Breastfeeding, Asthma and Allergies
Asthma and allergies have increased greatly in much of the world in recent decades, reaching levels that are commonly referred to as epidemic. According to an author from the U.S. National Center for Health Statistics, "why these allergies are on the rise remains a mystery."
According to a 2008 article in the New England Journal of Medicine, "The prevalence of atopic dermatitis has doubled or tripled in industrialized countries during the past three decades, affecting 15–30% of children."(3b) This finding parallels that of NIH researchers (quoted in the Journal of Allergy and Clinical Immunology) regarding allergy rates' doubling 1975 to 2005, with increases found especially among young people.(4) A 2008 article in the journal, Pediatrics, included asthma with the allergic diseases that have "increased steadily over the past several decades. (5)
According to the American Academy of Family Physicians, breastfeeding of infants was relatively rare in the United States in the middle of the 20th Century.(9b) But it started increasing rapidly in 1972 and had become typical infant feeding by the end of the 1970's; and breastfeeding rates continued to increase into the 2000's. When the movement promoting breastfeeding was building up, the case in favor of it was very strong on the basis of what was known at the time. A number of studies were done, most of which concluded that breastfeeding was beneficial, including apparently reducing risk of allergies and asthma. The focus at that time was on effects during very early childhood, and it was assumed that the beneficial effects detected at the early ages would mean overall benefits to the child. It was only in the 2000's that a large number of studies found that what had initially seemed beneficial turned out to be detrimental in the long run.
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The immune system and breastfeeding:
According to the NIH (www.ncbi.nlm.nih.gov) ”an allergy is an immune response or reaction to substances that are usually not harmful." The most common type of asthma is allergic asthma. Therefore proper functioning of the immune system is central to discussion of both asthma and allergies.
It is well known that immune cells from the mother are transmitted to an infant in breast milk, and that is clearly helpful to an infant in areas with poor sanitation. But in developed countries, the long-term benefits of those immune cells are very much subject to question. A web page of the U.S. Food and Drug Administration favorably presents a line of reasoning according to which proper infant development depends on “the necessary exposure to germs required to “educate” the immune system.... In the period immediately after birth the child’s own immune system must take over and learn how to fend for itself.” The FDA reports that this “hygiene hypothesis” is supported by epidemiological studies. A prominent doctor uses stronger language, describing the “critical importance of proper immune conditioning by microbes during the earliest periods of life.”(1) A study found on the NIH’s website discusses “the microbial exposure which may be critical for immune priming” and suggests it would be helpful to re-name the “hygiene hypothesis” as “microbial deprivation hypothesis.” (9) According to the UCLA Food and Drug Allergy Care Center, "Overwhelming evidence from various studies suggests that the hygiene hypothesis explains most of the allergy epidemic."(9a)
The modern sanitation that greatly reduced our microbial exposure in developed countries, as compared with the exposure that our bodies became adapted to during almost all of human history, came about in the late 19th and early 20th centuries. But the epidemics in allergies and asthma arose in the late 20th Century. It appears that, for several decades after modern hygiene was achieved, the remaining microbial exposure of infants was still sufficient to provide the stimulation that immune systems needed in order to develop properly. Then something seemed to change, approximately during the 1970's, which increasingly left infants' immune systems failing to develop properly.
It is undisputed that there are immune cells in breast milk, which destroy microbes. It is entirely possible that a major increase in infant ingestion of those immune cells (such as would have occurred during the rapid increase in breastfeeding beginning in 1972) was what tipped the balance of microbial exposure over to insufficiency, for a large and increasing number of infants.
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In addition to the above-suggested indirect effect of breast milk on development of the immune system, there are also known direct effects on the immune system resulting from toxins known to be contained in breast milk. The thymus, whose function is crucial to development of immune function, is heavily affected by dioxins. (see Section 1.h of www.breastfeeding-toxins.info) An assessment by a committee of the National Research Council of the U.S. National Academies states, “it is reasonable and prudent for EPA to regard TCDD (dioxin) as an immunotoxicant.”9c According to an extensive 2011 study on environmental toxicants and the developing immune system, toxins including not only dioxins but also PCBs, PAHs, BPA, and phthalates can harm development of the immune system.(10) A 2007 study listed those plus other environmental toxicants seen to harm development of an infant's immune system, including heavy metals, tobacco smoke, and pesticides.(10a) Note that all of the above toxins (or, in the case of tobacco smoke, components of that toxin) have been found in breast milk; dioxins have been found in human milk in doses scores to hundreds of times higher than the EPA-determined safe level, and mercury and PBDEs are also far above established safe levels, on average. (see http://www.breastfeeding-research.info )
According to a report prepared for the Danish Health and Medicines Authority (2013), “The immune system is among the most sensitive of all organ systems to PCBs. PCBs cause atrophy of the thymus gland and immunosuppression in laboratory animals.”(10c) Given that, be aware that, in an American/German study, PCB levels in children who had been breastfed merely for 12 weeks or more were still over twice as high as in bottle-fed children at 7 years of age.(10d) Also, PCBs in human milk, even three decades after their production was banned for most purposes in most developed countries, have been found to still be about 20 times the level allowed in U.S. public water systems.(10e)
By contrast, in a study by scientists with the U.S. National Institute of Environmental Health Services, who examined 104 samples of infant formula, no detectable PCBs were found in all but one sample.(10f)
Extensive evidence for the above statements, from the EPA and other authoritative sources, is readily available. (see www.breastfeeding-toxins.info)
Effects of toxins known to be present in breast milk (PCBs, dioxins, metals, and pesticides) include "increased incidences of respiratory and ear infections,... respiratory symptoms such as wheeze and allergic indications,... development of an asthmatic phenotype ... long-lasting and deleterious impact on immune function."(10)
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Statements that are made about health benefits of breastfeeding, in contrast with other authoritative information:
According to U.S. Surgeon General Regina Benjamin, children who are not breastfed have an excess risk for asthma of 35% to 67%, and atopic dermatitis is 47% more likely among children who are not breastfed. She acknowledges that these are only inferences, based on observational studies,(2) the kind that the U.S. Agency for Healthcare Research and Quality says are subject to false conclusion. And nowhere does the Surgeon General make any reference to any of the many studies summarized below, all of which found that asthma or allergies were higher among the more-breastfed.
