OK, so . . . many people have asked me to respond in specific detail to Katie Hinde’s blog column, following on Barbara King’s NPR post on breastfeeding. One colleague even accused me of being a “senior scholar in the field” and “bullying an untenured colleague” and implying that I think Katie Hinde is an idiot. So, to clarify.
I do not think Katie Hinde is an idiot. Not at all. I also do not think that being a professor at Harvard automatically makes anyone a “damn fine” member of their scientific field. A number of highly respected professors at Harvard have been fired over the years for plagiarism and academic dishonesty. Katie Hinde is NOT one of them. The point remains that it is not logical to claim that simply because someone is at Harvard their word must be taken as the definitive view on a subject.
Katie Hinde’s blog post is set up as a MYTH: vs. TRUTH: exercise. However, many of her myths are either what we like to call “straw men” – things no one really believes, or they are indeed “myths.” I’ve set this response up as “What she writes” vs. “What the reality is.”
What she writes: “When Barbara contacted me to provide comments for her thoughtful piece on very prolonged breastfeeding in response to the Mirror’s report on Denise Sumpter and the accompanying brouhaha, I groaned.”
What the reality is: By referring to Barbara King’s column as being a piece about “very prolonged breastfeeding” she gives us her first clue of her opinion on this issue. Opinion. Not fact. She thinks breastfeeding a 5-6+ year old is “very prolonged”. In reality, it is perfectly within our best understanding of the range of weaning ages for modern humans – 2.5 to 7.0 years (and yes, this is MY research, and NO, Hinde doesn’t refer to it or cite it). There have been, and continue to be, many thousands of children around the world nursing beyond the age of 3 years, which is usually the cut-off for “extended breastfeeding” as a descriptor to be applied. Many people object to the term “extended” even, and prefer ‘full-term” or “natural-term” breastfeeding, or simply “breastfeeding.” To describe nursing a 6 year old as “very prolonged breastfeeding” reveals a lack of understanding of how humans behave, both in the historic and prehistoric past, and today in modern populations around the world.
What she writes: “Myth: Humans are adapted to wean at a specific age. . .
Sometimes folks will posit that this adaptive sweet spot is at 2 years old, at 2.5 years, at 4 years, 5 years, or some even 7 years.”
What the reality is: No one says this, except pediatricians who like to claim that the specific age is 6 weeks, or 6 months, or 1 year. Many physicians have told their patients’ mothers that breast milk abruptly ceases to have any nutritional value after a certain length of time post-partum. Many pediatricians and others report that the American Academy of Pediatrics recommendation is to “breastfeed for a year.” In reality, one year is the AAP’s minimum for weaning, while the World Health Organization and the American Academy of Family Physicians place the minimum at two years. My research suggests a hypothetical range of 2.5 to 7.0 years – a very wide range of ages indeed. I don’t know anyone who has ever claimed 2 years, 2.5 years, 4 years, 5 years, or 7 years, as Hinde states. I don’t know anyone who has ever claimed there is one specific optimal age for all mother-child pairs. No one.
What she writes: “First of all, weaning is not an event, it is a process, so it can’t happen AT a time.”
What the reality is: The term “weaning” means different things to different people. Some researchers are sloppy and don’t define their terms at all, leaving the reader to guess. Some researchers define their terms and then aren’t consistent in using them as they just defined them. Some researchers define “weaning” as a process – Margaret Mead did. And some researchers, including me, are very careful to define “weaning” as “the end of any breastfeeding.” When weaning clearly is defined this way, weaning is an event. When mothers talk about weaning, they are almost always talking about the end of breastfeeding. When asked “How old was your baby when they were weaned?” they don’t respond “Well, she began solids at 4 months and nursed until 18 months.” Or “He began solids at 7.5 months and nursed until he was 4years and 3 months.” No – they say “She weaned when she was 18 months old,” “He weaned at a little over 4 years.” The “meaning of weaning” is how you define it. Most mothers of older nurslings will know very specifically how old their child was when they were weaned. In my research on moms in the US who breastfed longer than 3 years, the vast majority knew, often to the date, when the last breastfeeding session took place. Some kids wean once and then come back and nurse again for a while – one of my kids weaned at age 3 the first time, and at age 4 the second time. It’s true that you can continue to nurse/breastfeed beyond when you are lactating, and that during the last weeks and months of full-term breastfeeding there may not be a significant amount of milk transferred. But we need definitions, and “weaning” in much of the research literature as well as for most of the lay public means the end of breastfeeding.
