Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Length of Breastfeeding
- Lin Miles (16 March 2001)
-
Questions
- Claire Dobson (16 March 2001)
-
Eating a Western-style diet is the real public health issue-not prolonged breastfeeding
- Rona McCandlish (16 March 2001)
-
Breast feeding promotion undermined yet again
- Janet Medforth (17 March 2001)
-
Tempest in a teacup
- Valerie A Palda (17 March 2001)
-
The problem of confounding in observational studies
- Patricia B Cerrito (17 March 2001)
-
A dose-response cause and effect relationship between breastfeeding and heart disease seems unlikely
- Ted Greiner (17 March 2001)
-
Breastfeeding and Cardiovascular Disease
- Ing-Marie Logie (17 March 2001)
-
Arrogance of man
- Nikki Lee (17 March 2001)
-
no need to be defensive
- Wendy Holmes (19 March 2001)
-
Questions unanswered
- Ellen Shein (19 March 2001)
-
Breastfeeding and heart disease - is there a connection?
- Phyll Buchanan (19 March 2001)
-
Cleverer and cleverer strategy
- Nicole Bernshaw (19 March 2001)
-
Milk and arterial distensibility
- Jeffrey J Segall (20 March 2001)
-
A blow to the third world !
- Madhavan T Sethu (20 March 2001)
-
Beneficial effects of this article
- Aviram Rozin (21 March 2001)
-
Questions about the experimental design and analysis of the study
- Margaret Tyson (21 March 2001)
-
Heart disease expected to decline, is it?
- Julii Brainard (21 March 2001)
-
Limitations of study
- Luis Gabriel Cuervo (21 March 2001)
-
Why this Hypothesis?
- David (22 March 2001)
-
Some more thoughts from parents
- Paul Dark, Marie-Josee Rolli (23 March 2001)
-
Breastfeeding duration and later arterial distensibility
- Alan Lucas (23 March 2001)
-
Mothers panic and give up breastfeeding
- Patti Rundall (23 March 2001)
-
Quality
- Mark McAuley (23 March 2001)
-
LLLGB response to Duration of Breastfeeding article
- Rachel O'Leary (24 March 2001)
-
Breastfeeding is the norm, not formula
- Heleen Hayes (24 March 2001)
-
Comparison with another 'hot topic'
- Annelies Bon (25 March 2001)
-
Role of contaminants in human milk
- Allan Astrup Jensen (26 March 2001)
-
So what?!
- F Meyer-Bradfisch (26 March 2001)
-
Does this study herald the return of National Dried Milk?
- Anne Holt (27 March 2001)
-
Paper fails to discuss data from prospective studies
- Jim Sikorski (27 March 2001)
-
Outrageous!!!!
- Cassandra Webster (28 March 2001)
-
A counter argument- Barker's hypothesis
- Munleng Lim (30 March 2001)
-
objectivity, value of breastfeeding, dose-response & weaning age
- Elise E Morse-Gagné (3 April 2001)
-
A Valuable Lesson
- Martha Schatzle (5 April 2001)
-
Is breastfeeding duration more important than diet?
- Yap-Seng Chong (5 April 2001)
-
Re: A Valuable Lesson
- Wendy Holmes (6 April 2001)
-
aNOTHER BREASTFEEDING OBSTACLE
- Michelle Dexter (7 April 2001)
-
Duration of breast feeding and arterial distensibility in early adult life
- Dominic Horne (24 April 2001)
-
Inadequate assesment of Breasfeeding
- Roxana Saunero Nava (24 September 2001)
|
|
|||
|
Lin Miles, South West regional coordinator Breastfeeding Marlborough Medical practice, George Lane, Marlborough, W
Send response to journal:
|
As you can imagine I am a little disturbed by these results. Would like to ask several questions. What was your definition of breastfeeding ie were these adults exclusively breastfed for these length of time? How many of your subjects were exclusively breastfed for six months? the time which is recommended by the world health organization. Regards
|
|||
|
|
|||
|
Claire Dobson, La Leche League Breastfeeding Counsellor Glasgow
Send response to journal:
|
As someone who promotes the health benefits of breastfeeding I am shocked by the findings of this study. There is an omission in this work which I would like to ask: did the authors investigate when solids were started? There are a lot of other studies, Howie et al. Forsyth et al. who also look at timing of introduction of solids - this is surely relevant. As a retrospective study, I would also like to question the maternal recall. How accurate is it - you will never know. |
|||
|
|
|||
|
Rona McCandlish, Research Fellow National Perinatal Epidemiology Unit, Institute of Health Sciences, Oxford
Send response to journal:
|
Leeson et al's (2001) observational study exploring whether duration of breast feeding is related to changes in vascular function relevant to the development of cardiovascular disease is being reported extensively in public media (eg http://www.news.bbc.com). The main media message is that breastfeeding for longer than 4 months is linked with heart disease in later life. Reading the text of the BMJ paper it is apparent that this is not the primary conclusion of this study, and indeed the authors state that 'our observational data do not establish a causal relation between length of breast feeding and cardiovascular disease'. Public media coverage of this research once again highlights the problem of attempting to disseminate results to a lay audience which have written for and only published in a peer reviewed journal. The current media interpretation of these results is very likely to cause considerable anxiety amongst women who have breastfed or are currently breastfeeding. It is also unlikely to be useful to anyone trying to make decisions about the balance of benefits and dis-benefits associated with alternative feeding methods. Are Leeson and colleagues therefore intending to write up their work for effective, prompt dissemination in lay publications? In their final sentence the authors say that there is an urgent public health need to further study the possible influences of a longer period of breastfeeding on the evolution of arterial disease. Given that there is ample evidence of the effects of a western-style diet on ill- health surely research intended to provide evidence to inform public health interventions to alter diet would represent a better investment of resources. Yours sincerely Rona McCandlish
Leeson CPM, Kattenhorn M, Deanfield JE., Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ 2001; 322: 643-647 |
|||
|
|
|||
|
Janet Medforth, Midwifery Lecturer University of Sheffield, Department of Midwifery and Childrens Nursing
Send response to journal:
|
I read with interest the study by Leeson et al (BMJ 322(7287):643). This has been widely reported in many of the national newspapers today and was even to be found on ceefax. The promotion of breast feeding up to the age of six months has been endorsed since 1998 by the Department of Health(1988)and includes the advice that breast milk should form an important part of the infant diet after weaning. This advice is now standard and a major professional responsibility for midwives. The study presents a number of difficulties as it leaves fundamental questions unanswered.The cohort appears to be based on a convenience samle of self selected volunteers, introducing bias at an early stage of the study. Numerically the sample is small, limiting the ability to generalise the results. In grouping the sample there appears to be a rather crude division between 'only bottle fed' and 'having received breast milk'. This grouping does not identify those individuals who might have been exclusively breast fed, and therefore also omits to take into account those breast fed and receiving complements of formula - a common practice in the early 1970's. This ommission has disregarded a variable which may have had considerable impact on the nutritional status of this part of the cohort. The earlier study by Mott et al(1991) appears to support a link with vascular changes when either exclusive breast feeding or exclusive bottle feeding is compared. This study fails to identify such a link as the groups are not adequately separated. The fundamental problem now for midwives promoting breast feeding is how to interpret this study and continue to give sound advice to mothers, against a background which appears to undermine their practice. |
|||
|
|
|||
|
Valerie A Palda, Assistant Professor University of Toronto
Send response to journal:
|
