DiabetesNCT02598986
Effect of Macronutrient Supplementation on Glycemic Index of Pita Bread
A study testing Macronutrient supplementation in people with Diabetes, run by American University of Beirut Medical Center.
Trial summary
Glycemic index (GI) of food is known to be positively associated with the development of several diseases including type 2 diabetes, cardiovascular disease and age-related macular degeneration. Modest dietary changes from high-GI foods to low-GI foods have shown beneficial effects. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Diabetes
- What is being tested?
- Macronutrient supplementation
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 96 participants
- Where
- No sites listed yet
- Study dates
- Jun 2013to Jun 2015
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy subjects
Who cannot join
- any disease, pregnant and lactating
About this study
Official title: Glycemic Index of Bread: Fiber or Minerals? This is the Question.
Glycemic index (GI) of food is known to be positively associated with the development of several diseases including type 2 diabetes, cardiovascular disease and age-related macular degeneration. Modest dietary changes from high-GI foods to low-GI foods have shown beneficial effects. These findings have been translated to recommendations for increased dietary intake of whole grains. However, the inverse relationship between whole grain consumption and risk of the different components of metabolic syndrome has not been explained by their fiber content. Trials of added cereal fiber have failed to induce a protective effect and fiber has thus been proposed to be a marker of other components of whole grains that impart health advantages. Whole wheat grains are known to be a rich source of several minerals (phosphorus, potassium and magnesium) that play a role in glucose metabolism, and are depleted during the process of refinement. Thus, it is plausible to hypothesize that the benefits of whole grains previously ascribed to their fiber content are in fact due to these minerals. The proposed research aims to restore or fortify white bread with these minerals and determine the resulting glycemic index of mineral-fortified bread. With much evidence that most people prefer the taste and color of white bread, a low GI, mineral fortified white bread has the potential to reduce the risk of Metabolic Syndrome in those who consume it.
Read the detailed description
The production of white flour requires the milling of the wheat grain and extraction of a proportion of the grains. The level of 80% extraction is the most-commonly used in the production of white flour in the market and this process leads to a substantial loss of vitamins and minerals (Table 1). These vitamins and minerals are known to affect energy metabolism. For example, thiamin is known to affect carbohydrate metabolism and low thiamin intake is known to cause Beriberi. This has led to the establishment of an acceptable carbohydrate and energy: thiamin ratio (0.4mg of thiamin/1000 kcal) and many countries are fortifying their white wheat flour with thiamin to sustain an acceptable ratio. Although several minerals are known to affect energy and carbohydrate metabolism no clear ratio has been put in place yet.
Table 1: the effect of milling on mineral content of wheat flour Mineral content Wheat flour (white) Wheat flour (whole grain) Loss (%) Phosphorus (mg/100g) 108 346 69 Potassium (mg/100g) 107 408 74 Magnesium (mg/100g) 22 138 84
Specific Aim 1: Determine the acceptability of mineral fortified white bread. White flour will be supplemented with minerals to produce mineral-fortified bread. The acceptability of the bread will be tested.
White wheat flour (80% extraction) will be fortified with minerals. Potassium phosphate will be used as the source of phosphorus and potassium to fortify white flour. From previous experience, the addition of potassium phosphate to glucose solution was found to minimally affect the organoleptic properties. Unlike that of sodium phosphate that was not well tolerated by subjects due to development of unfavorable flavor (fishy flavor). At the same time, magnesium chloride will be used as the source of magnesium. Magnesium chloride is known to be highly soluble and is commonly used as a supplement or fortificant.
Locally produced white wheat flour (80% extraction) and whole grain wheat flour will be purchased and stored at the department. White and whole flour samples (n=3) will be analyzed for their content of phosphorus, magnesium and potassium according to standard procedures
Fortification:
White Bread Restoration (WB-R): A quantity of white flour will be fortified with minerals to a level that restores its content of minerals to that of whole grain wheat flour.
Based on data from the above table, white flour restoration requires the addition of:
250 mg of P/100g white flour (total P =358mg/100g) and 100 mg of Mg/100g white flour (total Mg =122mg/100g)
White Bread Fortification (WB-F): A quantity of white flour will be fortified with minerals to a level that is 100% higher than that of whole grain wheat flour.