What she writes: “Turns out, new research is demonstrating that tooth eruption schedules aren’t as meaningful for making this inference as we once thought (Smith 2013). In part this is because average tooth eruption patterns were linked to averages for “weaning age” at the species level, but that tells us little about the variation WITHIN SPECIES… which can be substantial.”
What the reality is: I am not aware of anyone claiming that there should be a link between an individual’s time of eruption of their first permanent teeth and that individual’s age at weaning. No one says this. Another straw man. In my original paper using nonhuman primates as a source of information about how long humans would nurse if we didn’t screw it up with cultural biases and beliefs, I pointed out that Smith’s early work showed a general relationship between age at weaning and eruption of the first permanent teeth in 21 primate species. In humans, eruption of the first permanent molar happens at 5.5 to 6.0 years of age. This gives us one clue as to what might be one indicator of a natural age of weaning for modern humans as a species. No one has ever claimed that this relationship will hold true at the individual level, or that there is no variation in these variables, because both of these life history variables –age at weaning and age at first molar eruption – occur as ranges of variation. We are comparing average to averages. If humans are like the other primates (other than chimpanzees, who have early first permanent molar eruption), and the average age for eruption of the first permanent molars in modern humans is 5.5-6.0 years, and if age at weaning should generally agree with that, as it seems to do for many mammalian species, including many primates, then the average age of weaning for humans would also be 5.5-6.0 years based on this ONE INDICATOR. Not “all children will wean at 5.5 to 6.0 years” or “all children should be nursed until they are 5.5-6.0 years” – merely that the average in a human population not yet influenced by contrary cultural beliefs would probably be close to this age, based on this ONE INDICATOR. There are other indicators that are down at 2.5-3.0 years of age, and others at 4.5 years, based on other life history variables, and all with their own ranges of variation!
Side note: I had a discussion with Dr. Hinde several years ago about the fact that it had been known for years that chimpanzee’s did not fit the general rule of “age at weaning = age at first permanent molar eruption” after she tried to argue that “new” data based on photos of yawning chimpanzees showed this lack of connection. Back in the mid-1990s, this was already in the published primate literature and I cited this anomaly in several of my papers. She was apparently unaware of the previous research literature on this topic.
What she writes:(with respect to parent-offspring conflict). “This is why I find the AAP recommendation of “for as long as is mutually desired by the mother and baby” suboptimal, since parent-offspring conflict theory tells us that adaptive optima for mothers and offspring are expected to differ.”
What the reality is: There is nothing – “Nothing, Lebowski” – in the AAP recommendations that would lead one to think they are implying that mother and child would agree on the time to stop breastfeeding. When they say “for as long as is mutually desired by mother and infant” they are saying “as long as both parties to the relationship want to continue.” It is a relationship – a close, physical relationship – between two people. If the child no longer wants to breastfeed, then the relationship ends. If the mother no longer wants to breastfeed, then the relationship ends. Sometimes the child weans before the mother really wanted them to. Sometimes the mother weans the child before the child really wanted to stop – and believe me, a 3-4-5-6 year old can express some pretty cogent verbal arguments as to why they should still be allowed to nurse. They don’t need to resort to “weaning tantrums” of the kind Jane Goodall has reported for chimpanzees. The AAP is simply saying that as long as both mother and child want to continue breastfeeding, it’s absolutely fine to do so. [Side-note: Think of it like sex between consenting adults: if either partner doesn’t want to have sex, then the other partner shouldn’t impose their wishes. But saying that both partners should feel free to have sex if they both want to, in no way implies that both of them will always want sex at the same time. As every adult knows.]
What she writes: “The gene expression that controls the production of lactase shuts down during development as infants transition into juveniles. But many humans have “lactase persistence genes” that express well into adulthood. These genes have been favored by a cultural context of dairying. Individuals who continued to express lactase post-weaning living in populations that had cows, goats, camels, mares, and sheep were able to digest animal milks gaining protein and fat in their diet. This complex interplay between the human genome and cultural practices is known as gene-culture coevolution. This complicates the inferences we can make about the duration of breastfeeding and weaning times. Selective favoring of lactase persistence may have been driven by animal herding (pastoralism), and as a byproduct facilitated very prolonged breastfeeding in some populations.”
What the reality is: The terms “infancy” and “juvenile” are defined by zoologists based on dental eruption. Infancy is birth until the eruption of the first permanent teeth. The juvenile stage begins with the eruption of the first permanent teeth and continues until the eruption of the last permanent tooth. For humans, the transition from infancy to the juvenile stage begins at 5.5 to 6.0 years. The juvenile stage lasts until the late teens/early 20s. So yes, the variant of the lactase gene that shuts down in most of the world’s population in childhood does not allow adults to digest dairy products without unfortunate symptoms (burping, bloating, flatulence). As for when this gene stops producing lactase in various populations, the research says 2 to 10 years. Not surprising. There is, no doubt, much population-level and individual-level variation in when and how this gene stops producing lactase – is it an on/off switch, or a rheostat? Is the gene’s activity affected by whether or not human milk is a constituent of a child’s diet, such that in a population where all adults are lactose intolerant, a child who is still nursing at age 5 will still be producing lactase, while a child who was weaned at 1 year is no longer producing lactase by age 2? It’s an interesting research question – someone should do some research.
However, the evidence does not at all support Hinde’s claim that nursing until the age of 5 or 6 is the result of the coevolution of culture and biology in dairying populations. Indeed, many of the groups with reported typically long durations of breastfeeding are not dairying populations (and have never consumed milk) and therefore have not been selected for lactase persistence. Breastfeeding until 5-6-7+ years in humans is not at all related to whether or not the culture has domesticated animals that they milk, and whether or not the adults consume nonhuman animal milks. I am not aware of any anecdotal reports, let alone research, reporting cases of a child who started having trouble digesting his own mother’s milk as he got older because his lactase gene shut down.
What she writes: “MYTH: We totes know the systematic effects of very prolonged breastfeeding.”
What the reality is: Sigh. Yet another straw man argument. NO ONE EVER CLAIMS THIS!! As I have written in all of my scholarly papers on this issue, and as I have concluded at the end of each of the hundreds (nay, thousands) of conference presentations I have done on this topic – there has been NO research on the comparative outcomes for children breastfed for various lengths of time beyond two years. There have been a few studies that included a category of “18-24+ months”– but there have never been any studies showing what, if any, difference there is in health outcomes, cognitive outcomes, emotional outcomes, etc. for children who nursed for only 3 years versus those who nursed for 5 versus those who nursed for 7. Again, an interesting research question, and definitely one worth exploring, for lots of reasons.
The research that has been done to date shows clearly that the longer you breastfeed, up to the study limits of 2 years, the better all the outcomes are for mother and child. Like an oil well, the benefits decline over time, such that nursing for an extra month early on (2 vs. 3 months) is going to be more significant than nursing for an extra month at age 5 years (60 vs. 61 months). There is no reason to expect that the benefits shut off abruptly at one year of age – as some pediatricians like to claim – nor is there any evidence to claim that the benefits are significant when a child is nursed 6 years rather than 5 years. This lack of research evidence is irrelevant to the point under discussion.
What she writes: “The information of very prolonged breastfeeding of 5+ years comes from rare self-selected cases, an extreme tail end of a continuous distribution of weaning ages.”
What the reality is: Indeed, information about “normal durations of breastfeeding that last up to 6 or 7 years” represents the extreme tail end of a distribution. But nursing to 5+ years is not “rare” – not now, not ever. There are lots of children – thousands and thousands – around the world who are nursing beyond the age of 3, with hundreds and hundreds nursing beyond the age of 5, and quite a few – though no one really knows – nursing beyond 6 and 7.