In their article entitled "Duration of breastfeeding and arterial distensibility in early adult life"; Leeson et al state that their objective is to relate breastfeeding to "changes in vascular function relevant to the development of cardiovascular disease". Their study is subject to several important methodologic flaws and biases which limit conclusions can be drawn from the data. If considered in the framework of "Can duration of breastfeeding have an adverse effect on cardiovascular outcomes?", the ideal study would sample a representative group of breastfed people, determine all potential confounders, and link the duration of breastfeeding to a clinical cardiovascular outcome, or known risk factor. This study had a response rate of 43% and a total entry rate of 28% (complete data on 23%). Is this group representative? Important confounders, which are not described, are those relating to the exposure (exclusivity of breastfeeding) and the outcome (no mention of family history of heart disease or diabetes-despite reporting that serum insulin and glucose levels were measured). The most important "leap of faith" in this article is the outcome: since when is vascular distensibility a recognized cardiovascular risk factor? Both article and editorial suggest the link as biologically plausible, but little epidemiologic evidence exists to establish risk factor status, let alone causality. Additionally, why wasn't the relationship between presence of breastfeeding (yes/no) and arterial distensibility reported? Is the effect of "duration" a post-hoc analysis? The results for duration and outcome were NOT significant among men, attributed to small sample size. Since the authors make conclusions about non-significant results, why wasn't the "almost" significant favourable difference in LDL among breastfed subjects (2.71 vs. 2.90, p=0.07) mentioned? How would this compete with reduced arterial distensibility to affect cardiovascular outcomes? The only conclusion that can be plausibly made is that among a small sample of people, there is an association between duration of breastfeeding and arterial distensibility. The authors should not discuss "the effect of breastfeeding on cardiovascular risk", since this study dose not reliably show that breastfeeding has ANY effect on cardiovascular risk. |
|||
|
|
|||
|
Patricia B Cerrito, Professor of Mathematics University of Louisville
Send response to journal:
|
There was only a 28% response rate in the study. No attempt was made to determine whether the responders differed from the non-responders; only a comparison to the general population was made. Therefore, the study was performed on a self-selected group of individuals. There was no reporting of socio-economic factors in the responders, although there is a small reference to social class. How was social class determined? It is very possible that the duration of breast feeding is confounded by these factors. Social class is identified as a statistically significant factor but interactions with breast feeding were not investigated in the study. Who was breast feeding 20+ years ago? Nutrition and exercise levels are important in investigating risk factors but these were excluded in the study. Therefore, there is another possible confounding factor that should have been examined. Any observational study of this type needs to examine a large number of possible confounders. Responders need to be compared to non-responders. Interactions need to be examined in the model. Type III SS (Sum of Squares) instead of Type I SS should be examined because of possible masking of effects. Then the results need to be validated on additional data. |
|||
|
|
|||
|
Ted Greiner, Head, International Nutrition Research Group Department of Women's and Children's Health, Uppsala University
Send response to journal:
|
Once again epidemiological data from the UK are leading to a claim that "extended breast feeding may lead to later adverse cardiovascular outcomes" in an article (Leeson CPM, Katternhorn M, Deanfield JE, Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ 2001; 322: 643-647) and accompanying editorial (Booth I. Does the duration of breast feeding matter? BMJ 2001; 322: 625-626). The authors of the article say that their findings are "consistent with" those of Fall et al (Fall CH, Barker DJP, Osmond C, Winter PD, Clark PM, Hales CN. Relation of infant feeding to adult serum cholesterol concentration and death from ischaemic heart disease. BMJ 1992; 304: 801- 805) which were widely publicized in the mass media. The causal mechanism postulated by Fall et al was not found to hold in this study and the "results do not support a hypothesis of deranged blood lipid profiles in adulthood." Will this failure to confirm the previous hypothesis receive attention or will the media say that this study "confirms" the findings of the previous one? We will never know the impact of breastfeeding on human health because it is unethical to randomize. Thus we have to be very careful to look for confounders when we do associative studies such as this, and the authors made an effort to do so. However, one must assume that families with children who breast fed for longer periods in the UK 20-30 years ago differed in many ways from those who fed their babies closer to the "norm" of the time. Slightly over 1/4 of British babies were breast-fed for longer than 4 months in 1980 (Martin J, White A. Infant Feeding 1985. London: Office of Population Censuses and Surveys); similar to the proportion of those contacted who agreed to participate in this study, by the way. The Demographic and Health Survey data for the South Asian countries (Haggerty PA, Rutstein SO. Breastfeeding and Complementary Infant Feeding, and the Postpartum Effects of Breastfeeding. Calverton MD: Macro International Inc., 1999) show that about half the children are breastfed for longer than two years in India, 2.5 in Nepal and 3 in Bangladesh. Hundreds of millions of adults currently alive in that region were probably breast fed for even longer periods than this. If there were any dose-response, cause-and-effect relationship between sustained breastfeeding and heart disease, why is not heart disease at much higher levels there among those who reach old age than it is in rich countries? This study was done by a group that included the Medical Research Council Childhood Nutrition Research Centre which "has collaborated with the infant food industry for its outcome studies on nutrition." Their honesty in admitting this (or is it the exemplary BMJ insistence on such declarations?) may not allay our fears regarding the potential affects on the research of this kind of conflict of interest. Whether or not the original scientists interpret their data properly, abuse of epidemiological findings seems continually to amuse those who have some kind of conscious or unconscious problem with breastfeeding. While the authors point out that their findings cannot be interpreted as cause and effect, normally anything negatively associated with breastfeeding quickly gets translated into just that by the media and receives wide dissemination. Let's see what happens with this one. |
|||
|
|
|||
|
Ing-Marie Logie, Cardiovascular Research Nurse Raigmore Hospital, Inverness
Send response to journal:
|
I live/work in the Highlands of Scotland and with the extremely low rate of breast feeding we have here one could expect us to have a very low rate of Cardiovascular Disease, unfortunately the opposite is true. Bottle feeding in the Highlands does not appear to have protected the population from Cardiovascular Disease. If breast feeding past the first four months is a risk factor for Cardiovascular Disease then we could expect to find Cardiovascular Disease to be more prevalent in countries where babies are breastfed for longer than 4 months and vice versa. I don’t think that is the case, is there any evidence to suggest that it is? I don’t think breastfeeding past 4 months can be considered as prolonged breast feeding as there is no naturally occurring milk suitable for babies under 1 year old. When I did my nurse training in this country in the early 80s, I was taught that breast milk does not contain enough iron (incorrect, as we now know) and therefore breastfed babies needed iron supplements. If babies who were breastfed were given iron supplements and maybe other supplements as well, which might have been different to that added to formula feeds, this could have affected long-term health. 331 adults were studied and this is a very small number. I doubt that one could draw any statistically relevant conclusions from such a small study. The adults studied were those who had lived to reach adulthood. To have any chance of giving conclusive evidence all babies would need to be followed from birth, also looking at the total mortality rate both in those bottlefed and those breastfed . Maybe those who were bottlefed and prone to a lower arterial distensibility died before reaching adulthood. What is the good of having a chance of a reduced risk of CHD when you are old, if you died as a baby? When it comes to giving health advice it is also important to recognise that not all people, even in Britain, eat an unhealthy “Western diet”. There are people who eat a healthy diet and give their children the same. Looking at men between 60 and 70 years old retrospectively, again means that all those who had already died would have been excluded. Maybe those older men who were breastfed past their first year would have died years ago if they had been bottlefed. How do we know? My subjective feeling is that there are more old (over 70 or so) people with Cardiovascular Disease who don’t smoke. If that is true I could draw the conclusion that not smoking is a risk factor for CHD in old age, while in fact most of the smokers would already have died as a result of their smoking. |
