consumed since the ancient era in the Arab region, particularly in Saudi Arabia. This study aims to assess the consumption of dates, its association with obesity in addition to estimate the nutrient indices of consumed dates among Saudi population in Al Ahsa region. Household Saudi males and females (n=477) were involved in this study. They were classified into three groups; children (n=46), Adolescents (n=72) and Adults (n=359). Data on anthropometric measurements, socioeconomic factors, and consumption of dates were collected from the respondents. Some nutrients of dates were analyzed to calculate the indices of energy, carbohydrates, non- starch polysaccharides (NSPs) in addition to determine some minerals and vitamin contents. The obtained results indicated that adolescents followed by adults consumed the highest amount of dates. The results also revealed that the consumed dates could secure about fourth of the recommended daily requirement of potassium and the fifth of both magnesium and NSPs. Moreover, the study found that obese persons dates consumption was the highest in comparison to underweight and normal weigh respondents (p<0.05), however; the correlation between dates consumption and body mass index (BMI) was low. The study confirmed the importance of daily consumption of dates in securing some minerals and indicated that dates consumption is not responsible for weight gaining.
... Moreover, date fruit consumption have low glycemic Index which was determined by low postprandial effect. It has beneficial effect on HbA 1c (Al-Mssallem & Brown, 2013;AlGeffari et al., 2016;Alkaabi et al., 2011) which is a reliable biomarker of diagnosis and prognosis of diabetes. One study reported that leaf extract of date palm was effective in reducing HbA 1c and secreting more insulin by increasing the β-cells number (Esfandiari et al., 2020). ...
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From the past decade, consumption of ready‐to‐eat food and ease of access to fast food increased the onset of several diseases. Thus, there is a need to shift the trend from consumption of unhealthy food item to natural and healthy alternatives. In this context, fruits can be considered as functional food, which have ability to provide essential nutrients and bioactive compounds. These compounds when consume in adequate amount would have the potential to lower the onset of diseases. In this regard, Phoenix dactylifera or date fruit is an important source of functional carbohydrates and bioactive compounds for their use as functional foods. The major functional carbohydrate in date fruit are in the form of dietary fiber, such as β‐glucan, cellulose and fructans along with other bioactive compounds. Additionally, it is also a good source of other important nutrients such as sugars, minerals, along with minor quantities of proteins and lipids. Due to these functional compounds, date fruit have shown a wide range of pharmaceutical properties such as antioxidant, anti‐inflammatory, anti‐diabetic, hepatoprotective and anticancer. This review provides latest information regarding functional and nutraceutical carbohydrates of date fruits along‐with mechanism of action on different diseases reported in recent years. Practical applications This will provide information to food industries for the development of innovative food products by using date fruit. Moreover, bioactive components from date fruit may prove to enhance global health and wellness. However, further research is needed on clinical trials for the development of functional food products by using date fruit for functional foods and pharmaceutical applications.
... Arabic coffee Coffea Arabica (Rubiaceae) is considered the most consumed hot beverage in Saudi Arabia and forms part of Saudi traditions (Al-Mssallem & Brown, 2013). It is mainly made from Arabica coffee beans (Butt & Sultan, 2011). ...
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Coffea arabica (Rubiaceae) is a basic drink for all Gulf societies, especially Saudi Arabia, it is the main part of the Saudi tradition. This investigation was carried out to track the chemical composition, caffeine content by UV–visible spectrophotometer, acrylamide content by using a gas chromatograph, free radical scavenging capacity by DPPH methods as well as determined the browning index and separated the volatiles compounds using GC–MS for the most common three degree of roasted Arabic coffee; light (180 ± 10 °C; 6.0 ± 1.0 min), medium (180 ± 10 °C; 8.0 ± 1.0 min), and dark (180 ± 10 °C; 10.0 ± 1.0 min). Data revealed that light roasted coffee has the highest significant (p < 0.05) value of moisture content (4.80%), crude protein (13.05%), and lowest value of ether extract (10.39%) and crude fiber (24.24%). The caffeine content was found to be 1.13% in light coffee, which increased to 1.17% in medium coffee, then decreased to 1.08% in dark coffee. The quantity of acrylamide detected in light roasted coffee (0.41 mg/100 g) was the greatest, whereas medium roasted coffee comparatively produced low amounts (0.31 mg/100 g). The light roasted coffee gave the highest antioxidant activity (88.72 mg TE/g), while the dark roasted coffee gave the least activity (78.76 mg TE/g). Browning index increases with roasting time. Hydrocarbons, alcohols, and esters were the most represented in roasted coffee headspace. Silanes and sec-butyl nitrite compounds were absent in the medium roasted headspace. Except for amines, all 11 classes of volatile compounds were present in the headspace of dark roasted coffee.
