I'm not sure why this study from 7 years ago is being dug up because it's not a particularly good, interesting, or definitive study. Some problems with it:
1. Small sample sizes.
2. Significance was only found in one subset of the population. Given enough ways to divide up groups of people, you will almost always get false positives.
3. Not an experimental design.
4. The study did not control for simple factors like income or the health of the parent.
Our study also helps provide a framework for future mechanistic studies on
I realize that repeat studies are important generally in science. But, many studies (particularly health related) seem to have such a result built into their design. If you get a result, it will just be preliminary and require a larger sample study moving on.
Is there a mechanism in science for actually taking these preliminary results and validating/falsifying them more conclusively? Does a result like this make a larger scale study this team's top priority for the next study? Will these results convince another team to do the full study?
Otherwise, it feels like there's something structurally wrong. If the study is designed as a non-conclusive prototype or framework, what's the point unless it leads to other studies?
I agree this is a weak, small study but I'm not sure I agree with your point 4. Obviously this all depends on having a large-enough sample size to start with, but if the groups are properly randomized they shouldn't have to control for income/health of parents (since it's not correlated with the independent variable).
As a recent parent I would love it if there was more realistic health information for parents about the benefits of breastfeeding. As best I can tell from metastudies (which I'm totally unqualified to read), the scientific answer right now is: there may be some effect, but if so it's too small to reliably measure and may be swamped by other interventions. (I could be wrong! That's why I want better info.)
(Compare to, say, the advice to have infants sleep on their backs to prevent SIDS, or the HPV vaccine, which have clear and measurable health impacts at a population level.)
This matters because breastfeeding has costs that tend to be ignored. Just from personal experience, it pushes disproportionate work onto my wife in a way that's hard to correct for and detracts from parenting. And given that she's working full time, it's also a huge investment of resources -- if you take her work time into account, we're spending tens or hundreds of dollars a day for this. And many women get injuries and infections, soldiering through months of agony for that health benefit that may or may not exist.
Setting aside the health of the parents (and we shouldn't, that's an easy trap), breastfeeding uses a lot of resources that could go toward other interventions for the child. Maybe it's all worth it? But I wish there was a better conversation about the tradeoffs.
Yeah, breastfeeding can take 4-6 hours a day. It's no simple thing. And if the mother is working, it's hard. Even pumping milk takes time.
Women who can afford to breastfeed exclusively are at least middle class, usually upper-middle class. That comes with a whole set of advantages and other correlations. Studies that try to figure out breast feeding advantages have to try and control for these things, but it's hard.
Here's what we know for sure: Breast feeding reduces infections in the child. It's a small, but detectable amount. And I do mean a small amount. Between six mothers that exclusively breast feed an infant for six months, on average one of those children will have one fewer infection during that time.
Everything else is up in the air, and if it has an effect on anything else (like intelligence) it's tiny. Save your energy for reading to the child and playing games with them, which definitely helps intelligence.
My wife and I looked very carefully into this, and we came to the same conclusion.[1] We decided that the very real costs were not worth the tenuous benefits.
Deciding to bottle feed made life way easier. My wife has trouble getting to sleep, while I can fall asleep in economy class on a 90 minute flight even before taking off. Our daughter woke up every 3 hours like clockwork for more than a year. My wife would've gone crazy if she was the one who was charged with feedings.
Medical professionals are socialized to always err on the safe side. No doctor or nurse ever got fired for scheduling an MRI or CAT scan "just to be safe." They approach breastfeeding the same way--the studies are inconclusive, so just do it to be safe.
[1] Like every engineer, I feel totally qualified to opine on scientific studies regardless of the field.
You are talking about breastfeeding. The article talks about breast milk. In the case the distinction is not clear, many mothers use breast pumps.
>WHO can now say with full confidence that breastfeeding reduces child mortality and has health benefits that extend into adulthood. On a population basis, exclusive breastfeeding for the first six months of life is the recommended way of feeding infants, followed by continued breastfeeding with appropriate complementary foods for up to two years or beyond.
Moreover this study, plus others, have suggested a strong relation on IQ and breastfeeding (this study 8 IQ points, one cited by 23-and-me is 7 points per copy of a certain gene 0-14 points).
My wife is a pediatrician who recently wrote a letter to the Washington Post about this. While she routinely recommends breast feeding, she pointed out that the many costs, or even just personal preference, can justify formula instead. For instance, maternal stress alone probably has a big impact on child welfare. As a result, the weird undercurrent of shame for mothers who don't breastfeed is unwarranted. She sees mothers who are brought to tears because they can't breast feed, when in reality it shouldn't be a big deal, even if it's just a personal choice.
