6 Jul 2008
For several years now, studies have emerged showing that breastfed babies often perform better on standardized tests and display higher overall levels of intelligence than their formula-fed counterparts. And since baby formula possesses, at least according to a number of mainstream researchers, many of the same basic characteristics as breast milk, the reality that breastfed babies tend to display higher levels of intelligence currently presents a conundrum for the medical community.
Of course, theories have been proposed. One such theory is that women who breastfeed their babies possess different personality traits than those women who chose to feed their infants formula. It’s been postulated that women who take the time to feed their babies from their own breasts are smarter. Perhaps the fact that such women harbor the desire to breastfeed also indicates that they are more invested in the future of their infant. And if they are more invested their baby, then it could be proposed that they interact more closely with the baby and initiate a greater number of activities to foster its intelligence.
The hypothesis is plausible and may be true to a certain extent. Yet a recent study by researchers at McGill University and conducted at a Belarrussian hospital has poked a serious hole in its accuracy, highly suggesting that other factors govern the level of mental development achieved by breastfed and formula fed babies.
Key to the Belarussian study is that unlike any of the previous studies conducted on breastfed/formula fed infants, the mothers of the babies were randomly assigned to two different groups. Other studies on the same topic have instead allowed mothers to chose whether or not they want to breastfeed or formula feed their infants. Or, research teams have simply tracked the children of breastfeeding mothers and then compared them to the children of mothers who had independently made the choice to use formula instead. The problem with such study designs is that in each case, the mothers themselves chose how to feed their infant, making it impossible to test whether children’s intelligence levels later in life are due to the milk/ formula or the characteristics of the mother.
However, in the Belarussian trial, about half the 14,000 babies under study were randomly assigned to a group in which prolonged and exclusive breastfeeding by the mother was encouraged at several hospitals and clinics. The mothers of the other babies received no special encouragement. The result was that those infants in the breastfeeding encouragement group were, on average, breastfed longer than the others and were less likely to have been given formula in a bottle, yet the decision to breastfed was largely influenced by the researchers conducting the study rather than the personalities of the mothers themselves.
“The design of the study — randomly assigning babies to two groups regardless of the mothers’ characteristics — was intended to eliminate the confusion [of whether breastfed babies are given more attention],” state the team.
At 3 months, 73 percent of the babies in the breastfeeding encouragement group were breastfed, compared to 60 percent of the other group. At 6 months, it was 50 percent versus 36 percent. In addition, the group given encouragement was far more likely to give their children only breast milk. The rate was seven times higher, for example, at 3 months.
The children were monitored for about 6 1/2 years, at which point the researchers proceeded to measure the differences between the children in two groups using IQ tests administered by the children’s pediatricians and by ratings by their teachers of their school performance in reading, writing, math and other subjects.
Interestingly, despite the fact that the study design had largely eliminated the “mothers who breastfeed are more likely to invest in their infants” variable, children who had been breastfed still scored higher on intelligence tests. In fact, the children in the group where breastfeeding was encouraged scored about 5 percent higher in IQ tests and did better academically.
Although Kramer and team were able to identify a causal relationship between breastfeeding and measured intelligence, they admit to being somewhat flummoxed by exactly how this happens. A number of mechanisms are suggested including the notion that maybe there’s some constituent unique to breast milk, such as polyunsaturated fatty acids, which offers breastfed infants an advantage. However studies that have attempted to add polyunsaturated acids to formula have yielded inconsistent results when tested on infants. Others have proposed that breast milk may superior to formula because it contains more insulin-like growth factor I, but it’s difficult to connect a growth factor to cognitive function.
One of the old refrains you hear on Bacteriality time and again is “What about the alternate hypothesis?” So, what about it? In this case, the variable which escaped the researchers’ consideration is right under their noses. Whereas natural breast milk is low in vitamin D, infant formula is fortified with the secosteroid,
So, it’s very likely that the characteristics of the baby formula itself, rather than the characteristics of breastfeeding mothers or possibly even the properties of natural milk, are the driving factor determining intelligence levels among formula-fed children. The vitamin D added to baby formula is in the form of 25-D – the vitamin D metabolite that slows activity of the Vitamin D Receptor. Since the Vitamin D Receptor is key to controlling the activity of the innate immune response, those infants fed formula gradually ingest enough 25-D to slow the activity of the receptor. It follows that the chronic, intraphagocytic bacteria capable of infecting the brain and causing numerous mental deficiencies, learning disorders, and overall mental sluggishness (the very conditions and diseases correctable by removing vitamin D from one’s diet) are able to infect and persist in the heads of the formula fed babies with greater ease.
Here then is a summary of the McGill study. People add unnatural substance to food for infants. Infants ingest said substance. Infants grow up to have lower intelligence.
Mothers and their doctors privy to this study will probably opt to breastfeed their babies, albeit for the wrong reason. So at least, even if based on misinformation, most doctors currently recommend breastfeeding over formula feeding. Still, the number of formula fed babies reigns in the millions, compromising their later health and well-being.
12 Responses for "Why are breastfed infants more intelligent? Examining the alternate hypothesis"
A fascinating possible link Amy. I’ve always wondered why breast milk is supposedly low in Vit D! If “breast is best” why on earth would formula milk need supplementing with Vit D?
I was wondering why breast fed babies and/or their mothers aren’t given Vit D as a matter of course and found this:
http://www.007b.com/vitamin-d-breast-milk.php
You are doing a great service examining all these reports through the MP lens thereby suggesting numerous new lines of research Amy. Hopefully some of them are being picked up somewhere. The breast feeding/Vit D issue would seem a particularly simple one to test. Trouble is, no one is going to dare deprive mothers of something that appears to give at least short-term protection from so many diseases.
Regards,
Anne
Hi Anne,
Yes, go figure that some vitamin D proponents would question the vitamin D content of breast milk. Don’t they find it a little odd that natural breast milk wouldn’t have evolved to have just the right concentration of substances to keep a child as healthy as possible, especially since it serves such a vital role? Why would we want to mess with its composition?
It’s sad, because one of my good friends has a baby who was formula fed for a while. But now that her mother is aware of vitamin D’s immunosuppressive effects, she asked me to help her find a brand of milk not fortified with vitamin D (the baby is now drinking milk). Apparently there is only one brand left in the US that does not fortify and it is soon changing its guidelines so that it will add D. So where is a mother to turn if she wants her child to benefit from the nutrition of milk yet not consume an immunosuppressive secosteroid? And ironically so many milk companies claim their products are completely organic. To me organic suggests that the product is in the form that nature intended. Yet they have no qualms about advertising fortified milk as “organic.”
The above dilemma is all the more reason why Dr. Marshall’s model of D need to be pushed forward with more vigor than ever.
Best,
Amy
This gets my goat. My mother’s doctor told her that I was allergic to her breast milk. Apparently this was somewhat common during my generation among doctors who were uncomfortable with their sexual perception of female bodies.
I’ve long suspected that formula was a big contributor to the Th1-based cognitive symptoms I’ve had since childhood. I’m glad that Dr. Marshall has shown that the brain heals along with the rest of the body as the CWD bacterial load is brought down.
Amy,
Do we know anything about the D supplementation of these babies post breast feeding until the 6.5 years when testing was conducted? Presumably they “got milk” and as you point out, its very hard to find milk without D supplementation.
Phil
Amy,
I’ll assume we can assume that these higher-scoring babies got D in their milk after breast-feeding, for a period probably 3X longer than breast milk. How does this affect your hypothesis? Do you ascribe a higher importance to initial D avoidance due to brain formation and growth in the early, formative years?
Hi Phil,
Good point. It is quite possible that after the breast-feeding period ended (is that around 1.5 years?) all the children were consuming vitamin D fortified milk. First off, that makes me wonder if all of them haven’t been cognitively affected to some degree, even those who were originally breast fed.
But I do feel that the formula fed babies scored lower on tests etc. because they were given extra vitamin D during what I consider to be the most delicate period of life. Take a look at the following article:
“Babies and Bacteria: How pathogens affect an infant during the first weeks of life”
http://bacteriality.com/2007/10/17/infants/
The piece describes how the adaptive immune system in infants takes several weeks to kick in. So a baby is much more unprotected from infection in the days and weeks following birth, until it starts producing antibodies.
Unfortunately, babies fed formula during that delicate time are probably passed around the whole family, where they can more easily pick up bacteria from other family members. Also, if they were passed any pathogens in the womb, those bacterial species probably get a head start on their quest to block the VDR and possibly other receptors.
Best,
Amy
When I was nursing my children, I belonged to the local La Leche League. We noticed that we had all been told that our breastfed babies were considered “above average” in terms of meeting most milestones etc. And a large percentage of older, formerly breastfed children were considered “gifted”. We began to wonder if our “above average children” were actually “normal” and their formula fed peers were in fact developmentally disabled by malnutrition.
Rather chilling thought.
Amy
From my point of view, it would be very interesting to get behind the large numbers of children investigated to see if there is data on children with very low IQs which could be a proxy for autism and/or other very intellectually disabling disorders. Perhaps it could be shown that the incidence of children with very low IQs is much higher for children that are formula fed vis-a-vis breast fed, even higher than possibly more subtle differences (though significant) reported in the study abstract acorss all the children.
Do you have access to the full text of the study?
Given our interest in looking at autism as a Th1 disease, this data could be very useful.
Presumably the data would not distinguish between ASD and other children. Given the large numbers involved, there would seem to be potential to study ASD children.
I note from the abstract that the improvement in verbal IQ (reading and writing) from breast feeding was greater than the improvement in IQ overall. This might be drawing a long bow but a weakness in reading and writing seems to me to suggest a particular weakness in language skills which, of course, is a hallmark of ASD. Autistics especially suffer more in this area than in other areas of intellectual activity.
Put simply, the relative weakness in language-based intellectual activity observed across all the children studied could be a pointer to ASD being caused, at least in part, by formula feeding and fortified vitamin D therein.
John
Hi John,
I see what you mean. Rather than confirming that the breast fed infants are “smarter”, it would be interesting if the researchers phrased the issue the other way around by asking, “Are the formula fed infants less intelligent?” The reason being is that the breast fed infants could have levels of intelligence that are simply normal, while the formula fed babies could have impaired intelligence levels indicative of several mental disorders including autism.
When it comes down to it, how has our medical system determined the “normal” IQ range for a 3-year-old when so many infants are given vitamin D starting at birth and the mother is often supplementing with vitamin D during and after pregnancy? Not to mention the fact that many infants already harbor the Th1 pathogens (that probably create substances that block the VDR) in the womb and at birth. These realities suggest that what is currently considered to be the “healthy” IQ range for the average 3-year-old is probably lower than it should be.
I am not familiar with data on expected IQ levels for young children so it’s hard for me to tell if any of the children in the study have low IQs that might correlate with the onset of a mental illness. However I’ll send the full text of the article to you via private email so you can look over the data.
Best,
Amy
Hi Amy
The full text study article does not reveal very much about autism and breast feeding or mental disorder more generally and breast feeding.
I suspect such children would have been excluded from the study since any severely disabled child would not be able to complete the IQ tests. I also have doubts whether Belarus would have schools or classes for severely disabled children and these children may be cared for in settings other than schools, perhaps they are kept at home.
The best way to assess whether formula feeding ’causes’ autism is to directly survey ASD children and find the incidence of formula feeding. It would be interesting to disaggregate the ASD group into Asberger types and degrees of impairment to see if there are different or stronger relations with formula feeding.
I have since found that such studies have been done and it has been shown that formula feeding increases the odds of an ASD child. Most recently, Shultz (2006 – see http://www.internationalbreastfeedingjournal.com/content/1/1/16) has verified this. He also found that formula fortified with the fatty acids DHA and ARA reduced the incidence of ASD a lot. However, a child that regresses to ASD after a period of normal development is still at an increased risk of becoming autistic if he/she is formula fed with DHA and ARA added but is at a much lower risk than if fed with formula without DHA and ARA.
From an MP point of view, formula feeding is another risk factor in causing autism but this, of course, is because of vitamin D being added. Shultz suggests DHA and ARA have immune system enhancing properties which prevents ASD developing. It is considered to be protective in breast milk and if added to formula (though to a lesser extent). I note that when added to formula, DHA and ARA did not eliminate the risk of ASD developing as ASD children who developed ASD after a period of normal development were more likely to have been formula fed (including with DHA and ARA added) than if they were breast fed.
However, added DHA and ARA did reduce the risk. Could DHA and ARA somehow offset the immunosuppressive effect of vitamin D that is added to formula in some way? As it happens, my boy was bottle fed and I suspect without added DHA and ARA as this was only added to formulas in the US from 2002. However, I wonder if the DHA added comes from fish and whether vitamin D levels have actually gone up in formulas since 2002?
The Shultz study suggest some formulas are worse than others in contributing to the development of ASD. Of course, we think formula feeding is not the sole factor involved in causing autism. Other probably more important factors risk factors include the health of the mother (whether she is Th1 sick), the over-use of beta-lactam antibiotics, the extent of (L-form) contaminated vaccines, sun exposure and post-utero exposure to Th1 pathogens from other family members.
A good study would be to see how strong is the correlation between blood D levels and ASD.
John
Well John,
You’ve certainly done your homework. Why am I not surprised to learn that a study has connected formula feeding with autism? Infants consuming formula are getting a steady supply of an immunosuppressive secostoroid….what else can be expected? Especially since I am quite convinced that autism is a Th1 disease.
At Karolinka a woman presenting a poster next to mine (from the NIH) came over gushing about the fact that her research has shown that high dose antibiotics can take the “edge” off autism, allowing children with the disease to become somewhat more stable. Of course they never get better. Immediately the word “immunosuppresion!” popped into by head, as that is clearly all the high-dose antibiotics are doing. But if immunosuppression can temporarily curb autistic tendencies, then autism is almost certainly a bacterial illness or at least involves the Th1 pathogens to a large extent.
In any case, I did some investigative work on DHA and ARA fatty acids. Turns out they are polyunsaturated omega 3 and omega 6 fatty acids that are chemically synthesized. Well, since vitamin D is the primary source used to derive the omega fatty acids, I’ll bet you a million bucks that DHA and AHA fatty acids contain vitamin D.
So I’m guessing that when the fatty acids are added to formula the immunosuppression experienced by the infant becomes even greater. Then, when doctors check in with them a while later, they still may be immunosuppressed to some degree and be described as “in better shape.” Of course the opposite is true and I would expect them to suffer from a more severe case of autism in the coming years.
At least that’s my take on what’s probably going on.
Best,
Amy
Amy
Your commentary about the immunosuppression produced by high dose abxs is spot on. A study was undertaken by Sandler (2000) which showed that high dose vancomycin temporarily reversed autism but only for a short period while the abxs were being taken and the children relapsed once the vancomycin was stopped. We actually did this therapy with Jason but got no positive response, ether transient or permanent.
This suggests his pathogen load was so high that he could not even get a temporary benefit and that his course of treatment on the MP will need to be longer than most.
The Sandler data suggests your commentary about immunosuppression goes beyond mere speculation. The Sandler study is yet another pointer to the validity of the MP view of autism.
I note that vancomycin is not a beta-lactam antibiotic but I understand it attacks bacterial cell walls. Would vancomycin therefore also cause bacteria to change to more pernicious L-forms as beta-lactam abxs do?
The long term effect of the vancomycin on the kids could have been to increase the ‘persister’ numbers and make the Th1 pathogens more virulent, as you describe in your biofilm piece which I found very informative indeed.
The hypothesis being tested by Sandler was that clostridia bacteria could cause autism since these were found to be in excessive numbers in the stools of ASD kids and the ‘regressive’ autism of the kids studied followed a course of abxs which was thought to wipe out other bacteria that compete with bugs such as clostridia difficille. Regressive ASD also seemed to follow abx-induced diarrhoea signalling major gastrointestinal flora disturbance – see Finegold (2002).
The idea was that that the toxins produced by clostridia species in the gut at an early age could impact the developing brain.
My own child’s very obvious signs of autism appeared to follow a double course of beta-lactam abxs to treat OM at age 18 months or thereabouts (as I have posted on the AUTISM forum on the MP site). He developed abx-induced diarrhoea – a possible sign of clostridia difficille infection – so he appeared to have the potential to be a vancomycin responder.
Having read your biofilm piece, it now seems more likely that his OM was actually a biofilm L-form infection made worse by the standard beta-lactam regime of penicillin.
I take it that the bugs in the ear or respiratory passages can travel from there to the brain which is a different model to that proposed by Sandler et al where the source of the problem is seen to be the gut. Jason’s OM did resolve but he has always been plagued by respiratory illness, such as nasal congestion (until now). He has not had much OM since infancy, to the extent we know.
I am wondering if a lot of regressive autism is brought on, if not caused, by OM infection in the same way you describe bugs in the mouth travelling to the brain of demented adults who have had their teeth removed. ASD kids are administered more abxs that normal kids (I can track down the research on this) and ASD, especilly more severe forms, shows up very early on in life when abxs are freely given for OM and other respiratory infections. I am wondering if this is more than just coincidence or just another risk factor. My Jason, like most ASD kids, had more than his fair share of penicillin-based abxs.
Dr Andrew Wakefield, who has been villified by the medical establishment for qerying whether vaccines cause gastro disease and autism, did have one child in his initial study whose ASD was preceded by an ear infection rather than a vaccine shot.
All this is to suggest that medicos need to treat abxs with extreme caution and need to ensure there is no underlying Th1 infection or potential Th1 infection, perhaps by D blood testing, especially if the child has been formula fed.
I am less sure about your speculations about the effect of DHA and ARA on temporarily inhibiting the development of ASD and causing it to increase at a later time. To my knowledge, most ASD sufferers are diagnosed early on and I doubt that a child that is formula fed with a DHA/ARA fortified version would be diagnosed as ASD at a later age after a period of immunosuppression when behaviour appears normal. It might be that they are diagnosed with some other Th1 illness as an older child.
I note that the Schultz study included children 2-18 years so any later or delayed emenegence of ASD would have been captured in the ASD cases reported. Hence, the reported reduction in ASD cases from fortified formula would seem to be a bona fide conclusion, setting aside the rather crude methodology, such as internet-based reporting by parents. This would seem to suggest that the fatty acids could have some beneficial effect.
Cheers
John