Lactose avoidance for young children with acute diarrhea.

Abstract

For the current issue of the Journal, we asked Drs Natasha Saunders and Jeremy Friedman to comment on and put into context the recent Cochrane Review on avoiding or reducing intake of lactose-containing milk or milk products for reducing the duration and severity of acute diarrhea in children. Background Young children with acute diarrhea, typically due to infectious gastroenteritis, may temporarily stop producing lactase, the intestinal enzyme that digests lactose. Thus, they may not digest lactose, the main sugar in milk, and this may worsen or prolong the diarrheal illness. However, there is uncertainty regarding whether avoiding lactose-containing milk or milk products helps young children recover from acute diarrhea more quickly. Methods Search strategy: The authors performed a search of the Cochrane Infectious Diseases Group Specialized Register (May 14, 2013), Cochrane Central Register of Controlled Trials (CENTRAL) published in The Cochrane Library (Issue 4, 2013), MEDLINE (1996 to May 14, 2013), EMBASE (1974 to May 14, 2013), LILACS (1982 to May 14, 2013) and the reference lists of potentially relevant trials and key conference proceedings, and wrote to individuals and organizations in the field. Selection criteria: Randomized or quasi-randomized controlled trials that assessed the effects of avoiding or reducing exposure to lactose in young children <5 years of age with acute diarrhea. Data analysis: Data were extracted using the standard methods of the Cochrane Infectious Diseases Group, and two review authors independently evaluated trial quality and data extraction. Continuous outcomes were compared using mean difference (MD) and dichotomous outcomes were compared using the risk ratio (RR). All results are presented with 95% CIs; the quality of evidence was assessed using the GRADE approach. Results Thirty-three trials enrolling 2973 children with acute diarrhea were included. Twenty-nine trials were exclusively conducted on inpatients, all from high- or middle-income countries. Fifteen trials included children <12 months of age, and 22 excluded children who were being breastfed. Compared with lactose-containing milk, milk products or foodstuffs, lactose-free products may reduce the duration of diarrhea by a mean of approximately 18 h (MD −17.77 [95% CI −25.32 to −10.21]; 16 trials, 1467 participants, low-quality evidence). Lactose-free products likely also reduce treatment failure (defined variously as continued or worsening diarrhea or vomiting, the need for additional rehydration therapy or continuing weight loss) by approximately one-half (RR 0.52 [95% CI 0.39 to 0.68]; 18 trials, 1470 participants, moderate-quality evidence). Diluted lactose-containing milk has not been shown to reduce the duration of diarrhea compared with undiluted milk or milk products (five trials, 417 participants, low-quality evidence), but may reduce the risk of treatment failure (RR 0.65 [95% CI 0.45 to 0.94]; nine trials, 687 participants, low-quality evidence). Conclusions In young children with acute diarrhea who are not predominantly breast-fed, a change to a lactose-free diet may result in earlier resolution of acute diarrhea and reduce treatment failure. Diluting lactose-containing formulas may also have some benefits; however, further trials are required to confirm this finding. There are no trials from low-income countries, where mortality for diarrhea is high and malnutrition is more common. The full text of the Cochrane Review is available in The Cochrane Library (1).