The media had fun this week with a study that told us:
"The early introduction of solids resulted in small but significant improvements in infant sleep characteristics."Not "changes" to infant sleep, but "improvements". A "making better" of.
Or in this case, a change reported as an improvement because of author bias that longer = better.
Human infants rouse and signal frequently when close to their caregivers. As I cover in my book, there's a whole host of reasons they do this, yet things can interfere with or even stop this normal communication entirely. As an example (and as this study confirms) the further away from their parents babies are, the less they signal. This is precisely why "baby tamers" are always keen to get baby in their own room despite safety guidelines.
These behaviours are assumed to be desirable by the study authors, because it results in a longer sleep stretch for caregivers and result in them feeling their baby is more "normal".
Attempting to manipulate and shift infant sleep patterns to be more like those of an adult and thus more convenient for parents isn't new, in fact it sells very well.
Whether it's comfort blankets (although nowadays we prefer to call them "transitional objects") to "condition" a baby to accept cloth over a caregiver, or cry it out so the baby realises signalling is futile - it's considered entirely normal in Western society. As such we like to pretend there are no consequences or cost to the infant of doing so.
In biological terms if we explore animals generally, the more mammals "signal" - the healthier they and their relationship with their caregivers is considered to be. As with anything, when we intervene to shift away from the biological norm- we have the potential for both risks and benefits.
If we examine the risk and rates of SIDS, studies show us that not hitting deep sleep levels and retaining the the ability to rouse and signal is the best protection infants under 6 months have. We know for example some studies find non-breastfed infants are less rousable, whilst others also link not breastfeeding an increased risk of SIDS, when compared to those who are mix-fed or exclusively breastfed.
What impact does introducing solids and reducing arousal ability further, have on SIDS?
It would seem prudent to ask given the authors note:
"Following the early introduction of solids, infants in the EIG slept significantly longer and woke significantly less frequently than infants in the SIG."Although this effect was only visible in babies around 5/6 months (despite some having food from 3), what impact does introducing solids before readiness have on rates of infection, longer term microbiome and overall health?
They didn't explore that either.
The "significant" change referenced is an average of 15 minutes total sleep in these older babies - which let's be honest, in knackered parent land is but a snifter.
As was highlighted on Twitter, it would take longer than this to give the food and deal with the solid poop that comes with it. Yet authors noted 10% fewer arousals, which is huge in terms of a shift from the biological norm.
What also isn't clear from reading the media coverage is the data is from "parental questionnaires".
Here tired new parent who barely has time to shower and eat some days, pick the baby sick from your hair and accurately recall your baby's sleep for the last week please. Make sure you're entirely honest about how much breast and formula you're giving too (rather than putting what you think we want to hear or what you'd rather be doing); after all your answers are going to influence the nation!
Seriously? Researchers have already established that this isn't a reliable method of data collection.
Although the study authors don't acknowledge this, they do comment:
"The commonly held belief that introducing solids early will help infants sleep better could have produced a reporting bias. Mothers, anticipating improved infant sleep, could have reported better outcomes."Ya think?
Given we have numerous studies highlighting babies can and do reach for food and start eating when ready and that there are risks before this time, why are researchers even going there with sleep?
A quick glance and no conflict of interest is disclosed. So I dug a little deeper:
First - you'll recognise the names from the EAT study:
Professor Gideon Lack states on his bio that he receives "Personal remuneration: Lectures (SHS Nutricia, Nestle, SHS International)"
Dr Michael Perkin says he receives "Personal remuneration: Lecture (SHS Nutricia)"
Next I checked out the author associations:
"The Population Health Research Institute, St George's, University of London, London, England."
I dug out their financial statement which outlines that they've received grants from a number of people including the "Wellcome Trust". A quick click later and we can see the Wellcome Trust's financial statement shows they own profitable shares in Nestle...
A cynic might propose parents may not be the only ones with a bias, but when has that ever stood in the way of a good headline?