Based on data from the above table, white flour fortification requires the addition of:
580mg of P/100g white flour (total P= 688mg/100g) 250mg of Mg/100g white flour (total Mg= 272 mg/100g)
Making of bread:
Four different types of bread will be made:
White bread (WB) White bread with mineral restoration (WB-R) White bread with mineral fortification (WB-F) Whole grain bread (WGB)
Acceptability of bread:
Bread samples (white bread and whole wheat bread controls and the 2 experimental samples) will be tested for acceptability. Panelists (n= 60) will be recruited based on their willingness to participate in the study and their consumption of Arabic bread.
Panelists will be asked to fill a questionnaire and to rate the served samples on a 9-point hedonic scale with 1 representing dislike extremely and 9 representing like extremely for overall acceptability, acceptability of appearance, texture and taste. The order of presentation of the samples will be counterbalanced.
Mineral and carbohydrate content of bread:
Phosphorus, potassium and magnesium and starch contents of the bread will be determined.
Specific Aim 2: Assess any sensory differences between the different bread treatments. The bread making step will be the same as the above. Panelists who are regular consumers of white bread will be recruited to assess any sensory differences between the white bread control and the white bread mineral supplemented experimental samples. The triangle test will be used in the difference tests. All subjects will be asked to sign human subjects consent forms and answer demographic information. Demographic information that will be requested will be: 1) age, 2) gender, 3) frequency of bread consumption, 4) type of bread typically consumed, and 5) what factors influence the panelists' bread purchase. Twenty four panelists will participate in three triangle test, comparing the white bread control vs. each of the three experimental samples in each test. In the session, subjects will be debriefed about a) the products they will consume, b) the procedures for the testing, c) instructions on how to sample the beverages, and d) how to use the score card. All samples will be presented in a random, balanced order .
Specific Aim 3: Determine the glycemic index of the mineral supplemented bread. Glycemic index of the above four different types of bread will be determined.
In this experiment, healthy subjects (n=12) will be asked to maintain their regular dietary and physical activity habits during the entire study course, avoid alcohol consumption as well as any unusual strenuous exercise 24 hours prior to the study. Exclusion criteria include: any significant medical diseases; pregnancy or lactation; regular use of medication that affects body weight; a weight loss of 3% or more in the preceding 3 months. Following a 12 hour (overnight) fast, they will be taken to the testing facility [Faculty of Agriculture and Food Sciences/Department of Nutrition or the Central research unit (CRU)/ American University Hospital] where: anthropometric measurements (height, weight) will be taken. A catheter will be inserted for blood withdrawal.
Glycemic index of food will be determined. In brief, overnight fasted subjects will be given the bread (50 g of carbohydrate) to ingest within 10-15 min and drink 250ml of water. Blood samples will be taken immediately before the meal and at 15, 30, 45, 60, 90 and 120 minutes after meal ingestion. Blood will be withdrawn by a trained practitioner and will be used for the determination of glucose.
Glucose area under the curve (AUC) will be calculated. The GI value of each food will be calculated as the mean value of : 100 x (AUC test food)/(AUC reference food) in the same subject.
In addition, mineral content of the blood will be determined and several metabolites (glucose, Tg, FFA, P), K, Mg and hormones (insulin) will be measured.
- Conditions
- Diabetes
- Being tested
- Macronutrient supplementation
- Keywords
- glycemic index, pita bread, phosphorus, potassium, magnesium
- Medical subject headings
- Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Macronutrient supplementationDietary supplement
adding of phosphorus, potassium and magnesium
| Study group | Role | What they receive |
|---|---|---|
| white pita bread | Placebo comparator | Pita bread made of white wheat flour Receives: Dietary Supplement: Macronutrient supplementation |
| Whole grain pita bread | No intervention | no macronutrient supplementation |
| Restored white pita bread | Experimental | macronutrient supplementation Receives: Dietary Supplement: Macronutrient supplementation |
| Fortified white pita bread | Experimental | macronutrient supplementation 2 Receives: Dietary Supplement: Macronutrient supplementation |
What is being measured
The primary outcome is the main question the study is designed to answer.