In my 2004 paper in Clinical Obstetrics and Gynecology, also titled “When to Wean” by the way, and available here on line for free: http://kathydettwyler.weebly.com/uploads/3/0/9/1/30918011/when_to_wean_clin_obstetrics_2004.pdfI report on a study I conducted in the mid-1990s on women in the US who breastfed longer than 3 years. I ended up with 1,280 mother-child pairs. The range of weaning ages was 3 to 9.17 years. Of the whole sample of 1,280, close to half had weaned by age 4years. The average age of weaning for the sample was 4.24 years, with a median of 4 years, a mode of 3.5 years, and a standard deviation of 1.08 years. In the years since I did this research, breastfeeding has become more common in the US, more mothers are nursing longer (according to the CDC statistics), and women are being more vocal and open about how long they nursed their children, in part due to the support now available via the interwebs and celebrity moms like Dr. Mayim Bialik (http://www.mayimbialik.net/beyondthesling/). Nursing until 5+ years of age may be somewhat invisible or cloaked in Western cultures, but it isn’t all that rare.
What she writes: “MYTH: The effects of breastfeeding are the same for all moms & infants in all places always.”
What the reality is: A “myth” is something that is commonly believed to be true, even though it isn’t true. Here we have yet another straw man. I don’t know anyone who believes that “the effects of breastfeeding are the same for all moms & infants in all places always.” Not any researchers, not any physicians, not any mothers. No one. NO. ONE.
What she writes: “MYTH: Moms have all the options.”
What the reality is: Please see the answer to the prior question. No one believes this. No one. NO. ONE. As many of the very same people who are the most outspoken breastfeeding advocates are the VERY SAME PEOPLE who are working for longer/better maternity leaves, on-site child care, flexible work schedules, laws to protect mothers breastfeeding in public, educational programs for partners and other family members and employers, etc. etc. etc. etc. If we “wait until the world has changed” and all these breastfeeding supports are in place before we start telling women the truth about the consequences of their infant feeding decisions, we will never have a breastfeeding-friendly society. Readers are encouraged to look at James Akre’s brilliant book on this topic from 2006. Akre was the head of Infant Nutrition for the World Health Organization for many many years. http://www.amazon.com/The-Problem-Breastfeeding-Personal-Reflection/dp/0977226840
What she writes: “We owe mothers better support and better options, including better formulas that include more bioactive features of breast milk.”
What the reality is: Indeed we do, and breastfeeding advocates have been saying this for as long as I’ve been involved in the field – since 1979. In fact, I state it explicitly in my 1995 chapter “Beauty and the Breast” and in my 1998 Skomp Lecture “Evolutionary Medicine and Breastfeeding: Implications for Research and Pediatric Advice.” Both are available for free on my website at www.kathydettwyler.weebly.org
What she writes: “Words have power. Words chastise, words shame, words bolster, and words buffer. So what do we do, as clinicians, as biologists, as friends, when a single statement about breastfeeding, pro or con, exerts each of those outcomes depending on the person reading and hearing them?”
What the reality is: Indeed, words have power. Words can be outright lies. Words can mislead people. Words can be used to try to make women feel better by denying the reality of how the world works. “Breastfeeding doesn’t matter, don’t worry if you have to stop when you go back to work.” Versus “Breastfeeding really does matter. It’s a shame that your employer won’t accommodate you. You should be angry about this. Let’s do something about it.” I have an entire presentation I have given at many many breastfeeding/lactation conferences on this whole topic of whether telling mothers the truth is wrong/immoral if it might make them feel GUILTY. I side with truth.
What she writes: So proscriptive attitudes about what women should and shouldn’t do with their bodies can suck it.
What the reality is: I agree 1000%. Proscriptive attitudes about what women should and shouldn’t do with their bodies can suck it. Realize that most of these proscriptive attitudes being expressed are aimed at demonizing women who nurse their children for longer than someone else thinks they should. Not at women who bottle-feed, and not at women who “only” nurse for 1 year or for 2 years or for 3 years. No one – least of all me – is saying that women “should” or “must” nurse their children at all, let alone for any specific length of time.
