Ever more desperate efforts to find ever more arcane “benefits” of breastfeeding

Middle age blonde therapist woman wearing white coat over isolated background suffering from headache desperate and stressed because pain and migraine. Hands on head.

Breastfeeding research is a flawed paradigm in which statistically illiterate methods, meaningless “benefits” and ideological censorship dominate the literature.

It’s the inevitable result of the fact that lactation professionals made extravagant claims about the benefits of breastfeeding more than a decade before they bothered to check if those claims were true. By now it’s become obvious even to them that their original predictions about lives and healthcare dollars saved and diseases and conditions prevented have utterly failed to materialize. We are constantly treated to ever more desperate efforts to find ever more arcane “benefits” of breastfeeding.

[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Breastfeeding did NOT prevent infant hospitalizations for respiratory or GI infections.[/pullquote]

A new paper, Breastfeeding Status and Duration and Infections, Hospitalizations for Infections, and Antibiotic Use in the First Two Years of Life in the ELFE Cohort, is a perfect example.

Spoiler alert: the authors found that breastfeeding didn’t have the anti-infective benefits claimed for it. But that’s not how they presented their findings. Because of ongoing pressure for ideological conformity in breastfeeding research, they concluded:

Predominant breastfeeding for <1 month was associated with higher risk of a single hospital admission while predominant breastfeeding for ≥3 months was associated with a lower risk of long duration (≥4 nights) of hospitalization.

Which is just another way to say breastfeeding does NOT reduce the risk of infant hospitalization.

Let’s see what the authors found and examine how they had to slice and dice the data to arrive at the misleading conclusion.

They start by rehearsing the claims made for breastfeeding benefits:

The World Health Organization (WHO) recommends exclusive breastfeeding for 6 months, or at least the first 4 months of life. These recommendations were mainly based on the protective effect of breastfeeding against infectious morbidity and mortality. In fact, breast milk components, such as immunoglobulin A (IgA) or maternal leukocytes, can both supplement and promote the newborn’s immature immune system and therefore lead to protective effect against infections.

More precisely, recent literature has shown that breastfeeding is related to a reduced rate of hospital admission for diarrhea and respiratory infections as well as a protective effect on otitis media in children up to 2 years old. Of note, otitis media studies were mostly from high-income countries, whereas results on diarrhea and respiratory infection studies were mostly found in settings from low- and middle-income countries. In high-income countries, the preventive effect of breastfeeding on respiratory tract infections is less consistent across studies. In the cluster-randomized trial on promotion of breastfeeding (PROBIT), which took place in Belarus in the 1990s, breastfeeding was related to a reduced risk of gastrointestinal infections in the first year of life.

This is an excellent summary. Contrary to the claims of lactation professionals, the existing research shows that breastfeeding reduces the risk of ear infections in high income countries and respiratory infections and diarrheal illnesses in low income countries.

The authors set out to investigate whether breastfeeding in a high income country (France) reduces the risk of serious respiratory and gastrointestinal infections by looking at the impact of breastfeeding on pediatric hospital admissions.

Here’s what they found:

AB97EDB2-85CC-4B25-9EB4-BBF0C922B480

There was NOT EVEN ONE statistically significant association between breastfeeding and hospitalization for fever, gastrointestinal infection or respiratory infection.

Oops!

It’s hardly surprising. No one has ever been able to show that breastfeeding reduces the risk of hospitalization in term infants.

But given the mandated ideological conformity in breastfeeding research, no one was going to publish that inconvenient fact. Therefore, the authors began data dredging, slicing and dicing the data to come up with any association, no matter how arcane.

They looked at parent reported “events” of respiratory infection, ear infection and antibiotic use.

Finally they found a few statistically significant results:

3111A960-4D30-4865-A258-5B7BA880747B

Compared to never-breastfed infants, infants who were predominantly breastfed for <1 month were at higher risk of being hospitalized …

Oops!

How did the authors deal with that finding? They excluded early hospitalizations.

Why? They provide no compelling reason.

Compared to never-breastfed infants, infants who were predominantly breastfed for at least 3 months were at lower risk of long duration (≥4 nights) of hospitalizations…

And:

Compared to never-breastfed infants … any breastfed for <1 month infants were at higher risk of hospitalization from gastrointestinal infections.