... Caffeine is widely consumed in Saudi Arabia and other gulf countries in the form of Arabic Coffee (Qahwah) which is a local favorite in the Gulf region. 19 The prevalence of diabetes mellitus in Saudi Arabia in adults is 18.3%, which is one of the highest across the globe. 20 Majority of food-drug interactions alter the bioavailability of drugs, and a wide array of data suggests that CAF influences the bioavailability of several drugs. ...
Objectives: To determine the influence of caffeine on pharmacokinetics and pharmacodynamics of pioglitazone (PIO) in diabetic rats. Methods: This was a preclinical study conducted in the College of Pharmacy, Najran University, Saudi Arabia, using 5 groups of Wistar rats: normal rats, untreated diabetic rats, diabetic rats + caffeine (20 mg/kg), diabetic rats + PIO (10 mg/kg), and diabetic rats + PIO (10 mg/kg) + caffeine (20 mg/kg). The drugs were administered for 14 days, and fasting plasma glucose concentrations were determined on the first day, and thereafter at weekly intervals. On day 14, rat sacrifice was followed with assay of levels of biomarkers. To estimate the pharmacokinetic parameters, the diabetic animals were assigned to 2 groups: one group received PIO (10 mg/kg), while the other received PIO + caffeine (20 mg/kg). Blood samples were drawn from the retro-orbital plexus at different time intervals, and pharmacokinetic parameters were measured using high performance liquid chromatography. Results: Caffeine caused statistically marked increases in area under the curve, Cmax, Tmax, and half-life of PIO, and decreased clearance. Combination of PIO and caffeine produced a synergistic effect on percentage reduction in blood glucose, with 67.1% reductions observed on day 7 and 68.9% reductions observed on day 14. Liver and cardiac biomarkers were significantly decreased, suggesting cardioprotective and hepatoprotective effects. Conclusion: Co-administration of PIO with caffeine enhances its antidiabetic effect, probably due to enhanced bioavailability of PIO, leading to clinical benefits in diabetic patients.
... Beyond enzyme inhibition coffee has an effect on both high and low GI test meals, but each meal type is affected to a different extent [96] . A 2009 paper found that coffee and tea did not affect the GI and also reduced the statistical variability [97] . However, 5 participants for coffee and 5 participants for tea lacks the statistical power of a normal GI test of a minimum 10 participants per variable and would not meet the ISO 2010 standard for testing. ...
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Glycaemic index (GI) testing provides a useful point of comparison between carbohydrate sources. For this comparison to be meaningful, the methods used to determine GI values need to be rigorous and consistent between testing events. This requirement has led to increasing standardization of the GI methodology, with an international standard developed in joint consultation with FAO/WHO (ISO 26642:2010) currently the most up to date document. The purpose of this review is to compare the international standard to methods of published studies claiming to have performed a GI test. This analysis revealed that the international standard permits a wide range of choices for researchers when designing a GI testing plan, rather than a single standardized protocol. It has also been revealed that the literature contains significant variation, both between studies and from the international standard for critical aspects of GI testing methodology. The primary areas of variation include; what glucose specification is used, which reference food is used, how much reference food is given, what drink is given during testing, the blood sampling site chosen and what assay and equipment is used to measure blood glucose concentration. For each of these aspects we have explored some of the methodological and physiological implications of these variations. These insights suggest that whilst the international standard has assisted with framing the general parameters of GI testing, further stan-dardization to testing procedures is still required to ensure the continued relevance of the GI to clinical nutrition.
