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Pak J Med Sci 2013 Vol. 29 No. 1 Special Supplement IUMS www.pjms.com.pk 275
Open Access
INTRODUCTION
Diabetes patients are increasing by population
growth, aging, urbanization, increasing prevalence
of obesity and physical inactivity.1 Lipid prole
abnormality, increasing blood glucose and glaciated
hemoglobin (HbA1c) and obesity are the most risk
factors for diabetes and lead to complications of this
disease.2
Important factor to control and manage diabetes
is dietary habits and nutrition. A novel approach in
dietary habits is glysemic index (GI) and glycemic
load (GL). Different interventions were made to
lower the glycemic response. Studies showed
soluble and non-soluble ber and low GL diet can
control glycemic response. Rened carbohydrate
1. Gholamreza Askari,
Assistant Professor of Clinical Nutrition,
Food Security Research Center,
2. Motahar Heidari-Beni,
Food Security Research Center,
3. Maryam Bakhtiari Broujeni,
Isfahan Endocrine and Metabolism Research Center,
4. Alireza Ebneshahidi,
Isfahan Endocrine and Metabolism Research Center,
5. Massoud Amini,
Professor of Internal Medicine and Endocrinology,
Isfahan Endocrine and Metabolism Research Center,
6. Reza Ghisvand,
Assistant Professor of Clinical Nutrition,
Food Security Research Center,
7. Bijan Iraj,
Assistant Professor of Internal Medicine and Endocrinology,
Isfahan Endocrine and Metabolism Research Center,
1-7: Isfahan University of Medical Sciences, Isfahan, Iran.
Correspondence:
Bijan Iraj,
E mail: bijaniraj@gmail.com
Original Article
Effect of whole wheat bread and white bread
consumption on pre-diabetes patient
Gholamreza Askari1, Motahar Heidari-Beni2, Maryam Bakhtiari Broujeni3,
Alireza Ebneshahidi4, Massoud Amini5, Reza Ghisvand6, Bijan Iraj7
ABSTRACT
Background and Objective: Soluble dietary bers reduce postprandial glucose, total and LDL cholesterol
level. Finding about the efcacy of whole grain on chronic disease such as diabetes and ischemic heart
disease (IHD) and mortality is controversial. Bread is the most important source of carbohydrate diet and
investigation the effect of bread on glycemic response is important. The aim of this study was to compare
the effect of whole wheat bread and white wheat bread on risk factors of pre-diabetes patients.
Methodology :Nine hundred forty six (946) men and women 35 to 55 year of age were included in the
study. Dietary intake was assessed with 3 days record. Whole breads involve sangak and barbary (are a kind
of Iranian breads) that were considered 270 and 250 grams for each one, respectively. White breads involve
bagets, lavash and taftoon (are a kind of Iranian breads) that were considered 90, 88 and 120 grams for
each one, respectively. Biochemical assessments and anthropometric indices were determined according
to the standard protocol.
Results: About 23% of participant was men and 77% were women. Signicant positive correlation between
white bread consumption and WC, BS 120, HbA1C, TG and SBP were found. We didn’t nd any signicant
correlation between white bread and other variables. After controlling some confounding factors such as
age, sex and total energy intake, we found a positive association between white bread consumption and
BS120, HbA1C and TG.
Conclusions: According to our nding white breads have an inverse effect of healthy status and whole
wheat bread didn’t have any signicant effect of risk factors of diabetes.
KEY WORDS: Whole bread, White bread, Pre-diabetes.
doi: http://dx.doi.org/10.12669/pjms.291(Suppl).3516
How to cite this:
Gholamreza A, Heidari-Beni M, Broujeni MB, Alireza E, Amini M, Reza G, et al. Effect of whole wheat bread and white bread
consumption on pre-diabetes patient. Pak J Med Sci 2013;29(1)Suppl:275-279. doi: http://dx.doi.org/10.12669/pjms.291(Suppl).3516
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
276 Pak J Med Sci 2013 Vol. 29 No. 1 Special Supplement IUMS www.pjms.com.pk
and grains without bran have higher GL and GI than
whole grains and have adverse effect on health.3
According to ndings soluble dietary bers reduce
postprandial glucose, total and LDL cholesterol
levels.4 Finding about the efcacy of whole grain
on chronic disease such as diabetes and ischemic
heart disease (IHD) and mortality is controversial.5
Studies showed high intake of carbohydrates
increase TG levels by enhancing hepatic synthesis of
very low-density lipoprotein (VLDL) and decrease
activity of lipoprotein lipase.6 Large portion of
energy be obtained from carbohydrates.7
Bread is the most important source of
carbohydrate diet. Since bread is low cost and is the
most part of Iranian diet and approximately more
people consume it in all days of week, investigation
about the effect of bread on glycemic response is
important. Findings about whole and rened grains
in recent studies are inconsistent so the aim of this
study was to compare the effect of whole wheat
bread and white wheat bread on risk factors of pre-
diabetes patients.