It's barely worth it. There is a marginal improvement from breast milk but it's not strong enough to justify the level of breast milk promotion over formula.
This study does not control for maternal IQ or socio-economic status. Later studies show that much of the link between breastfeeding and cognitive development is due to confounding effects (in particular, higher SES mothers are more likely to breastfeed): http://bmjopen.bmj.com/content/3/8/e003259
> Conclusions Much of the reported effect of breastfeeding on child neurodevelopment is due to confounding. It is unlikely that additional work will change the current synthesis. Future studies should attempt to rigorously control for all important confounders. Alternatively, study designs using sibling cohorts discordant for breastfeeding may yield more robust conclusions.
> RESULTS: Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children’s hyperactivity (difference score, –0.84; 95% confidence interval, –1.33 to –0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years.
The linked study also yields some odd results:
> In the total group %EBM correlated significantly with Verbal IQ (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with grey matter.
A meta-study that adjusted for maternal IQ only (but not socioeconomic status, which independently correlates with higher rates of breastfeeding) found a very small effect on IQ: https://www.ncbi.nlm.nih.gov/pubmed/26211556
> We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model, breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression, none of the study characteristics explained the heterogeneity among the studies.
There are at this time 112 comments on this page. I searched for "emotion" and got zero hits, and only one comment mentioned "bonding." A problem with any scientific assessment of the human condition is the narrow focus, and these studies only take into account a few variables out of thousands.
Emotional bonding between mother and child is a huge factor in breastfeeding -- that's common sense that doesn't require scientific validation, although it would be very interesting to see studies from that perspective.
I'd call it handwaving rather than common sense. What does emotional bonding even mean? Are bottle fed children more emotionally distant and less clingy? Remember: in the 1970s, only 25% of children were ever breastfed. Are Gen X-ers emotionally distant compared to boomers and millenials?
Parents that bottle feed (bm or formula) can still bond with their babies. I exclusively pump, and it made me really happy to see that my male partner was able to feed the baby and do a lot of skin-to-skin/holding time in the early days. I love cuddling with my kid too. Bottle didn't change that at all.
What's amazing is that people even feel the need to study whether breastmilk is superior to processed alternatives -- would a zoologist ever recommend baby mammals receive any food other than their mother's milk to facilitate optimal development? Why do humans think they're any different?
Sorry, this comes across as ... really ignorant. Of course there is a need. Some people have to make the decision whether to breast feed or not (e.g. because of medication the mother is taking) and ideally they need this kind of information to make an informed decision.
would a zoologist ever recommend baby mammals receive any food other than their mother's milk to facilitate optimal development?
Why, yes. I'm not a zoologist, but I know giving a replacement milk is the best solution when the mother either is absent for whatever reason, cannot produce milk, or cannot produce enough quality milk. This is why we have milk for infant cats and dogs, actually. Otherwise, the animal would die. There is a similar nutrition for birds (as they don't produce milk) and it is common for folks to buy pigmy goats as an infant and bottle feed them.
Why do humans think they're any different?
We don't. Replacement breast milk saved lives, and these sorts of issues were the original use of infant formula. When applied to current society, it still saves lives and helps to keep folks from financial ruin because some countries (like the US) don't really give mothers time off work to properly breast feed, and it is usually difficult to pump milk at work. At some point while pumping, people usually have to supplement formula as well. As a side note, I was one of the babies that would have died without a wet nurse, as my mother had gall bladder surgery before I was 6 weeks old (fairly major surgery in '78) and could not breast feed.
"What's amazing is that people even feel the need to study whether breastmilk is superior to processed alternatives "
Well it would be great to know just if they're different at all. You seem to think it's 'obvious' that breastmilk is always better; I don't see a logical reason to think so, or at least not so strong that it shouldn't be studied.
Yes, the research does show that breastmilk is better. My wife nursed our children until they were 15 and 18 months old, respectively. I'm not some pro-formula-campaigner. But I don't see any reason for naturalistic fallacy-based reasoning, either.
The truth isn't obvious. In the 1930s, 1940s, 1950s, it was 'obvious' to many people including doctors that bottle feeding with evaporated milk or formula milk was more scientific, more hygienic, and better all round.
