In the News:

Source: Unknown

Source: Unknown

Contrary to what we have been led to believe all these years, it seems that the public health initiatives to push vaccination may need to be reconsidered.  Recent research out of the UK has found that vaccines actually offer far fewer benefits in terms of protection against various diseases.  This comes as welcome news to the families who have faced immense criticisms for choosing to either forego vaccination or selectively vaccinate.

The research in question looked at over 1,000 children and grouped them by vaccination status: those who received had received no vaccinations and those who had received at least one shot during their lifetime.  The researchers found that there was no difference in immune response between the two groups for a number of diseases (both those in and not in the current vaccine schedule).  The researchers speculated that the reason for previous findings that supported the current vaccination schedule was a failure to control for many other variables that might influence the results. 


“One of the biggest problems with vaccination research is the failure to consider either a family history of disease or general immune health,” said lead researcher Dr. Bickham. “One of the big benefits of our study was that we controlled for all of these variables – family history of disease, breastfeeding status, general immune health of the child, and so on.  The fact that children who received at least some vaccines did not show a better immune response to the various diseases is evidence that vaccination is not working as completely as we have been led to believe.  The shaming of families who choose alternatives is unwarranted and the public policies in place that push vaccination should be reconsidered in favour of more inclusive policies that don’t make these families feel bad for their choices.”

It’s important to note that the researchers are not saying there are no benefits to vaccination, but rather they have been over stated and that we need to start looking at other factors that might play a role – factors like family history of disease – that may tell us more about a child’s likelihood of having an appropriate immune response to various diseases. 


Can you imagine? 

Can you imagine an article like this hitting the press?  Of course not, because it’s utterly ludicrous.  Research like this would never even be published because the methods used are so inappropriate to study the effectiveness of vaccination. (If you haven’t guessed yet, the aforementioned bit is completely made up.  As such, I apologize if there is a real Dr. Bickham who studies immunology.  I completely made up that name and in no way has any bearing on any possible current or future Dr. Bickham.)

I would imagine most of you reading this immediately spotted the biggest problem: the groups used in the “analyses”.  If someone were to suggest that we could study vaccine effectiveness by looking at those who only received only one shot and treat their outcomes the same as those who had received the full schedule, we would think they were more than a few cards short of a full deck.  More like they were missing full suits.  Add to it, no one suggests that a decision on effectiveness should be made under the assumption that vaccination should protect against everything.  Some outcomes one would expect, some not, and if a vaccine doesn’t protect against some different disease, it doesn’t damn the vaccine.

Vaccines were never designed or made to work in such a way.  When we look at vaccine efficacy and effectiveness, we have to be cognizant of the fact that they were developed with a certain number of doses in mind and that these doses are to be given in certain age brackets.  When people deviate from this, we cannot then claim that these people belong to the same group as those who did not deviate.  Especially in research.  It puts a ridiculous onus on vaccines to do something they were not designed to do.  It treats them as a magical elixir or panacea, if you will, and as such, we wouldn’t give a second thought to research that did this.

So why is it okay that we do this with breastfeeding?

Source: MomJunction

Source: MomJunction

Lately the backlash against the science of breastfeeding has been overwhelming.  Far too many people are out there claiming that the research on breastfeeding doesn’t support the public policies in place to “push” (a.k.a., support) breastfeeding.  Yet most of the research cited is of the same quality as the aforementioned made-up vaccine research because it blatantly ignores that breastfeeding evolved to occur in a specific manner.

[It’s worth sharing here, before I explain the problem, that I have been accused by some of missing the point because I am a social scientist by training (PhD in psychology) whilst ignoring that I also trained in quantitative methods (a combination of statistics and research methodology).  It was a graduate minor I completed while doing my PhD.  Part of what we learned was that too often the “harder” sciences fail to grasp the effect of groupings or the problems with variable assessment because in their fields the measures are typically clear-cut and they extend that to areas that are not as clear-cut, but may seem so.  Breastfeeding research is the perfect example of this problem and one that is ignored by far too many people.]

Although many of the outcome measures associated with breastfeeding are health related and thus clear-cut (e.g., obesity, diabetes), the assessment of breastfeeding seems to be clear cut, but it isn’t.  The problem has been that many researchers, and thus most of the breastfeeding research, has treated breastfeeding in a dichotomous way.  It has been treated as all-or-none – you breastfeed or you don’t – without understanding the nuances in feeding methods and the potential implications of this to various outcomes.

Just as vaccines were created with a specific use in mind, breastfeeding has evolved biologically in a specific way; biologically, it is something that is to be done exclusively for approximately six months and then continued, along with solids, until the child weans, typically after age 2, though in some cases beforehand.  Any research that fails to take this into account is grouping their participants erroneously and potentially masking any effects.  (There are also other problems in that mixed groups may lump together babies who had formula for one week with those who breastfed for one week, treating them the same, but that’s yet another methodological grouping issue that masks any possible effects.)  People are now using this research to try and claim that breastfeeding is “oversold”.

It’s not.  Really.


What if we look at the research that doesn’t make this mistake?  Although there is no research that truly has what we could call a “biological” or “evolutionary” breastfeeding group (i.e., exclusive breastfeeding for six months followed by complementary breastfeeding with solids until a minimum of two years), there is research that has started to examine exclusivity and/or duration of breastfeeding as an additional factor in their analyses.  When we look at that data, we see that breastfeeding has hardly been oversold.  In fact, we may be underselling it.

Take breastfeeding and obesity, for example.  Although data has been mixed, when exclusivity or  duration is examined (along with controlling for other known confounders such as parental BMI, SES, and the child’s lifestyle behaviours), we can see a dose-effect with those children who were breastfed for less time or who had formula the majority of the time having a greater risk of being obese[1][2].  The same can be said for analyses examining the relationship between breastfeeding and IQ, despite some researchers suggesting no relationship (even though, in some cases,their own analyses showing significant dose-effects[3]), which is likely explained by the paucity of studies that have actually included appropriate assessment of breastfeeding duration or exclusivity[4].  Most recently, research suggests a dose effect of breastfeeding on IQ, even after controlling for parental IQ (a confound that has previously been ignored), and declares previous null results may be in part due to the type of IQ test used[5].  In Denmark, a large prospective study using two samples and two different measures of IQ examined the relationship to breastfeeding duration (but not exclusivity) while controlling for myriad confounds (including those typically claimed to be the cause of any relationship, such as SES and parental education) and found a significant dose-effect of breastfeeding on later IQ (assessed in adulthood)[6].  In perhaps the most persuasive study – the PROBIT study, which is a randomized controlled trial in Belarus – both duration and exclusivity were assessed and it was found that with greater duration and exclusivity (controlling for confounds), clear evidence of a positive relationship to intelligence emerged[7].

Even more importantly than links to obesity and IQ, when we look at biological or evolutionary breastfeeding we can see strong evidence of the risks of not breastfeeding in this manner to more serious health conditions such as childhood cancer[8] and SIDS[9].  In the cancer research, we still face the issue of exclusivity being ignored with only duration being considered, yet significant results remain.  (You can read more on the breastfeeding-childhood cancer research here.)  In the SIDS research, exclusivity and duration were examined and found to have a greater effect than any breastfeeding at all, though any breastfeeding was also related to a “reduced risk” of SIDS.

We have to ask ourselves: how much more significant would these findings be if we actually were able to assess biological breastfeeding in its entirety?

Of course none of this is to say that formula shouldn’t be available or that women should lack choice, but rather to say that this push to say the science doesn’t support breastfeeding is not only misguided, but is hurting women’s ability to make an informed choice when it comes to how they feed their babies.  (Yes, as hard as it may be to hear, choosing formula is accepting risk.  Trying to pretend it’s not doesn’t help anyone.  Just remember that we all accept risk, just in different areas.)  It also affects the likelihood that society gets its proverbial shit together to better support new mothers in breastfeeding so that 60% of moms don’t report not being able to meet their own breastfeeding goals thanks to the numerous traps set up for them[10].

It is equally important to make sure people understand that increased or decreased risk does not equal certainty.  Too often people bring up anecdotes of people that don’t “fit” the research and take it to mean the research needs to be thrown out; sadly, this is an effect of a science-illiterate population and one that needs to be addressed.  Increased or decreased risk simply refers to the chances and does not dictate individual outcomes.  It gives us information about general or population-level outcomes, but does not say a given individual will or will not face that specific effect, only their chances based on patterns in a larger group.

In closing, if we are going to talk about breastfeeding research, let’s make sure we do it correctly.  Breastfeeding hasn’t evolved to be done partially or even for shorter durations; the biological norm is for a period of exclusive breastfeeding followed by continued complementary breastfeeding for a significant time period.  If we are to look at any outcomes of breastfeeding, this is the standard to which it needs to be held.  Then we can start to see the effects of deviating away from this and figure out the best way to support all parents in their feeding choices (yes, knowing the risks means we can also help minimize them when people don’t reach this biological norm for any reason).  Once we have this information, then parents can make the decisions about what kind of risk they are willing to accept and how to minimize it, for then they will have the appropriate data to make such a conclusion.


[1] McCrory C, Layte R.  Breastfeeding and the risk of overweight and obesity at nine years of age.  Social Science & Medicine 2012; doi: 10.1016/j.socscimed.2012.02.048

[2] Gillman MW, Rifas-Shiman SL, Camargo CA, Berkey CS, Frazier AL, et al. Risk of overweight among adolescents who were breastfed as infants.  JAMA 2001; 285: 2461-7.

[3] Der G, Batty GD, Deary IJ.  Effect of breast feeding on intelligence in children: prospective study, sibling pairs analysis, and meta-analysis.  BMJ 2006; 333: 945

[4] Jain A, Concato J, Leventhal JM.  How good is the evidence linking breastfeeding and intelligence?  Pediatrics 2002; 109:

[5] Kanazawa S.  Breastfeeding is positively associated with child intelligence even net of parental IQ.  Developmental Psychology 2015; 51: 1683-9.

[6] Mortensen EL, Michaelsen KF, Sanders SA, Reinisch JM.  The association between duration of breastfeeding and adult intelligence.  JAMA 2002; 287: 2365-71.

[7] PROBIT Study Group.  Breastfeeding and child cognitive development: new evidence from a large randomized trial.  Arch Gen Psychiatry 2008; 65: 578-84.

[8] Amitay EL, Keinan-Boker L.  Breastfeeding and childhood leukemia incidence: a meta-analysis and systematic review.  JAMA Pediatrics 2015; 169: e151025.

[9] Hauck FR, Thompson JMD, Tanabe KO, Moon RY, Vennemann MM.  Breastfeeding and reduced risk of sudden infant death syndrome: a meta-analysis.  Pediatrics 2011; doi: 10.1542/peds.2010-3000.