METHODOLOGY
Participant: This cross sectional research was per-
formed in Isfahan Endocrine and Metabolism Re-
search Center (IEMRC). We choose participants
from a cohort study that was conducted from 2003
until now with 3454 member in this center. Aims
of this cohort study were prevention of type 2 dia-
betes by changing in life style or by medical inter-
vention among high risk people. Inclusion criteria
were men and female 35 to 55 years who were rst
relative history of type 2 diabetes. Exclusion crite-
ria were those who used medication that has ef-
fect on glucose tolerance test and lipid proles. One
thousand three hundred fteen subjects were pre-
diabetes and 1050 of them had food record. Nine
hundred forty six participants reported that they
consume white or whole bread. According to ADA
criteria8 three hundred sixty eight subjects were
impaired fasting glucose (IFG), those with 100-125
mg/dl of fasting blood glucose. In IFG group, 117
subjects consumed whole bread and 251 subjects
consumed white bread. Three hundred three sub-
jects were Impaired Glucose Tolerance (IGT), those
with 140-199 mg/dl of blood glucose 120 minute
after intake 75gr oral glucose. In IGT group, 133
subjects consumed whole bread and 170 subjects
consumed white bread. Two hundred seventy ve
subjects were combined pre-diabetes (IFG +IGT)
that 87 subjects consumed whole bread and 188
subjects consumed white bread. The Isfahan En-
docrine and Metabolism Research Center (IEMRC)
Medical Ethics Committee approved this study and
each participant gave written informed consent.
Assessment of anthropometric indices: Weight
was measured by Seca scales (Germany) to the
nearest 100g with minimal clothing and without
shoes. Height was measured in a standing position,
without shoes while the shoulders were in a normal
position to the nearest 0.5 cm. Waist circumference
(WC) was measured using un-stretchable tape in a
standing position without applying any pressure to
the body’s surface, and was recorded to the nearest
0.1 cm. WC was measured in the middle of the
lowest gear and the top of the iliac crest (the most
narrow waist circumference) Body mass index was
estimated as weight (kg) divided by height (m)
squared. WC was considered as abdominal obesity
index and BMI was considered as general obesity
index.
Biochemical assessment: Blood samples were taken
from 7:30 to 9:30 AM, after 12 hours overnight fasting
to determine serum lipids and whole blood glucose
levels. Blood glucose, serum triglyceride (TG), total
cholesterol and high density lipoprotein cholesterol
(HDL-C) levels were determined by using an
enzymatic method. Oral Glucose Tolerance Test
(OGTT) was done after 10-12 hours of overnight
fasting, a 75gr oral glucose was administered and
plasma glucose concentrations were measured at
fasting and 120 minutes after glucose taking (BS120).
The analysis of sample was performed with an auto
analyzer (BT 3000, Rome, Italy) using commercial
kits (Chem Enzyme, Tehran Iran). Serum total
cholesterol and triglycerides levels were measured
by enzymatic reagents (Chem. Enzyme, Tehran
Iran) adapted to Selecta auto analyzer.
HDL-C levels were measured by using available
commercial kits (Pars Azmun, Tehran Iran). Low
density lipoprotein cholesterol levels (LDL-C) were
calculated from the values of serum triglyceride
(TG), total cholesterol and HDL cholesterol
according to the Fried Wald formula in triglyceride
<400 mg/dl9: LDL-C=Total cholesterol –HDL-C-
TG/5.
HbA1c were assessed with DS5 analyzer uses
low pressure cat ion exchange chromatography
in conjunction with gradient elution to separate
human hemoglobin subtypes and variants from
hemolyse whole blood.10,11
Inter assay coefcients of variations were 1.25
for triglycerides, 1.2 for cholesterol and 1.25 for
glucose. The corresponding intra-assay coefcients
of variations were 1.97, 1.6 and 2.2, respectively.
Gholamreza Askari et al.
Pak J Med Sci 2013 Vol. 29 No. 1 Special Supplement IUMS www.pjms.com.pk 277
Assessment of dietary intake: Dietary intake was
assessed by three days record and trained dietitian
adjusted it. These records had eleven columns that
included cereals group, legumes, dairy, meat, fat,
nuts, fruit, vegetable, sweet and sugar free and
drinks. Dietitians educated the groups in classes
how to prepare records. Then dietitians changed
record’s contents to gram.12 According to the kind
of breads consumption in their record we divided
subjects in two groups (white bread consumer and
whole bread consumer). Whole breads involve
sangak and barbary (are a kind of Iranian breads)
that were considered 270 and 250 grams for each
one, respectively. White breads involve bagets,
lavash and taftoon (are a kind of Iranian breads)
that were considered 90, 88 and 120 grams for each
one, respectively.
Statistic Analysis: SPSS (version 13) was used for
statistical analysis. Continuous variables presented
as mean ± standard deviation. Correlation between
dependent variables (glucose and lipid parameters,
anthropometric indices and blood pressure) and
independent variables (whole and white bread)
was evaluated by Pearson correlation. The
relationships between dependent variable with
bread consumption were examined using multiple
linear regression analysis, after controlling for
potential confounders (adjusted with age, sex,
energy intake). P<0.05 was considered statistically
signicant.
RESULTS
About 23% of participant were men and 77%
were women. Clinical and characteristics of the
study participant are shown in Table-I.
Signicant positive correlation between white
bread consumption and WC, BS 120, HbA1C, TG
and SBP were found. We didn’t nd any signicant
correlation between white bread and other variables.
Any signicant correlation between whole bread
and variables was not observed.
After controlling some confounding factors
such as age, sex and total energy intake, we
found a positive association between white
bread consumption and BS120, HbA1C and TG.
Increasing the amount of white bread consumption
lead to enhance BS120, HbA1C and TG levels. Any
signicant association was not observed between
whole bread consumption and variables.
DISCUSSION
In this study we observed a positive association
between white bread consumption and BS120,
HbA1C and TG levels with and without adjusting of
confounding factor. There were positive correlation
between white bread consumption and WC and
SBP without adjusting. High intake of whole grains
is related to a reduced risk of type 2 diabetes and
consumed regularly, may reduce body weight,
improving insulin sensitivity, blood pressure and
lipid metabolism;13,14 however we didn’t observe
any signicant association between whole wheat
bread and risk factors of pre-diabetes. Similarly
our ndings; studies showed whole grains have no
signicant effect on metabolic syndrome variables
such as TG, LDL-C, HDL-C, SBP, DBP, FBS and
BMI.15 A cross sectional study did not show any
association between whole grain consumption and
HDL-C, HbA1c and TG.16 An interventional study
Table-I: Clinical and biochemical
variables of participants.
Variables mean±SD*
Age 44.25±6.82
Waist circumference 90.78±9.42
Hip circumference 108.4±9.26
BMI 29.59±4.25
FBS 105.7±10.84
Bs120 143.51±38.39
HbA1C 5.22±0.82
TG 174.95±107.57
TC 202.35±40.45
HDL-C 45.63±12.33
LDL-C 109.03±24.73
SBP 11.7±1.67
DBP 7.6±1.22
*Mean ± Standard Deviation
BMI=body mass index, FBS=fasting blood sugar, BS
120=blood sugar 120, HbA1C= glycosylated hemoglobin,
TG=triglycerides, TC=total cholesterol, HDL-C= high-density
lipoprotein cholesterol, LDL-C= low-density lipoprotein
cholesterol, SBP= systolic blood pressure, DBP= diastolic
blood pressure.
Table-II: Correlation coefcient of risk factors of pre-diabetes and type of bread consumption.
