EAL

NNNS: Polyols (2010)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate the gastrointestinal (GI) tolerance of sucrose, erythritol or xylitol among young adults (18 to 24 years).

Inclusion Criteria:

Subjects were healthy, non-adapted, volunteer undergraduate students of both genders, aged 18 to 24 years. Other inclusion criteria were not described, and a reference was made to another study for that description.

Exclusion Criteria:

Exclusion criteria were not described. Implied exclusion criteria included illness not associated with the experimental treatments since this was the explanation for study non-completion among three male subjects.

Description of Study Protocol:

Recruitment

Students of both genders aged 18 to 24 were recruited as subjects from University of Salford, Belgium, using methods that are not described. Students were allowed to drop out at any time and compensation for travel and study participation was provided.

Design

Subjects consumed two 200ml bottles of beverages in Latin square designed randomized order, which included six treatments (20, 35 and 50g erythritol, 20, 35 and 50g xylitol) and one placebo (45g sucrose). Subjects recorded the incidence and magnitude of various GI symptoms (nausea, borborygmi, colic, bloating, flatulence for 24 hours following each treatment using a hedonic (zero=none; one to three = slightly, moderately or considerably more symptom than usual). Subjects recorded the number of bowel movements to pass feces of normal, watery or hard consistency.

Blinding Used

Subjects and researchers were both blinded to study treatments.

Intervention

Test beverages were orange flavored non-carbonated drinks containing either 45g sucrose or 20, 35 or 50g respectively of both erythritol and xylitol for a total of seven treatments. Beverages were adjusted for comparable sweetness by the addition of aspartame. Test beverages were assigned a code for anonymity.

Statistical Analysis

Symptoms were considered non-parametric categorical data and differences in GI symptoms were analyzed using McNemar's chi-square method. The analysis summed each subjects' scores for the occurrence of multiple GI symptoms and tested differences between subject scores. Analysis of variance and Dunnet's post-hoc analysis examined the frequency of bowel movements to pass normal, watery and hard feces.

Data Collection Summary:

Timing of Measurements

Beverage treatments were separated by a seven-day washout; subjects were asked to avoid consumption of other polyol items during treatment and were told to consume a typical breakfast or lunch prior to treatment. They were to consume each treatment within a 15-minute period, as either a mid-morning or mid-afternoon snack at the discretion of the subject. Subjects abstained from any consumption up to two hours following treatment, other than 300ml of water.

Dependent Variables

Variable 1: Perception of various GI symptoms (nausea, bloating, borborgymi, colic, flatulence) , rated as zero (none) or one to three (slightly to considerably more symptom than usual)
Variable 2: Number of bowel movements to pass watery feces.

Independent Variables

20g erythritol
20g xylitol
35g erythritol
35g xylitol
50g erythritol
50g xylitol.

Control (Placebo) Variables

45g sucrose beverage.

Description of Actual Data Sample:

Initial N: 70 (34 males; 36 females)
Attrition (final N): 65 total subjects; three males lost to unrelated illness; two males lost to adverse GI effects with xylitol treatments of the study
Age: 18 to 24 (no mean age given)
Anthropometrics: Male Body Mass Index (BMI): 24.54 4.46kg/m²; Female BMI: 22.34±2.6kg/m²
Location: Belgium.

Summary of Results:

Key Findings

Significant differences between reports of some symptoms were found when consuming some of the treatment beverages (xylitol at all levels and the highest level for erythritol) compared to control (sucrose).

Variables

N=64

45g

Sucrose

20g

Xylitol

35g

Xylitol

50g

Erythritol

50g

Xylitol

Total subjects with nausea	6	17*	15	20*
Total subjects with bloating	11	11	19	19	23*
Total subjects with borborygmi	15	22	22	24*	33**
Total subjects with colic	8	10	11	16	20*
Total subjects with watery feces	9	14	22*	19	28**

* P<0.05.

** P<0.01.

Other Findings

No significant differences were found for the symptom of flatulence
The only significant differences in the mean number of bowel movements occurred with passing watery bowel movements under the 35g xylitol (0.66±1.13, P<0.05) and 50g xylitol (1.09±1.07, P<0.01) compared to all levels of erythritol (0.08±0.27, 0.28±0.77 and 0.62±1.22) and with total bowel movements under the 50g xylitol treatment (2.0±1.62, P<0.01) compared to 45g sucrose (1.29±0.99).
Symptom scores were dose-dependent; with significantly increasing means occurring in both 50g xylitol and 50g erythritol treatments (P<0.001) compared to 45g sucrose. Mean symptom scores were significantly higher with xylitol at 35 and 50g levels (P<0.05) but not 20g levels compared to sucrose. All xylitol levels (20, 35 and 50g) produced significantly higher mean frequency of symptom scores compared to equivalent levels of erythritol (P<0.025; 0.05 and 0.005, respectively).
Few subjects reported more than three symptoms following any treatment beverage; a significant increase in the number of subjects experiencing three or more symptoms occurred with the 50g xylitol treatment (P<0.001).

Author Conclusion:

Gastrointestinal symptoms associated with polyol consumption have been documented but less so for xylitol and erythritol.
Dose is a factor that influences tolerance as does polyol and saccaride type, ingestion medium and pattern, as well as individual differences.
Molecular size impacts the absorption; erythritol (compared to xylitol and sorbitol) has a molecular weight allowing for quick absorption at the small intestine via passive diffusion, avoiding osmotically induced lower GI symptoms. Erythritol is rapidly absorbed, with some urinary but little fecal excretion.
In this study, both 35 and 50g xylitol produced watery feces and upper levels of xylitol produced other GI symptoms except flatulence. High doses of erythritol provoked only mild nausea and borborgymi, suggesting that xylitol produces greater symptoms due to the osmotic and fermentation effects taking place in the large bowel.
Overall, the data in this study indicate that when erythritol is consumed as a liquid drink, it is not associated with multiple GI symptoms found when xylitol is consumed in similar gram levels. Even at the highest doses in this study, erythritol produced significant increases in only mild symptoms.

Funding Source:

Other:

Cerestar Vilvoorde Research and Development Center

Reviewer Comments:

Not all data was available for examination.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	???
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	No
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	???
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	N/A
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	???
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		N/A
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
10.	Is bias due to study's funding or sponsorship unlikely?		???
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes