CD: Oats and Gluten Intolerance (2005)


Storsrud S, Hulthen LR, Lenner RA. Beneficial effects of oats in the gluten-free diet of adults with special reference to nutrient status, symptoms and subjective experiences. Br J Nutrition 2003; 90: 101-107.

PubMed ID: 12844381
Study Design:
Non-Randomized Controlled Trial
C - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To investigate the effects of including large amounts of oats in the GFD regarding nutrient quality, bioavailability of iron, nutritional status and occurrence of GI symptoms, as well as subjective experiences in the patients.
Inclusion Criteria:
Over 18 years, established diagnosis of CD, based on presence of partial, subtotal or total villous atrophy of duodenal mucosa before GFD initiation. Also had to have normal or almost normal mucosal villous architecture after treatment with GFD for at least 12 months.
Exclusion Criteria:
Not eating strict GFD or having any serious medical condition.
Description of Study Protocol:


  • Adult subjects with CD were recruited in 1996-1997 from the GI clinic at Sahlgrenska University Hospital.


  • Nonrandomized clinical trial.

Blinding used (if applicable)

  • No blinding used.

Intervention (if applicable)

  • 20 adult patients with CD included large amounts of oats in their diet for two years.

Statistical Analysis

  • Results are presented as mean values and standard deviations and medians with ranges when appropriate. Comparisons were made using non-parametric Wilcoxon signed rank test or paired t-test for comparisons between means.
Data Collection Summary:

Timing of Measurements

  • Food intake, GI symptoms, blood samples and body weight were examined at baseline, 1.5 months, six months and two years. Endoscopy and serological tests for antibodies to gliadin and endomysium performed to check tolerance to oats. Dietary habits and GI symptoms also examined at one year and 1.5 years. Compliance to the diet and GI symptoms checked monthly through unannounced telephone interviews throughout study. At end of study, subjects completed questionnaire regarding subjective experience with oats in diet.

Dependent Variables

  • Food intake measured through four-day food records
  • GI symptoms through completion of questionnaire concerning abdominal pain and distension, flatulence, non-specified abdominal symptoms, frequency and appearance of stools.
  • Nutritional status: Serum concentrations of Hgb, ferritin, vitamin B12, zinc, folate, albumin and alkaline phosphatase measured in blood sample after overnight fast
  • Subjective experiences through completion of multiple choice questionnaire with blank spaces for personal comments, regarding positive and negative aspects of including oats in the diet, whether or not they would continue eating oats after the study and in which form they preferred oats.

Independent Variables

  • Subjects were to include 100 g rolled oats per day in their diet. Subjects received oats that were determined to be free of wheat, rye and barley as judged by ELISA technique, performed by National Food Administration in Uppsala, Sweden.
Description of Actual Data Sample:

  • Initial N: 20 adult CD patients, 12 women, eight men
  • Attrition (final N): 15 followed diet for two years and 18 followed for six months. One woman withdrew after one month and one man after six months, due to distension and flatulence, but these symptoms did not differ from symptoms induced by oats in most other subjects. One woman and one man left the study after six months for non-medical reasons and one woman was excluded after one month due to lack of cooperation.
  • Age: Mean age 41 years (22-71 years)
  • Ethnicity: Not mentioned. 
  • Other relevant demographics: Mean body weight 71 kg (53-93 kg).   
  • Location: Gothenburg, Sweden.
Summary of Results:

Other Findings

  • Mean daily intake of oats was 93 g per day (27-137 g) and compliance was good.
  • One or several symptoms at the baseline exam were reported by 55% of the participants and two out of 20 subjects included dropped out because of abdominal symptoms. Temporary increased flatulence was experienced the first few weeks, as well as improved bowel function with oats in the diet for six out of 18 patients.
  • The mean intakes of Fe and dietary fibre increased ( P<0.001) with the oat diet, as well as the intakes of thiamin and Zn (P<0.02). The bioavailability of Fe tended to decrease; this seems to not have influenced the Fe status.
  • Antibodies to gliadin or endomysium could not be demonstrated in any of the participants, except for one person who had demonstrable anti-endomysium antibodies at six months. This might have been caused by accidental consumption of gluten before the exam. She continued eating oats and at the next measurement antiendomysium antibodies were no longer demonstrable in this person.
  • All patients who completed the study wanted to continue eating oats after the study, as they found that the addition of oats to the GFD yielded more variation, better taste and satiety.
Author Conclusion:
The inclusion of oats in the GFD had beneficial effects in adult patients with CD in remission. The beneficial effects were most pronounced in the subjective experiences of the patients, i.e., a better taste, the satiating effect, more variability, as well as helping to regulate bowel function. These effects were independent of the amount of oats consumed. As shown in the present study, allowing oats in the diet could increase the nutritional value of the GFD, as well as make the diet more pleasant for the patients and so increase compliance to the treatment.
Funding Source:
Kungsörnen AB (Sweden), BioDoc AB
Food Company:
Foundation associated with industry:
In-Kind support reported by Industry: Yes
Reviewer Comments:
Early dropouts (two out of 20) cited abdominal symptoms. 100 g oats per day was high target for daily consumption.
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? Yes
  2.2. Were criteria applied equally to all study groups? N/A
  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? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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? Yes
  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? Yes
  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? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  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? Yes
  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? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes