Case-control studyindependent cross-checkabstract checked★ key study I-VEG-113 in-depth review

Stored vegetable purees caused infant methaemoglobinaemia

Methemoglobinemia induced by vegetable intake in infants in northern Spain.

Overview

Martinez A et al.. J Pediatr Gastroenterol Nutr 2013 · PMID 23287806 · DOI 10.1097/MPG.0b013e3182849d2b

In 78 Spanish infants, purees made more than a day in advance and nitrate-rich leaves such as borage and chard were linked to methaemoglobinaemia.

Does the study support the specific claim? Yes · Methodological quality: low

Study explained simply

What did the researchers want to find out?: Identify risk factors for vegetable-related methaemoglobinaemia.
How was the study done?: Case series with case-control comparison.
How many people, animals or samples were studied?: 78 cases, 78 controls.
What was actually found?: Storage >24 h and borage/chard strongly associated.
How large was the observed effect?: OR 17.4 to 24.9 for stored purees.
What do the results mean in everyday life?: Prepare infant vegetable purees fresh or freeze them; avoid very high-nitrate leaves for young infants.
What are the study's limitations?: Small, bivariate.
What does it say about Elawady's specific claim?: Supports the infant-specific claim.
Do the results apply to Germany and Europe?: European; applicable.
What can explicitly not be concluded from this study?: Cannot show risk for adults or for fresh, properly stored purees.

Which vegetables and practices are associated with diet-induced methaemoglobinaemia in infants?

Study design: Case-control study – Case series (78 cases, 1987-2010) with matched case-control analysis and nitrate measurement of vegetables
Population: Infants with diet-induced methaemoglobinaemia, Pamplona; 78 age- and sex-matched controls
Country: Spain
Period: 1987-2010
Sample size: 78 cases, 78 controls
Inclusion and exclusion criteria: not stated in abstract

Exposure / intervention: Vegetable types in purees, time from preparation to use, breast-feeding
Comparator: Matched controls
Endpoints: Methaemoglobinaemia
Statistical methods: Bivariate logistic regression

Results: Borage OR 5.2 (1.1-24.6); chard OR 2.0 (0.4-8.7); puree prepared 24-48 h before OR 17.4 (3.5-86.3), >48 h OR 24.9 (3.3-187.6); breast-feeding OR 10.4 (1.9-57.2). Mean nitrate: borage 3,968 mg/kg, chard 2,811 mg/kg.
Absolute risks: not reported
Authors' conclusion: Main factors: time from puree preparation to use (>24 h), certain vegetables (borage, chard), and breast-feeding.

CIs log-symmetric but very wide (stats/C-VEG-07_infant_nitrate.py); storage time has the strongest and most precise association.

Confirms vegetable-induced methaemoglobinaemia in infants and shows that storage of purees is a key modifiable factor.

None contradicting the infant risk.

European data.

Supports the claim for infants and refines it: freshness/storage and specific high-nitrate vegetables matter.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	low
Risk of bias	high
Precision of results	low
Directness	direct
Reproducibility	partly replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Incidence per exposed infant.