Do colicky infants show an improvement when breastfeeding mothers follow a low-allergen diet, or when formula-fed infants are fed a special formula?
Infantile colic is a common problem afflicting otherwise healthy infants in the first three months of life. It is characterised by episodes of inconsolable crying lasting for longer than three hours per day, for more than three days a week, for at least three weeks.
It can be very distressing for parents.
Dietary changes, such as removing cows' milk from a breastfeeding mother's diet or switching formula-fed babies to a special soy-based formula, might reduce the symptoms of colic.
We found 15 randomised controlled trials, a type of study in which participants are randomly assigned to one of two or more treatment groups, involving a total of 1121 babies with colic. The evidence is current to July 2018.
Infants (balanced between boys and girls) were less than three months of age.
Most studies reported data on a combination of outcomes: duration of crying, number of responders in each group after treatment (i.e. those who experienced a decrease in daily crying), or frequency of crying episodes. No study reported on parental or family quality of life, infant sleep or parental satisfaction. Six studies reported that there were no side effects as a result of the dietary changes.
One study (90 infants) found that more breastfed infants responded to a low-allergen maternal diet than infants on a standard diet containing known potential allergens.
One study (120 infants) found little difference in breastfed infants whose mothers were given a low-allergen diet (10/16, 62.5%) and formula-fed babies who were given soy milk (29/44, 65.9%), but the researchers did find that breastfed babies responded more to dicyclomine hydrochloride (a tablet for treating stomach spasms) than formula-fed babies.
Hydrolysed formula milk
Two studies (64 infants) found no difference in duration of crying between the hydrolysed (hypoallergenic) and standard cow's milk groups. Of these, one study (43 infants) reported a greater reduction in crying time at study end in infants who were given hydrolysed milk.
A third study (22 infants) found that two types of hydrolysed formulas were equally effective in resolving symptoms of colic for babies started on standard formula.
A fourth study (21 infants) reported that infants whose parents were given information and support experienced a more rapid reduction in crying time than infants who were given a hydrolysed formula or dairy- and soy-free diet (within nine days).
A fifth study (267 infants) found that both partially hydrolysed formula with oligosaccharides (carbohydrates) and a standard formula with simethicone (a drug for treating symptoms of gas) reduced colic episodes after seven days, but effects were greater in the hydrolysed plus oligosaccharides group after two weeks.
Lactase enzyme supplementation
Three studies (138 infants) tested the effect of adding lactase (an enzyme which helps break down the lactose (sugar) in milk) to the infants' milk. The results were not presented in a form to allow analysis.
Fennel, chamomile and lemon balm extract
One study (93 infants) found that average daily crying time in breastfed babies reduced within one week of treatment with a fennel, chamomile and lemon balm extract.
Soy protein-based formula
One study (19 infants) found that, compared with cows' milk formula, soy formula reduced crying time and increased the number of responders. However, international guidance does not support the use of soy milk due to concerns that they can impact hormones in babies, so these results are not relevant.
One study (27 infants) compared soy formula plus polysaccharide (carbohydrate) with soy formula alone but did not present results in a form we could analyse.
Quality of the evidence
Many of the studies included only small numbers of participants and were of poor quality. We did not find evidence of effectiveness for most dietary interventions. Where studies did report some benefit, this was not large enough to be meaningful.
Based on the available evidence, we are not able to recommend any of the dietary modifications assessed in this review.
Currently, evidence of the effectiveness of dietary modifications for the treatment of infantile colic is sparse and at significant risk of bias. The few available studies had small sample sizes, and most had serious limitations. There were insufficient studies, thus limiting the use of meta-analysis. Benefits reported for hydrolysed formulas were inconsistent.
Based on available evidence, we are unable to recommend any intervention. Future studies of single interventions, using clinically significant outcome measures, and appropriate design and power are needed.
Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. This condition appears to be more frequent in the first six weeks of life (prevalence range of 17% to 25%), depending on the specific location reported and definitions used, and it usually resolves by three months of age. The aetiopathogenesis of infantile colic is unclear but most likely multifactorial. A number of psychological, behavioural and biological components (food hypersensitivity, allergy or both; gut microflora and dysmotility) are thought to contribute to its manifestation. The role of diet as a component in infantile colic remains controversial.
To assess the effects of dietary modifications for reducing colic in infants less than four months of age.