AUC of serum glucose
Measured: two hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2015 (estimated)
- Study startJun 2013
- Primary completionJun 2015
- Study completionJun 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DiabetesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 96 participants (actual)
Sponsor and investigators
- Lead sponsor
- American University of Beirut Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Omar Obeid, American University of Beirut Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02598986
- Sponsor's protocol ID
- NUT.OO.19
- Status last verified
- Nov 2015
- First submitted
- 4 Nov 2015
- Last updated
- 6 Nov 2015
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Glycemic Index of Bread: Fiber or Minerals? This is the Question.
- ClinicalTrials.gov ID
- NCT02598986
- Acronym / sponsor ID
- NUT.OO.19
- Conditions
- Diabetes
- Keywords
- glycemic index, pita bread, phosphorus, potassium, magnesium
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 96 participants (actual)
- Lead sponsor
- American University of Beirut Medical CenterUniversity, hospital or other
- Study start
- Jun 2013
- Primary completion
- Jun 2015 (actual)
- Study completion
- Jun 2015 (actual)
- First posted
- 6 Nov 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Glycemic index (GI) of food is known to be positively associated with the development of several diseases including type 2 diabetes, cardiovascular disease and age-related macular degeneration. Modest dietary changes from high-GI foods to low-GI foods have shown beneficial effects. These findings have been translated to recommendations for increased dietary intake of whole grains. However, the inverse relationship between whole grain consumption and risk of the different components of metabolic syndrome has not been explained by their fiber content. Trials of added cereal fiber have failed to induce a protective effect and fiber has thus been proposed to be a marker of other components of whole grains that impart health advantages. Whole wheat grains are known to be a rich source of several minerals (phosphorus, potassium and magnesium) that play a role in glucose metabolism, and are depleted during the process of refinement. Thus, it is plausible to hypothesize that the benefits of whole grains previously ascribed to their fiber content are in fact due to these minerals. The proposed research aims to restore or fortify white bread with these minerals and determine the resulting glycemic index of mineral-fortified bread. With much evidence that most people prefer the taste and color of white bread, a low GI, mineral fortified white bread has the potential to reduce the risk of Metabolic Syndrome in those who consume it.
Detailed description
The production of white flour requires the milling of the wheat grain and extraction of a proportion of the grains. The level of 80% extraction is the most-commonly used in the production of white flour in the market and this process leads to a substantial loss of vitamins and minerals (Table 1). These vitamins and minerals are known to affect energy metabolism. For example, thiamin is known to affect carbohydrate metabolism and low thiamin intake is known to cause Beriberi. This has led to the establishment of an acceptable carbohydrate and energy: thiamin ratio (0.4mg of thiamin/1000 kcal) and many countries are fortifying their white wheat flour with thiamin to sustain an acceptable ratio. Although several minerals are known to affect energy and carbohydrate metabolism no clear ratio has been put in place yet.
Table 1: the effect of milling on mineral content of wheat flour Mineral content Wheat flour (white) Wheat flour (whole grain) Loss (%) Phosphorus (mg/100g) 108 346 69 Potassium (mg/100g) 107 408 74 Magnesium (mg/100g) 22 138 84
Specific Aim 1: Determine the acceptability of mineral fortified white bread. White flour will be supplemented with minerals to produce mineral-fortified bread. The acceptability of the bread will be tested.
White wheat flour (80% extraction) will be fortified with minerals. Potassium phosphate will be used as the source of phosphorus and potassium to fortify white flour. From previous experience, the addition of potassium phosphate to glucose solution was found to minimally affect the organoleptic properties. Unlike that of sodium phosphate that was not well tolerated by subjects due to development of unfavorable flavor (fishy flavor). At the same time, magnesium chloride will be used as the source of magnesium. Magnesium chloride is known to be highly soluble and is commonly used as a supplement or fortificant.
Locally produced white wheat flour (80% extraction) and whole grain wheat flour will be purchased and stored at the department. White and whole flour samples (n=3) will be analyzed for their content of phosphorus, magnesium and potassium according to standard procedures
Fortification:
White Bread Restoration (WB-R): A quantity of white flour will be fortified with minerals to a level that restores its content of minerals to that of whole grain wheat flour.
Based on data from the above table, white flour restoration requires the addition of:
250 mg of P/100g white flour (total P =358mg/100g) and 100 mg of Mg/100g white flour (total Mg =122mg/100g)
White Bread Fortification (WB-F): A quantity of white flour will be fortified with minerals to a level that is 100% higher than that of whole grain wheat flour.