Before summarizing the studies below, an explanation should be presented as to why there should be such stark disagreement between the studies referred to by the Surgeon General and most of those that will follow. Bear in mind what was said in Section 1, including
(a) the undisputed presence of immune cells in breast milk, which are helpful to the infant as long as those transmitted cells are still active in the child (note that typical blood cells live a few months or less); and
(b) "Overwhelming evidence from various studies suggests that the hygiene hypothesis explains most of the allergy epidemic." (quoting from the UCLA Food and Drug Allergy Care Center."(9a)
The immune cells in human milk are helpful to the health of a very young child. But it should be expected that they would reduce the microbial challenges that otherwise would be stimulating the optimal development of the child's own immune system. Studies that focus on the health of very young children would be expected to find benefits of breastfeeding, whereas studies that look at longer-term effects would be expected to find something different, which is exactly what seems to have happened.
Section 2.a Asthma at earlier vs. older ages:
In a large Italian study, breastfeeding for 6 months or more reduced the risk of wheeze in the first 2 years of life but increased the risk of late-onset wheeze.(11v)
In an Arizona study of 1043 children, 359 of whom were exclusively breastfed 3 months or more, the following was found: in the first 2 years of life, exclusive breastfeeding was associated with lower rates of recurrent wheeze, but exclusive breastfeeding increased the risk of asthma at ages 6 through 13 among children of asthmatic mothers, OR (odds ratio) 8.7. (11p) (that's 770% higher risk)
In a 2007 Australian study, at age 7, exclusively breast-fed children with a maternal history of atopy had a marginally lower risk of current asthma than those not exclusively breast-fed. However, after age 7, the risk reversed, and exclusively breastfed children had an increased risk of current asthma at ages 14 (OR, 1.46), becoming still higher at age 32 (OR, 1.84), and 44 (OR, 1.57). Exclusively breastfed children also had a reduced risk of food allergy at age 7 years but an increased risk of food allergy (OR, 1.26) and allergic rhinitis (OR, 1.2) at 44 years. (11s)
In a U.S. study provided by the National Library of Medicine, questionnaires were completed at age 6, 9 or 11 years by parents of 1043 children enrolled at birth. "For children with maternal asthma, the percent developing active MD asthma increased significantly with longer duration of exclusive breastfeeding. Odds of developing asthma among these children were significantly elevated (OR: 5.7), after adjusting for confounders."(11h) (that's 470% higher likelihood of asthma among the more-breastfed of these children)
In a Japanese study of 2,315 students at age 6-15 with asthma and 21,513 controls, the risk of breastfeeding for asthma was compared with that of artificial feeding. After adjustment for age, gender, parental smoking status, and parental history of asthma, a significantly higher prevalence of asthma was noted among children who had been breastfed (adjusted odds ratio = 1.198) (11u)
In a 2003 study in Brazil, breastfed children were found to have higher rates of asthma than non-breastfed children in all breastfeeding duration categories, with the association reaching a high level of statistical significance in the 9-month duration category. For two other duration periods, the statistical significance was 1 percentage point above the normal cutoff point for significance, and 2 percentage points above the cutoff for the remaining period.(11u1)
In a 2011 Chinese study, breastfed children were found to be at 1.5 times higher risk for food sensitivity than never-breastfed children. Children with a certain genetic type and who were exclusively breastfed for over four months were found to have over 13 times the risk of having food sensitivity than non-breastfed children.
Sibling studies are a way of minimizing effects of confounders in studies. The typical studies that have found benefits of breastfeeding are, according to former U.S. Surgeon General Regina Benjamin, all observational studies, which she acknowledges can only lead to inferences about effects of breastfeeding.(11h1) As the U.S. Agency for Toxic Substances and Disease Registry points out, such studies are subject to false conclusion, because of “confounders,” or underlying real causes of associations found between factors being measured.(11h2) Confounders that apply in the case of breastfeeding studies are low family income and smoking, both of which are far more prevalent with bottle-feeding mothers, and both of which are firmly linked to various health disorders including asthma, providing a misleading impression that bottle feeding is a cause of the disorders. Sibling studies, in which bottle-fed children are compared with breastfed children within the same family, are a way of minimizing effects of confounders. A 2014 sibling study found that asthma was “one outcome for which breastfeeding duration is consistently associated with poorer childhood health and wellbeing across all three models.” In addition, outcomes of breastfeeding were negative for body mass index, obesity, and intelligence. The authors considered this data to be “suggesting that, for some outcomes, breastfed children may actually be worse off than children who were not breastfed.” Of 11 outcomes examined in this sibling study, none showed statistically significant benefits of breastfeeding. Continuing, “The findings presented here are consistent with those from a small but growing literature that seeks to more accurately assess the association between breastfeeding and child health and well-being.”(11h3)
Advantages of exclusive breastfeeding with regard to allergies?
The first column of every pair below represents allergy prevalence with exclusive breastfeeding (“standard introduction”). Allergy prevalences with early introduction of other foods are on the right in each pair. Effects were reported to have followed a dose-response pattern.
Section 2.b Allergies at younger vs. older ages:
In a 2011 U.S. study (see data Table 2 on right), 739 young children (up to age 6) were found to have far higher levels of food sensitization with greater age.(11j) Note that before age 2, the increase in allergies (OR's above 1.0) for the breastfed children were small; but for children past age 2 the increases in allergies associated with breastfeeding became quite large. In both cases, the increases in allergies were greater for children who were breastfed for longer durations.
In a 2004 Danish study of 15,430 mother-child pairs, it was found that, although overall current breastfeeding was not associated with atopic dermatitis, exclusive breastfeeding for at least 4 months was associated with an increased risk of atopic dermatitis in children with no parents with allergies. (IRR (incidence rate ratio)= 1.29).(11f) Note that this substantial but relatively moderate increased risk of atopic dermatitis was assessed at only 18 months of age, which was very young by comparison with the studies that followed up at later ages and found higher risk ratios for breastfeeding.
In a 2010 study of children in the Faroes Islands, it was found that risk of allergy development increased with each additional month of breastfeeding.(11u2)
In an Armenian study, breastfeeding by a mother with atopic condition was associated with development of atopic dermatitis after just 12 months of age.(11w)
In a 2011 Taiwan study of 18,733 babies, it was found that, "After adjustment for potential confounders, the overall results showed that the increased duration of breastfeeding seemed to increase the risk of AD at 18 months in children.(11x)
In a 2009 Japanese study of 763 infants, surveyed at 16 to 24 months after birth (as well as earlier), it was found that both exclusive breastfeeding for 4 months or more and partial breastfeeding for 6 months or more were associated with an increased risk of atopic eczema among infants with no parental history of allergic disorders (odds ratios were 2.41 and 3.39. (11g)
In a 2005 New Zealand study, which assessed 550 children at 3½ years of age, 87 of whom were diagnosed with AD (atopic dermatitis), the odds ratios for AD were 6.13 and 9.7 respectively for children with less than 6 months or more than 6 months of breastfeeding, as compared with children who were never breastfed.(11e) Here again, as in other cases, there was a conspicuous dose-response relationship, with greater exposure to breastfeeding apparently leading to greater amounts of allergy.
In a 2006 Finnish study, strictly exclusive breastfeeding for at least 9 months was found to be associated with increased atopic dermatitis and food allergy symptoms at age 5, particularly among children with a positive family history of allergy.(11n) This study was cited in a subsequent study that pointed out, "most recent studies do not confirm the 'conventional wisdom' that breastfeeding is protective against allergy and asthma."(11o)
In a 2007 Australian study, 516 children were evaluated at age 5, and breastfeeding for 6 months or more was associated with an increased risk of atopy. (11c) In a 2012 Australian study, 15,142 new entrants to primary schools with parent-reported nut allergy were studied, and it was found that children fed only foods other than breast milk before six months were least likely to develop a parent-reported nut allergy (OR = 0.63) compared with children who were exclusively breast fed (OR = 1.43). Children who were only partially breastfed were also far better off than the exclusively breastfed, but worse off than the totally-non-breastfed (OR = 0.83). (This again is a conspicuous dose-response relationship.) The authors continued, "Furthermore, prolonged breast feeding has been shown to increase the odds of developing peanut allergy by almost 3 times that of children who were weaned at or before 6 months. Our study results concur...."(11t)
A randomized study: The Promotion of Breastfeeding Intervention Trial (PROBIT) in Belarus was exceptional among studies in this area in using randomization, a feature of high-quality studies, which helps avoid the problem of confounders to which observational studies are especially subject. (Bear in mind that, according to the U.S. Surgeon General, observational studies are the category that includes almost all other studies related to health effects of breastfeeding) Outcomes were examined at 6.5 years of age, and it was found that risk of allergy was "increased from two-fold to three-fold in the intervention (highly-breastfed) group for the majority of antigens."(11b)
In a German study of 1314 infants born in 1990, analyzing the effect of any breastfeeding duration on the prevalence of atopic eczema, it was found that the prevalence of atopic eczema in the first seven years increased with each additional month of breastfeeding.(11a) Again, a dose-response relationship, and a finely-tuned one at that.
In a 2006 U.S. study provided by the National Library of Medicine, assessing 405 children age 6 to 7 from the Childhood Allergy Study, "children who were exclusively breastfed were 50% more likely to show allergic sensitization than exclusively formula-fed only children."(11k)
In a 2007 Canadian study provided by the National Library of Medicine, breastfeeding increased the risk for atopy among boys at age 13 with paternal atopy (OR, 7.39) compared with non-breastfed boys with paternal atopy. For girls at age 13, breastfeeding increased the risk for atopy in those with maternal atopy (OR, 3.13) compared with non-breast-fed girls with maternal atopy. (11r)
In a 2000 Finnish study, it was found that prolonged breast-feeding, either exclusively or combined with infrequent exposure to small amounts of cow's milk during the first 2 months of life, induces development of allergic reaction to cow's milk, with odds ratios of 5.1 and 5.7. (11r2)
In a New Zealand study, 504 children were breastfed (4 weeks or longer) and 533 were not. "More children who were breastfed were atopic at all ages from 13 to 21 years ..." Multifactor analysis controlling for socioeconomic status, parental smoking, and birth order showed odds ratios of .....1.83 for the breastfed children (vs. non-breastfed) for current asthma at 9-26 years by repeated-measures analysis, at each assessment within that age range.(11d)
To summarize: There is good evidence indicating health benefits to a child of breastfeeding while the breastfeeding is taking place, and probably for a few months following weaning. But the evidence appears to be overwhelming that the medium- and long-term effects of breastfeeding regarding asthma and allergies are adverse. The above studies are only part of the evidence for the above relationship. To be shown below (in Section 4) is considerable historical health data helping to verify the above.
Section 2.c: Additional explanation of how breastfeeding contributes to asthma:
Bearing in mind the link between asthma and tobacco smoke, note that a 1998 study (of 330 mother-infant pairs) found that "breast-fed infants of smoking mothers have urine cotinine levels 10-fold higher than bottle-fed infants whose mothers smoke."11r3 (Cotinine is a marker for smoke exposure) So it appears that the results of smoke in the air are dramatically increased due to the strong concentrating effect of the lactation process, taking in moderate doses of environmental contaminants and transferring them to the infant in far more potent form. This would almost certainly apply in the case of other atmospheric contaminants also.
Section 2.d: Relevant links:
Although this article is devoted to effects of breastfeeding as related to asthma and allergies, it is worth mentioning in passing that there is also excellent evidence linking increased breastfeeding with increased
-- obesity (see www.child-obesity.us),
-- diabetes (see www.breastfeeding-and-diabetes.info),
-- childhood cancer (see www.breastfeeding-and-cancer.info),
-- ADHD and psychological problems (see www.breastfeeding-health-effects.info), and
-- autism (see www.breastfeeding-and-autism.net). There is an interesting quote in this last-mentioned website, in which a very highly-published scientist with the distinguished status of Fellow of the American College of Nutrition (R.A. Shamberger, PhD) summarizes his study of autism and breastfeeding data in all 50 U.S. states and 51 U.S. counties as follows: "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."(11y)
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An apparent contradiction regarding asthma that nobody seems to be able to explain, but which has a perfectly logical explanation:
Concerning air pollution as a determinant of asthma prevalence, a seeming contradiction to previously-accepted beliefs has been observed: "pediatric asthma prevalence is substantially lower in relatively highly polluted European countries such as the former East Germany, Poland, and Estonia." (citing studies published in 1992 and 1994)(11z) This finding was so contrary toward established beliefs about effects of coal-burning pollution on asthma that it was responsible for shifting the entire focus of research on the subject.(11m)
However, there was in actuality no good reason to doubt the established beliefs about the underlying environmental toxins. Those toxins are apparently harmful only if the child's immune system is not well developed; and apparently there were fewer children in the former Iron Curtain countries with impaired immune systems. It is apparently not common knowledge, but is nevertheless true, that breastfeeding rates were very low in the Soviet-controlled states as long as that control continued. (see footnote 8fa at www.breastfeeding-and-diabetes.info. See Section 1 about negative effects of breastfeeding on development of the immune system, and also see Section 2 for ample evidence that breastfeeding leads to increased asthma incidence, especially as the breastfed children become older. The studies finding surprisingly-low asthma prevalence in the former Soviet lands were published in 1992 and 1994, reflecting apparent effects of the low breastfeeding rates that had prevailed during the infancies of the children who were surveyed. So there appears to be no reason to question the well-observed connection between pollution and asthma, if one is aware of why the percentage of children with compromised immune systems can vary substantially between regions with different breastfeeding rates.
