CD: Villous Atrophy (2006)


Peraaho M, Kaukinen K, Mustalahti K, Vuolteenaho N, Maki M, Laippala P, Collin P. Effect of an oats-containing gluten-free diet on symptoms and quality of life in celiac disease. A randomized study.  Scand J Gastroenterol 2004; 39:27-31.

PubMed ID: 14992558
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To compare an oats-containing GFD to the traditional one, focusing especially on general well-being and GI symptoms in CD patients in clinical and histological remission. The effect of an oats-containing GFD on the small-intestinal mucosa was also evaluated.
Inclusion Criteria:
Biopsy proven CD on a GFD without oats.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:


  • 39 patients with biopsy-proven CD recruited.


  • Randomized Controlled Trial.

Blinding used (if applicable)

  • Each patient entered the trial before random assignment revealed.

Intervention (if applicable)

  • Patients were randomized to take 50 g oats-containing gluten-free products daily or continue current diet without oats for one year.

Statistical Analysis

  • Data were analyzed using ANOVA for repeated measures. Equality of the baseline was tested with a t-test, which also applied in the analysis of the biopsy samples. Data characteristics are displayed crude, using mean, median and standard deviations. The required number of participants was determined to achieve necessary statistical power.
Data Collection Summary:

Timing of Measurements

  • Dietary assessment at zero, six and 12 months. Quality of life, GI symptoms, serology and small bowel biopsies evaluated before and after study.

Dependent Variables

  • Quality of life assessed using Psychological General Well-Being questionnaire
  • GI symptoms assessed through Gastrointestinal Symptom Rating Scale
  • Small bowel biopsy specimens taken from the distal part of the duodenum by endoscopy. Morphometric analysis and IEL counts completed.
  • Serum IgA EMAs determined through indirect immunofluorescence and serum IgA class tTG antibodies investigated through ELISA. Blood Hgb, serum iron and RBC folate measured using routine lab methods.

Independent Variables

  • Oat intake was targeted at 50 g/day. Dietary assessment and history measured through detailed dietary analysis, interview and four-day food records. Purity of oats was not tested.
Description of Actual Data Sample:

  • Initial N: 23 randomized to oats (six male, 17 female) and 16 to controls (four male, 12 female)
  • Attrition (final N): 20 oats (six male, 14 female) and 16 controls. Three females in the oats group withdrew after developing GI pain and abdominal distension.
  • Age: Oats group, 48 years (25-69 years); controls, 46 years (22-65 years)
  • Ethnicity: Not mentioned
  • Other relevant demographics: Average daily fiber consumption similar at the time of enrollment.
  • Anthropometrics: Groups were similar with respect to age and gender.
  • Location: Department of Medicine. Tampere University Hospital, Finland.
Summary of Results:

Oats Group

Non-Oats Group

P value

Villous Height:Crypt Depth ratio (mean)





44.6 (22.7)

26.7 (21.0)


alpha beta + cells

29.8 (18.8)

19.9 (20.3)


gamma delta + cells

11.3 (6.1)

5.3 (6.2)


Hgb (mean)




RBC folate (mean)




Serum Fe (mean)




Other Findings

Average daily consumption of oats was 30 g; less than allowed in the protocol. Quality of life did not differ between the groups. In general, there were more GI symptoms in the oats-consuming group. Patients taking oats suffered significantly more often from diarrhea (p=0.010), but there was a simultaneous trend towards a more severe average constipation symptom score. The villous architecture did not differ between the groups, but the density of IELs was slightly but significantly higher in the oats group (p=0.039). The severity of symptoms was not dependent on the degree of inflammation. There were no statistical differences between the study groups in blood hemoglobin, serum iron, folic acid or antibody levels. Regarding the three dropouts in the oats group, control biopsies taken in two cases showed incomplete recovery, and the serological tests were normal in all three.

Author Conclusion:
In this randomized study, oats had no effect on quality of life, as measured by the PGWB questionnaire. The oats-containing GFD caused more intestinal symptoms than the traditional diet. Mucosal integrity was not disturbed, but more inflammation was evident in the oats group. Oats provide an alternative in the GFD, but celiac patients should be aware of the possible increase in intestinal symptoms. We conclude that oats can be included in the celiac diet.
Funding Source:
University/Hospital: Tampere University Hospital
Foundation associated with industry:
Reviewer Comments:
There were three dropouts in oats group, but their characteristics were evaluated. Average oat consumption of 30 g was below the targeted daily intake of 50 g. Authors noted that wheat contamination of the oat products was possible in this study.
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? 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? No
  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.) Yes
  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? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  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? Yes
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)? Yes
  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