|||
|
|
|||
|
Nikki Lee private practice
Send response to journal:
|
Very interesting to read that infant food industry research (via Dr. Lucas and his team) has uncovered a possible link between breastfeeding and arterial stiffness later in life. But why look only at method of infant feeding? Could arterial stiffness be related to birth in a hospital? Drinking soda as a child? Watching television? Eating certain fats during adolescence? Associated with maternal medication in labor? Paternal smoking? Childhood immunizations? Vitamin K injection? Lack of use of seat belts? Amount of physical activity in youth? One could name any variable, ridiculous or sublime, and look for relationships. Fats derived from palm and coconut oils have been removed from adult breakfast foods in the USA because of their link to cardiovascular disease yet they continue to serve as fat sources in the making of breastmilk substitutes. Does this research imply that fats deemed risky for adults are protective for infants? Or do humans need to be programmed to eat poorly from the beginning of life to condition them for lousy food through adulthood? |
|||
|
|
|||
|
Wendy Holmes, Women and Children's Health Specialist International Health Unit, Macfarlane Burnet Centre for Medical Research, Melbourne, Australia
Send response to journal:
|
Perhaps it is not surprising that so many who have sent responses are shocked by the report of Leeson et al’s study. Breastfeeding is a sensitive topic. The normalising of artificial feeding by formula companies, the media, and baby doll manufacturers require efforts to protect breastfeeding, which epidemiological studies (including those of Lucas et al) have proved has significant health benefits for babies and mothers. But we should not allow our necessarily protective stance to become blindly defensive. This is a sound study, by reputable researchers, cautiously reported. The appropriate response is to study it carefully and think about the implications. It is easy to fall into the teleological trap of thinking that breastfeeding was designed to have only desirable effects. Evolution may well have had this result. During our evolution we have had much shorter lifespans than we've recently achieved, and an altogether different diet in terms of fats. The possible explanation suggested by the researchers is therefore plausible. Some have countered that if these findings are true then we should expect high rates of cardio-vascular disease in developing countries where breastfeeding for two years or more is common. But Leeson et al’s hypothesis includes the suggestion that it is breastfeeding followed by a high cholesterol, high saturated fat diet that may be associated with less elastic arteries. In fact, with changing diets and a higher proportion of elderly, we are indeed seeing rapidly increasing rates of cardio-vascular disease in developing countries. Clare Dobson suggests that we cannot know about the accuracy of maternal recall. This is an important issue in the epidemiology of breastfeeding which can be studied by comparing mother’s recall with clinic records. There is evidence from several studies that mothers can accurately recall the duration of breastfeeding, but are less reliable at recalling age at introduction of formula. Eaton-Evans et al studied the reliability of recall of mothers in Queensland, against clinic records(1). Length of recall tested was between one and 10 years. "Of the 75 infants on whom data were available, the differences of duration of breastfeeding as recalled by the mother and recorded by the clinic were less than one month for 79% of children, and less than two months for 95% of children." They found no difference in accuracy of recall between mothers with different levels of education, or with numbers or ages of children. Other studies have found that mothers can reliably recall the duration of breastfeeding for periods as long as 17 and 29 years (2,3). Some of the responses suggest that the research is less valid because it did not investigate whether exclusive breastfeeding has this association. However the researchers were investigating a possible association between arterial stiffness and duration of breastfeeding, as practiced by mothers in the 1970s. There is much evidence that exclusive breastfeeding for six months is the optimal infant feeding practice for child health - but we know that this is a rare practice in all societies. If the finding is confirmed by further studies the public health significance will relate to breastfeeding as commonly practiced. Janet Medforth draws attention to the important role of midwives and maternal and child health nurses in advising mothers about duration of breastfeeding in the face of the media stories about this study. They could say something like: "You may be worried about the findings of a study that has been reported in the press lately about a link between heart disease in adult life and breastfeeding. This is just an early study so far and the findings are not yet confirmed. The researchers recommend that to do the best for their babies mothers should follow the current recommendations, that is, breastfeed exclusively for the first six months, and continue to breastfeed into the second year or as long as you and your baby wish. These same researchers have found that breastfeeding benefits development of the brain. There are many influences on adult heart disease - the theory that these researchers are investigating is that it might be that breastfeeding for more than four months, followed by a fatty diet, may cause a small increase in the risk of heart disease. Parents can help to reduce the risk of adult heart disease for their children by encouraging good eating habits, exercise and not smoking. The balance of risk is still in favour of breastfeeding." In their report Leeson et al have taken care to describe the limitations of the study and to emphasise that it should not lead to any change in infant feeding recommendations. 1. Eaton-Evans J, Dugdale AE. Recall by mothers of the birth weights and feeding of their children. Human Nutrition: Applied nutrition (1986)40A, 171-175 2. Kark JD, Troya G, Friedlander Y , Slater PE, Stein Y. Validity of maternal reporting of breastfeeding history and the association with blood lipids in 17 year olds in Jerusalem. Journ Epi Comm Health 1984;38:218- 225 3. Troy LM, Michels KB, Hunter DJ, et al Self-reported birthweight and history of having been breastfed among younger women: an assessment of validity. Int J Epi 1996;25:122-127 No competing interests |
|||
|
|
|||
|
Ellen Shein, IBCLC Mamash, Tel Aviv
Send response to journal:
|
As those before me seem to have addressed many questions, I have only one remaining. What value does a study have when reliant only upon the mothers' memory, in some cases 2 decades later regarding early feeding methods of their infants? Even today, many mothers are not even aware of modern day hospital practices of "topping up" their 1-3 days old newborns in their communal nurseries with artificial baby formulas - without prior consent or knowledge of the mothers! To the best of my knowledge hospitals today are trying to steer away from this practice, but even 20 years ago the practice was more rampant than today. This does not seem to be very conclusive. |
|||
|
|
|||
|
Phyll Buchanan, Breastfeeding Supporter The Breastfeeding Network
Send response to journal:
|
