Is ‘breast only’ for first 6 months best?

Boy did those headlines grab my eyes.  And my breath.   And my gut.  How could this be?  Exclusive breastfeeding for the first six months is a tenet we hold to in breastfeeding medicine.  There are loads of data to support it.  Isn’t is up there with one of the Ten Commandments?  What had I missed that changed so drastically while I was quietly celebrating Christmas and bringing in the New Year with my family and friends?

I had a “heads up” on this  “editorial” the day before it came out, as ABC news asked me to comment on it.  In case you somehow managed to miss it, (maybe you were unconscious that night?) the British Medical Journal released an editorial the night of January 13 on bmj.com questioning current guidance advising mothers in the UK to exclusively breastfeed for the first six months of their baby’s life.

My very first thought was—“No this cannot be true—must be some sort of joke.”  Or, “This is one of those dreams where you are running as fast as you can but you cannot get away from the monster and I will wake up any minute, and all will be right with the (breastfeeding) world.”  But I was awake—my kids were all talking to me at once, and my dog was chiming in just for effect.  So I then looked at the authors, Dr Mary Fewtrell, Dr. Alan Lucas, Dr. David Wilson and Dr. Ian Booth.  I am not familiar with the later two, but the first two authors—I quote their work all the time when I lecture on the multitude of health benefits to premature babies who receive their own mothers’ or donor human milk, AND how there is a dose-related response, i.e. the more milk you get, the more protected you are.  So what am I missing?????  Maybe I had a small stroke??

 Exclusive breastfeeding for the first 6 months (meaning nothing but human milk except medicine or vitamins) has been and IS what we strive for, for all babies, a “rule to live by” if you will, for the vast majority of lactation experts and specialists worldwide for a number of years now.  We in lactation and breastfeeding medicine have worked hard over the past 10 years literally fighting both our medical colleagues who are not educated in lactation, and our culture, to establish exclusive breastfeeding for the first 6 months as the evidence-based norm and standard of care for virtually every baby.  It is based on a huge and ever-growing body of evidence, that when taken as a whole, tells us about the lowering of risk in human babies of a whole host of acute and chronic illnesses and conditions, both in infancy and all the way to adulthood, by starting out life on species-specific human milk, and human milk alone, for that first 6 months.  Not to mention the fact that exclusively human-milk fed babies for the first 6 months and then breastfeeding continuing with complimentary foods added form the standards of growth for human infants. 

So no wonder my first reaction was one of shock.  But then it was followed by curiosity.  Why would Dr. Fewtrell, who is a well-known, well-published and well-respected researcher in our field question this “given” at this time?  I am not aware of anything new in the literature that has come out to make us think any differently.  So, I was very anxious to read the editorial and see what her reasoning was.  And, after carefully reading what these authors have written, I am not convinced any differently than before.

What they are talking about is the introduction of solid foods, often thought of as “weaning” foods, or “complimentary” foods.   They cite a number of individual papers that have been used in the arguments for 6 months of exclusive breastfeeding, and point out flaws in the separate studies.  That is always an issue in this field.  The gold standard of research is the double-blind, randomized controlled trial.  We have few true Level-I randomized controlled trials that are large, and can never be blinded (it is pretty easy to see which babies are breastfed and which are not)! Many smaller studies are done, so that to have any meaning at all, they are combined into what are known as meta-analyses, where data from multiple smaller studies are looked at together to try to make a more meaningful result and conclusions.  But this is also hard, because if the studies are not done in the same ways, it is hard to combine them.  The point being, that in the field of lactation it is not hard to pick apart individual studies because of the nature of the research.

Personally, I have full confidence, based on the literature, that human milk, which is species specific to human babies, is the best nutrition, and first immunization and protection against a myriad of diseases, both acute and chronic, during infancy all the way into adulthood.  I believe that breastfeeding, which is not the same as breast milk feeding, is the best way to feed our babies, with breast milk feeding next, and that all babies have the right to be breastfed, just as all women have the right to be helped and supported to breastfeed their babies, which in this country, we do not do a good job of accomplishing. 

When a mother “can’t” breastfed, it is almost always because the supports were not in place for her to do it, and those supports come from our society and our culture and the health care profession.  Almost all babies will thrive and accrue the best benefits by breastfeeding exclusively for six months, with the addition of appropriate complementary foods around six months (supported to my mind by the current literature).  Those foods should have iron and zinc, which babies begin to require above what they are getting in human milk at that time.  It is important to note that babies also need to be developmentally ready to handle solid foods in their mouth when they start, which is around 6 months, but may be a bit earlier, or a bit later.  I also believe, again based on the evidence, mothers and babies should breastfeed at least through the first year of life, preferably the second (based on studies which show a “dose-response” of accruing more good in virtually any end-point benefit studied directly related to the more human milk consumed) and for as long as is mutually desired by mother and child.

As I think about some of the specifics of the Fewtrell, paper I think of some of the studies that are cited which have their own issues and have been taken out of context.  An example—if babies don’t eat green leafy vegetables, they will never acquire a taste for them.   Formula always tastes the same—every time it is mixed up—it tastes the same.  It is the same “formulation” (no pun intended of course…) of components—it never varies within any given brand.  Human milk changes all the time—and it changes in taste dependent on what mom eats!  So it doesn’t taste the same, and from the beginning, breastfed babies are exposed to different tastes that may in fact HELP them to acquire tastes for different foods.  Think of the foods in different cultures.  The baby born into that culture is already becoming acquainted with the flavors and tastes of his/her culture from the very beginning!  How cool is that!