Historical health data showing what happened regarding asthma and allergy incidences following increases in breastfeeding
Note from these charts that breastfeeding in the U.S. increased very substantially in the decades following 1971. (These two charts were from different surveys, but they appear to be the best available for their respective periods, and they indicate rapid growth beginning in about 1972.)
For the period from 1969–1970 to 1994–1995, Newacheck and Halfon (2000) reported that the prevalence of disabilities related to asthma among U.S. children (based on the National Health Interview Survey) increased 232%, or more than tripled.(12) Notice how compatible that is with the increases in breastfeeding rates that took place during those years.
Data on serious asthma problems, provided by the U.S. CDC, only goes back to 1980, but it shows much of the increase (through 1995) referred to by Newacheck and Halfon. And, at least as significantly, it shows that there was no increase taking place in the adult population while hospitalizations for asthma were rapidly increasing among children. See (below) data for those below age 18 (on the first line) and for adults on the second line.
(Source of chart: Table 29 at www.cdc.gov/mmwr/preview/mmwrhtml/ss5608a1.htm)
Note that hospitalizations of both age groups declined after 1995, probably due to advances in treatments and reductions in air pollution. The decline was 35% among the adult age group between 1995 and 2004 but only 20% among the children; so it appears that, even after the increases in their major asthma problems had peaked, children (born at a time of greatly increased breastfeeding) were still at a substantial disadvantage in benefitting from conditions that permitted general declines in asthma.
For additional evidence along the above lines, see Appendix B.
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It is also revealing to see how closely the changes in asthma rates among black children correlate with earlier changes in breastfeeding. The CDC points out, "The greatest rise in asthma rates was among black children from 2001 through 2009" (almost a 50% increase), whereas the increase in asthma among U.S. children overall during that time was only about 10%. (17) Having read of that remarkably high increase in asthma only among black children in 2001-2009, then note the huge change in breastfeeding rates that took place only among black women during the period leading up to that increase: those rates increased "among non-Hispanic black women from 36% in 1993-1994 to 65% in 2005-2006." By contrast, changes in breastfeeding rates during that time period in the only other ethnic groups reported on were far smaller -- 62% increasing to 79% among non-Hispanic whites, and 67% increasing to 80% among Mexican-Americans;(18) those comparatively minor increases were compatible with the minor increases that took place in asthma in those other groups, during the time period under consideration.
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Atopic dermatitis is a form of skin allergy. Notice in this CDC chart what has been happening in prevalence of allergies as breastfeeding rates have been rising, including a 37% increase in food allergies and a 65% increase in skin allergies for the 0-4 age group in just 12 years. Note, in Figure 1 above, that the increase in the U.S. breastfeeding rate at six months shown for the years relevant to that period (1995 to 2010) was 57%.
For the period before the years shown in the above chart, the CDC apparently does not provide data, but the following from an article in the New England Journal of Medicine fills in as follows: (as published in 2008) "The prevalence of atopic dermatitis has doubled or tripled in industrialized countries during the past three decades, affecting 15–30% of children."(20) That doubling or tripling over that time period bears a close resemblance to the increases in breastfeeding during the years that would have been relevant, as seen in Figures 1.
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More on asthma in relation to breastfeeding: In an American study published in 2004, it was found that children in California day-care settings who were exclusively breastfed for four months or more were 34% more likely to have any asthma and twice as likely to have late-onset asthma, compared with children breastfed for less than four months.(21)
According to the Pew Commission on Environmental Health, “little is known about the factors that cause asthma to develop (and even less about why prevalence rates are going up)." (13) There is some support for the idea that the drug acetaminophen contributes to the increase, but 13 years and over 20 studies after that idea was first authoritatively proposed, there is still no agreement on that hypothesis.(14) However, there are good reasons to believe that the increases in breastfeeding are a crucial factor underlying the increases in asthma, as follows:
a) The amounts of the increases in breastfeeding rates were compatible with the amounts of increases in asthma.
b) The times of the variations in breastfeeding rates generally tracked accurately ahead of the times of the changes in asthma prevalence, individually by age group for various different age groups as described above; and those increases came at the same times during which asthma rates were uniformly declining among those age groups not affected by the changing breastfeeding.
c) As indicated in Section 1 above, there is excellent biological evidence for seeing harmful effects of breastfeeding in contemporary developed countries on development of children's immune systems, which are central to vulnerability to asthma and allergies.
d) As indicated in Section 2 above, many studies have found substantially increased levels of asthma and allergies among those who were more highly breastfed, especially as they became older.
*As the author of the above, my role has not been to carry out original research, but instead it has been to read through very large amounts of scientific research that has already been completed on the subjects of environmental toxins and infant development, and then to summarize the relevant findings; my aim has been to put this information into a form that enables readers to make better-informed decisions related to these matters. The original research articles and government reports on this subject (my sources) are extremely numerous, often very lengthy, and are usually written in a form and stored in locations such that the general public is normally unable to learn from them.
My main qualification for writing these publications is ability to find and pull together large amounts of scientific evidence from authoritative sources and to condense the most significant parts into a form that is reasonably understandable to the general public and also sufficiently accurate as to be useful to interested professionals. My educational background included challenging courses in biology and chemistry in which I did very well, but at least as important has been an ability to correctly summarize in plain English large amounts of scientific material. I scored in the top one percent in standardized tests in high school, graduated cum laude from Oberlin College, and stood in the top third of my class at Harvard Business School.