As previous responses have noted this study’s results rests on the assurance that the group of breastfed adults were homogenous. Table 1 gives the characteristics of the population studied; comparing those breastfed as babies with those bottle-fed. There would appear to be little significant difference between these two groups – yet we know this is unlikely to be the case (1,2). Later on confirmation is given that no relationship was found between duration of breastfeeding and smoking, family history, social or economic differences but we are not given the opportunity to see this data or the p values. Such a surprising finding-- which varies for most published research on breastfeeding (3) seems to call for some discussion. Should we not have been given the chance to see for ourselves by displaying the characteristics of the breastfed group in two distinct groups - those breastfeeding up to 4 months and those feeding beyond this time? Intriguingly the number of people breastfed beyond 4 months was not given; it is likely to have been small. The average duration of breastfeeding is given as 3.3 months, which fits with statistics gathered from 1980, which says that of those breastfed at birth only 34% were still breastfeeding at 6 months (2). We also know that these adults were unlikely to have been exclusively breastfed – in 1980 nearly half of all breastfed babies were given bottles of formula within the first week in hospital and 56% of all babies at 3 months were having solid food, rising to 89% by 4 months, with rusks and rice cereal listed as the usual first foods. The effects of mixed breast and bottle-feeding as distinct from a period of exclusive breastfeeding (when a baby receives nothing other than her mother's milk from birth) are only now beginning to be understood as definitions of breastfeeding become more rigorous. (4,5,6) The question that these results could have occurred by chance remains unanswered. I would like to propose that the BMJ leads the way by involving in the peer reviewing process someone who understands the intricacies of breastfeeding research and understands normal uncomplicated breastfeeding. This would improve the quality of research and also mean that research results could be more easily translated into clinical practice and health promotion efforts. That this person should be independent of the infant feeding industry is crucial. (1) Foster K, Lader D and Cheesbrough S. Infant Feeding 1995 ONS: TSO (2) White A, Freeth S, O’Brien M, Infant Feeding 1990. OPCS: HMSO (3) Fairbank L, O'Meara S, Renfrew MJ, Woolridge M, Sowden AJ, Lister -Sharp D A systematic review to evaluate the effectiveness of interventions to promote the initiation of breastfeeding. HTA report 2000: Vol4: No 25. (4) Miriam Labbok. What Is the Definition of Breastfeeding? Breastfeeding Abstracts LLLI Feb 2000 Vol 19 No 3, p19-20 (5) Coutsoudis A, et al Method of feeding and transmission of HIV-1 from mothers to children by 15 months of age: prospective cohort study from Durban, South Africa. AIDS 2001, 15:379-387 (6) Association between breastfeeding and asthma in 6-year-old children: findings of a prospective birth cohort study. W H Oddy, BMJ 1999;319:815-819 |
|||
|
|
|||
|
Nicole Bernshaw, Book Review Editor Journal of Human Lactation
Send response to journal:
|
One point for the formula industry. Paying scientists to do research to be published in prominent scientific journals cannot be said to go against the International Code of Marketing of Breast-milk Substitutes (the Code). Yet, the results of this study (Leeson CPM, Katternhorn M, Deanfield JE, Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ 2001; 322: 643-647) will be picked up by the press which has no sense of critical reading (making no connection between the soure of funding and the results), they will reach the very mothers that the formula companies are prohibited to advertize to directly according to the Code, and they will undermine the practice of breasteeding. There is no doubt that these results will be overturned with future research, but the damage will have been done. Advertizing strategies by formula companies are just like computer viruses: no sooner have we worked out a way to protect ourselves against one virus (eg the Code fighting against formula companies marketing directly to mothers) that another more dangerous one is developed (this time using the very researchers who should know better than to accept funding from formula companies and to publish preliminary results which make no sense anthropologically and medically). Furthermore, I cannot help but to question the motive of BMJ in publishing such questionable results in the light of the hesitancy of the public to adopt breastfeeding despite its irrefutable health-promoting properties. Lactation advocates, let’s get back to the drawing board. |
|||
|
|
|||
|
Jeffrey J Segall, Retired (former general practitioner) Home
Send response to journal:
|
EDITOR - Leeson et al conclude from their study that the reduced arterial distensibility in the participants who 20 to 28 years earlier were breast fed for four months or more was probably caused in infancy. [1] Another possibility is that these participants in childhood obtained greater enjoyment from milk, or received more parental encouragement to drink it, than did the participants who were breast fed for less than four months or who were exclusively bottle fed; and that they continued a childhood dietary habit of a high milk intake into adulthood. It is surprising that Leeson et al apparently did not include current milk intake in their assessment of possible cardiovascular risk factors, especially as reported evidence linking a high intake of milk with ischaemic heart disease (IHD) [2] has not been invalidated. If prolonged breast feeding does act on arterial distensibility in infancy, and is irreversible, a possible explanation lies in the high lactose content of human milk (72g/kg). There is dietary, epidemiological and biological evidence to suspect that lactose is responsible for the association of a high milk intake with IHD.[3,4] Unfortunately, Leeson et al are unable to distinguish between human simulated formula milk, unsimulated formula milk and cow milk in the infant feeding of the exclusively bottle fed participants. Lactose enhances absorption and retention of calcium and phosphate, which could result in arterial wall microcalcification and reduced distensibility.[4] In baboons experimentally it enhanced aortic atherosclerosis, an effect which hypothetically was attributed to altered glycosaminoglycan formation.[5] The question now arises, does lactose (or its galactose) stiffen our arteries at any age? Jeffrey J Segall 1 Leeson CPM, Kattenhorn M, Deanfield JE, Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ 2001;322:643-7. 2 Segall JJ. Is milk a coronary health hazard? Br J Prev Soc Med 1977;31:81-5. 3. Segall JJ. Dietary lactose as a possible risk factor for ischaemic heart disease: review of epidemiology. Int J Cardiol 1994;46:197-207. 4. Segall JJ. Epidemiological evidence for the link between dietary lactose and atherosclerosis. In: Colaco CALS, ed. The glycation hypothesis of atherosclerosis. Austin, Texas: Landes Bioscience, 1997: 186-209. 5. Kritchevsky D, Davidson LM, Kim HK, Krendel DA, Malhotra S, et al. Influence of type of carbohydrate on atherosclerosis in baboons fed semipurified diets plus 0.1% cholesterol. Am J Clin Nutr 1980;33:1869-87. |
|||
|
|
|||
|
Madhavan T Sethu, Specialist registrar,Paediatrics Dryburn Hospital,Durham,DH1 5TW
Send response to journal:
|
I am appalled by this study. Coming from a developing country where infant nutrition relies heavily upon breast feeding, I can assure you that this is going to be a terrible blow. I am also astounded that this is not the case in Indian population -though this study vaguely emphasises on the 'western diet'. I am however baffled that a sudy like this which has so many laudable objective parameters for measuring effects depends upon such a flimsy and subjective parameter as maternal memory for the cause. It feels terribly concocted with an attempt at statistical substatiation.I wouldnt be surprised if someone thought of an idea that 'all road traffic accidents are caused by immunisation in childhood'-I can prove it statistically !! Thats beside the point--but it makes me lose my faith in statistics as it is currently being used to armtwist people into believing things they dont want to. I sincerely do wish that such studies would not get ethical approval. |
|||
|
|
|||
|
Aviram Rozin
Send response to journal:
|
