Impact of peanut consumption in the LEAP Study: Feasibility, growth, and nutrition

Abstract

Background: Early introduction of peanut is an effective strategy to prevent peanut allergy in high-risk infants; however, feasibility and effects on growth and nutritional intake are unknown.

Objective: We sought to evaluate the feasibility of introducing peanut in infancy and explore effects on growth and nutritional intake up to age 60 months.

Methods: In the Learning Early About Peanut Allergy trial, 640 atopic infants aged 4 to 11 months were randomly assigned to consume (6 g peanut protein per week) or avoid peanut until age 60 months. Peanut consumption and early feeding practices were assessed by questionnaire. Dietary intake was evaluated with prospective food diaries. Anthropometric measurements were taken at all study visits.

Results: Peanut was successfully introduced and consumed until 60 months, with median peanut protein intake of 7.5 g/wk (interquartile range, 6.0-9.0 g/wk) in the consumption group compared with 0 g in the avoidance group. Introduction of peanut in breast-feeding infants did not affect the duration of breast-feeding. There were no differences in anthropometric measurements or energy intakes between groups at any visits. Regular peanut consumption led to differences in dietary intakes. Consumers had higher intakes of fat and avoiders had higher carbohydrate intakes; differences were greatest at the upper quartiles of peanut consumption. Protein intakes remained consistent between groups.

Conclusions: Introduction of peanut proved feasible in infants at high risk of peanut allergy and did not affect the duration of breast-feeding nor impact negatively on growth or nutrition. Energy balance was achieved in both groups through variations in intakes from fat and carbohydrate while protein homeostasis was maintained.

Keywords: Food allergy; allergy prevention; breast-feeding; growth; infant feeding; nutrition; peanut; prospective food diary; protein homeostasis.

Fig 1. Average peanut consumption over time (grams peanut protein per week)

Peanut consumption summarized throughout the study from FFQs completed at baseline and between study visits. Median weekly consumption during the first 2 years of life (per-protocol adherence) has been previously published.(1) Grey dots denote subjects randomized to the avoidance group. Green dots denote subjects randomized to the consumption group. Red circles denote participants who were peanut allergic at 60 months.

Fig 2. Growth & anthropometry in avoidance and consumption groups (ITT sample)

Measures are weight, height, body mass index (BMI), subscapular skinfold thickness, triceps skinfold thickness, waist circumference. The bottom panel displays the difference in means (consumption – avoidance) and 95% confidence intervals between the two randomized groups resulting from a model adjusted for randomization assignment and gender.

Fig 3. Macronutrient intakes in avoidance & consumption groups as percentage of total energy intake (ITT sample) and differences in mean macronutrient intakes by quartile of peanut consumption

Panel A displays all data for both randomized groups. Panel B displays the difference in means (consumption – avoidance) and 95% confidence intervals between the two randomized groups resulting from equivariance T-tests. Panel C displays the difference in means (consumption – avoidance) and 95% confidence intervals between the avoidance group and each quartile of peanut consumption resulting from equivariance T-tests.