>By the 1940s and 1950s, physicians and consumers regarded the use of formula as a well known, popular, and safe substitute for breastmilk. Consequently, breastfeeding experienced a steady decline until the 1970s (Fomon, 2001)
Evolution primarily serves the population, not the individual. Mother cats reject their runts, for instance. That's bad for the kitten - kills it but benefits the rest of them.
We tend to care about the individual more than the population, so we treat sick children instead of letting them die. Since nature isn't always helping, maybe natural food isn't always the best option.
Nature "learns" by trial and error while humans have the capacity to reason about things. In the long run intellect will win (although in most cases we are far far from that point).
Breastfeeding makes it harder for women to escape traditional gender roles at home (dads can get up in the middle of the night to feed the baby a bottle, but can't breastfeed; pumping isn't much easier than just breastfeeding). It also makes it more difficult when mothers return to work. It's also just inconvenient and unpleasant for a lot of women.
Obviously, before anyone makes that sacrifice, it makes a lot of sense to study whether it has any corresponding benefits.
Legs are natures' intended way to get around. I don't get why people even wonder if processed alternatives like cars or bikes might be superior to running.
Even if you take it as a given that it has a positive impact, it's useful to study to better understand the scale of the impact. When evaluating multiple interventions and not having the resources to do all of them, it's useful for policy makers to better understand the cost/benefit analysis and make informed decisions.
We shouldn't do it because we already know? How do we already know, based on what?
We don't know what a Zoologist might recommend in 10 years when new results are found from studies like these. That's exactly why studies like this are done, so we all learn.
Surely it depends on the health and diet of the mother. My understanding is that there is little benefit to breast milk over formula unless water supplies are poor quality and definitely formula is better when the mother is malnourished.
Some people choose not to breastfeed because it is a pain in the butt (or, rather, pain in the breast). If they are educated on why breast milk is a better choice then more people will choose to breast feed.
Why would it matter what a zoologist recommends? Do they have evidence to back up their recommendation or are they just guessing? That's all that matters.
It's funny to me that everyone shits on Soylent and how obviously bad it is and yet needs a PhD to figure out if they should breastfeed instead of giving their newborn "formula". Have any of you looked at the ingredients in formula? It's garbage.
Even George Costanza knows it's okay to eat garbage if it's on top.~
People in general are way too picky about what they shove down their gullets. It's just chemicals, and the chemicals in formula are close enough to natural milk that it won't kill fragile human babies. Likewise, the chemicals in Soylent are close enough to food that you can quaff it in lieu of eating.
The only problem is determining which chemicals are actually important, which is somewhat difficult, because yadda yadda yadda unethical human experimentation....
But that wire-mom vs. cloth-mom monkey experiment should also suggest that there's more to breastfeeding than just nutrition.
Sightly offtopic, but recent or prospective parents on HN may appreciate the book "Expecting Better" by Emily Oster, which takes a critical economists eye to advice and studies about pregnancy. Sort of in the vein of Freakonomics.
Apart from claims of positive IQ impact, breastfeeding has many other proven benefits (as widely reported by WHO and in Sweden): "Breastfed children are at a lower risk of infections such as acute otitis, gastroenteritis, and respiratory tract infections. ... Women who have breastfed also receive health benefits through a somewhat reduced risk of developing breast and ovarian cancer and diabetes type 2."
to all expectant mothers nervous about whether you should breast feed or not, it's definitely a huge and important decision, so i have devised an experiment you can undertake right now to try to gather more data so you can make an informed decision.
ask your husband* to suck your nipple then gauge reaction, offer a favorite bottle as an alternative just to be sure.
[+] [-] c3534l|8 years ago|reply
1. Small sample sizes.
2. Significance was only found in one subset of the population. Given enough ways to divide up groups of people, you will almost always get false positives.
3. Not an experimental design.
4. The study did not control for simple factors like income or the health of the parent.
[+] [-] petters|8 years ago|reply
That is not fair. You're making it sound like it's a JS framework.
Seven years is nothing in this case.
[+] [-] dalbasal|8 years ago|reply
I realize that repeat studies are important generally in science. But, many studies (particularly health related) seem to have such a result built into their design. If you get a result, it will just be preliminary and require a larger sample study moving on.
Is there a mechanism in science for actually taking these preliminary results and validating/falsifying them more conclusively? Does a result like this make a larger scale study this team's top priority for the next study? Will these results convince another team to do the full study?
Otherwise, it feels like there's something structurally wrong. If the study is designed as a non-conclusive prototype or framework, what's the point unless it leads to other studies?
[+] [-] DangerousPie|8 years ago|reply
I'm also not sure what you mean by #3.
[+] [-] slededit|8 years ago|reply
It would be much more useful to talk about the statistical significance in more quantitative terms.
[+] [-] alexandercrohde|8 years ago|reply
Because it's my understanding that the evidence shows a breastmilk->IQ correlation as well as all the other health benefits [https://en.wikipedia.org/wiki/Breastfeeding#Baby]
[+] [-] samat|8 years ago|reply
[+] [-] JackC|8 years ago|reply
(Compare to, say, the advice to have infants sleep on their backs to prevent SIDS, or the HPV vaccine, which have clear and measurable health impacts at a population level.)
This matters because breastfeeding has costs that tend to be ignored. Just from personal experience, it pushes disproportionate work onto my wife in a way that's hard to correct for and detracts from parenting. And given that she's working full time, it's also a huge investment of resources -- if you take her work time into account, we're spending tens or hundreds of dollars a day for this. And many women get injuries and infections, soldiering through months of agony for that health benefit that may or may not exist.
Setting aside the health of the parents (and we shouldn't, that's an easy trap), breastfeeding uses a lot of resources that could go toward other interventions for the child. Maybe it's all worth it? But I wish there was a better conversation about the tradeoffs.
[+] [-] Pharylon|8 years ago|reply
Women who can afford to breastfeed exclusively are at least middle class, usually upper-middle class. That comes with a whole set of advantages and other correlations. Studies that try to figure out breast feeding advantages have to try and control for these things, but it's hard.
Here's what we know for sure: Breast feeding reduces infections in the child. It's a small, but detectable amount. And I do mean a small amount. Between six mothers that exclusively breast feed an infant for six months, on average one of those children will have one fewer infection during that time.
Everything else is up in the air, and if it has an effect on anything else (like intelligence) it's tiny. Save your energy for reading to the child and playing games with them, which definitely helps intelligence.
[+] [-] rayiner|8 years ago|reply
Deciding to bottle feed made life way easier. My wife has trouble getting to sleep, while I can fall asleep in economy class on a 90 minute flight even before taking off. Our daughter woke up every 3 hours like clockwork for more than a year. My wife would've gone crazy if she was the one who was charged with feedings.
Medical professionals are socialized to always err on the safe side. No doctor or nurse ever got fired for scheduling an MRI or CAT scan "just to be safe." They approach breastfeeding the same way--the studies are inconclusive, so just do it to be safe.
[1] Like every engineer, I feel totally qualified to opine on scientific studies regardless of the field.
[+] [-] Nokinside|8 years ago|reply
>WHO can now say with full confidence that breastfeeding reduces child mortality and has health benefits that extend into adulthood. On a population basis, exclusive breastfeeding for the first six months of life is the recommended way of feeding infants, followed by continued breastfeeding with appropriate complementary foods for up to two years or beyond.
http://www.who.int/maternal_child_adolescent/topics/newborn/...
[+] [-] alexandercrohde|8 years ago|reply
Moreover this study, plus others, have suggested a strong relation on IQ and breastfeeding (this study 8 IQ points, one cited by 23-and-me is 7 points per copy of a certain gene 0-14 points).
[+] [-] egocodedinsol|8 years ago|reply
[+] [-] dekhn|8 years ago|reply
[+] [-] rayiner|8 years ago|reply
> Conclusions Much of the reported effect of breastfeeding on child neurodevelopment is due to confounding. It is unlikely that additional work will change the current synthesis. Future studies should attempt to rigorously control for all important confounders. Alternatively, study designs using sibling cohorts discordant for breastfeeding may yield more robust conclusions.
See also: http://pediatrics.aappublications.org/content/early/2017/03/...
> RESULTS: Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children’s hyperactivity (difference score, –0.84; 95% confidence interval, –1.33 to –0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years.
The linked study also yields some odd results:
> In the total group %EBM correlated significantly with Verbal IQ (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with grey matter.
A meta-study that adjusted for maternal IQ only (but not socioeconomic status, which independently correlates with higher rates of breastfeeding) found a very small effect on IQ: https://www.ncbi.nlm.nih.gov/pubmed/26211556
> We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model, breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression, none of the study characteristics explained the heterogeneity among the studies.
[+] [-] all_usernames|8 years ago|reply
Emotional bonding between mother and child is a huge factor in breastfeeding -- that's common sense that doesn't require scientific validation, although it would be very interesting to see studies from that perspective.
[+] [-] rayiner|8 years ago|reply
[+] [-] silencio|8 years ago|reply
[+] [-] sbenitoj|8 years ago|reply
[+] [-] lsd5you|8 years ago|reply
[+] [-] Broken_Hippo|8 years ago|reply
Why, yes. I'm not a zoologist, but I know giving a replacement milk is the best solution when the mother either is absent for whatever reason, cannot produce milk, or cannot produce enough quality milk. This is why we have milk for infant cats and dogs, actually. Otherwise, the animal would die. There is a similar nutrition for birds (as they don't produce milk) and it is common for folks to buy pigmy goats as an infant and bottle feed them.
Why do humans think they're any different?
We don't. Replacement breast milk saved lives, and these sorts of issues were the original use of infant formula. When applied to current society, it still saves lives and helps to keep folks from financial ruin because some countries (like the US) don't really give mothers time off work to properly breast feed, and it is usually difficult to pump milk at work. At some point while pumping, people usually have to supplement formula as well. As a side note, I was one of the babies that would have died without a wet nurse, as my mother had gall bladder surgery before I was 6 weeks old (fairly major surgery in '78) and could not breast feed.
[+] [-] roel_v|8 years ago|reply
Well it would be great to know just if they're different at all. You seem to think it's 'obvious' that breastmilk is always better; I don't see a logical reason to think so, or at least not so strong that it shouldn't be studied.
Yes, the research does show that breastmilk is better. My wife nursed our children until they were 15 and 18 months old, respectively. I'm not some pro-formula-campaigner. But I don't see any reason for naturalistic fallacy-based reasoning, either.
[+] [-] roceasta|8 years ago|reply
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684040/
>By the 1940s and 1950s, physicians and consumers regarded the use of formula as a well known, popular, and safe substitute for breastmilk. Consequently, breastfeeding experienced a steady decline until the 1970s (Fomon, 2001)
[+] [-] averagewall|8 years ago|reply
We tend to care about the individual more than the population, so we treat sick children instead of letting them die. Since nature isn't always helping, maybe natural food isn't always the best option.
[+] [-] std_throwaway|8 years ago|reply
[+] [-] rayiner|8 years ago|reply
Obviously, before anyone makes that sacrifice, it makes a lot of sense to study whether it has any corresponding benefits.
[+] [-] MichaelBurge|8 years ago|reply
[+] [-] 0xfeba|8 years ago|reply
[+] [-] shalmanese|8 years ago|reply
[+] [-] muppetman|8 years ago|reply
We don't know what a Zoologist might recommend in 10 years when new results are found from studies like these. That's exactly why studies like this are done, so we all learn.
[+] [-] dalbasal|8 years ago|reply
Science is about knowing the details. The hows, whys and how muches.
[+] [-] GalacticDomin8r|8 years ago|reply
[+] [-] ekianjo|8 years ago|reply
[+] [-] flarg|8 years ago|reply
[+] [-] dumbfounder|8 years ago|reply
[+] [-] jasonkostempski|8 years ago|reply
[+] [-] _pmf_|8 years ago|reply
If he is employed by Nestlé, yes.
[+] [-] colordrops|8 years ago|reply
[+] [-] logfromblammo|8 years ago|reply
People in general are way too picky about what they shove down their gullets. It's just chemicals, and the chemicals in formula are close enough to natural milk that it won't kill fragile human babies. Likewise, the chemicals in Soylent are close enough to food that you can quaff it in lieu of eating.
The only problem is determining which chemicals are actually important, which is somewhat difficult, because yadda yadda yadda unethical human experimentation....
But that wire-mom vs. cloth-mom monkey experiment should also suggest that there's more to breastfeeding than just nutrition.
[+] [-] spraak|8 years ago|reply
[+] [-] nollbit|8 years ago|reply
[+] [-] unknown|8 years ago|reply
[deleted]
[+] [-] eli|8 years ago|reply
[+] [-] mkempe|8 years ago|reply
[+] [-] cerealbad|8 years ago|reply
ask your husband* to suck your nipple then gauge reaction, offer a favorite bottle as an alternative just to be sure.
*results may be vary based on husband iq.
[+] [-] d--b|8 years ago|reply
[+] [-] epx|8 years ago|reply
[+] [-] coldtea|8 years ago|reply
[+] [-] libeclipse|8 years ago|reply
[+] [-] fgjjgutjvnu|8 years ago|reply
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