How often does science say you should sterilize baby bottles?

I cook bottles forever. My wife and I have a new baby, and we make “mixed” formulas – some from the breast, others from the bottle. And if you’re a bottle feeder, you’ll soon learn all about the need to sterilize bottles.

The NHS clearly states:

“It’s important to sterilize all your baby’s feeding supplies, including bottles and nipples, until he’s at least 12 months old.”

And so with every feeding. The idea is that a child’s immune system is still developing, making it especially vulnerable to germs that cause diarrhea and vomiting. Therefore, you should not only wash the bottles they eat from with soap and water, but also sterilize them to kill as many bacteria as possible.

You can do this by boiling the bottles in water for 10 minutes, leaving them in a container of sterilizing solution for a while, or using one of the many different steam sterilization products on the market.

And since newborns can eat eight or more times a day, do the following: a lot of.

But how necessary is it really? Late one night, as I stood in the kitchen with tears in my eyes, watching the bottles swirl in the microwave sterilizer, it occurred to me to see if there was evidence of what I was doing.

The first thing that came to my mind was to ask what another recommend countries. One of the most notable things you’ll notice while pregnant is that advice on what to do and eat varies greatly from country to country: sushi, for example, is banned during pregnancy in the UK and the US, but is absolutely normal. even healthy ones are for pregnant women in Japan.

The same applies to bottle sterilization. While the Irish and Australian government websites give the same advice as the NHS, recommending sterilization after every feeding for 12 months, the New Zealand government says you only need to sterilize bottles for the first six months, after which “Wash thoroughly and rinse adequately.” “. . “. On the other hand, the government of Alberta in Canada states that sterilization must continue for four months.

In the US, the rules are different. The Centers for Disease Control and Prevention website recommends sterilizing bottles only the first time. two Months or longer if your child has an illness that weakens their immune system. And even then, it’s best to only do it once a day, rather than after every use. Texas Children’s Hospital goes even further: they recommend sterilizing bottles only once, when you first buy them, and then not worrying about it again.

The French Ministry of Health is taking the final step, pointing out that “there is no need to sterilize bottles and teats as recommended in the past.”

All these disparate councils from different countries have one thing in common: they do not quote every scientific sources supporting their recommendations. All but one are just plain rude – only Canadian rules recognize that there is no evidence to point to.

But it must be some research there? I looked and was surprised to find it horrible lean crop. The scientific literature was last reviewed in 2008; They found a “lack of high-quality evidence” for the most effective bottle washing methods.

There are several studies where samples of used bottles were taken to a lab to check their level of contamination. Probably the most comprehensive, from 2009, found that bacteria most likely live in the nooks and crannies of bottle rims and screw caps, and this is the place Were less bacteria on steam sterilized bottles. However, they also noted that touching the bottles while they are out of the sterilizer will only add more bacteria, and also that steam sterilization can “bake” the remaining parts if the bottles were not washed properly. Milk on it, which provides a special hotbed for bacterial growth. You really can’t win.

The most recent current study from 2019 found that bacteria can be transferred from a person’s hand to the scoop they use to pour powdered infant formula into a bottle. However, this would mean that handwashing is really important, just like when preparing food.

These studies of bacteria left on bottles are very good, but they don’t tell us what we’re doing. Real wants to know, namely: How important are different cleaning methods for the health of our children? There is almost no evidence for this.

I could only find three studies that compared the health of babies whose bottles were sterilized and those who were not. The first was published in 1974 – it included only 26 infants and is so old that it can be practically ignored (it found no difference in incidence rates). The second dated 1987, in which 284 infants took part, and found no difference in gastroenteritis when comparing those who were neutered and those who were not neutered.

A third study, published in 2006, used data from England in the 1990s and found that the incidence of diarrhea was higher in children fed from non-sterile bottles. But only a small number of study participants (39) were not spayed, leading to huge uncertainty in the results. They also found that children older than 6 months had no effect. And it wasn’t a randomized experiment, which means other factors – perhaps the parents, who were generally more careless, forgot to sterilize the bottles. AND making their children less healthy in other ways, such as for example, the result may be due to not washing your hands.

As far as I’ve been able to determine after much searching, no one has continued this study – there are no other studies examining at what age sterilization is important or not; and there are no studies (at least not in the public domain) testing which of the various sterilization methods or devices work best.

Isn’t it wonderful? It’s a common health advice that affects the health of the most vulnerable of us newborns, and scientists seem to have little interest in revising it.

In the absence of adequate studies, we could use an even rougher analysis: we could look at the infant mortality rates in each country. If some countries take much less care of their babies – and if sterilizing baby bottles is so important in the first few months of life – perhaps we could see it in these dismal statistics. At first glance, you might think that the looser rules in the US could contribute to a much higher infant mortality rate in this country than in the UK, where we have much stricter rules. But in France, where it is recommended not to sterilize bottles at all, it is basically the same (albeit slightly lower) as ours. We cannot draw any real conclusions from this kind of data.

Can we draw conclusions about bottle sterilization in the absence of much evidence? It makes sense to take extra care when washing bottles during the first few months when your baby’s immune system is at its weakest. Some even more careful people can go even further and also spay. But advice from the NHS that recommends continuing to sterilize bottles at every feed for at least a year, after your baby has been crawling on the floor, playing with your pets and who knows what foreign objects have been put in their mouth… works ridiculous exaggerated. This is yet another burden for already stressed parents – and as we have seen, there is actually no scientific evidence to back this up.

Of course, there is a lot of speculation here. That I even ask this question – and not alone has provided That sterilization is a good idea because we live in a country with clean drinking water. This has not always been the case: as noted in the French guidelines we saw above, the quality of the water was not as good “in the old days”, so it would be wiser to make every effort to sterilize the bottles. Now that we can be sure that the water is pure, for the neurotic among us, sterilization is something of a rarity rather than a requirement.

But in many other countries, especially developing ones, water quality is far from guaranteed. You may remember the Boycott Nestlé campaign that began in the late 1970s and continues to this day. The argument was that the food company was marketing its infant formula in those parts of the world with very poor water quality, discouraging breastfeeding and putting children at risk of contracting waterborne diseases. As valid as the argument was then (or now) specifically for Nestlé, the point about water quality is good: in low-income countries, there is strong evidence that improving water quality (using methods such as chlorination) reduces the number of babies. maybe mortality.

For those of us who are lucky enough to live in countries with good water quality and where we remember to wash our hands before making a baby bottle, this seems like too much of a step to worry about sterilization after the first few months. As for me, in a few months I will try to focus on some of the millions of other things that I need to take care of as a new parent – and put the bottle sterilizer aside.