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. We present these findings below. 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.
Another 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
One study (43 infants) found no clear difference in resolving symptoms of colic between the hydrolysed (hypoallergenic) and standard cow's milk groups. They also reported a greater reduction in crying time at study end in infants who were given hydrolysed, and reported no adverse effects.
A third 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 fourth 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. The study author confirmed there were no adverse effects.
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. There were no adverse effects in any of the studies.
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. There were no adverse effects.
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.
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, making the use of meta-analysis unfeasable. 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. Colic 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 usually resolves by three months. 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 it. 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 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 Cochrane methodological procedures. 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 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 no scope for meta-analysis. Using GRADE, we assessed the quality of the evidence as very low.
No study reported on parental or family quality of life, infant sleep duration per 24 h, or parental satisfaction.
Low-allergen maternal diet versus a diet containing potential allergens: one study (90 infants) found that 35/47 (74%) of infants responded (reduction in cry/fuss duration of 25%) to a low-allergen maternal diet, compared with 16/43 (37%) of infants with a maternal diet containing potential allergens (37% difference; 95% confidence interval (CI) 18 to 56; P < 0.001).
Low-allergen diet or soy milk formula versus standard diet or cow's milk formula and dicyclomine hydrochloride: one study (120 infants) found that 10/15 (66.6%) breastfed babies responded to dicyclomine hydrochloride and a normal diet, compared with 10/16 (62.5%) on a low-allergen diet, while 24/45 (53.3%) standard formula-fed babies taking dicyclomine hydrochloride improved compared with 29/44 (65.9%) on soy milk formula. Response was defined as a reduction of crying to less than one hour per day after 48 hours of treatment, with remission persisting for one month.
Hydrolysed formula versus standard formula: one study (43 infants) reported that the number of infants who responded to the intervention (cried for less than 3 hours per day on at least 3 days a week) was 8/23 in the whey hydrolysate group versus 5/20 in the standard formula group (χ2 using yate's correction = 0.20, P = 0.65).
The same 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); difference = 101 min/d, 95% CI 25 to 179; P = 0.02).
The author confirmed there were no adverse effects.
Hydrolysed formula or dairy- and soy-free maternal diet versus standard diet/formula and 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 maternal diet group compared with 1.08 h/d (SD 0.7) in the parent education or counselling group, nine days postintervention.
Partially hydrolysed, lower lactose, whey-based formulae containing oligosaccharide versus standard formula with simethicone: one study (267 infants) found both groups experienced decreased colic episodes 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)); 95% CI 95% −0.7 to −1.8; P < 0.001). This difference was significant after two weeks (partially hydrolysed: 1.76 episodes (SD 1.60); standard formula: 3.32 episodes (SD 2.06); P < 0.001). The study author confirmed there were no adverse effects.
Lactase enzyme supplementation versus placebo: three studies (138 infants) assessed this comparison, but they are cross-over trials that did not report data from before washout. 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 (95% CI −102.89 to −83.11; P < 0.01). 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 cross-over study (27 infants) assessed this comparison but did not provide disaggregated data for the pre-wash-out data.