In July 2018 we searched CENTRAL, MEDLINE, Embase , 17 other databases and 2 trials registers. We also searched Google, checked and handsearched references and contacted study authors.
Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of dietary modifications, alone or in combination, for colicky infants younger than four months of age versus another intervention or placebo. We used specific definitions for colic, age of onset and the methods for performing the intervention. We defined 'modified diet' as any diet altered to include or exclude certain components.
We used standard methodological procedures expected by Cochrane. Our primary outcome was duration of crying, and secondary outcomes were response to intervention, frequency of crying episodes, parental/family quality of life, infant sleep duration, parental satisfaction and adverse effects.
We included 15 RCTs involving 1121 infants (balanced numbers of boys and girls) aged 2 to 16 weeks. All studies were small and at high risk of bias across multiple design factors (e.g. selection, attrition). The studies covered a wide range of dietary interventions, and there was limited scope for meta-analysis. Using the GRADE approach, we assessed the quality of the evidence as very low.
Low-allergen maternal diet versus a diet containing known potential allergens: one study (90 infants) found that 35/47 (74%) of infants responded to a low-allergen maternal diet, compared with 16/43 (37%) of infants on a diet containing known potential allergens.
Low-allergen diet or soy milk formula versus dicyclomine hydrochloride: one study (120 infants) found that 10/15 (66.6%) breastfed babies responded to dicyclomine hydrochloride, compared with 24/45 (53.3%) formula-fed babies. There was little difference in response between breastfed babies whose mother changed their diet (10/16; 62.5%) and babies who received soy milk formula (29/44; 65.9%).
Hydrolysed formula versus standard formula: two studies (64 infants) found no difference in duration of crying, reported as a dichotomous outcome: risk ratio 2.03, 95% confidence interval (CI) 0.81 to 5.10; very low-quality evidence. The author of one study confirmed there were no adverse effects. One study (43 infants) reported a greater reduction in crying time postintervention with hydrolysed formula (104 min/d, 95% CI 55 to 155) than with standard formula (3 min/d, 95% CI −63 to 67).
Hydrolysed formula versus another hydrolysed formula: one study (22 infants) found that two types of hydrolysed formula were equally effective in resolving symptoms for babies who commenced with standard formula (Alimentum reduced crying to 2.21 h/d (standard deviation (SD) 0.40) and Nutramigen to 2.93 h/d (SD 0.70)).
Hydrolysed formula or dairy- and soy-free maternal diet versus addition of parental education or counselling: one study (21 infants) found that crying time decreased to 2.03 h/d (SD 1.03) in the hydrolysed or dairy- and soy-free group compared with 1.08 h/d (SD 0.7) in the parent education or counselling group, nine days into the intervention.
Partially hydrolysed, lower lactose, whey-based formulae containing oligosaccharide versus standard formula with simethicone: one study (267 infants) found that both groups experienced a decrease in colic episodes (secondary outcome) after seven days (partially hydrolysed formula: from 5.99 episodes (SD 1.84) to 2.47 episodes (SD 1.94); standard formula: from 5.41 episodes (SD 1.88) to 3.72 episodes (SD 1.98)). After two weeks the difference between the two groups was significant (partially hydrolysed: 1.76 episodes (SD 1.60); standard formula: 3.32 episodes (SD 2.06)). The study author confirmed there were no adverse effects.
Lactase enzyme supplementation versus placebo: three studies (138 infants) assessed this comparison, but none reported data amenable to analysis for any outcome. There were no adverse effects in any of the studies.
Extract of Foeniculum vulgare, Matricariae recutita, and Melissa officinalis versus placebo: one study (93 infants) found that average daily crying time was lower for infants given the extract (76.9 min/d (SD 23.5), than infants given placebo (169.9 min/d (SD 23.1), at the end of the one-week study. There were no adverse effects.
Soy protein-based formula versus standard cows' milk protein-based formula: one study (19 infants) reported a mean crying time of 12.7 h/week (SD 16.4) in the soy formula group versus 17.3 h/week (SD 6.9) in the standard cows' milk group, and that 5/10 (50%) responded in the soy formula group versus 0/9 (0%) in the standard cows' milk group.
Soy protein formula with polysaccharide versus standard soy protein formula: one study (27 infants) assessed this comparison but did not provide disaggregated data for the number of responders in each group after treatment.
No study reported on our secondary outcomes of parental or family quality of life, infant sleep duration per 24 h, or parental satisfaction.