Based on data from the above table, white flour fortification requires the addition of:
580mg of P/100g white flour (total P= 688mg/100g) 250mg of Mg/100g white flour (total Mg= 272 mg/100g)
Making of bread:
Four different types of bread will be made:
White bread (WB) White bread with mineral restoration (WB-R) White bread with mineral fortification (WB-F) Whole grain bread (WGB)
Acceptability of bread:
Bread samples (white bread and whole wheat bread controls and the 2 experimental samples) will be tested for acceptability. Panelists (n= 60) will be recruited based on their willingness to participate in the study and their consumption of Arabic bread.
Panelists will be asked to fill a questionnaire and to rate the served samples on a 9-point hedonic scale with 1 representing dislike extremely and 9 representing like extremely for overall acceptability, acceptability of appearance, texture and taste. The order of presentation of the samples will be counterbalanced.
Mineral and carbohydrate content of bread:
Phosphorus, potassium and magnesium and starch contents of the bread will be determined.
Specific Aim 2: Assess any sensory differences between the different bread treatments. The bread making step will be the same as the above. Panelists who are regular consumers of white bread will be recruited to assess any sensory differences between the white bread control and the white bread mineral supplemented experimental samples. The triangle test will be used in the difference tests. All subjects will be asked to sign human subjects consent forms and answer demographic information. Demographic information that will be requested will be: 1) age, 2) gender, 3) frequency of bread consumption, 4) type of bread typically consumed, and 5) what factors influence the panelists' bread purchase. Twenty four panelists will participate in three triangle test, comparing the white bread control vs. each of the three experimental samples in each test. In the session, subjects will be debriefed about a) the products they will consume, b) the procedures for the testing, c) instructions on how to sample the beverages, and d) how to use the score card. All samples will be presented in a random, balanced order .
Specific Aim 3: Determine the glycemic index of the mineral supplemented bread. Glycemic index of the above four different types of bread will be determined.
In this experiment, healthy subjects (n=12) will be asked to maintain their regular dietary and physical activity habits during the entire study course, avoid alcohol consumption as well as any unusual strenuous exercise 24 hours prior to the study. Exclusion criteria include: any significant medical diseases; pregnancy or lactation; regular use of medication that affects body weight; a weight loss of 3% or more in the preceding 3 months. Following a 12 hour (overnight) fast, they will be taken to the testing facility [Faculty of Agriculture and Food Sciences/Department of Nutrition or the Central research unit (CRU)/ American University Hospital] where: anthropometric measurements (height, weight) will be taken. A catheter will be inserted for blood withdrawal.
Glycemic index of food will be determined. In brief, overnight fasted subjects will be given the bread (50 g of carbohydrate) to ingest within 10-15 min and drink 250ml of water. Blood samples will be taken immediately before the meal and at 15, 30, 45, 60, 90 and 120 minutes after meal ingestion. Blood will be withdrawn by a trained practitioner and will be used for the determination of glucose.
Glucose area under the curve (AUC) will be calculated. The GI value of each food will be calculated as the mean value of : 100 x (AUC test food)/(AUC reference food) in the same subject.
In addition, mineral content of the blood will be determined and several metabolites (glucose, Tg, FFA, P), K, Mg and hormones (insulin) will be measured.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| white pita bread | Placebo comparator | Dietary Supplement: Macronutrient supplementationPita bread made of white wheat flour |
| Whole grain pita bread | No intervention | –no macronutrient supplementation |
| Restored white pita bread | Experimental | Dietary Supplement: Macronutrient supplementationmacronutrient supplementation |
| Fortified white pita bread | Experimental | Dietary Supplement: Macronutrient supplementationmacronutrient supplementation 2 |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Healthy subjects
Key exclusion criteria (1 listed)
- any disease, pregnant and lactating
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Macronutrient supplementationadding of phosphorus, potassium and magnesium | Dietary supplement | Fortified white pita bread, Restored white pita bread, white pita bread |
Primary outcome
AUC of serum glucose
Time frame: two hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2015.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Macronutrient supplementation in people with Diabetes, run by American University of Beirut Medical Center.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Nov 2015. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
AUC of serum glucose (time frame: two hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2015.