Waist BMI FBS BS120 HbA1C TG TC HDL LDL SBP DBP
circumference
White bread 0.14*(0.001) 0.04(0.32) 0.03(0.52) 0.16(0.001) 0.01(0.04) 0.1(0.01) -0.01(0.92) -0.02(0.54) 0.13(0.48) 0.11(0.007) 0.05(0.2)
Whole bread 0.07(0.18) 0.02(0.62) -0.04(0.48) -0.03(0.63) 0.67(0.23) 0.06(0.21) -0.01(0.86) -0.02(0.7) 0.23(0.41) -0.02(0.61) 0.024(0.65)
* Correlation coefcient (p-value), Abbreviations as in Table-I
278 Pak J Med Sci 2013 Vol. 29 No. 1 Special Supplement IUMS www.pjms.com.pk
showed three month consumption of wheat bran
didn’t change FBS and HbA1c in diabetes patients.17
However some ndings indicated that whole grain
may have benecial affect on glucose and lipid
metabolism. Epidemiological studies showed
an inverse effect of whole grain on risk factors of
diabetes and benecial effect to prevention of type
2 diabetes but ndings are inconsistent.2 Exact
biological mechanisms related to the benecial
effects of whole grains are unknown.15
Whole grains are a rich source of ber, minerals,
vitamins, phenolic compounds, phytoestrogens
and antioxidants and these components are related
to benecial effects of whole grains on healthy and
improve insulin sensitivity. High ber of whole
grains leads to slower absorption of macronutrient,
decrease blood glucose and insulin secretion. Soluble
ber can decrease cholesterol concentrations.
However whole wheat (whole bread) contain little
soluble ber and cannot be responsible for reduce
cholesterol levels.5 Lack of association between
whole wheat bread and risk factors of diabetes in
our study and other studies may be due to little
amount of soluble ber in whole wheat bread. In
addition to whole breads that subjects consumed
may not have enough bran to effect of glucose and
lipid parameters.
In contrast to our nding, some studies showed
whole grains were associated with less weight
gain.18 Results of cohort prospective studies have
reported whole grain foods decrease BMI and
improve the metabolic abnormalities that related
to diabetes progression.19 Whole grains effect on
satiety and decrease energy intake.4 However, other
studies reported no signicant effects.20,21
Our study showed white bread may increase BS120,
HbA1C and TG levels. White bread and rened
carbohydrates have high GI and rapidly absorb
from intestine and lead to increase blood glucose
and insulin secretion. The Nurses’ Health Study
showed high dietary GL and low grain ber and
bran intake was associated with higher risk of type
2 diabetes mellitus.22 High intake of carbohydrates
induces hypertriglyceridemia.23,24 Among healthy
people, high rened-carbohydrate consumption
reduces levels of HDL.25 Many metabolic studies
have shown that high carbohydrate diets increase
levels of fasting triglycerides and increase in plasma
remnant lipoprotein cholesterol and remnant
lipoprotein triglycerides.26 Studies have also
showed rened grains increase dietary glycemic
load, insulin demand and glysemic responce
that may enhance the risk of type 2 diabetes and
coronary heart disease.6 Despite the contradictory
ndings, whole grains because of high content of
ber and many enzymatic inhibitors are digested
and absorbed more slowly than rened grains
and associated with small postprandial glucose
responses and little insulin demand.27
CONCLUSION
According to our nding white breads have an
inverse effect of health status and whole wheat
bread didn’t have any signicant effect of risk
factors of diabetes. Efcacy of whole wheat breads
because of low content of soluble ber must be
further investigated to assess benecial effect of
them on healthy status.
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White bread Whole bread
B±SE P B±SE P
Model 1: Bs0 0.002±0.001 0.14 0.002±0.002 0.32
Model 2: Bs120 0.011±0.003 0.001 0.004±0.004 0.24
Model 3: HbA1c 0.01±0.001 0.04 0.01±0.001 0.26
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Model 6: HDL 0.01±0.002 0.69 0.01±0.003 0.82
Model 7: LDL 0.013±0.43 0.51 0.001±0.43 0.97
Model 8:WC 0.01±0.001 0.38 0.001±0.001 0.57
Model 9:BMI 0.01±0.001 0.73 0.01±0.001 0.32
*Data are B-coefcient ± Standard Error. Values are
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Gholamreza Askari et al.
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