Oops!

So they sliced and diced the data even more and finally came up with something:

…[P]redominant breastfeeding for over 3 months was related to lower risk of at least 4 nights of hospitalization up to 2 years, while any breastfeeding for over 3 months was related to higher risk of 1 or 2 bronchiolitis events in the first 2 years of age. Finally, both any and predominant breastfeeding durations were negatively associated with frequency of antibiotic use.

What does this mean? Absolutely nothing because it is an example of data dredging (aka p-hacking).

According to Wikipedia:

Data dredging (also data fishing, data snooping, data butchery, and p-hacking) is the misuse of data analysis to find patterns in data that can be presented as statistically significant when in fact there is no real underlying effect. This is done by performing many statistical tests on the data and only paying attention to those that come back with significant results, instead of stating a single hypothesis about an underlying effect before the analysis and then conducting a single test for it.

Why are these results meaningless?

Conventional tests of statistical significance are based on the probability that a particular result would arise if chance alone were at work, and necessarily accept some risk of mistaken conclusions of a certain type … When enough hypotheses are tested, it is virtually certain that some will be statistically significant but misleading, since almost every data set with any degree of randomness is likely to contain (for example) some spurious correlations…

In other words if a significance level of 0.05 is used (as in this paper), there’s a 5% chance that statistically significant conclusions will be spurious. In a large dataset with only a few statistically significant associations, that virtually ensures that those associations are not valid. Hence data dredging is considered a misuse of data analysis.

The authors of the paper claim:

Even in the context of a high-income country with short breastfeeding duration, we highlighted a lower risk of infectious morbidity related to breastfeeding duration, especially for duration of hospitalization and antibiotic use.

But the truth is they found nothing of the kind.

This is just the latest example of statistically illiterate methods, meaningless “benefits” and ideological censorship that render invalid most of the scientific literature on the benefits of breastfeeding.

  • mabelcruet

    Surely a reviewer should have picked up on all this? Unless, of course, the reviewer isn’t independent and has the same ulterior motives as the authors, which then calls into question the validity of the whole damn journal if they resort to that sort of tactic to slip through such worthless garbage masquerading as research.

    • The Bofa on the Sofa

      I have to say, the problems associated with p-hacking are well-recognized these days, and so you wouldn’t think we should be seeing papers that do it as much any more.

  • rational thinker

    Here is a study they can do. How about we get the exact number of infants in the USA who were admitted to the hospital due to jaundice from exclusive breastfeeding problems. Then they can figure out the total amount of money that was spent to treat these infants. My guess is they do not want to know that number.

    • mabelcruet

      You’ll never make a breast milk researcher. Applying logic, common sense and rationality to research? Whoever heard of that working?!

  • Mel

    Oh, I love reading the data set exclusion portions of these papers.

    The original data set included 18,329 babies. Once babies whose parents pulled consent, who had missing data points, and only one baby from sets of twins were selected to avoid over-representing, the data set had been winnowed down to 10,349 kids.

    The three largest reasons to drop a given baby from the data set were 1) no follow-up at 2 years (4,705), 2) missing data on infections (1,894) and 3) missing health/family info (889).

    The authors then run some data analysis assuming that the families that disappeared or didn’t give needed information were different than the included families and found out that – surprise, surprise – that included families were more likely to be older, have a co-parent, have a higher education level, be employed, be born in France (where the study took place), AND breastfed longer.

    TL;DR – the study group was wealthier, older, more comfortable in the local culture, had more resources AND were more likely to breastfeed – and the authors still needed to exclude early hospitalizations (646 babies) to get a pro-breastfeeding outcome.