So please stop implying that I am.
I do not think Katie Hinde is an idiot. Not at all. I also do not think that being a professor at Harvard automatically makes anyone a “damn fine” member of their scientific field. A number of highly respected professors at Harvard have been fired over the years for plagiarism and academic dishonesty. Katie Hinde is NOT one of them. The point remains that it is not logical to claim that simply because someone is at Harvard their word must be taken as the definitive view on a subject.
Katie Hinde’s blog post is set up as a MYTH: vs. TRUTH: exercise. However, many of her myths are either what we like to call “straw men” – things no one really believes, or they are indeed “myths.” I’ve set this response up as “What she writes” vs. “What the reality is.”
What she writes: “When Barbara contacted me to provide comments for her thoughtful piece on very prolonged breastfeeding in response to the Mirror’s report on Denise Sumpter and the accompanying brouhaha, I groaned.”
What the reality is: By referring to Barbara King’s column as being a piece about “very prolonged breastfeeding” she gives us her first clue of her opinion on this issue. Opinion. Not fact. She thinks breastfeeding a 5-6+ year old is “very prolonged”. In reality, it is perfectly within our best understanding of the range of weaning ages for modern humans – 2.5 to 7.0 years (and yes, this is MY research, and NO, Hinde doesn’t refer to it or cite it). There have been, and continue to be, many thousands of children around the world nursing beyond the age of 3 years, which is usually the cut-off for “extended breastfeeding” as a descriptor to be applied. Many people object to the term “extended” even, and prefer ‘full-term” or “natural-term” breastfeeding, or simply “breastfeeding.” To describe nursing a 6 year old as “very prolonged breastfeeding” reveals a lack of understanding of how humans behave, both in the historic and prehistoric past, and today in modern populations around the world.
What she writes: “Myth: Humans are adapted to wean at a specific age. . .
Sometimes folks will posit that this adaptive sweet spot is at 2 years old, at 2.5 years, at 4 years, 5 years, or some even 7 years.”
What the reality is: No one says this, except pediatricians who like to claim that the specific age is 6 weeks, or 6 months, or 1 year. Many physicians have told their patients’ mothers that breast milk abruptly ceases to have any nutritional value after a certain length of time post-partum. Many pediatricians and others report that the American Academy of Pediatrics recommendation is to “breastfeed for a year.” In reality, one year is the AAP’s minimum for weaning, while the World Health Organization and the American Academy of Family Physicians place the minimum at two years. My research suggests a hypothetical range of 2.5 to 7.0 years – a very wide range of ages indeed. I don’t know anyone who has ever claimed 2 years, 2.5 years, 4 years, 5 years, or 7 years, as Hinde states. I don’t know anyone who has ever claimed there is one specific optimal age for all mother-child pairs. No one.
What she writes: “First of all, weaning is not an event, it is a process, so it can’t happen AT a time.”
What the reality is: The term “weaning” means different things to different people. Some researchers are sloppy and don’t define their terms at all, leaving the reader to guess. Some researchers define their terms and then aren’t consistent in using them as they just defined them. Some researchers define “weaning” as a process – Margaret Mead did. And some researchers, including me, are very careful to define “weaning” as “the end of any breastfeeding.” When weaning clearly is defined this way, weaning is an event. When mothers talk about weaning, they are almost always talking about the end of breastfeeding. When asked “How old was your baby when they were weaned?” they don’t respond “Well, she began solids at 4 months and nursed until 18 months.” Or “He began solids at 7.5 months and nursed until he was 4years and 3 months.” No – they say “She weaned when she was 18 months old,” “He weaned at a little over 4 years.” The “meaning of weaning” is how you define it. Most mothers of older nurslings will know very specifically how old their child was when they were weaned. In my research on moms in the US who breastfed longer than 3 years, the vast majority knew, often to the date, when the last breastfeeding session took place. Some kids wean once and then come back and nurse again for a while – one of my kids weaned at age 3 the first time, and at age 4 the second time. It’s true that you can continue to nurse/breastfeed beyond when you are lactating, and that during the last weeks and months of full-term breastfeeding there may not be a significant amount of milk transferred. But we need definitions, and “weaning” in much of the research literature as well as for most of the lay public means the end of breastfeeding.
