Two-year recall of maternal peanut consumption using a food-frequency questionnaire

Follow-up to Adolescence after Early Peanut Introduction for Allergy Prevention

BACKGROUND

A randomized trial demonstrated consumption of peanut from infancy to age 5 years prevented the development of peanut allergy. An extension of that trial demonstrated the effect persisted after 1 year of peanut avoidance. This follow-up trial examined the durability of peanut tolerance at age 144 months after years of ad libitum peanut consumption.

METHODS

Participants from a randomized peanut consumption trial were assessed for peanut allergy following an extended period of eating or avoiding peanuts as desired. The primary end point was the rate of peanut allergy at age 144 months.

RESULTS

We enrolled 508 of the original 640 participants (79.4%); 497 had complete primary end point data. At age 144 months, peanut allergy remained significantly more prevalent in participants in the original peanut avoidance group than in the original peanut consumption group (15.4% [38 of 246 participants] vs. 4.4% [11 of 251 participants]; P<0.001). Participants in both groups reported avoiding peanuts for prolonged periods of time between 72 and 144 months. Participants at 144 months in the peanut consumption group had levels of Ara h2-specific immunoglobulin E (a peanut allergen associated with anaphylaxis) of 0.03 ± 3.42 kU/l and levels of peanut-specific immunoglobulin G4 of 535.5 ± 4.98 μg/l, whereas participants in the peanut avoidance group had levels of Ara h2-specific immunoglobulin E of 0.06 ± 11.21 kU/l and levels of peanut-specific immunoglobulin G4 of 209.3 ± 3.84 μg/l. Adverse events were uncommon, and the majority were related to the food challenge.

CONCLUSIONS

Peanut consumption, starting in infancy and continuing to age 5 years, provided lasting tolerance to peanut into adolescence irrespective of subsequent peanut consumption, demonstrating that long-term prevention and tolerance can be achieved in food allergy. (Funded by the National Institute of Allergy and Infectious Diseases and others; ITN070AD, ClinicalTrials.gov number, NCT03546413.).

The accuracy of dietary recall of infant feeding and food allergen data

BACKGROUND

Research investigating the association of infant dietary factors with later health outcomes often relies on maternal recall. It is unclear what the effect of recall bias is on the accuracy of the information obtained. The present study aimed to determine the extent of recall bias on the accuracy of infant feeding and food allergen data collected 10 years later.

METHODS

Mothers were recruited from a prospective birth cohort from the Isle of Wight. When their child was 10 years of age (2011/2012), mothers were requested to complete a retrospective infant feeding questionnaire asking the same questions as those solicited in 2001/2002.

RESULTS

In total, 125 mothers participated. There was substantial agreement for recollection of any breastfeeding (κ = 0.79) and the duration of breastfeeding from 10 years earlier (r = 0.84). Some 94% of mothers recalled accurately that their child had received formula milk. The exact age at which formula milk was first given was reliably answered (r = 0.63). The brand of formula milk was poorly recalled. Recall of age of introduction of solid food was not reliable (r = 0.16). The age of introduction of peanuts was the only food allergen that was recalled accurately (86%).

CONCLUSIONS

The present study highlights the importance of maternal recall bias of infant feeding practices over 10 years. Recall related to breastfeeding and formula feeding were reliable, whereas recalls related to age of introduction of solid or allergenic foods, apart from peanut, were not. Caution should be applied when interpreting studies relying on dietary recall.

Assessing Peanut Consumption in a Population of Mothers and Their Children in the UK

Background:

Food frequency questionnaires (FFQs) are essential tools to investigate the relationship between peanut consumption and the development of peanut allergy. The aim was to validate a 50-item FFQ for use in peanut protein sensitization studies.

Methods:

There were 38 mother-child pairs visiting a pediatric clinic of a London hospital included. Mothers recorded their own and their child's diet, using a 7 day food diary (7DFDR), completed prospectively over week. Six months later, they tried to recall the consumption of food items for the index week on a FFQ.

Results:

Of these, 33 out of 38 mothers completed both the 7DFDR and the recall FFQ. Although there was considerable variation at the individual level between the 2 tools, there was extremely close agreement between the mean 7DFDR response and the FFQ when considering groups of fives with similar FFQ levels. Agreement was apparent on both peanut and other control foods consumption patterns.

Conclusion:

The FFQ will reliably divide the population into groups with markedly different peanut consumption levels. It accurately reflects true adults and children peanut consumption, especially at low levels of peanut consumption, as it was validated against the gold standard, the 7DFDR. It also provides a good measure of other foods consumption.