There were important aspects of the business school case-study method that have been helpful in making my work more useful than much or most of what has been written on this subject, as follows: After carefully studying large amounts of printed matter on a subject, one is expected to come up with well-considered recommendations that can be defended against criticisms from all directions. The expected criticisms ingrain the habits of (a) maintaining accuracy in what one says, and (b) not making recommendations unless one can support them with good evidence and logical reasoning. Established policies receive little respect if they can’t be well supported as part of a free give-and-take of conflicting evidence and reasoning. That approach is especially relevant to the position statements on breastfeeding of the American Academy of Pediatrics and the American Academy of Family Physicians, which statements cite only evidence that has been
(a) selected, while in no way acknowledging the considerable contrary evidence,a1 and
(b) of a kind that has been authoritatively determined to be of low quality. Former U.S. Surgeon General Regina Benjamin acknowledged that essentially all of the research supporting benefits of breastfeeding consists merely of observational studies.a1a One determination that evidence from observational studies is of low quality has been provided by Dr. Gordon Guyatt and an international team of 14 associates;a2 Dr. Guyatt is chief editor of the American Medical Association’s Manual for Evidence-based Clinical Practice, in which 26 pages are devoted to examples of studies (most of which were observational) that were later refuted by high-quality studies.a2a A similar assessment of the low quality of evidence from observational studies has been provided by the other chief authority on medical evidence (Dr. David Sackett),a2c writing about “the disastrous inadequacy of lesser evidence,” in reference to findings from observational studies.a2b
When a brief summary of material that conflicts with their breastfeeding positions is repeatedly presented to the physicians’ associations, along with a question or two about the basis for their breastfeeding recommendations, those associations never respond. That says a great deal about how well their positions on breastfeeding can stand up to scrutiny.
The credibility of the contents of the above article is based on the authoritative sources that are referred to in the footnotes: The sources are mainly U.S. government health-related agencies and reputable academic researchers (typically highly-published authors) writing in peer-reviewed journals; those sources are essentially always referred to in footnotes that follow anything that is said in the text that is not common knowledge. In most cases a link is provided that allows easy referral to the original source(s) of the information. If there is not a working link, you can normally use your cursor to select a non-working link or the title of the document, then copy it (control - c usually does that), then “paste” it (control - v) into an open slot at the top of your browser, for taking you to the website where the original, authoritative source of the information can be found.
The reader is strongly encouraged to check the source(s) regarding anything he or she reads here that seems to be questionable, and to notify me of anything said in the text that does not seem to accurately represent what was said by the original source. Write to firstname.lastname@example.org. I will quickly correct anything found to be inaccurate.
For a more complete statement about the author and Pollution Action, please go to www.pollutionaction.org.
Fredericksburg, VA, USA
Studies cited by another author indicating negative effects of breastfeeding related to asthma and allergies:
“…. in all samples, children who were breast-fed were at higher risk for asthma.”..
is taken from a 2007 AHRQ Report on breastfeeding
“It should also be noted that the fourth study, which did not qualify for inclusion in our new meta-analyses, reported an increase in asthma risk with increased duration of breastfeeding in those subjects with a maternal history of asthma.
“In summary, at the present time, it is not possible to conclude that exclusive breastfeeding protects young infants who are at risk of atopic disease from developing asthma in the long term (>6 years of age), and it may even have a detrimental effect.
“The associating risk factors identified were being boys, later commencement of mixed feeding, exclusive breast feeding for 3 months,
“Breastfeeding was positively associated with AD, with dose-response association. Furthermore, children with a longer breastfeeding duration were also significantly more likely to have AD (P for trend < .001).
"The risk of eczema was increased in infants with increasing duration of breast-feeding.”
"FA was associated with recurrent wheeze, eczema, aeroallergen sensitization, male sex, breast-feeding….” http://www.ncbi.nlm.nih.gov/pubmed/26130398
"Having been breastfed correlated with likelihood of food allergy…”
The chart just below considerably updates the above charts, while showing continuation of the same relationships observed above. Note that outpatient hospital visits for children increased by 24% during the few years between 2001-2003 and 2007-2009, while such visits by adults over age 35 declined by 20%. That is, those who were heavily exposed to the increases in breastfeeding had rapidly increasing asthma at the same exact time as those with very little or no exposure to breastfeeding had declining rates of asthma.
Table 19 just above also shows similarities to the earlier pattern with regard to deaths from asthma. Although the overall trend is downward during this period, again we see a vastly less favorable trend among those greatly exposed to breastfeeding as compared with those who had very little or no such exposure: a 5% decline as opposed to a 27% decline in deaths.
(1) Dr. Richard Blumberg, in Cell Research, advance online publication 24 April 2012; doi: 10.1038/cr.2012.65 "Early exposure to germs and the Hygiene Hypothesis," Division of Immunology, Children's Hospital Boston, Harvard Medical Sch'l; and FDA website, at www.fda.gov/biologicsbloodvaccines/resourcesforyou/consumers/ucm167471.htm
(2) "Surgeon General's Call to Action to Support Breastfeeding, 2011," including p. 33, which can be found at http://www.surgeongeneral.gov/library/calls/breastfeeding/calltoactiontosupportbreastfeeding.pdf
(3) Environmental Epidemiology of Pediatric Asthma and Allergy, Christine Cole Johnson et al., Epidemiologic Reviews, Oxford Journals, Volume 24, Issue 2 Pp. 154-175
(3b) "Atopic dermatitis" Bieber T N Engl J Med. 2008 Apr 3; 358(14):1483-94.
(4) quoted in website of USA Today, posted 8/7/2005, "Allergy sensitivity doubles since 1970s" found at http://usatoday30.usatoday.com/news/health/2005-08-07-allergy-sensitivity_x.htm?POE=click-refer
(5) Management of Atopic Dermatitis in the Pediatric Population Andrew C. Krakowski, MD et al., Found at http://pediatrics.aappublications.org/content/122/4/812.long
(8k) Lack of association between early exposure to cow's milk protein and beta-cell autoimmunity. Diabetes Autoimmunity Study in the Young (DAISY) Norris JM et al., JAMA. 1996 Aug 28;276(8):609-14.
(8l) Indian J Pediatr.
2001 Feb;68(2):107-10. IDDM and early exposure of infant to cow's milk and solid food. Esfarjani F et al., National Nutrition and Food Technology Research Institute, Shaheed Beheshti University, Tehran, IR, Iran.
(8m) IDDM and early infant feeding. Sardinian case-control study. Meloni T et al., Diabetes Care. 1997 Mar;20(3):340-2. Istituto di Clinica Pediatrica e Neonatologica, University of Sassar, Italy.
(8n) Early infant feeding and type 1 diabetes. Savilahti E et al., Eur J Nutr. 2009 Jun;48(4):243-9. doi: 10.1007/s00394-009-0008-z. Epub 2009 Mar 5. Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland
(8o) The relation of early nutrition, infections and socio-economic factors to the development of childhood diabetes. Telahun M et al., Department of Paediatrics and Child Health, Faculty of Medicine, Addis Abeba University. Ethiop Med J. 1994 Oct;32(4):239-44.