... A study performed in healthy women consuming Arabic coffee with added spices like cardamom demonstrated a neutral effect on blood pressure and biomarkers of inflammation (e.g., C-reactive protein), but resulted in an increased level of low-density lipoprotein cholesterol and total cholesterol [30]. In addition, Arabic coffee consumption in healthy individuals modestly increased the plasma glucose response of dates compared to that of dates consumed with water, probably due to the presence of caffeine, which could impair glucose tolerance and decrease insulin sensitivity [31]. A recent study of Taibah university students and employees (18-45 years of age) demonstrated a high level of Arabic coffee consumption and its positive association with obesity (28% overweight and 33% obese), indicating a health warning against its excessive intake [32]. ...
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Abstract: This study aimed to investigate the prevalence, trends, and predictors of coffee consumption among Saudi female students and its association with anthropometric and demographic variables. A survey-based study using a face-to-face interview was designed, and 930 (aged 21.5 ± 2.1 years) apparently healthy female students from different departments of King Saud University participated. The prevalence of coffee consumption was significantly higher (88.2%, p < 0.03) in the central Riyadh region. Coffee consumers had significantly higher prevalence of being overweight than non-consumers (p = 0.02). The frequency of coffee consumption was significantly higher (p < 0.02) in students who were single and belonged to families with a moderate income level. Coffee consumption was significantly higher among first-year students with a high-scale grade point average (GPA) (p < 0.001 and p = 0.03, respectively). Increased coffee consumption during exam and stress conditions was associated with unhealthy dietary habits such as using more sugar and spices. The prevalence of coffee consumption was high among Saudi females. High body mass index (BMI) and increased family income level were strong determinants for coffee consumption. Continued nutritional education and awareness about the potential positive and negative health effects of coffee consumption and the importance of food label use should be provided to younger generations in order to correct the wrong perceptions.
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Current international tables published on the glycaemic index (GI) of foods represent valuable resources for researchers and clinicians. However, the vast majority of published GI values are of Western origin, notably European, Australian and North American. Since these tables focus on Western foods with minimal inclusion of other foods from non-Western countries, their application is of limited global use. The objective of this review is to provide the GI values for a variety of foods that are consumed in non-Western countries. Our review extends and expands on the current GI tables in an attempt to widen its application in many other regions of the world.
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Despite the fact that date palm (Phoenix dactylifera L.) fruits are characterised by a high content of carbohydrates, the quality of their carbohydrates results in a low glycaemic response. In comparison to common fruits consumed such as strawberries and guava, Date Palm Fruits (DPFs) have exhibited the highest antioxidant activity. DPFs have been shown to act effectively as free radical scavengers due to their content of bioactive compounds such as phenolic acids, carotenoids, flavonoids, and polyphenols. These bioactive substances can absorb and neutralise free radical intermediates resulting from oxidation reactions in the human body. The vital action of DPF constituents contributes significantly in reducing physiological cellular damage and protecting the human body against oxidative stress-related diseases such as cardiovascular diseases, neurodegenerative diseases and cancer. From this point, it can be concluded that regular consumption of DPFs may be associated with a reduced risk of some chronic diseases due to the antioxidant, antimicrobial, antidiabetic, anticancer, and antimutagenic activities of DPFs. In fact, DPFs have been widely used since ancient times in folk medicine to treat various health conditions, demonstrating the importance of DPFs as a nutraceutical and a source of functional nourishment. This review aims to consolidate most of the work carried out on DPFs in terms of their contents of nutrients and biologically active components such as phenolic compounds, with special emphasis on their functions in improving general health.
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Coffee is a complex mixture of potentially active chemicals. It contains significant amounts of phenolic polymers, chlorogenic acid and also caffeine. Agricultural factors, roasting, blending, and brewing determine coffee’s chemical composition. Recent epidemiological studies suggest that habitual coffee consumption may help to prevent some chronic diseases including type 2 diabetes. Despite reports from the clinical trials of the effect of caffeine on decreasing insulin sensitivity, long-term prospective studies revealed that coffee may improve fasting glucose, glucose tolerance and insulin sensitivity as well. In the most recent publication habitual coffee drinkers have a lower total and cardiovascular mortality rate among diabetic subjects.
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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. 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. 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). 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. NCT01307904.
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Date palm (Phoenix dactylifera L.), a member of Arecaceae family, is one of the three major economically important woody palms--the two other palms being oil palm and coconut tree--and its fruit is a staple food among Middle East and North African nations, as well as many other tropical and subtropical regions. Here we report a complete sequence of the data palm chloroplast (cp) genome based on pyrosequencing. After extracting 369,022 cp sequencing reads from our whole-genome-shotgun data, we put together an assembly and validated it with intensive PCR-based verification, coupled with PCR product sequencing. The date palm cp genome is 158,462 bp in length and has a typical quadripartite structure of the large (LSC, 86,198 bp) and small single-copy (SSC, 17,712 bp) regions separated by a pair of inverted repeats (IRs, 27,276 bp). Similar to what has been found among most angiosperms, the date palm cp genome harbors 112 unique genes and 19 duplicated fragments in the IR regions. The junctions between LSC/IRs and SSC/IRs show different features of sequence expansion in evolution. We identified 78 SNPs as major intravarietal polymorphisms within the population of a specific cp genome, most of which were located in genes with vital functions. Based on RNA-sequencing data, we also found 18 polycistronic transcription units and three highly expression-biased genes--atpF, trnA-UGC, and rrn23. Unlike most monocots, date palm has a typical cp genome similar to that of tobacco--with little rearrangement and gene loss or gain. High-throughput sequencing technology facilitates the identification of intravarietal variations in cp genomes among different cultivars. Moreover, transcriptomic analysis of cp genes provides clues for uncovering regulatory mechanisms of transcription and translation in chloroplasts.
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Human subjects drank coffee containing 412 mumol of chlorogenic acids, and plasma and urine were collected 0 to 24 h after ingestion and were analyzed by high-performance liquid chromatography-mass spectrometry. Within 1 h, some of the components in the coffee reached nanomole peak plasma concentrations (C(max)), whereas chlorogenic acid metabolites, including caffeic acid-3-O-sulfate and ferulic acid-4-O-sulfate and sulfates of 3- and 4-caffeoylquinic acid lactones, had higher C(max) values. The short time to reach C(max) (T(max)) indicates absorption of these compounds in the small intestine. In contrast, dihydroferulic acid, its 4-O-sulfate, and dihydrocaffeic acid-3-O-sulfate exhibited much higher C(max) values (145-385 nM) with T(max) values in excess of 4 h, indicating absorption in the large intestine and the probable involvement of catabolism by colonic bacteria. These three compounds, along with ferulic acid-4-O-sulfate and dihydroferulic acid-4-O-glucuronide, were also major components to be excreted in urine (8.4-37.1 mumol) after coffee intake. Feruloylglycine, which is not detected in plasma, was also a major urinary component (20.7 mumol excreted). Other compounds, not accumulating in plasma but excreted in smaller quantities, included the 3-O-sulfate and 3-O-glucuronide of isoferulic acid, dihydro(iso)ferulic acid-3-O-glucuronide, and dihydrocaffeic acid-3-O-glucuronide. Overall, the 119.9 mumol excretion of the chlorogenic acid metabolites corresponded to 29.1% of intake, indicating that as well as being subject to extensive metabolism, chlorogenic acids in coffee are well absorbed. Pathways for the formation of the various metabolites within the body are proposed. Urinary dihydrocaffeic acid-3-O-sulfate and feruloylglycine are potentially very sensitive biomarkers for the consumption of relatively small amounts of coffee.
Background: The ingestion of caffeine (5 mg/kg body weight) and a 75-g oral glucose load has been shown to elicit an acute insulin–insensitive environment in healthy and obese individuals and in those with type 2 diabetes. Objective: In this study we investigated whether a similar impairment in blood glucose management exists when coffee and foods typical of a Western diet were used in a similar protocol. Design: Ten healthy men underwent 4 trials in a randomized order. They ingested caffeinated (5 mg/kg) coffee (CC) or the same volume of decaffeinated coffee (DC) followed 1 h later by either a high or low glycemic index (GI) cereal (providing 75 g of carbohydrate) mixed meal tolerance test. Results: CC with the high GI meal resulted in 147%, 29%, and 40% greater areas under the curve for glucose (P < 0.001), insulin (NS), and C-peptide (P < 0.001), respectively, compared with the values for DC. Similarly, with the low GI treatment, CC elicited 216%, 44%, and 36% greater areas under the curve for glucose (P < 0.001), insulin (P < 0.01), and C-peptide (P < 0.01), respectively. Insulin sensitivity was significantly reduced (40%) with the high GI treatment after CC was ingested compared with DC; with the low GI treatment, CC ingestion resulted in a 29% decrease in insulin sensitivity, although this difference was not significant. Conclusion: The ingestion of CC with either a high or low GI meal significantly impairs acute blood glucose management and insulin sensitivity compared with ingestion of DC. Future investigations are warranted to determine whether CC is a risk factor for insulin resistance.
Coffee is a major source of caffeine, which has been shown to acutely reduce sensitivity to insulin, but also has potentially beneficial effects. We prospectively investigated the association between coffee consumption and risk of clinical type 2 diabetes in a population-based cohort of 17 111 Dutch men and women aged 30-60 years. During 125 774 person years of follow-up, 306 new cases of type 2 diabetes were reported. After adjustment for potential confounders, individuals who drank at least seven cups of coffee a day were 0-50 (95% CI 0.35-0.72, p=0.0002) times as likely as those who drank two cups or fewer a day to develop type 2 diabetes. Coffee consumption was associated with a substantially lower risk of clinical type 2 diabetes.
Coffee is the leading worldwide beverage after water and its trade exceeds US $10 billion worldwide. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health promoting potential; however, some researchers have argued about the association of coffee consumption with cardiovascular complications and cancer insurgence. The health-promoting properties of coffee are often attributed to its rich phytochemistry, including caffeine, chlorogenic acid, caffeic acid, hydroxyhydroquinone (HHQ), etc. Many research investigations, epidemiological studies, and meta-analyses regarding coffee consumption revealed its inverse correlation with that of diabetes mellitus, various cancer lines, Parkinsonism, and Alzheimer's disease. Moreover, it ameliorates oxidative stress because of its ability to induce mRNA and protein expression, and mediates Nrf2-ARE pathway stimulation. Furthermore, caffeine and its metabolites help in proper cognitive functionality. Coffee lipid fraction containing cafestol and kahweol act as a safeguard against some malignant cells by modulating the detoxifying enzymes. On the other hand, their higher levels raise serum cholesterol, posing a possible threat to coronary health, for example, myocardial and cerebral infarction, insomnia, and cardiovascular complications. Caffeine also affects adenosine receptors and its withdrawal is accompanied with muscle fatigue and allied problems in those addicted to coffee. An array of evidence showed that pregnant women or those with postmenopausal problems should avoid excessive consumption of coffee because of its interference with oral contraceptives or postmenopausal hormones. This review article is an attempt to disseminate general information, health claims, and obviously the risk factors associated with coffee consumption to scientists, allied stakeholders, and certainly readers.
Although protective relationships between coffee consumption and type 2 diabetes mellitus have consistently been observed, few studies have examined the relationships between coffee consumption and underlying pathophysiological defects that characterise diabetes aetiology. The aim of this study was to explore the associations between caffeinated and decaffeinated coffee consumption and measures of insulin sensitivity and secretion. The study population included 954 multi-ethnic non-diabetic adults from the Insulin Resistance Atherosclerosis Study (IRAS). Multiple regression analyses were performed to examine the cross-sectional relationships between caffeinated and decaffeinated coffee intake and insulin sensitivity and acute insulin response, measured by a frequently sampled intravenous glucose tolerance test, 2 h postload glucose measured by OGTT, fasting insulin, and proinsulin to C-peptide ratios. Caffeinated coffee intake was positively associated with insulin sensitivity (β = 0.054; SE = 0.026; p = 0.04) and inversely related to 2 h postload glucose (β = -0.37; SE = 0.10; p = 0.0003) in fully adjusted models. Caffeinated coffee intake was not associated with acute insulin response or proinsulin ratios. Decaffeinated coffee intake was inversely related to 2 h postload glucose (β = -0.47; SE = 0.18; p = 0.0096) and positively related to acute insulin response (β = 0.191; SE = 0.077; p = 0.0132). Decaffeinated coffee intake was inversely related to the ratios of both intact and split proinsulin to C-peptide (β = -0.150; SE = 0.061; p = 0.0148; β = -0.254; SE = 0.068; p = 0.0002, respectively). In this cross-sectional study, caffeinated coffee was positively related to insulin sensitivity and decaffeinated coffee was favourably related to measures of beta cell function. These results provide pathophysiological insight as to how coffee could impact the risk of type 2 diabetes mellitus.