What she writes: “Turns out, new research is demonstrating that tooth eruption schedules aren’t as meaningful for making this inference as we once thought (Smith 2013). In part this is because average tooth eruption patterns were linked to averages for “weaning age” at the species level, but that tells us little about the variation WITHIN SPECIES… which can be substantial.”
What the reality is: I am not aware of anyone claiming that there should be a link between an individual’s time of eruption of their first permanent teeth and that individual’s age at weaning. No one says this. Another straw man. In my original paper using nonhuman primates as a source of information about how long humans would nurse if we didn’t screw it up with cultural biases and beliefs, I pointed out that Smith’s early work showed a general relationship between age at weaning and eruption of the first permanent teeth in 21 primate species. In humans, eruption of the first permanent molar happens at 5.5 to 6.0 years of age. This gives us one clue as to what might be one indicator of a natural age of weaning for modern humans as a species. No one has ever claimed that this relationship will hold true at the individual level, or that there is no variation in these variables, because both of these life history variables –age at weaning and age at first molar eruption – occur as ranges of variation. We are comparing average to averages. If humans are like the other primates (other than chimpanzees, who have early first permanent molar eruption), and the average age for eruption of the first permanent molars in modern humans is 5.5-6.0 years, and if age at weaning should generally agree with that, as it seems to do for many mammalian species, including many primates, then the average age of weaning for humans would also be 5.5-6.0 years based on this ONE INDICATOR. Not “all children will wean at 5.5 to 6.0 years” or “all children should be nursed until they are 5.5-6.0 years” – merely that the average in a human population not yet influenced by contrary cultural beliefs would probably be close to this age, based on this ONE INDICATOR. There are other indicators that are down at 2.5-3.0 years of age, and others at 4.5 years, based on other life history variables, and all with their own ranges of variation!
Side note: I had a discussion with Dr. Hinde several years ago about the fact that it had been known for years that chimpanzee’s did not fit the general rule of “age at weaning = age at first permanent molar eruption” after she tried to argue that “new” data based on photos of yawning chimpanzees showed this lack of connection. Back in the mid-1990s, this was already in the published primate literature and I cited this anomaly in several of my papers. She was apparently unaware of the previous research literature on this topic.
What she writes:(with respect to parent-offspring conflict). “This is why I find the AAP recommendation of “for as long as is mutually desired by the mother and baby” suboptimal, since parent-offspring conflict theory tells us that adaptive optima for mothers and offspring are expected to differ.”
What the reality is: There is nothing – “Nothing, Lebowski” – in the AAP recommendations that would lead one to think they are implying that mother and child would agree on the time to stop breastfeeding. When they say “for as long as is mutually desired by mother and infant” they are saying “as long as both parties to the relationship want to continue.” It is a relationship – a close, physical relationship – between two people. If the child no longer wants to breastfeed, then the relationship ends. If the mother no longer wants to breastfeed, then the relationship ends. Sometimes the child weans before the mother really wanted them to. Sometimes the mother weans the child before the child really wanted to stop – and believe me, a 3-4-5-6 year old can express some pretty cogent verbal arguments as to why they should still be allowed to nurse. They don’t need to resort to “weaning tantrums” of the kind Jane Goodall has reported for chimpanzees. The AAP is simply saying that as long as both mother and child want to continue breastfeeding, it’s absolutely fine to do so. [Side-note: Think of it like sex between consenting adults: if either partner doesn’t want to have sex, then the other partner shouldn’t impose their wishes. But saying that both partners should feel free to have sex if they both want to, in no way implies that both of them will always want sex at the same time. As every adult knows.]