(8p) IDDM and Early Infant Feeding: Sardinian case-control study Tullio Meloni, MD (+5 other MDs and one PhD) Istituto di Clinica Pediatrica e Neonatologica, University of Sassari Sassari American Diabetes Assn., Diabetes Care, Copyright © 1997 by the American Diabetes Association
(8x) V Mijac et al., Role of environmental factors in the development of insulin-dependent diabetes mellitus (IDDM) in Venezuelan children (in Spanish but good abstract in English), Invest Clin. 1995 June;36(2): 73-82 at http://www.ncbi.nim.nih.gv/pubmed/7548302
(9)http://www.fda.gov/biologicsbloodvaccines/resourcesforyou/consumers/ucm167471.htm Also "Too clean, or not too clean: the Hygiene Hypothesis and home hygiene," SF Bloomfield et al. Clin Exp Allergy. 2006 April; 36(4): 402–425. Blackwell Publishing Ltd found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448690/
Also "Early exposure to germs and the Hygiene Hypothesis" Dale T Umetsu Cell Research advance online publication 24 April 2012; doi: 10.1038/cr.2012.65 Division of Immunology, Karp Laboratories, Children's Hospital Boston, Harvard Medical School, Boston, MA http://www.nature.com/cr/journal/vaop/ncurrent/full/cr201265a.html
(9b) "Breastfeeding, Family Physicians Supporting (Position Paper)" -- AAFP Policies -- American Academy of Family Physicians
(9c) Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment, p. 150, Committee on EPA's Exposure and Human Health Reassessment of TCDD and Related Compounds, National Research Council, ISBN: 0-309-66273-7, 268 pages, 6 x 9, (2006) Available from the National Academies Press at:
(10) "Environmental toxicants and the developing immune system: a missing link in the global battle against infectious disease?" Bethany Winans, et al., Reprod Toxicol. 2011 April; 31(3): 327–336. Published online 2010 September 22. doi: 10.1016/j.reprotox.2010.09.004 PMCID: PMC3033466 NIHMSID: NIHMS245165 accessed at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033466/ citing the following:
Heilmann C, Grandjean P, Weihe P, Nielsen F, Budtz-Jorgensen E. "Reduced antibody responses to vaccinations in children exposed to polychlorinated biphenyls." PLoS Med. 2006;3:e311. [PMC free article
Weisglas-Kuperus N, Patandin S, Berbers GA, Sas TC, Mulder PG, Sauer PJ, et al. "Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children." Environmental health perspectives. 2000;108:1203. [PMC free article]
Glynn A, Thuvander A, Aune M, Johannisson A, Darnerud P, Ronquist G, et al. "Immune cell counts and risks of respiratory infections among infants exposed pre- and postnatally to organochlorine compounds: a prospective study". Environmental Health. 2008;7:62. [PMC free article]
Dallaire F, Dewailly E, Muckle G, Vezina C, Jacobson SW, Jacobson JL, et al. "Acute infections and environmental exposure to organochlorines in Inuit infants from Nunavik." Environ Health Perspect. 2004;112:1359–63. [PMC free article]
Dewailly E, Ayotte P, Bruneau S, Gingras S, Belles-Isles M, Roy R. "Susceptibility to infections and immune status in Inuit infants exposed to organochlorines.” Environ Health Perspect. 2000;108:205–11. [PMC free article]
Jedrychowski W, Galas A, Pac A, Flak E, Camman D, Rauh V, et al. "Prenatal ambient air exposure to polycyclic aromatic hydrocarbons and the occurrence of respiratory symptoms over the first year of life." European journal of epidemiology. 2005;20:775–82.
Weisglas-Kuperus N, Vreugdenhil HJ, Mulder PG. "Immunological effects of environmental exposure to polychlorinated biphenyls and dioxins in Dutch school children." Toxicol Lett. 2004;149:281–5.
Guo YL, Lambert GH, Hsu CC, Hsu MM. Yucheng: "Health effects of prenatal exposure to polychlorinated biphenyls and dibenzofurans." Int Arch Occup Environ Health. 2004;77:153–8.
Vos JG, Moore JA. "Suppression of cellular immunity in rats and mice by maternal treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin." International archives of allergy and applied immunology.
(10a) Potential for early-life immune insult including developmental immunitoxicity in autism and autism spectrum disorders: Focus on critical windows of immune vulnerability Dietert and Dietert, Journal of Toxicology and Environmental Health, PartB, 11:600-680, 2008 Taylor and Francis Group, LLC
(10c) Danish Health and Medicines Authority, 2013, Health risks of PCB in the indoor climate in Denmark, at http://sundhedsstyrelsen.dk/publ/Publ2013/12dec/HAofPCBindoorDK_en.pdf
(10d) Pediatric Research (2001) 50, 331–336; doi:10.1203/00006450-200109000-00007 Early Childhood Determinants of Organochlorine Concentrations in School-Aged Children, Wilfried Karmaus et al.