Medical Science has an evolution process of it’s own. Survival is only the privilege of the well-designed studies. Since the current study is poorly designed, its main future beneficial contribution will be to serve as an incentive for researchers to perform better studies. In these future studies, the questionable findings of the current study might be reversed, and additional benefits of breastfeeding might be empirically proven. Breastfeeding has survived much bigger obstacles than this study, over millions of evolution years. |
|||
|
|
|||
|
Margaret Tyson, Independent Scientist
Send response to journal:
|
As breast-feeding is a practice that needs to be promoted, it was very disconcerting to read the conclusions of the paper by Leeson et al. in 17th March 2001 issue of the BMJ “Duration of breast feeding and arterial distensiblity in early adult life: population based study”. The media has taken the results out of context and exaggerated the conclusions. Any mother wanting an excuse not to breast-feed will immediately cite the media response despite the presence of possibly thousands of studies that demonstrate the opposite result. In my opinion, the experimental design and analysis were flimsy. The study was one-dimensional using one cohort from one area of the country - Cambridge. This is only the equivalent of a pilot study. For the work to be seen as a complete research report, several contrasting areas should have been sampled (possibly three). A more deprived area should have been compared. Cambridge is a middle class area in the South with a higher than average breast-feeding rate (in the 331sample, 149 were breast-fed - 45%). This is similar to the highest breast-feeding average in Scotland in 1999. The survey showed the highest rate was 47% of 6-8 week old babies in the Borders, whereas the lowest was 25% in Lanarkshire (NHS Information and Statistics (ISD) (1999)). Therefore, a deprived area such as inner city Manchester should have been sampled. A rural area may have also been sampled for comparison. Cambridge is situated in a hard water area, which has been linked to lower levels of CHD, possibly because of the mineral content of the water. This could possibly give bottle-feeding beneficial properties. Consequently, a population situated in a soft water area should have also been sampled because soft water has been linked to increased CHD levels (Punser & Karvonen, 1979). It was not clear how the sample groups were chosen. Although the subjects were chosen randomly, they were invited and very little detail was given about them. Also the average BMI of the group is high, 24.2 and 24.3 breast-fed and bottle-fed respectively. One flaw in the study that has been noticed by several people is the lack of data on weaning. It was very unusual for anybody to continue breast-feeding exclusively for longer than 3 months in 1969-1975. I had my children at that time and I breast-fed for 3 months exclusively, started weaning and gradually reduced the duration and frequency of breast-feeding until I finished at 10 months. I do not know of anybody who breast-fed for longer than this in the area where I live. This means that the children in this study will have been weaned at different times independently of the length of breast-feeding duration. Some mothers breast feed for perhaps one month and then transfer to bottle feeding. This behavior was not allowed for and could possibly have skewed the data. If these data represent people who were breast-fed exclusively up to the age of 10mths or more then they would have suffered nutritionally and damage may be expected (as shown in several references e.g. Fall et al. 1992), but I suspect this is not the case. What I think is most important is the lack of comparison between the two groups. A controlled experiment would have been desirable. However, this is not possible because both groups have to receive treatment (infant feeding), but the bottle-fed group should have been tested in the same way as the breast-fed group. Those who were bottle-fed should have been directly compared with the breast-fed group at 0-1, 2-3, 4-5 months etc. A graph should have been produced showing "Mean (SE) distensiblity coefficient for brachial artery in relation to duration of bottle-feeding" to make a more realistic comparison. If the groups are equalised in another way by taking the mean of the distensibility coefficient for the breast-fed group it gives a result of approximately 0.13. I suspect that this is not significantly different from the bottle-fed group at about 0.14. The confidence level of the regression coefficient looks very wide (-7.29 to - 0.57) and the results state that the regression coefficient is only significant in women. Although the study was related to other variables and these were found to have no relationship to the results, it is difficult to believe that smoking was unrelated to arterial function. Other variables that could have been investigated are maternal nutrition, which has been linked to CHD in the infant once he or she becomes an adult; birth weight; homocysteine levels in the blood; and the subjects' dietary habits. Also, there is possibly a character difference between mothers who breast-feed and those who do not. It is possible that breast-feeding mothers spent more on food for the growing family, therefore feeding them more meat and dairy products at a time before the recent emphasis on a low fat diet. So that although the mothers breast-fed their children, the consequent diet was higher in fat than that given to children by bottle feeding mothers. Nevertheless, this cannot be measured. Despite this, my conclusion is that the experimental method used was unsound and that the work is only worthy of being a pilot study. Because of this, the work should been withheld from publishing until a more thorough research project had been carried out. References Fall CH, Barker DJP, Osmond C, Winter PD, Clark PM, Hales CN, Relation of infant feeding to adult serum cholesterol concentration and death from ischaemic heart disease. BMJ 1992; 304: 801-805. NHS Information and Statistics (ISD) Common Services Agency for the NHS in Scotland (1999). www.show.scot.nhs.uk/isd/child_health/ch_breastfeeding/ch_breastfeeding.htm Punser S, Karvonen MJ. Drinking water quality and sudden death: Observations for West and East Finland. Cardiology (1979); 64: 24-34. |
|||
|
|
|||
|
Julii Brainard, Senior Research Associate (but my job isn't really relevant) University of East Anglia
Send response to journal:
|
I'm bemused by the Leeson et al work. If the effect noted by the researchers is correct, then we can all expect heart disease to experience a significant decrease in the next 25 years -- no? After all, breastfeeding in the UK has been in persistent decline for the last 50 years. In fact, shouldn't this decrease in heart disease already be apparent? Else, I am left with an obvious conclusion. The possible importance of Leeson et al.'s findings is trivial in comparison with other known risk factors for heart disease -- namely diet, activity, smoking, stress levels... As a mother I am left thinking that it matters not one whit whether I breastfeed for 4, 14 or 24 months. Rather, it is incumbent on *all* mothers to teach their children good, lifelong habits with regard to exercise, diet, not smoking, etc. Now, would the BMJ please consider writing an editorial about *that*? |
|||
|
|
|||
|
Luis Gabriel Cuervo
Send response to journal:
|
Dear Editor, The misleading publicity that the paper by Leeson et al[1] is receiving in the media proves that the main limitations of this paper were not sufficiently highlighted. Nor were the consequences of limiting breastfeeding to four months. Surrogate outcomes, such as elasticity of an artery, should not be used to infer causality. The paper does not address any relevant clinical outcome. It is a small observational study. Chance, bias or confounding may be responsible for the effects the authors found. The evidence the paper provides suggesting a causative effect of breastfeeding on heart disease is weak. Tobacco industry manipulated research to obtain commercial benefit regardless of the harms they caused. The way the media has manipulated information provided by this paper, raises my concern of the role these study may have in the agenda of the weaning food industry. The brief note written in the competing interest section does not provide a clear picture on the degree of involvement of the authors with the weaning food industry. BMJ has a responsibility not only to publish evidence. It also has to foresee the effect of the published paper on global health and clearly address it. The breach that allowed the media to manipulate the results and jump into the conclusion stating that breastfeeding more than four months causes cardiovascular disease is inadmissible and will for sure be commercially exploited by unscrupulous purposes, here and in the developing world, with terrible consequences. Further explanatory letters may not have the same impact in media and may not compensate the damage that has been done. Luis Gabriel Cuervo