What she writes: “The gene expression that controls the production of lactase shuts down during development as infants transition into juveniles. But many humans have “lactase persistence genes” that express well into adulthood. These genes have been favored by a cultural context of dairying. Individuals who continued to express lactase post-weaning living in populations that had cows, goats, camels, mares, and sheep were able to digest animal milks gaining protein and fat in their diet. This complex interplay between the human genome and cultural practices is known as gene-culture coevolution. This complicates the inferences we can make about the duration of breastfeeding and weaning times. Selective favoring of lactase persistence may have been driven by animal herding (pastoralism), and as a byproduct facilitated very prolonged breastfeeding in some populations.”
What the reality is: The terms “infancy” and “juvenile” are defined by zoologists based on dental eruption. Infancy is birth until the eruption of the first permanent teeth. The juvenile stage begins with the eruption of the first permanent teeth and continues until the eruption of the last permanent tooth. For humans, the transition from infancy to the juvenile stage begins at 5.5 to 6.0 years. The juvenile stage lasts until the late teens/early 20s. So yes, the variant of the lactase gene that shuts down in most of the world’s population in childhood does not allow adults to digest dairy products without unfortunate symptoms (burping, bloating, flatulence). As for when this gene stops producing lactase in various populations, the research says 2 to 10 years. Not surprising. There is, no doubt, much population-level and individual-level variation in when and how this gene stops producing lactase – is it an on/off switch, or a rheostat? Is the gene’s activity affected by whether or not human milk is a constituent of a child’s diet, such that in a population where all adults are lactose intolerant, a child who is still nursing at age 5 will still be producing lactase, while a child who was weaned at 1 year is no longer producing lactase by age 2? It’s an interesting research question – someone should do some research.
However, the evidence does not at all support Hinde’s claim that nursing until the age of 5 or 6 is the result of the coevolution of culture and biology in dairying populations. Indeed, many of the groups with reported typically long durations of breastfeeding are not dairying populations (and have never consumed milk) and therefore have not been selected for lactase persistence. Breastfeeding until 5-6-7+ years in humans is not at all related to whether or not the culture has domesticated animals that they milk, and whether or not the adults consume nonhuman animal milks. I am not aware of any anecdotal reports, let alone research, reporting cases of a child who started having trouble digesting his own mother’s milk as he got older because his lactase gene shut down.
What she writes: “MYTH: We totes know the systematic effects of very prolonged breastfeeding.”
What the reality is: Sigh. Yet another straw man argument. NO ONE EVER CLAIMS THIS!! As I have written in all of my scholarly papers on this issue, and as I have concluded at the end of each of the hundreds (nay, thousands) of conference presentations I have done on this topic – there has been NO research on the comparative outcomes for children breastfed for various lengths of time beyond two years. There have been a few studies that included a category of “18-24+ months”– but there have never been any studies showing what, if any, difference there is in health outcomes, cognitive outcomes, emotional outcomes, etc. for children who nursed for only 3 years versus those who nursed for 5 versus those who nursed for 7. Again, an interesting research question, and definitely one worth exploring, for lots of reasons.
The research that has been done to date shows clearly that the longer you breastfeed, up to the study limits of 2 years, the better all the outcomes are for mother and child. Like an oil well, the benefits decline over time, such that nursing for an extra month early on (2 vs. 3 months) is going to be more significant than nursing for an extra month at age 5 years (60 vs. 61 months). There is no reason to expect that the benefits shut off abruptly at one year of age – as some pediatricians like to claim – nor is there any evidence to claim that the benefits are significant when a child is nursed 6 years rather than 5 years. This lack of research evidence is irrelevant to the point under discussion.
What she writes: “The information of very prolonged breastfeeding of 5+ years comes from rare self-selected cases, an extreme tail end of a continuous distribution of weaning ages.”
What the reality is: Indeed, information about “normal durations of breastfeeding that last up to 6 or 7 years” represents the extreme tail end of a distribution. But nursing to 5+ years is not “rare” – not now, not ever. There are lots of children – thousands and thousands – around the world who are nursing beyond the age of 3, with hundreds and hundreds nursing beyond the age of 5, and quite a few – though no one really knows – nursing beyond 6 and 7.