As I explained above, many studies in this field are small and flawed, because it is difficult to do large-scaled, ethical randomized controlled trials of infant feeding.  So we are left designing the best trials we can, and looking at retrospective data, and data collected as part of large governmental surveys, and doing our best to ferret out what it really means.  There will be flaws in individual studies.  But the strength comes when we have large numbers of these trials and we can look at them together.  And in that way, the data supports exclusive breastfeeding for 6 months.  Not back to the more wishy-washy “4 to 6 months” that we were dealing with 10 years ago.  But firmly at 6 months.  We have worked hard, and continue to work hard, to get that message out to both the medical profession and families.  But publishing this paper, taking apart a few individual studies, and the media attention it aroused, families (and health care professionals) will become more confused. 

It is interesting to me that we always have to “prove” the merits of human milk and breastfeeding, and that the public and the medical profession are so willing to believe that chemistry can do better than millions of years of evolution in designing the perfect food and source of immunity and health for our babies.  It seems to me it should be the other way around.  We should always strive to increase our knowledge in medicine, and never be complacent that we have all the answers.  If Dr. Fewtrell and colleagues want to challenge the 6 months exclusive breastfeeding, then by all means, they should design studies to do so. But taking a few studies, pointing out their flaws and generalizing them to whole populations, which will make a splash in the press and further confuse the issue, is not, in my humble opinion, the best way or even an effective way to go about this.

A side message that could come from this paper—if it is ok to start solids at 4 months, then human milk is not as important as we have said, and so not only can we start solids, but what would be wrong with substituting formula as well? And breastfeeding duration could plummet!  Again—we have worked hard to educate families to understand why duration is important—that as I said before, many of the “lack of risks” or “benefits” (depending on how you are looking at this) come as a dose-dependent response—the more milk, over the more time, the less the risk, the better the protection.  So duration is important too!!  Being told that it is ok to substitute solid foods for human milk at 4 months opens the Pandora’s box of “…then it must be ok to use formula then too…” 

We have done well with initiation of breastfeeding in the US, with many places up close to the 75% initiation rates called for in Healthy people 2010 (except some pockets where there are still problems, like in the South for example).  But overall, we have made good strides in this area.  The place we need to work harder already is in duration, meaning how long a woman breastfeeds.  Many things interfere with a woman’s ability to keep up breastfeeding—such as return to work before breastfeeding is well established (some woman have to go back within 2 weeks of birth for financial reasons; some after 6 weeks).  And other moms quit whenever they return to work because it is so difficult to express or feed their babies at work, regardless of whether their rights to express at work are covered by law.  The recently announced Healthy People 2020 Goals have increased any breastfeeding at 6 months from 43.4% baseline to 60.5%; at 1 year any breastfeeding from 22.7% baseline to 34.1%. This isn’t exclusive breastfeeding—this is ANY breastfeeding.  We DO NOT need more confusing messages that will interfere with duration even more!

The Fewtrell article says that in the US we use 4 months to supplement.  Where did they get this from??  The American Academy of Pediatrics Section on Breastfeeding Policy Statement on Breastfeeding (2005); currently being updated—and as an AAP Policy therefore should be followed by Pediatricians as it is the Policy of our Academy—states to begin complementary foods at “approximately first 6 months of life”.

The Allergy data—this is a very open, changing area.  You can find papers that show breastfeeding protects against allergy and those that show it contributes.  It is much more complicated than black and white exclusive breastfeeding for 3 months vs. 6 months.  There is emerging data about sensitization occurring in utero in some populations.  There are studies looking at exposing some populations to tiny amounts of the offending allergen at early ages to try to build up tolerance.  The immune/allergic response system is multi-layered and quite complicated.  There appear to be differences in families that are highly allergic versus those that are not (genetic predisposition).  Environmental causation has been implicated in the increasing incidence of allergies and allergic-related diseases—asthma, eczema, etc.  One study coming into question does not provide evidence for change in practice.

Anemia—as stated in the paper, things that happen at delivery can affect potential for anemia greatly.  Iron stores are transported across the placenta in the third trimester—premature babies by definition loose all or part of the third trimester—so they are born deficient in iron stores and need iron supplementation, breastfed or not.  If the cord is clamped immediately at birth, blood that belongs in the baby (along with the iron that it carries) does not make it into the baby, so these babies are at risk for anemia.  Delayed cord clamping can avoid this.  It is also important to know what mother’s iron status is during pregnancy.  If she is iron deficient, the baby may be iron deficient to start out, and will need supplementation with iron before complementary foods are added at 6 months. 

One last thought.  The study that came out in 2010 by Melissa Bartick and colleagues which made headlines last year was pretty convincing for the argument of 6 months of exclusive breastfeeding.   They found that if in the US 90% of families complied with medical recommendations to exclusively breastfeed for 6 months, the US would save $13 billion per year in health care costs and an excess of almost 1000 deaths, nearly all of which would be infants, would be prevented.  Pretty compelling evidence for exclusivity to 6 months!

Kathleen Marinelli MD, IBCLC, FABM is a neonatologist a Board member of the Academy of Breastfeeding Medicine, and Chair of the ABM Protocol Committee.

Posts on this blog reflect the opinions of individual ABM members, not the organization as a whole.