Competing interests: I am also Clinical Editor for Clinical Evidence. 1 Leeson CPM, Kattenhorn M, Deanfield JE, Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ 2001; 322: 643-647 |
|||
|
|
|||
|
David , IBCLC
Send response to journal:
|
I am intrigued as to why the working hypothesis of this research was against the biological norm for our species. Also, the question needs to be asked why the conclusion was reached that the result was related to breastfeeding being a danger, when the other cardio-vascular risk factors were not increased in the 'ever' breastfed group, and the current lipid profiles were normal. I see this research as a deliberate attempt to scare parents away from the biological norm of breastfeeding, by drawing unsubstantiated conclusions from irrelevant research. The working hypothesis was unusual, and that the research was funded by companies with an interest in the baby formula indusry makes me question the ethical motives of the study. I find it an enourmous leap to state that there is "an urgent public health need to study further the possible influence of a longer period of breastfeeding on the evolution of arterial disease" When did "less distensible arteries" become "arterial disease"? Going back to first principles, if a group of children were studied, who had been EXCLUSIVELY breastfed for 4 months (as a NORMAL human baby would be) and these children showed the same result, an obvious conclusion would be that this was NORMAL for the human race and that less resilient arteries were a risk factor. In conclusion, this was a very small study from people in one area. It didn't allow for the fact that most of the 'breastfed' subjects probably had other foods or artificial milk formulas (given the dates of birth of the subjects and the community norm at the time) The study also classes more than 4 months of breastfeeding as 'prolonged' when the biological norm is probably 2-5 years. I do not consider that this is a credible study, nor that the conclusions are logical. Querida David IBCLC |
|||
|
|
|||
|
Paul Dark, MRC Clinical Training Fellow University of Manchester, Marie-Josee Rolli
Send response to journal:
|
Dear Editor, The conclusions from the paper by Leeson and colleagues seems to rely, in part, on the statistical treatment of their limited observational data. In particular, the use of multiple regression analysis and t tests. Multiple regression was used to determine regression coefficients as a measure of association between length of breast feeding and non-invasive brachial artery distensibility. The t tests were used to test the null hypothesis (presumably) that there were no differences in brachial artery distensibility between those that were not breast fed, those breast fed to 4 months, and those breast fed above four months. Firstly, we are uncertain whether the regression analysis incorporated all subjects, but this is implied in the paper. Therefore, we are presented with a larger number of those adults who were either breast fed for a short period or not breast fed at all, and smaller numbers at longer periods of breast feeding (although numbers are not specifically given in the paper at each time grouping). We now need to interpret the regression coefficients (Table 3), actually quite broad at the 95% confidence intervals. The paper tells us that the p values associated with these regressions are just significant but no mention is made of the R2 values that will tell us how much of the variability of arterial distensibility is explained by all variables, including duration of breast feeding. Furthermore, there appears to be no analysis of the breast fed adults alone and certainly no R2 value. Second, for the dichotomised groups, arterial distensibility is compared (t test) with the non-breast fed group, and a similar comparison is made between the dichotomised groups. Although two comparisons are reported, we suggest that these sort of comparisons should be conducted using one way analysis of variance with appropriate post hoc testing (e.g. Bonferroni), or if multiple t tests are used, then the level of significance (presumably set at p=0.05 here) should be reduced to account for multiple comparisons (we suggest 3 comparisons in this case). The low level of significance reported between the dichotomised groups (p=0.02) is unlikely to survive such conservative statistical treatment. These approaches are more conservative, but give us greater confidence in the assertion that some arbitrarily determined time point could be important in determining future risk of cardiovascular disease. We find little in this paper that will change our current personal habits or advice we give to other parents. We are delighted that the authors agree. Yours, Paul Michael Dark
Marie-Josée Rölli
Competing interests: Parents of breast fed infants and children. |
|||
|
|
|||
|
Alan Lucas, Director, MRC Childhood Nutrition Research Centre Institute of Child Health, London WC1N 1EH
Send response to journal:
|
Sir We should like to respond to the extensive correspondence concerning our paper on breast feeding duration and arterial distensibility in early adult life. As expected, this paper particularly evoked comment from those who promote breast-feeding. Indeed some were so alarmed by the title of the paper and subsequent sensationalist media coverage that they may not have noted the cautious way we framed our study in the paper itself - and our clear recommendation that our findings should not change breast-feeding practice. Some have suggested our work was motivated by formula industry objectives. This was certainly not so. The study was hypothesis-driven and independent. Our Childhood Nutrition Centre is the largest in Europe, and supported by government (MRC) core-funding. We have published many papers (generally cited in our BMJ article) collectively providing some of the strongest scientific evidence available in favour of breast feeding - including beneficial effects on cognitive development, blood pressure, bone health, atopic disease, infection, gut disease and catch-up growth. This work is much cited internationally by professional organisations involved with breast-feeding. We have also done studies to test the efficacy and safety of novel advances in infant formula design - though we emphasise our current study on breast-feeding and arterial distensibility has no industrial connection whatsoever. As an independent Centre we publish what we find - in the interests of child and adult health - quite regardless of any pressures from either Industry or advocacy groups. Our large patho-physiological study permitted exploration, in a statistically robust way, the relationship between breast-feeding duration and the sophisticated vascular outcome measure chosen. It was not a purpose of this initial study to take a 'National sample', though our paper does address potential selection bias. Nevertheless, our cohort was heterogeneous (obviously so, for the principal variable - duration of breast feeding) - and was typical of the UK population for a number of characteristics. It seems unlikely that such a strong relationship between arterial distensibility and breast feeding duration should be unique to this cohort - but exploration of other cohorts - including those in developing countries - is now an objective. The lack of data on age of weaning, types of weaning foods used, or use of formulas or cow's milk was because this was a retrospective study that relied on the subject's mother's recall. Total duration of breast-feeding (regardless of weaning food intake) has been shown to be reliably recalled by mothers up to 30 years later - the other factors listed above have not. Our paper emphasises that information on weaning, which could be relevant, will need to be collected prospectively in future studies. Nevertheless, since partial breast-feeding, likely to be common in our cohort, is also currently practised, our data should have contemporary relevance. Importantly, we wish to re-emphasise why we would not suggest any change in breast feeding practice. Firstly, the data are at too incomplete to be translated into health policy. Secondly, a balance of risks is needed - any possible downside must be set against the many positive effects of breast feeding on outcome. Finally, if the hypothesis we raised proves correct - that prolonged breast feeding followed by a western diet explains our results - then future intervention might be better directed to our western diet rather than breast-feeding. Recent public interest in medical science has resulted in public release of data at a stage when they may cause concern and yet their full significance is uncertain. We would, however, defend the need to publish objectively findings like ours that have broad public health implications - to stimulate research. We should also not hide from findings that may appear to conflict with established ideas and we direct attention to the pertinent points made on 19th March by Wendy Holmes in her rapid response to our article. Professor Alan Lucas |
