Randomised controlled trialindependent cross-checkabstract checked I-EGG-107 standard review

Cutting out 'intolerant' foods did not clearly prevent headaches

Randomised controlled trial of food elimination diet based on IgG antibodies for the prevention of migraine like headaches.

Overview

Mitchell N et al.. Nutr J 2011 · PMID 21835022 · DOI 10.1186/1475-2891-10-85

No significant difference at 12 weeks; small effect at 4 weeks.

Does the study support the specific claim? Unclear · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Test an elimination diet for headaches.
How was the study done?: Randomized, sham-controlled trial.
How many people, animals or samples were studied?: 167 adults.
What was actually found?: Primary outcome not improved.
How large was the observed effect?: IRR 1.15 (0.94-1.41) at 12 weeks.
What do the results mean in everyday life?: Removing foods based on IgG tests is not proven to help headaches.
What are the study's limitations?: Unvalidated test; eggs not separately reported.
What does it say about Elawady's specific claim?: Does not support that stopping eggs relieves headaches in general.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: It cannot rule out that some individuals react to eggs.

Authors: Mitchell N et al.
Journal: Nutr J
Year: 2011
Identifier: PMID 21835022 DOI 10.1186/1475-2891-10-85
Verification: verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: not stated in abstract

Does removing foods identified by IgG testing reduce migraine-like headaches?

Study design: Randomised controlled trial – Randomized controlled trial, true vs sham elimination diet based on IgG (ELISA) food testing, 12 weeks
Population: UK community volunteers with migraine-like headaches and at least one IgG-detected food 'intolerance'
Country: United Kingdom
Period: not stated in abstract
Sample size: 167 (84 true diet, 83 sham diet)
Inclusion and exclusion criteria: not detailed in abstract

Results: Primary outcome at 12 weeks: small, non-significant decrease in headache days (IRR 1.15, 95% CI 0.94-1.41, p = 0.18). At 4 weeks: significant reduction (IRR 1.23, 1.01-1.50, p = 0.04). Disability and impact scores did not differ between groups.
Absolute risks: not reported
Authors' conclusion: The IgG test with elimination advice did not reduce headache disability or headache days at 12 weeks, but reduced headache days at 4 weeks.

Orienting tool: RoB 2
Type of assessment: simplified assessment (abstract only)
Full formal assessment: no
Overall risk of bias: some concerns
Rationale: Primary endpoint null; secondary time point positive (multiplicity).

Primary endpoint null; the 4-week result is a secondary time point and could be chance.

Tests the general idea that removing suspected foods prevents headaches: no effect on the primary outcome. Does not test eggs specifically.

Short-term reduction at 4 weeks.

UK trial.

Weak, indirect; does not support a general effect of food (including egg) elimination on headaches.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	low
Directness	very indirect
Reproducibility	unknown
Consistency with the overall evidence	unknown
Regional transferability	moderate
Adequacy of the interpretation (by the archive)	not applicable

Whether a subgroup with true food triggers benefits.