Colic in breast fed infants is due to hypersensitivity to dietary proteins excreted in breast milk

Abstract

Rationale

Excessive crying and distress (colic) affects 10 to 20% of infants. Breast milk contains trace amounts of maternally ingested dietary antigens. We hypothesized hypersensitivity to trace amounts of proteins in breast milk elicits infantile colic.

Methods

Breast-fed infants, <6 weeks of age with colic (distress ≥3 hours/24 hours for ≥3 days in the week prior to presentation) were studied over 7 days. Mothers were randomly allocated to a “low-allergen” diet which excluded milk, egg, wheat, peanut, tree nuts and fish or a “control” diet which contained these foods. Based on our previous studies 45 patients in each “low-allergen” and “control” diet group would detect an 80% probability of a significant effect at the 0.05 level. The response to diet intervention was assessed using previously validated infant distress score charts. The primary criteria of a response was a fall in distress scores ≥25% after 7 days.

Results

Of 107 infants who entered the study 90 completed the program; 47 received the “low-allergen” and 43 “control” diet. Distress was reduced by ≥25% in 74% of the “low-allergen” group vs 34% of the “control” group (p<0.001). In the last 48 hours of the study the “low-allergen” group had 128 minutes less distress than the “control” group (p=0.01). Including “non-completers” (drop-out's) as either “responders” or “non-responders” did not affect the conclusions.

Conclusions

Colic in breast fed infants, less than 6 weeks of age is associated with intolerance to dietary proteins excreted in breast milk and responds to a “low-allergen” maternal diet.