|||
|
|
|||
|
Patti Rundall, Policy Director Baby Milk Action, Cambridge
Send response to journal:
|
The study suggesting a link between breastfeeding and heart disease in later life published on Friday 16th March in the British Medical Journal.(1) has led to extensive Media coverage worldwide, including in Canada, Israel and at least five reports in India on the following day. In the UK numerous women are giving up breastfeeding because of it. Although the authors state that the observational data does not “establish a causal relationship between the length of breastfeeding and cardiovascular disease...” and that “further early dietary information was limited as the study was retrospective,” such fine distinctions are not stated in the summary and have not been picked up by the media. The fact that the study might actually say more about the risks of a Western diet later in life, or about poor infant feeding practices, is being over-looked. Although I am sure the scientists involved in this study did not intend this, infant health - in the UK and globally - will certainly suffer, while companies will reap the benefits. Some of them spend billions encouraging us later in life to eat high-fat, high-salt and high-sugar foods which are known be risky in relation to heart disease. Phyll Buchanan, a Breastfeeding Counsellor with the Breastfeeding Network states,“Mothers are suffering terrible distress because of this, and in some cases have become ill with mastitis because they stopped breastfeeding so suddenly. The people most affected are those who have stood up to the social pressures to give up or to add other foods and have continued breastfeeding exclusively until 6 months.” Prof Alan Lucas, one of the authors of the study told me that he is saddened to hear that the wrong messages are going out. "It was never our intention that mothers should stop breastfeeding because of this very preliminary and incomplete data. If our theory proves to be correct that it is breastfeeding followed by a western style diet that accounts for our findings, then the public health message should be that we should deal with the Western style diet rather than breastfeeding which has so many advantages.” Although valid research should never be suppressed, the high profile launch of such an inconclusive study, just a couple months before a crucial debate in the World Health Assembly about exclusive breastfeeding and marketing (2) raises important questions about how health research is funded, designed and disseminated and how corporations use ‘science’ in pursuit of global marketing strategies. While this particular study was funded by the Medical Research Council, the authors admitted a ‘competing interest’ of collaboration with the infant food industry on previous studies. Prof. Alan Lucas has done extensive research which has demonstrated the clear advantages of breastfeeding, but at the same time is a well-known advocate of industry funding of research. His views, alongside Baby Milk Action were published in the British Medical Journal in 1998. (3) Only last month, Prof. Lucas published a randomised control which showed that premature breastfed babies are likely to have lower blood pressure and less risk of heart disease.(4) Other studies have shown the risks of too early introduction of complementary foods and that breastfeeding is likely to decrease the incidence of obesity in childhood - a major cause of heart disease. (5). For a number of reasons this latest study would not be used in a scientific review of infant feeding. It has shortcomings in its focus and in its methodology, which the authors themselves acknowledge and which have been well outlined by other respondents. For example, its sample is self-selected and the research is based on recall - some 20 - 28 years after the event. Nor did it contain clear definitions on patterns of breastfeeding. In other areas of research, for example, in relation to obesity, HIV transmission or infections generally, whether - and for how long - breastfeeding has been exclusive (ie with nothing else added) or mixed with other foods, have proved to be key factors. For the last 3 - 6 millions years of evolution of our species, it has been normal to breastfeed until the child is aged 3 to 5 years. The many known risks of artificial feeding, and the estimated 1.5 million infant deaths caused each year through lack of breastfeeding, prompted the World Health Assembly in 1981 to recommend that all governments ban the promotion of artificial feeding. In subsequent years the Assembly has repeated these calls and called for the fostering of exclusive breastfeeding followed by complementary feeding from 'about 6 months.' (6) This policy is in place in 61 countries but is continually challenged by the $8 billion dollar baby food industry which lobbies for weaker and weaker controls. If the industry can get global labelling standards to refer to foods as suitable 'from 4 months' rather than from 'about 6 months' it can sell an estimated extra $1 billion dollars worth of foods. The question is, will this study, which leaves so many questions unanswered be allowed to influence policy makers and undermine mothers who are trying to do the best for their babies? refs: (1) Leeson et al, (2001) Duration of breastfeeding and arterial distensibility in early adult life: population based study, BMJ, Vol. 322, (643-647) (2) Brown P, (2001) Campaigners for breastfeeding claim partial victory, BMJ, Vol. 322 (3) Lucas A, (1998) Collaborative research with infant formula companies should not always be censured, Rundall P, How much research in infant feeding comes from unethical marketing? BMJ, 317, 337- 339 (http://www.bmj.com/cgi/content/full/317/7154/333) (4) Singhal et al, (2001) Early nutrition in pre-term infants and later blood pressure: two cohorts after randomised trials, Lancet Vol. 357, no 9254 (5) Van Kries et al (1999) B |
|||
|
|
|||
|
Mark McAuley, General Practitioner Kirkintilloch
Send response to journal:
|
I am surprised and concerned that such a poor quality study has been published in the BMJ. We should expose the media in the UK to good quality research. This is exactly the type of "evidence" the media hone in on, to the detriment of the unsuspecting general public. |
|||
|
|
|||
|
Rachel O'Leary, LLLGB Editorial Consultant
Send response to journal:
|
Response from La Leche League GB to: Duration of breastfeeding and arterial distensibility in early adult life. Leeson C et al. BMJ 2001;322:643-647 LLLGB has been contacted by many mothers concerned about recent news reports that 'breastfeeding is linked to heart disease.' These reports are based on a study in the British Medical Journal, 16 March 2001, indicating a link between breastfeeding for longer than four months and reduced arterial distensibility (greater artery stiffness). It is noteworthy that the authors of this paper conclude that their findings should *not* influence current advice on the importance of breastfeeding or change infant feeding recommendations. The authors emphasise that the data does 'not establish a causal relation between length of breastfeeding and cardiovascular disease'. They also state that 'there was no direct record of infant feeding method or duration' and that maternal recall was the source of infant feeding information about the participants, aged 20-28 years. Participants were grouped according to 'either only bottlefed or having received breastmilk'. This means that other aspects which may affect the outcome of the research were not taken into account - such as whether the breastfeeding was exclusive or partial, when solids were introduced, what the weaning diet consisted of, and how much exercise the children