    I can only imagine the results they would have gotten if they ran the data set with only the data from 2 months……

  • swbarnes2

    As always, xkcd has an illustration

    https://xkcd.com/882/

  • Rebecca Fett

    Dear Dr. Tuteur, I am in the process of finalizing a book that debunks some of the myths around the benefits of breastfeeding, and covers the risks of heavy-handed encouragement of early breastfeeding, with material contributed by Dr. Christie del Castillo-Hegyi of the Fed is Best Foundation. I wanted to ask your permission to include a couple of quotes from your blog posts. May I send you an advance copy to review? My email address is rebeccafett.author@gmail.com

  • MainlyMom

    My first was exclusively breastfed from birth. At 12 days old, she was hospitalized with an infection. As a first time, postpartum mom, this was awful. I’m pretty sure it was the cause of panic attacks during her first year, abd I’m certain it wss the reason I’d break down and sob every time she ran a fever for her first few years (they were high and often. She’s 14 and fine now, she just had a thing for running high fevers as a kid). Parents don’t need any nonsense making something that’s already extremely difficult ever harder. Thank goodness i had a great pediatrician who suspected, and was right, that she was a healthy kid who’s body just fevered easily. And who made sure she had every vaccine as soon as she could, in case it was something else.

  • Cartman36

    This makes me angry because some more new mom, all exhausted and hurting, sees something like this and has no idea that it is complete garbage and thinks she has to keep breastfeeding to protect her baby. I also noticed this nutrients journal appears to be a pay to publish.

    • alongpursuit

      Yup! That was me! Coming from abusive family, terrified of becoming an abuser myself, and willing to do absolutely anything to protect my baby, the pressure to BF + my inability to produce more than 2 oz/day and the specter of what would happen if I didn’t (cancer, viruses, infections, hospitalizations, allergies, parasites, no mother-child bond, lower IQ..) drove me to a bottomless pit of despair. I’ve gotten help, but remain deeply traumatized by my experience with nurses and lactation consultants coercing me to try harder to breastfeed to increase my supply to protect my baby. I hope I see the day when this nonsense stops.

      Ironically, my baby (who is almost 2) had only one mild ear infection, zero gastrointestinal illnesses and a few runny noses/coughs but is otherwise healthy, healthy, healthy. And she goes to daycare and likes to put kinda dirty things in her mouth regularly.

      Why do these women (all the authors of the paper have female names and it was only ever women who shamed me for my BFing failures) do this to other women? What a shame.

      • PeggySue

        What you went through is horrible. I’m really glad you got help, and hope you realize how well you’ve cared for your baby!

        • alongpursuit

          Thank you!

          • Cartman36

            Yes, I am sorry you went through that as well but glad you have come out the other side.

      • alongpursuit

        https://uploads.disquscdn.com/images/faa878404849207eb45325f5f6b8c15409bfb98f6f0f247cf7ba007f1b04c6c9.jpg

        Nonsense from these papers ends up in public health posters like this one. It’s plastered all over the hospitals and dr’s offices where I have been for care related to my pregnancies.

        • fiftyfifty1

          An almost identical poster (in English of course) was displayed in the bathroom at our local food co-op. I had no time that day to complain to the management so I just wrote “this is crap” on it.

          • alongpursuit

            Beautiful! Well done!

      • Cartman36

        I can’t tell you how angry I was after I found Dr. Amy and read Joan Wolf’s book about the lies that I had been told. I almost had a nervous breakdown from the stress and exhaustion of breastfeeding. My doctor told me at 4 months that I needed to stop for my mental health. When I learned how much about breastfeeding is sold as fact when it is nothing more than a stinking pile of garbage lies, I can’t even describe the rage I felt. I still get ragey because it is happening to other women every single day.

        • alongpursuit

          I’m enraged too and I hate it, but I’m now very wary of other mothers and nurses. The breast is best stuff is taken as absolute truth and is pushed in the name of “protecting the babies”. It’s twisted and unethical and it just makes me so tired. I’m so grateful for Dr. Amy’s writing and the enlightened community that comments on the blog and on Twitter. I’m just so sad that the mommy wars seem unavoidable and that mothers are still subject to behavior policing in 2019.

  • JDM

    Thanks for the post outlining the problems with that study. I just want to emphasize the length of time it takes to counter the “facts” in the paper’s conclusions versus how little time and effort it will be for people to point to and summarize the paper. This is one of the classic always present difficulties in combatting pseudoscience. Worse than many re this subject since the pseudoscience may well come from the medical professionals a woman is working with during and after her pregnancy, and of course because this pseudoscience has potentially serious health problems attached.