Breastfeeding, Formula, and the Space Between: A Pediatric NP's Take

Breastfeeding, Formula, and the Space Between: A Pediatric NP's Take

Recently, economist and author Emily Oster made waves in parenting circles when she suggested that many of the long-term benefits of breastfeeding are more correlation than causation - that the research, when scrutinized, isn't as airtight as clinicians have led parents to believe. I understand why that framing resonates. Parents are exhausted, overwhelmed, and drowning in guilt. And yes, some early breastfeeding studies did fail to adequately control for socioeconomic factors and other confounders.

But here's where I, as a pediatric nurse practitioner, have to respectfully push back.

The Research Is Real

When we look at large-scale, peer-reviewed data (we're talking tens of thousands of mother-infant dyads across diverse populations and income levels), the benefits of breastfeeding are not subtle. The landmark Lancet Breastfeeding Series, one of the most comprehensive analyses ever conducted on the topic, found that scaling breastfeeding to near-universal levels could prevent 823,000 child deaths annually and 20,000 maternal deaths from breast cancer every year (Victora et al., 2016).

For babies, the data shows breastfeeding is associated with protection against infections, improved cognitive development, reduced risk of obesity, and lower rates of type 1 and type 2 diabetes later in life (Victora et al., 2016). A significant piece of this is the gut microbiome. Breast milk acts as both a prebiotic and a probiotic. It seeds the infant gut with beneficial bacteria like Bifidobacterium and Lactobacillus that formula simply cannot replicate (Kariyawasam et al., 2025). That microbial foundation has downstream effects on immune function, inflammation, and long-term health that we are still only beginning to fully understand.

For mothers, breastfeeding is linked to reduced risk of breast cancer, ovarian cancer, type 2 diabetes, and hypertension (Binns et al., 2016). These are not trivial findings. They are documented across thousands of studies and affirmed by the WHO, the AAP, and major research institutions worldwide.

Correlation concerns are worth discussing, but they are not a reason to dismiss the body of evidence entirely.

I've Lived Both Sides of This

I don't just come at this as a clinician. I come at it as a mom of two, with two completely opposite breastfeeding journeys.

With my first, I tried everything. Lactation consultants and every pumping schedule you could think of. It wasn't enough. We eventually moved to full formula feeding, and I grieved that transition in a way I didn't expect. It felt like failure, even when I knew intellectually it wasn't. I understand that journey - the guilt, the desperation, the exhaustion of trying to do something your body or your circumstances simply won't cooperate with.

My second child was the opposite. Breastfeeding came easily. We had an extended breastfeeding relationship with very few hurdles. It was, genuinely, night and day.

Those two experiences taught me more than any textbook: feeding your baby is deeply personal, and it rarely goes according to plan.

Holding Both Truths at Once

Here's what I want you to hear: breastfeeding has real, documented, meaningful benefits. And not everyone can breastfeed, and that is okay.

Those two things are not in conflict with each other.

We do not have to mute the evidence on breastfeeding in order to make formula-feeding parents feel seen. And we do not have to shame parents who formula feed in order to advocate for breastfeeding support. The nuance lives in holding both truths simultaneously.

If you breastfed for two weeks and stopped - your baby received colostrum, that liquid gold packed with immune-protective antibodies, and that matters. If you never breastfed at all - your baby was fed, nourished, and loved, and that matters too. If you're combo feeding right now and feeling like you're failing at both - you're not. You're doing the work.

How you feed your baby is a decision shaped by your body, your mental health, your work situation, your support system, your baby's needs, and a hundred other factors that no researcher, influencer, or economist can fully account for.

The goal was never just breastfeeding. The goal was always a thriving baby and a supported parent.

References

Binns, C., Lee, M., & Low, W. Y. (2016). The long-term public health benefits of breastfeeding. Asia-Pacific Journal of Public Health, 28(1), 7–14. https://doi.org/10.1177/1010539515624964

Kariyawasam, T., & colleagues. (2025). Comparative analysis of breastfeeding and infant formulas: Short‐ and long‐term impacts on infant nutrition and health. Food Science & Nutrition. https://doi.org/10.1002/fsn3.70788

Victora, C. G., Bahl, R., Barros, A. J. D., França, G. V. A., Horton, S., Krasevec, J., Murch, S., Sankar, M. J., Walker, N., Rollins, N. C., & Lancet Breastfeeding Series Group. (2016). Breastfeeding in the 21st century: Epidemiology, mechanisms, and lifelong effect. The Lancet, 387(10017), 475–490. https://doi.org/10.1016/S0140-6736(15)01024-7