(10e) U.S. Agency for Toxic Substances and Disease Registry, Toxicological Profile for Polychlorinated Biphenyls (PCBs), 2000, at http://www.atsdr.cdc.gov/toxprofiles/tp17.pdf This ATSDR report quotes a range of concentrations of PCBs in human milk as from 238 to 271 ng/g lipid weight. 1 g lipid weight = about 25g whole weight (assuming 4% fat in human milk). So the concentrations found in the studies were about 250 ng/25g whole weight, which = 10ng/g whole weight. 1 g (gram) = 1 ml of water., so the 10 ng/g whole weight is the same as 10ng/ml. That is the same as 10,000 ng per liter, which is the same as .01 mg/liter. So the levels of PCBs in human milk seem to be about .01 mg/liter, compared with .0005 mg/liter, the maximum allowed by law in U.S. public water systems. That is, about 20 times the concentration that would be allowed in public water systems. (U.S.EPA, Drinking Water Contaminants, National Primary Drinking Water Regulations, at http://water.epa.gov/drink/contaminants/index.cfm#Organic)
10f) Rogan et al., Polychlorinated Biphenyls (PCBs) and Dichlorodiphenyl Dichloroethene (DDE) in Human Milk: Effects of Maternal Factors and Previous Lactation, American Journal of Public Health, A1JPH February 1986, Vol. 76, No. 2, at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1646471/pdf/amjph00265-0062.pdf
(11) Genetic and Perinatal Risk Factors for Asthma Onset and Severity: A Review and Theoretical Analysis Michael B. Bracken et al., Oxford Journals Medicine Epidemiologic Reviews Volume 24, Issue 2, Pp. 176-189 2003 found at http://epirev.oxfordjournals.org/content/24/2/176.full
Many studies that found apparent adverse effects of breastfeeding (from here down to bottom of indented section)
(11a) Breastfeeding duration is a risk factor for atopic eczema. Bergmann RL et al., Clin Exp Allergy. 2002 Feb;32(2):205-9. Found at http://www.ncbi.nlm.nih.gov/pubmed/11929483
(11b) Breastfeeding and allergies: time for a change in paradigm? Duncan JM, et al., Curr Opin Allergy Clin Immunol. 2008 Oct;8(5):398-405. doi: 10.1097/ACI.0b013e32830d82ed. found at www.ncbi.nlm.nih.gov/pubmed/18769191
(11c) The association between infant feeding practices and subsequent atopy among children with a family history of asthma, Mihrshahi S, et al., Clin Exp Allergy. 2007 May;37(5):671-9. found at http://www.ncbi.nlm.nih.gov/pubmed/17456214
(11d) Long-term relation between breastfeeding and development of atopy and asthma in children and young adults: a longitudinal study. Sears MR, et al., Lancet. 2002 Sep 21;360(9337):901-7. Found at http://www.ncbi.nlm.nih.gov/pubmed/12354471
(11e) Risk factors for atopic dermatitis in New Zealand children at 3.5 years of age. Purvis DJ, et al., Br J Dermatol. 2005 Apr;152(4):742-9. http://www.ncbi.nlm.nih.gov/pubmed/15840107
(11f) Breastfeeding and risk of atopic dermatitis, by parental history of allergy, during the first 18 months of life. Benn CS, Am J Epidemiol. 2004 Aug 1;160(3):217-23. Found at http://www.ncbi.nlm.nih.gov/pubmed/15257994
(11g) Breastfeeding and atopic eczema in Japanese infants: The Osaka Maternal and Child Health Study. Miyake Y, et al., Pediatr Allergy Immunol. 2009 May;20(3):234-41. doi: 10.1111/j.1399-3038.2008.00778.x. Found at http://www.ncbi.nlm.nih.gov/pubmed/19438982
(11h) Maternal asthma status alters relation of infant feeding to asthma in childhood.
(11h1) "Surgeon General's Call to Action to Support Breastfeeding, 2011," p. 33 at http://www.surgeongeneral.gov/library/calls/breastfeeding/calltoactiontosupportbreastfeeding.pdf
(11h2) Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services, "Systems to Rate the Strength of Scientific Evidence, Evidence Report/Technology Assessment: Number 47" at http://archive.ahrq.gov/clinic/epcsums/strengthsum.pdf
(11h3) Colen et al., Is breast truly best? Estimating the effects of breastfeeding on long-term child health and wellbeing in the United States using sibling comparisons, Soc Sci Med. 2014 May;109:55-65. doi: 10.1016/j.socscimed.2014.01.027. Epub 2014 Jan 29. at http://www.ncbi.nlm.nih.gov/pubmed/24698713
(11h4) Perkin et al., Randomized Trial of Introduction of Allergenic Foods in Breast-Fed Infants, N Engl J Med 2016; 374:1733-1743 May 5, 2016, at http://www.nejm.org/doi/full/10.1056/NEJMoa1514210?query=TOC
(11j) Gene polymorphisms, breast-feeding, and development of food sensitization in early childhood. Hong X, J et al., Allergy Clin Immunol. 2011 Aug;128(2):374-81.e2. doi: 10.1016/j.jaci.2011.05.007. Found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149737/
(11k) Breastfeeding history and childhood allergic status in a prospective birth cohort. Wegienka G, et al., Ann Allergy Asthma Immunol. 2006 Jul;97(1):78-83. Found at http://www.ncbi.nlm.nih.gov/pubmed/16892786
(11m) The Asthma Epidemic, Waltraud Eder, M.D., et al, New England Journal of Medicine, N Engl J Med 2006;355:2226-35. Copyright © 2006 Massachusetts Medical Society.found at http://physio.ucsf.edu/GEMS/courses/Immunology/materials/fa11_essential_immunology/september_6_asthma/elder_nejm.pdf
*(11n) Prolonged exclusive breastfeeding is associated with increased atopic dermatitis: a prospective followup study of unselected healthy newborns from birth to age 20 years. Pesonen M et al., Clin Exp Allergy 2006; 36:1011–1018.*
(11o) *NOTE: The studies listed in footnotes 11n and 11p were found in Breastfeeding and allergies: time for a change in paradigm? Duncan JM, et al., Curr Opin Allergy Clin Immunol. 2008 Oct;8(5):398-405. doi: 10.1097/ACI.0b013e32830d82ed. found at www.ncbi.nlm.nih.gov/pubmed/18769191
*(11p1) Factors influencing the relation of infant feeding to asthma and recurrent wheeze in childhood. Wright AL,et al., Thorax 2001; 56:192–197. Also:
*(11p2) Effect of breastfeeding on lung function in childhood and modulation by maternal asthma and atopy. Guilbert TW et al., Am J Respir Crit Care Med 2007; 176:843–848.*
(11r) Interactions between breast-feeding, specific parental atopy, and sex on development of asthma and atopy. Mandhane PJ et al., J Allergy Clin Immunol. 2007 Jun;119(6):1359-66. Epub 2007 Mar 13. Found at http://www.ncbi.nlm.nih.gov/pubmed/17353035/
(11r2) Saarinen KM, et al., Infant feeding patterns affect the subsequent immunological features in cow's milk allergy. Clin Exp Allergy. 2000 Mar;30(3):400-6. at http://www.ncbi.nlm.nih.gov/pubmed/10691899
(11r3) M A Mascola,et al., Exposure of young infants to environmental tobacco smoke: breast-feeding among smoking mothers. Am J Public Health. 1998 June; 88(6): 893–896. PMCID: PMC1508233 found at www.ncbi.nlm.nih.gov/pmc/articles/PMC1508233