In my 2004 paper in Clinical Obstetrics and Gynecology, also titled “When to Wean” by the way, and available here on line for free: http://kathydettwyler.weebly.com/uploads/3/0/9/1/30918011/when_to_wean_clin_obstetrics_2004.pdfI report on a study I conducted in the mid-1990s on women in the US who breastfed longer than 3 years. I ended up with 1,280 mother-child pairs. The range of weaning ages was 3 to 9.17 years. Of the whole sample of 1,280, close to half had weaned by age 4years. The average age of weaning for the sample was 4.24 years, with a median of 4 years, a mode of 3.5 years, and a standard deviation of 1.08 years. In the years since I did this research, breastfeeding has become more common in the US, more mothers are nursing longer (according to the CDC statistics), and women are being more vocal and open about how long they nursed their children, in part due to the support now available via the interwebs and celebrity moms like Dr. Mayim Bialik (http://www.mayimbialik.net/beyondthesling/). Nursing until 5+ years of age may be somewhat invisible or cloaked in Western cultures, but it isn’t all that rare.
What she writes: “MYTH: The effects of breastfeeding are the same for all moms & infants in all places always.”
What the reality is: A “myth” is something that is commonly believed to be true, even though it isn’t true. Here we have yet another straw man. I don’t know anyone who believes that “the effects of breastfeeding are the same for all moms & infants in all places always.” Not any researchers, not any physicians, not any mothers. No one. NO. ONE.
What she writes: “MYTH: Moms have all the options.”
What the reality is: Please see the answer to the prior question. No one believes this. No one. NO. ONE. As many of the very same people who are the most outspoken breastfeeding advocates are the VERY SAME PEOPLE who are working for longer/better maternity leaves, on-site child care, flexible work schedules, laws to protect mothers breastfeeding in public, educational programs for partners and other family members and employers, etc. etc. etc. etc. If we “wait until the world has changed” and all these breastfeeding supports are in place before we start telling women the truth about the consequences of their infant feeding decisions, we will never have a breastfeeding-friendly society. Readers are encouraged to look at James Akre’s brilliant book on this topic from 2006. Akre was the head of Infant Nutrition for the World Health Organization for many many years. http://www.amazon.com/The-Problem-Breastfeeding-Personal-Reflection/dp/0977226840
What she writes: “We owe mothers better support and better options, including better formulas that include more bioactive features of breast milk.”
What the reality is: Indeed we do, and breastfeeding advocates have been saying this for as long as I’ve been involved in the field – since 1979. In fact, I state it explicitly in my 1995 chapter “Beauty and the Breast” and in my 1998 Skomp Lecture “Evolutionary Medicine and Breastfeeding: Implications for Research and Pediatric Advice.” Both are available for free on my website at www.kathydettwyler.weebly.org
What she writes: “Words have power. Words chastise, words shame, words bolster, and words buffer. So what do we do, as clinicians, as biologists, as friends, when a single statement about breastfeeding, pro or con, exerts each of those outcomes depending on the person reading and hearing them?”
What the reality is: Indeed, words have power. Words can be outright lies. Words can mislead people. Words can be used to try to make women feel better by denying the reality of how the world works. “Breastfeeding doesn’t matter, don’t worry if you have to stop when you go back to work.” Versus “Breastfeeding really does matter. It’s a shame that your employer won’t accommodate you. You should be angry about this. Let’s do something about it.” I have an entire presentation I have given at many many breastfeeding/lactation conferences on this whole topic of whether telling mothers the truth is wrong/immoral if it might make them feel GUILTY. I side with truth.
What she writes: So proscriptive attitudes about what women should and shouldn’t do with their bodies can suck it.
What the reality is: I agree 1000%. Proscriptive attitudes about what women should and shouldn’t do with their bodies can suck it. Realize that most of these proscriptive attitudes being expressed are aimed at demonizing women who nurse their children for longer than someone else thinks they should. Not at women who bottle-feed, and not at women who “only” nurse for 1 year or for 2 years or for 3 years. No one – least of all me – is saying that women “should” or “must” nurse their children at all, let alone for any specific length of time.
So please stop implying that I am.