took. These confounding variables were not controlled for in the study. The authors recognise that 'early dietary information was limited as the study was retrospective' and that 'prospective investigations could take account of age of weaning and subsequent diet.' Prospective investigations - where information is collected while the study is in progress - are generally thought to provide more useful information. The authors declaration states: "Competing interests: The centre has collaborated with the infant food industry for its outcome studies on nutrition." In other recent studies breastfeeding has been consistently linked with a lower risk of cardiovascular risk factors. Indeed, evidence is now emerging that it is the early introduction of non-human milks/solids which appears to be a crucial determining factor in increased cardiovascular risk factors. La Leche League welcomes independent research which adds to scientific knowledge about breastfeeding. LLLI publishes "Breastfeeding Abstracts", a quarterly summary of breastfeeding research from many scientific journals. For subscription details, contact LLLI or LLLGB. Global recommendations are that mothers be enabled to practise exclusive breastfeeding for about six months, when appropriate complementary foods are to be introduced alongside continued breastfeeding for as long as the mother wishes, ideally into the second year and beyond. Department of Health recommendations in Great Britain are for exclusive breastfeeding and for solids not to be introduced before four months and by six months, with breastfeeding continuing for as long as the mother wishes, ideally for the first year. LLLGB continues to help breastfeeding mothers with support and information based on current evidence; national and global recommendations; and experience in helping breastfeeding mothers for over 45 years. LLLI states that: • Breast milk is the superior infant food. • For the healthy, full-term baby breastmilk is the only food necessary until baby shows signs of needing solids, about the middle of the first year after birth. • Ideally, the breastfeeding relationship will continue until baby outgrows the need. • Good nutrition means eating a well-balanced and varied diet of foods in as close to their natural state as possible. La Leche League GB Registered Charity Number 283771 Helpline for mothers 020 7242 1278 |
|||
|
|
|||
|
Heleen Hayes, Mom of nursing 2 year old Home
Send response to journal:
|
Dear Editor, People before me have commented on the size and way of making up the test population, I would like to rephrase the results. Rather than stating that Breastfeeding has a disadvantage, the researchers have found the first possible advantage of artificial milk. And maybe it still is a disadvantage of formula, I am a lay person and can imagine that this stiffness of the veins may be a risk for heart disease in later age, but it might have advantages as well. |
|||
|
|
|||
|
Annelies Bon, Lay counsellor Vereniging Borstvoeding Natuurlijk
Send response to journal:
|
Dear Editor, As a lay breastfeeding counsellor AND mother of a nursing 5 year old, I am concerned about this research (Leeson et.al) and the editorial that accompanies it (Booth) I would therefore, like to make the follow points. Firstly, I am concerned about how newspapers around the world have picked up this report and have used headlines that state, "breastfeeding for longer than 4 months is dangerous". While I do not think that publication policy should take the political correctness of the study into account, I do believe that the researchers involved and the editor of the BMJ should have taken steps to avoid the miss-representation of this study in the media. For example, a good editorial would not have suggested that premature weaning should be considered. Secondly, I am concerned about how this will influence the current debate on the change of the WHO recommendation for exclusive breastfeeding. The infant food industry is lobbying hard to keep the official recommendation of exclusive breastfeeding at four months (1). A new recommendation from the WHO that would advocate six months exclusive breastfeeding instead of the current four months would have a big impact on their profits. I am sure that this research, that coincidentally also has a marker of four months, will become a very convenient tool used by the baby food industry in its argument against raising the recommended period of exclusive breastfeeding. Thirdly, I see a similarity with a debate that started 25 years ago. In the Netherlands research demonstrated that environmental toxins enter human milk in high doses. Many researchers warned against breastfeeding. Many recommended to wean prematurely at 6 weeks, if nursing at all. Investigations were started and nowadays we know that while the toxin load in breastfed children is high (too high) it has not shown to cause adverse effects on the future health of babies. Instead, one of the researchers concluded that breastfeeding counteracts the damage, caused by these toxins, that occurs in utero. "Our studies showed evidence that breast feeding counteracts the adverse developmental effects of PCBs and dioxins." (2) My final point is that I believe we should further investigate the issue of the relation between breastfeeding and cardiovascular disease. While this research shows a positive correlation between these, there are other studies that indicate the opposite. For example the recent study of Singhal, Cole and Lucas in the Lancet (3), the follow-up of the Dundee study (4), Ravella et al (5), and the German study that shows a correlation between not breastfeeding and obesity (6). We should also take this issue as a challenge and look closely at these studies, compare them and use them to undertake well designed studies that address the issues that these studies have brought to light. Well-designed studies, with suitable and relevant control groups, would address all the confounding factors that ensue from these studies. With kindly regards, Annelies Bon Lay breastfeeding counsellor and mother of three breastfed children. (1) Baby food industry lobbies WHO on breast feeding advice , Gavin
Yamey, BMJ 2000;321:591 ( 9 September ),
http://bmj.com/cgi/content/full/321/7261/591
|
|||
|
|
|||
|
Allan Astrup Jensen, Research Director dk-TEKNIK ENERGY & ENVIRONMENT
Send response to journal:
|
It is an interesting and important paper. I think the many critical responses tries to kill the messenger, because the message is unpleasant for them and may hurt common health policies. No paper is perfect including this. There may always be raised questions and critics to method, execution and reporting. I miss a reference to chemical pollutants in the breast milk as a possible explanation for the findings. The persistent POPs: DDT/DDE, PCB and dioxins, have at least for the last 50 years contaminated human milk everywhere in the World. Levels in Breast milk are higher than in all other foodstuffs. Because of the life-long persistence of these toxic chemicals, breast-fed infants will receive a much higher body burden than formula-fed infants. These chemicals are associated with lipoproteins and interact e.g. with the cholesterol metabolism. Breast milk from smokers do also contain high levels of nicotin and Cd, chemicals known to affect blood vessels. (More reading in e.g.: AA Jensen & SA Slorach. Chemical Contaminants in Human Milk. CRC Press, 1991.) |
|||
|
|
|||
|
F Meyer-Bradfisch, -- home
Send response to journal:
|
What if a study on breastfeeding and future obesity had found the following: "Formular fed infants weight 68.45 kg as adults, while breastfed infants end up at 67.21 kg. Obesity is a risk factor for cardio-vascular diseases." The approbriate reaction to a study like that would be a shrug and the comment "So what?!" The study would only have found formular fed infants to be slightly heavier as an average, but the risk factor is not one more kg, but obesity! So the Leeson et al. study would perhaps be a reason to think about the "optimal" duration of breastfeeding, if it had found a significantly higher proportion of DANGEROUSLY inflexible arteries with those breastfed longer than 4 months. Like it is, my reaction to their findings is "So what?!!" Unfortunately the content of the study has been distorted and blown completely out of proportion in the media, so I´m having a hard time explaining why I´m still breastfeeding - and with a good concience, too. Competing interests: Still breastfeeding my son at 4 times 4 months |
|||
|
||||