(11s) Breast-feeding and atopic disease: a cohort study from childhood to middle age. Matheson MC, et al., J Allergy Clin Immunol. 2007 Nov;120(5):1051-7. Epub 2007 Aug 31. Found at http://www.ncbi.nlm.nih.gov/pubmed/17764732
(11t) Infant Feeding Practices and Nut Allergy over Time in Australian School Entrant Children, Jessica Paton, et al., Int J Pediatr. 2012; 2012: 675724. Published online 2012 July 3. doi: 10.1155/2012/675724 PMCID: PMC3397206 found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3397206/
(11u) Relation between Breastfeeding and the Prevalence of Asthma: The Tokorozawa Childhood Asthma and Pollinosis Study, Yousuke Takemura et al., Oxford Journals Medicine American Journal of Epidemiology Volume 154, Issue 2 Pp. 115-119. American Journal of Epidemiology aje.oxfordjournals.org Am. J. Epidemiol. (2001) 154 (2): 115-119. doi: 10.1093/aje/154.2.115 found at http://aje.oxfordjournals.org/content/154/2/115.abstract?ijkey=119530f7421c3b14e82a501acb68c2f174e4b041&keytype2=tf_ipsecsha
(11u1) Costa Lima et al., Do Risk Factors for Childhood Infections and Malnutrition Protect Against Asthma? A Study of Brazilian Male Adolescents, Am J Public Health. 2003 November; 93(11): 1858–1864. at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448063/
(11u2) Philippe Grandjean et al., Allergy and Sensitization during Childhood Associated with Prenatal and Lactational Exposure to Marine Pollutants Environ Health Perspect. 2010 October; 118(10): 1429–1433. PMCID: PMC2957924 found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2957924
(11u3) Hong et al., Gene Polymorphisms, Breastfeeding, and Development of Food Sensitization in Early Childhood,. J Allergy Clin Immunol, 2011;128(2):374 at http://pediatrics.aappublications.org/content/pediatrics/130/Supplement_1/S8.2.full.pdf
(11v) Risk factors for early, persistent, and late-onset wheezing in young children. Rusconi F, , et al. Am J Respir Crit Care Med 1999; found at http://www.atsjournals.org/doi/pdf/10.1164/ajrccm.160.5.9811002
(11w) Feeding practices of babies and the development of atopic dermatitis in children after 12 months of age in Armenia: is there a signal? Sahakyan A, et al., Eur J Epidemiol. 2006;21(9):723-5. Epub 2006 Oct 18. Found at http://www.ncbi.nlm.nih.gov/pubmed/17048079
(11x) Infant feeding practices and physician diagnosed atopic dermatitis: a prospective cohort study in Taiwan. Chuang CH et al., Pediatr Allergy Immunol. 2011 Feb;22(1 Pt 1):43-9. doi: 10.1111/j.1399-3038.2010.01007.x. Found http://www.ncbi.nlm.nih.gov/pubmed/20573037
The indented studies inserted below are placed there only to bring together in one place (along with the above, starting with 11a) a large number of scientific studies that found breastfeeding to lead to increases in disease:
. . . . . . . . . . . . . . . . . . . . . . .
(11y) Autism rates associated with nutrition and the WIC program. Shamberger RJ., King James Medical Laboratory, Cleveland, Ohio J Am Coll Nutr. 2011 Oct;30(5):348-53. At http://www.ncbi.nlm.nih.gov/pubmed/22081621
(11z) Prevalence of asthma and atopy in two areas of West and East Germany. von Mutius E, Martinez FD, Fritzsch C, Nicolai T, Roell G, Thiemann HH. Am JRespir Crit Care Med 1994;149:358-64.
(12) Cited in The Future of Disability in America, Ch. 3, p. 77 Institute of Medicine (US) Committee on Disability in America; Field MJ, et al., ed., National Academies Press (US); 2007 bookshelf ID: NBK11437 found at www.ncbi.nlm.nih.gov/books/NBK11437
(12a) “New Asthma Estimates: Tracking Prevalence, Health Care and Mortality,” NCHS, CDC, 2001.
(12b) from CDC: Summary of Trends in Breastfeeding 2011 Pediatric Nutrition Surveillance National Table 13D Children Aged < 5 Years
(15) Table 13d of CDC's 2011 Pediatric Nutrition Surveillance at http:/www.cdc.gov/pednss/pednss_tables/pdf/national_table13.pdf
(16) "Environmental toxicants and the developing immune system: a missing link in the global battle against infectious disease?" Bethany Winans, et al., Reprod Toxicol. 2011 April; 31(3): 327–336. at https://www.ncbi.nlm.nih.gov/pubmed/20851760. See footnote 10 for details.
(16a) The childhood asthma epidemic G Russell et al., Thorax. 2006 April; 61(4): 276–278. doi: 10.1136/thx.2005.052662 PMCID: PMC2104623 found at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2104623/ Also The Asthma Epidemic, Waltraud Eder, M.D., et al., N Engl J Med 2006; 355:2226-2235November 23, 2006DOI: 10.1056/NEJMra054308 Also U.S. Department of Health and Human Services at http://aspe.hhs.gov/sp/asthma/overview.htm Also "While increasing numbers of Britons are suffering from allergies, more believe - falsely – that they are." Barbara Lantin investigates, Daily Telegraph 24 Apr 2006" "...in the past 20 years, asthma, hayfever and eczema have increased two- to threefold." Found at http://www.telegraph.co.uk/health/alternativemedicine/3338707/The-allergy-epidemic.html Also The epidemic of asthma and allergy Stephen T Holgate, DSc FRCP J R Soc Med. 2004 March; 97(3): 103–110. PMCID: PMC1079317 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1079317/
(16b) http://fooddrugallergy.ucla.edu/body.cfm?id=40 "About Allergies/ Why Are Allergies Increasing?"
(17) CDC's "Asthma in the U.S." at http://www.cdc.gov/vitalsigns/asthma
(18) "Breastfeeding in the United States: Findings from the National Health and Nutrition Examination Survey, 1999-2006"
(20) "Atopic dermatitis" Bieber T N Engl J Med. 2008 Apr 3; 358(14):1483-94.
183. Miller JE. Predictors of asthma in young children: does reporting source affect our conclusions? Am J Epidemiol 2001;154:245–50. Abstract/FREE Full Text
184. Oddy WH, Holt PG, Sly PD, et al. Association between breast feeding and asthma in 6 year old children: findings of a prospective birth cohort study. BMJ 1999;319:815–19. Abstract/FREE Full Text
188. Sears MR, Greene JM, Willan AR, et al. Long-term relation between breastfeeding and development of atopy and asthma in children and young adults: a longitudinal study. Lancet 2002;360:901–7. CrossRefMedlineWeb of Science
190. Takemura Y, Sakurai Y, Honjo S, et al. Relation between breastfeeding and the prevalence of asthma: the Tokorozawa Childhood Asthma and Pollinosis Study. Am J Epidemiol 2001;154:115–19.Abstract/FREE Full Text
Exposures to environmental factors during the first year of life have also been shown to impact asthma risk (Peden, 2000). Prenatal or postnatal exposures may alter early development of the airways and immune system, resulting in permanent alterations that create a lasting vulnerability to asthma later in life (Ho, 2010; Dietert and Zelikoff, 2008).
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