Tag Archives: Breastfeeding

Breast may be best, but why isn’t it better?

In honor of World Breastfeeding Week (yes, yes, I know–it ended yesterday), we need to talk about a widely overlooked aspect of breastfeeding, its recipients!

Nope, I am not talking about our babies. (After all, who could overlook them?) I am talking about their gut bacteria.

Breast milk contains special carbohydrates (called HMOs for Human Milk Oligosaccharides) designed to nourish specific gut bacteria, especially a type known as Bifidobacteria. Bifidobacteria contain genes desiged to metabolize HMOs–implying they have co-evolved with us for a long time.

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Drinking While Nursing: 7 Things to Know

While over half of mothers in the U.S. drink alcohol while breastfeeding, many of us are foggy on how this does (or does not) affect our babies.

Can you drink a glass of wine while breastfeeding your baby? Or do you need you wait 2-3 hours for the alcohol to clear? And exactly how much alcohol is too much alcohol to nurse?

Doctors and trusted sources like KellyMom and Babycenter give wildly conflicting advice on these points.

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Don’t Count on Breastfeeding to Help You Shed Your Baby Weight

Before giving birth, I had always heard that breastfeeding melts off baby weight.

This was not just some old wives tale. Even the American Academy of Pediatrics (AAP). claims that breastfeeding leads to an “earlier return to prepregnancy weight”.

This is because, as many popular websites, like WebMd claim, “breastfeeding burns extra calories, so it can help you lose pregnancy weight faster.”

Sounds pretty convincing, right?

So when I failed to lose weight while breastfeeding my first child, I was shocked. Weren’t those pregnancy pounds supposed to practically fall off? Why were my pre-pregnancy jeans still relegated to the back of my closet?

By exclusively breastfeeding, I was burning an average of 480 calories a day, but the pregnancy pounds were still clinging to my waist and hips.

So, naturally, I turned to the research, and learned that, like so many other widely alleged benefits of breastfeeding, breastfeeding-aided weight loss is vastly overblown.

My experience was not weird, but completely normal. For most well-nourished women, long-term breastfeeding results in only a trivial amount of extra weight loss by 6 months postpartum, of around 1-2 lbs.

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Questioning Breastfeeding’s Benefits Does Not Make Me Anti-Breastfeeding

Earlier this week, I wrote about the alleged benefits of breastfeeding being vastly overstated.

My goal in writing that post was not to nurse some long-standing grudge against breastfeeding advocates. Nor was it an attempt to justify my own parenting choices: I breastfed both my children for well over a year.

(And yes, as some readers have inquired, I know just how wonderful breastfeeding can be. How breastfeeding your baby can be calming and joyful, even magical. But whether I found breastfeeding magical or a chore–or, in actuality, both–has nothing to do with whether it lowers the risk of asthma, or heart disease, or anything else.)

In response to my post, someone shared this comment on Facebook:

“Anyone who thinks this [my post] a solid piece of work needs to read my latest book, Milk Matters: infant feeding and immune disorder. No one has to prove that breastfeeding (the evolutionary and physiological norm that provides free stem cell transplants) makes a positive difference. Those who assume, claim or promote artificial feeding as safe or adequate need to prove that deviating from such basic physiological norms is safe, that there are no short or long term harms from doing so. …”

I am sharing this comment not because I find it particularly compelling, but because I think it nicely illustrates the problem with arguments made by many breastfeeding advocates: They start with the assumption that breast is best. And then, inevitably, they fail to scrutinize the evidence, no matter how flimsy, that supports that assumption.

And the evidence is flimsy indeed. Most of the alleged benefits of breastfeeding are found only in observational studies, which are widely acknowledged as biased. On average, breastfeeding mothers have a higher levels of education, higher incomes, and live in safer neighborhoods than formula-feeding mothers, granting their children an early leg up in life. Separating the effects of breastfeeding from these other advantages is next to impossible.

How do we know that these observational studies are biased? Primarily because we do not find the same benefits in better-designed studies–sibling comparison studies and the PROBIT randomized controlled trial. The only clear-cut benefit seen in these studies is a lower risk of severe vomiting and diarrhea during infancy. (For a detailed summary, see my earlier post).

To be fair, breastfeeding advocates are right, in a way. Breastmilk does contains numerous hormonal, antimicrobial, immunological, and nutritional factors not found in formula. This is why breastmilk helps protect against vomiting and diarrhea during infancy.

Before the advent of clean water, sanitation, and modern medicine, breastfeeding was frequently life-saving. In countries where access to these resources remains limited, it still is. There’s no bigger possible benefit than survival.

But these beneficial properties do not imply that breastmilk has any long-term benefits for the panoply of modern ailments: allergies, asthma, obesity, type 2 diabetes, and cardiovascular disease. We cannot claim such long-term benefits without sound empirical evidence. And that is entirely lacking.

If the American Academy of Pediatrics, and others were to say, “We recommend breastfeeding because it reduces the risk of severe diarrhea and vomiting during infancy, and because breastmilk contains unique immune, hormonal, and nutritional factors not found in formula, the long-term benefits of which are unknown,” I would have no problem with their claims.

But instead, they have chosen to present poor quality evidence as fact. Playing fast and loose with the evidence in this way undermines their credibility. Worse, it violates the trust that women have placed in them.

Breastfeeding Benefits: The Real, the Imagined, and the Exaggerated

Breast is best is the mantra of most major medical organizations. Women have it drummed into them well before giving birth. As a result, women for whom breastfeeding is not working often make themselves miserable pumping round the clock trying desperately to get their babies this “liquid gold”.

It is unfortunate, especially since despite all the hype, the best research does not find longterm benefits of breastfeeding.

Here’s the thing about those oft-stated benefits to IQ, obesity, and allergies and asthma: They only show up observational studies. 

Why does that matter? Because observational studies of breastfeeding all suffer from the same huge flaw: Breastfed infants tend to differ from formula-fed infants not just in how they are fed in infancy, but in nearly every other possible way–in their mother’s education level, in their mother’s IQ, poverty, neighborhood safety, exposure to environmental toxins, race, and type and quality of childcare. In scientific terms, breastfeeding is confounded, out the wazoo.

We cannot tell which benefits found in an observational study derive from breastfeeding rather than from the myriad other advantages linked with breastfeeding.

(The “good” observational studies attempt to control statistically for the other relative advantages of breastfed infants. Unfortunately, controlling for confounds only works well when (1) all the important potential confounds are known, and (2) when there is sizeable overlap between the compared groups. Neither is true when it comes to breastfeeding.)

In an ideal world, we would settle this question by conducting several large randomized controlled trials (RCTs), in which new mothers would be randomly assigned to breastfeed. RCTs are the gold standard in medicine for determining whether a true cause and effect relationship exists. In practice, though, such trials are neither feasible nor ethical.

Fortunately, we have the next best thing: a handful of studies that have cleverly circumvented the problem of confounding. These fall into two categories:

  • sibling studies, which compare siblings from the same families who were breastfed for different lengths of time, or who were not both breastfed.
  • a large RCT of a highly successful breastfeeding intervention (PROBIT Trial).

(Is the PROBIT Trial an exception to the no-RCT rule? No. Women in the PROBIT trial were not randomly assigned to breastfed or not; they were randomly assigned to receive a breastfeeding intervention or not.)

After my friend and I spoke about his irritation with the medical organizations like the American Academy of Pediatrics (AAP) and NHS overstating the benefits of breastfeeding, I was dissatisfied with my vague sense that he was right. I wanted to know exactly which benefits had been oversold and exactly which were supported not just by observational studies but by better-designed studies.

The short answer: Nearly all the alleged long-term benefits are likely the result of confounding, not breastfeeding. Better-designed studies find only a handful of real benefits: a reduced chance of severe gastrointestinal infections and a lower risk of eczema during infancy, and perhaps a small boost in childhood IQ.

Alleged Breastfeeding Benefits According to the NHS

According to the NHS, breastfed infants are…

  • less likely to suffer from vomiting or diarrhea and therefore less likely to go to hospital
  • less likely to develop type 2 diabetes in later life
  • less likely to become obese in later life
  • less likely to suffer from heart disease in later life
  • less likely to suffer from constipation
  • less likely to get a chest or ear infection and therefore less likely to go to hospital
  • less likely to suffer from tooth development problems
  • more likely to have good communication and speech skills
  • more likely to have good circulation
  • less likely to suffer from wind, colic and constipation
  • less likely to develop eczema or asthma

Sounds pretty impressive, right? Until you set aside the evidence from observational studies…

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Continue reading Breastfeeding Benefits: The Real, the Imagined, and the Exaggerated