Evidence about Negative Effects of Breastfeeding


Note:  This web page contains considerable detail about adverse trends in health of young Americans since breastfeeding rates increased greatly beginning in the early 1970's, along with some explanation connecting those trends with possible effects of breastfeeding.  It is therefore rather heavy reading.  If you are not prepared to spend much time going through the details presented, it might be better to start out with one or more of the following overall summaries, if you haven't already read them:


For a very brief introduction to the subject:  see  www.breastfeeding-subject.info .

For a more complete summary of negative aspects of breastfeeding, but still rather condensed:  go to www.breastfeeding-effects.info .


For a larger presentation, related principally to ADHD and other serious psychological disorders that have increased as breastfeeding has increased:  go to www.breastfeeding-health-effects.info .


For a complete presentation, rather long but with a good summary at the front with links to detailed sections, go to http://www.pollution-effects.info .


Fig. 1



Section 1:  General health information:

Fig. 2


For general health information regarding children whose infancies would have occurred during the period of increasing breastfeeding, the CDC charts above and below are relevant. Notice that limitations of activities of all groups of children increased during these years, which followed increases in breastfeeding rates.


Also notice the downward kinks in all of the trend lines in the middles of the charts in Figure 2; then notice that those dips came after the downturns in breastfeeding rates during the middle and late 1980's (see Figure 1).


For the period following the data in Figure 2, most of the remaining years to present are provided in Figure 3 below.

Fig. 3




This same recent trend in child activity limitations, but including the entire 1997-2010 period, is verified in data from the National Health Interview Survey of the U.S. National Center for Health Statistics:  7.8% of children with limited activity in 1997, rising to 9.3% over those years.



Other noteworthy increases in childhood disorders

Note that most of the increases listed below have been referred to as epidemics among children (there is debate concerning whether autism is an epidemic):

- - To see similar unfavorable trends regarding the huge increases in child obesity since the early 1970's, in CDC data, click here.

- - To see CDC data regarding increases in asthma and allergies in recent decades, click here.

- - To see authoritative data about increases in childhood diabetes in recent decades, click here.

- - To read about the apparently greatly increasing autism in recent decades, click here.

- - To read about childhood cancer continuing to increase while cancer has been decreasing in the general population, click here.



Section 2: Trends in Mental Retardation and Developmental Disabilities

According to a 2008 consensus statement signed by 57 scientists, health professionals and researchers (with 49 doctoral degrees among them), “Recognition of the contribution of chemical contaminants to learning and developmental disabilities has increased substantially in recent years as new evidence has emerged both about the ability of neurotoxic chemicals to interfere with brain development and the susceptibility of the brain to chemicals.”(1)



Fig. 4


Because of lack of available data that is consistent over recent decades,(313a) it is impossible to show accurately the changes in levels of mental retardation and other developmental disabilities that would apply to the entire period of our concern. But some data is available for substantial segments of the overall period, showing a clear trend.


This chart shows a 29% increase in serious mental retardation among U.S. ten-year-olds over a period of 6 years, which is clearly a huge increase over a short period. Consider first the year in which the ten-year-olds whose data is shown at the left end of this chart would have been born: 1975; then find 1975 on the breastfeeding rates chart (Figure 1). It is obvious that there were major increases in breastfeeding rates taking place, with especially rapid increases during the years of the infancies of the ten-year-old children whose data is shown along the length of this chart (1975-1981). Bear in mind, as pointed out in more detail in the first paragraph of www.breastfeeding-toxins.info, that contemporary breast milk in developed areas has been found to contain neuro-developmentally-toxic dioxins in concentrations scores of times higher than the EPA-determined safe level, and in many times higher levels than in infant formula.


Unfortunately, prevalence figures for serious mental retardation for periods before and after the period shown do not appear to be available. For earlier periods (at 3 per 1000 or less) it may not have been considered to be sufficiently common to justify the gathering of specific data about it, especially compared with the many physical disorders that merited attention.  After the end of Figure 4's period of study, the classification was changed, with diagnoses of new classifications (ASD, developmental delay, learning disability, etc.) now being assigned to many children who formerly would have been simply diagnosed as retarded. 


Fig. 5




Of what is available for more recent years (after 1998), Figure 5 seems to be a useful one to look at for trend data about children diagnosed with various classifications of neurological impairment that are currently in use. (Classifications that are included in the data used for Figure 5 include intellectual disability, learning disability, autism, other delay, ADHD, stutter/stammer, and seizures, as well as hearing loss and blindness.) Providing a more precise figure regarding the general upward trend shown in this CDC chart, a publication of the American Academy of Pediatrics refers to a 17% increase in developmental disability over the 12-year period ending 2006-2008.(314).


Fig. 6




 One cause of developmental disabilities is known to be complications of pregnancy. But complications of pregnancy have been greatly declining, as a result of ongoing general advances in medicine (see Figure 6 here).  Down’s syndrome, "the most frequently recognized cause of mental retardation in the United States,"(315) has had a stable rate of live births.(316)  Another known cause of developmental disabilities is lead; and we have seen huge declines in lead both in the environment and in children's blood levels of lead, during this period (see Figure 7 below).


Fig. 7




Notice that, in many different respects, including better air quality as shown above and better water quality as seen below, the environment in which children are growing up has been improving.  The EPA administrator reported in 2014 thatin over four decades, we’ve cut air pollution by 70 percent.”(2)  Low birth weight, a risk factor for disabilities, was no higher than it had been in 1968 (p. 60 of (316a).)  These overwhelmingly-favorable developments, together with the normal progress in medical science and improvements in various teenage health habits (including smoking and binge drinking)(316a) and reductions in other risk factors (including parental smoking and low income)(316b) mean that declines in important child health indicators should not have been expected. 

Fig. 8



Higher rates of increases in both disabilities and breastfeeding during one major timespan, and lower rates of increases in both disabilities and breastfeeding during another major timespan:

It is instructive to compare some of the separate increases in disabilities described earlier in this section. The increase in mental retardation (shown in Figure 4) was high (29%) over the period of only about 6 years, and the increase in breastfeeding rates during the years of the infancies of the children studied (1975-82, Figure 1) was also high (breastfeeding at 6 months increased about 50% during those years).  By contrast, the later increases in developmental disability (Figure 5) were much smaller (17%) and were spread over twice the number of years; the increases in breastfeeding during the infancies of the children represented in that chart (after 1980, see Figure 1) were also much smaller and were spread over many more years.


Fig. 9





Providing additional evidence of a decline in child health during the period of increasing breastfeeding, notice what appears to be an 18% increase in the proportion of children with special health care needs within one decade, as shown in Figure 9.  Unfortunately, as with the other surveys shown above, there was no data for years before those shown on the chart.(317)


A recent nationally-representative study reported that the rate of hospital stays among children for mood disorders increased 80% during 1997–2010.317k




In a background paper prepared for an Institute of Medicine workshop held in August 2005, R.E.K. Stein, MD, observed that “over a 40-year period, the proportion of children reported to have major limitations in their activities related to play and school has gone from less than 2 percent to close to 7 percent.”(307d)  (emphasis added) 


A research team, using data from three National Longitudinal Survey of Youth cohorts aged 2 to 8, reported end-study prevalence of any chronic health condition of 12.8 percent for the 1988-1994 cohort and 26.6 percent for the 2000-2006 cohort;(307f) which indicated a 108% increase over a 12-year period.


A 2014 study (Houtrow et al.), published in the Journal Pediatrics, by a team with six doctoral degrees among them, provided an important update on the information quoted above.  They drew on data from an NHIS survey that “has been the principal source of information for the Department of Health and Human Services to monitor health trends in the United States since 1957.”  This report stated that “Analysis of National Health Interview Survey (NHIS) data between 1960 and 2010 shows that parentally reported rates of childhood disability, as defined by activity limitations due to chronic conditions, have increased from 2% to 8%.”   This study also found an updated increase in mental retardation and other mental problems in children in the 2000’s, as follows:  “there was marked increase in disability associated with speech problems (63.1% increase), mental retardation or intellectual impairment (63% increase), and other mental, emotional, or behavioral problems (64.7% increase).”(307h)




Considering the lack of consistency among surveys conducted over the decades, as well as other possible problems, there is reason to question whether activity limitations of children actually fully quadruped (from 2% to 8%) in recent decades. But there does appear to be strong reason to see substantial real declines in child health over recent decades, considering all of the following:


a) the many examples of major medium-term increases in disabilities and chronic health conditions among children during recent decades, shown in individual survey comparisons above,


b) epidemics and apparent major increases that have arisen among children in recent decades in diabetes, obesity, allergies, asthma, and autism (see "Other noteworthy increases" at http://www.breastfeeding-health-effects.info),


c) the sheer magnitude of the long-term increase found in major limitations in activities of children (2% to 8%); even if child activity limitations haven't actually quadrupled, they have nevertheless almost certainly increased substantially, and


d) the magnitudes of the recent increases in other disorders -- not included in the activity-limitations data because their detrimental effects are mainly long-term – such as childhood obesity (quadrupling since the early 1970's, to over 18%(307g)) and ADHD (increasing from unrecognized and unmeasured in the 1970's to over 11% among 10-17-year-olds recently – see Section 2 in www.breastfeeding-health-effects.info).


All of the above have come when there have not been substantial increases in limitations among adults (see Figure 10 below), and when many risk factors for disabilities among children have been declining, as noted above.


Fig. 10




Given all of the above, there is good reason for serious concern about any increased exposures that children, specifically, have had during the last 40 years, which could be contributing to health decline.


When seeing these surprising increases in disorders and physical limitations in children, as well as the evidence of increasing psychological problems specifically among children, one should bear in mind that infants since 1972 were increasingly ingesting a food that (in its contemporary form in developed countries) is known to the EPA to be scores of times higher in certain developmental toxins than the EPA-determined safe level. That food is also known to be many times higher in those toxins than the feeding type that it increasingly replaced. (See www.breastfeeding-toxins.info)


But it is not merely a matter of general increases in disorders roughly tracking with increases in that specific exposure to developmental toxins. Highs and lows as well as mid-levels of diseases and disorders have correlated closely with highs, lows and mid-levels of breastfeeding rates, across nations, U.S. states, and demographic groups, with correlations in time also found in many cases; correlations have been especially noticeable in autism and childhood cancer (for many details and authoritative sources, go to www.autism-correlations.info and www.pollutionaction.org/breastfeeding-and-autism-and-cancer.htm), obesity (see www.child-obesity.us), and diabetes (see www.breastfeeding-and-diabetes.info).



Section 3:  Relationship of breastfeeding to growth of infants   – in reference to growth of nerve tissue, specifically

An international research group, studying growth of 182 children in the Faroe Islands, arrived at findings of interest.  Looking at previous studies by other scientists, they noted that "Breast feeding is often associated with slowed postnatal growth.....Breast feeding is thought to confer an advantage for growth during the first few months, but data on continued growth generally suggest that continued breastfeeding has a negative effect."  This group's study added considerable support to those earlier findings.  The breastfeeding mothers and children in the Faroe islands had elevated mercury exposure due to a high seafood diet, but the researchers pointed out that "exposure to seafood contaminants is a worldwide concern, and levels similar to or in excess of those recorded in the Faroes have been published from other communities with high seafood or freshwater fish intakes."(320)(italics added)


Figures 13 and 14





The 5% reduced growth of the breastfed children as shown above may seem to some not to be a very major concern, especially since it was found in children of mothers who had elevated levels of methylmercury due to high seafood consumption.  But most women in developed countries have some of that exposure, and some have higher mercury levels than were observed in this group.  And it is worth considering the particular body organ(s) or systems that might be bearing the brunt of any growth reduction.  By far the greatest effect that has been observed of methylmercury is on neurological development. A reduction of a few percent in body weight could be especially significant if most of that reduction is in neurological tissue, which includes the brain. That is entirely possible.


This apparent effect of mercury in breast milk should be seen together with the fact that mercury has been increasing in the environment (it originates basically from combustion, and it keeps accumulating in water bodies as well as in air and soil).  And it should be remembered that mercury is only one of various developmental toxins in human milk, including dioxins in especially high concentrations (see www.breastfeeding-toxins.info).  The overall significance becomes more serious given the major increases in breastfeeding rates in recent decades in most of the developed world (see Fig. 1 and www.breastfeeding-rates.info).  All of these combined could help explain the increases in mental retardation and developmental disabilities described earlier, as well as the increases in autism (see www.breastfeeding-and-autism.net).  Specifically, it could help explain why a study of all 50 U.S. states and 51 U.S. counties, carried out by a highly-published scientist who is also a Fellow of the American College of Nutrition, found that "exclusive breast-feeding shows a direct epidemiological relationship to autism," and also, "the longer the duration of exclusive breast-feeding, the greater the correlation with autism." (319)




And now a special word from the author:

Q:  If authorities are advising mothers to feed infants a food that (in today's developed countries) is known to the EPA to typically contain high concentrations of developmental toxins,1


       at a time when there are several epidemics of unknown origin that have arisen among children since frequency of that feeding went from low to high,2


       shouldn't those authorities be prepared to answer some questions from a serious inquirer about the evidence on which they base their advice? 


A:  They obviously ought to respond.   But they don't.3


What does that say about the probable quality of their advice?


1) dioxins in concentrations that the EPA has found to be over 300 times their estimated safe dose during initial breastfeeding, and in concentrations many times higher than in formula;  also containing PCB's, PBDE's and often mercury; see www.breastfeeding-toxins.info.


2) U.S. breastfeeding rates went from low to high during the 1970's, when childhood diabetes, obesity, allergies, asthma and ADHD all started increasing rapidly; see www.breastfeedingprosandcons.info.


3) The American Academy of Pediatrics, American Academy of Family Physicians, American Congress of Obstetricians and Gynecologists, and the World Health Organization have all failed to respond to any of three or more letters to each of them from the Director of Pollution Action, challenging the evidence on which they base their positions on breastfeeding, as of many months after mailing of the letters.


Any reader is invited to see if you can get a response from those organizations on this subject.  A suggested one-page set of points, any of which you could to ask for response to, is at www.breastfeeding-subject.info.  If they respond to you, please send a copy of it to dm@pollutionaction.org or Pollution Action, 33 McWhirt Loop, Ste. 115, Fredericksburg, VA  22406  USA, since they don't respond to us. 



From the inception of these publications in early 2012 until present, the invitation has been extended to all readers to submit criticisms, asking them to point out how anything written here is not well supported by authoritative sources (as cited) or is not logically based on the evidence presented. As of June, 2014, more than two years later, only two criticisms of accuracy of our articles have been received in response to that invitation. (That is significant, considering the tens of thousands of visits we receive from readers every month.) Our publications have been improved as a result of those two criticisms, and we look forward to receiving more. To read those criticisms and our responses to them, as well as to read several other e-mails containing comments or questions and our responses to them, go to www.pollutionaction.org/comments.htm. All comments are welcome, especially those that point out any deficiencies in our evidence in relation to conclusions drawn or any lack of quality in the reasoning as presented. Please send comments, criticisms, or questions to dm@pollutionaction.org . Quite clearly, many people don't like our conclusions; they just can't find anything wrong with the evidence or reasoning that leads to the conclusions. Those who can't provide any criticisms of any of our content also include officials of government agencies that promote breastfeeding, who have received several letters from us, as well as the World Health Organization and the American physicians' associations that advocate breastfeeding. The latter organizations haven't even responded to our letters (two or more to each organization) questioning them about the evidence on which they base their advocacy of breastfeeding.




(1) Scientific Consensus Statement on Environmental Agents Associated with Neurodevelopmental Disorders at http://www.healthandenvironment.org/initiatives/learning/r/consensus


(2) Remarks by EPA Administrator Gina McCarthy at Resources for the Future, as Prepared for Delivery Sept. 25, 2014, as published 9/28/2014 in U.S. Environmental Protection Agency Weekly Digest Bulletin (usaepa@service.govdelivery.com)


(307a) Girls With ADHD At Risk for Self-Injury, Suicide Attempts As Young Adults, Says New Research American Psychological Assn. August 14, 2012 reported in Medline Plus Weekly Digest Bulletin, 11/25/2012

(307b) Data table for Figure 37, Death rates for leading causes of death among young adults 18-29 years of age, by sex: United States, 1980-2005 in CDC's Health United States, 2008 At http://www.cdc.gov/nchs/data/hus/hus08.pdf That data table can be found at http://www.pollutionaction.org/HUS_08data2.jpg

(307c) "ADHD Can Cause Lifelong Problems, Study Finds." In HealthDay News of NIH, in Medline Plus Weekly Digest Bulletin of 12/23/12 at http://www.nlm.nih.gov/medlineplus/news/fullstory_132091.html

(307c1) Vanderbilt University study cited at http://www.psychmedaware.org/statement.html

(307c2) Table 4 of Fariz Rani et al., Epidemiologic Features of Antipsychotic Prescribing to Children and Adolescents in Primary Care in the United Kingdom, online at http://pediatrics.aappublications.org/content/121/5/1002.full

(307d) NIH-provided study, Ch. 3 Disability Trends – The Future of Disability in America. Institute of Medicine (US) Committee on Disability in America; Field MJ, Jette AM, editors. Washington (DC): National Academies Press (US); 2007 bookshelf ID: NBK11437 found at http://www.ncbi.nlm.nih.gov/books/NBK11437/

(307e) The Increase of Childhood Chronic Conditions in the United States, James M. Perrin, MD; Sheila R. Bloom, MS; Steven L. Gortmaker, PhD JAMA. 2007;297(24):2755-2759. doi:10.1001/jama.297.24.2755.

(307f) Dynamics of obesity and chronic health conditions among children and youth, Van Cleave J, Gortmaker SL, Perrin JM JAMA. 2010 Feb 17; 303(7):623-30. At http://www.ncbi.nlm.nih.gov/pubmed/20159870

(307g) see www.child-obesity.us

(307h) Houtrow et al., Changing Trends of Childhood Disability, 2001–2011, Pediatrics Vol. 134 No. 3 September 1, 2014 at http://pediatrics.aappublications.org/content/134/3/530.abstract

(313) http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6007a7.htm?s_cid=mm6007a7_w

(313a) A summary of the available surveys of disabilities during the recent decades, showing their spotty, inconsistent nature that isn't helpful in showing long-term trends, see The Internet Journal of Pediatrics and Neonatology ISSN: 1528-8374 A Review On The Prevalence Of Disabilities In Children, Joav Merrick MD, DMSc et al., at http://archive.ispub.com/journal/the-internet-journal-of-pediatrics-and-neonatology/volume-3-number-1/a-review-on-the-prevalence-of-disabilities-in-children.html#sthash.HVVV345a.dpbs

(313b) at http://www.cdc.gov/nchs/data/nhis/earlyrelease/earlyrelease201303_11.pdf, Data table for Figure 11.2

(314) AAP publication at http://pediatrics.aappublications.org/content/127/6/1034.full.pdf. TheCDC chart shown was found at http://www.cdc.gov/nchs/ppt/nchs2012/SS-22_BLUMBERG.pdf

(315) CDC document found at http://wonder.cdc.gov/wonder/help/populations/bridged-race/NationalVitalStatisticsReportsVol50Number05.pdf


(316) From website http://www.ndss.org/Down-Syndrome/Down-Syndrome-Facts/ "All people with Down syndrome experience cognitive delays, but the effect is usually mild to moderate and is not indicative of the many strengths and talents that each individual possesses.


(316a) Federal Interagency Forum on Child and Family Statistics. America’s Children: Key National Indicators of Well-Being, 2005, p. 43. Federal Interagency Forum on Child and Family Statistics, Washington, DC: U.S. Government Printing Office

(316b) Childhood Health: Trends and Consequences over the Life-course, Liam Delaney et al., Future Child. 2012 Spring; 22(1): 43–63. PMCID: PMC3652568 NIHMSID: NIHMS461654


(317) http://childhealthdata.org/browse/survey/results?q=234&r=1&t=1&ta=161


(317a) Smith James P., Smith Gillian C. Long-term Economic Costs of Psychological Problems during Childhood. Social Science and Medicine. 2010;71(no. 1):110–15. Also Goodman Alissa, Joyce Robert, Smith James P. The Long Shadow Cast by Physical and Mental Problems on Adult Life. PNAS; Proceedings of National Academy of Sciences. 2011;108(no. 15):6032–37


(317b) First- and Second-Generation Antipsychotics for Children and Young Adults (Internet); NIH publication found at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0040944/


(317c) Increasing Off-Label Use Of Antipsychotic Medications In The United States, 1995-2008 G. Caleb Alexander, MD, MS, et al., found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3069498/ Pharmacoepidemiol Drug Saf. 2011 February; 20(2): 177–184. Published online 2011 January 6. doi: 10.1002/pds.2082 PMCID: PMC3069498 NIHMSID: NIHMS275845


(317d) National trends in the outpatient treatment of children and adolescents with antipsychotic drugs. Olfson M, et al., Arch Gen Psychiatry. 2006 Jun;63(6):679-85. http://www.ncbi.nlm.nih.gov/pubmed/16754841


(317e) National trends in the outpatient diagnosis and treatment of bipolar disorder in youth. Moreno C, et al., Arch Gen Psychiatry. 2007 Sep;64(9):1032-9.


(317f) WHO/Europe, European HFA database, Jan. 2012

(317g) Use of antipsychotic drugs among Dutch youths between 1997 and 2005. Kalverdijk LJ, et al., Psychiatr Serv. 2008 May;59(5):554-60. doi: 10.1176/appi.ps.59.5.554.http://www.ncbi.nlm.nih.gov/pubmed/18451016

(317h) Fariz Rani et al., Epidemiologic Features of Antipsychotic Prescribing to Children and Adolescents in Primary Care in the United Kingdom, online at http://pediatrics.aappublications.org/content/121/5/1002.full

(317j) Health Care Cost Institute. Children's health care spending report: 2007–2010. Washington, DC: Health Care Cost Institute; 2012.

(317k) Pfuntner A, Wier LM, Stocks C. Most frequent conditions in U.S. hospitals, 2010 Rockville, MD: Agency for Healthcare Research and Quality; 2013. January Contract No.: HCUP Statistical Brief #148.

(318) http://childstats.gov/americaschildren/tables/health5.asp?popup=true


(319) Autism rates associated with nutrition and the WIC program.  Shamberger R.J., Phd, FACN, King James Medical Laboratory, Cleveland, OH  J Am Coll Nutr. 2011 Oct;30(5):348-53.  Abstract at http://www.ncbi.nlm.nih.gov/pubmed/22081621  The full text, including the quoted passages, can be purchased for $7 or reference librarians at local libraries could probably obtain it at no charge. 


(320) Attenuated growth of breast-fed children exposed to increased concentrations of methylmercury and polychlorinated biphenyls, P. Grandjean et al., FASEB J. (February 5, 2003) 10.1096/fj.02– 0661fje  at http://www.fasebj.org/content/17/6/699.full.pdf


* For information about Pollution Action and for a listing of our other free online publications, go to http://www.pollutionaction.org .