Don’t give your baby solids until 6 months of age. This is the unambiguous advice of the world’s most highly regard medical organizations, including the American Academy of Pediatrics, the UK’s National Health Service, and the World Health Organization.
Ignore the “mistaken” belief that introducing solids earlier will help your baby sleep better. Early solids could have the opposite effect, worsening your baby’s sleep, according to popular parenting sites like Kelly Mom and the Baby Sleep Site.
Or so we have been told.
It turns out that the claim that solids don’t help baby sleep was based upon the shoddiest of studies–small, non-randomized, poorly controlled–like this one, which simply looked at whether babies were eating solids and how well they slept.
(To be clear–I am not trying to knock this research as research. Small exploratory studies can be very useful for hypothesis generation and deciding on which large studies to run, but the stuff of sound public health pronouncements they are not.)
Now, we finally have much better data, from a randomized trial of over a thousand babies. And surprise, surprise, your mum (or in my case, my mother in law) was right all along: Introducing solids early, at around 3 to 4 months, does improve babies’ sleep. Not just then, but for their entire first year.
The new study is a secondary analysis of the UK-based Enquiring About Tolerance (EAT) randomized clinical trial, a trial whose main goal was to assess whether early solids lowered the risk of food allergy.
In the trial, researchers randomly assigned 1,303 exclusively breastfed infants to either begin solids at three months (the experimental group) or at around 6 months of age (the control group).
Parents in the experimental group began feeding their babies solids at around 3 months of age, with specific instructions to expose them to six common food allergens (eggs, peanuts, white fish, cow’s milk, wheat, and sesame seeds).
The randomization was highly successful. Nearly all babies in the early introduction group began taking in solids by 4 months of age, whereas almost none of the control babies started solids until after 5 months of age. Notably, nearly all these babies continued to be breastfed, almost none received formula.
Although the EAT trial’s original purpose was to determine if early solids would help prevent food allergies, the study also carefully assessed the babies sleep. Each month, parents reported how long their babies slept at night, how often they awoke at night, and if they felt their babies had mild or severe sleep problems. They also described where their baby slept and how they put their babies to sleep.
Thus, this study represents the largest, carefully constructed randomized trial of how solids affect infant sleep ever performed.
So what did they find?
Babies who received solids early, starting around 3 to 4 months, slept better than controls. They slept a tiny bit longer each night during their first year of life (an average of 6-7 minutes overall, with the biggest difference–17 minutes longer each night–seen at 6 months of age). They were also about 10% less likely to wake up at night. So good, but not really much to write home about.
Where early solids packed the biggest punch, however, was in preventing sleep problems. While only a small percentage of babies had sleep problems (fewer than 5% overall), control babies were much more likely to be problematic sleepers.
As shown in the graph below, severe sleep peaked at around 9 months, and then dropped off sharply at a year (good news for many a bleary-eyed sleep beleaguered parent).
Most strikingly, parents of early introduction babies were far less likely to say their babies had mild or severe sleep problems throughout their first year of life–long after the controls were also taking in solids. It appears that early solids helped babies consolidate their nighttime sleep earlier, and this benefit persists throughout infancy.
This latter point was surprising to me, but appears well supported. In fact, the more solids experimental babies ate earlier, the better they slept. (This was a follow-on analysis, and not randomized, but it does lend further support to their main findings.)
The Bottom Line
So, does this study mean we should all give our babies solids early to help them–and us, let’s not forget us!–sleep better?
By itself, probably not. The effects on sleep are pretty small, overall, (6-7 minutes extra sleep a night; about one less night awakening a week). And before we run completely in the opposite direction and overinterpret these findings, I would really love to see at least one other randomized trial examine the same question.
And we need to note that the babies who slept best in this study (as we already know) were not co-sleeping, slept in their own rooms, and went to sleep by themselves, without parental assistance. These practices had a much bigger impact than solids on baby sleep and remain the foundation for helping your baby sleep well.
That said, let’s step back a second and consider the larger context. Many studies now suggest early solids lower the risk of allergies. This is why many medical organizations that focus specifically on allergies recommend starting solids earlier (4-6 months) than their umbrella counterparts (6 months)–creating schizophrenic, headache-inducing advice for well-meaning parents.
For me personally, speaking as a parent, I would look at these findings and choose to start giving my baby solids at around 4 months of age.
(Introducing peanuts early lowers the risk of peanut allergies. Although the EAT trial did not actually show significantly lower risk of food allergies, there was a trend in that direction.)
As I have written about earlier, the recommendation to breastfeed exclusively for 6 months really only makes sense for women living in developing countries, where access to clean water and safe food sources can be limited. There are no demonstrated benefits for women living in developed countries like the US and the UK. It’s past time for medical organizations to reconsider this misguided blanket advice.