Emily Oster

9 min Read Emily Oster

Emily Oster

Diet, Alcohol, and Breastfeeding

What to eat and drink while you’re nursing

Emily Oster

9 min Read

Even if they have read Expecting Better, most people restrict what they eat during pregnancy at least somewhat. When the baby finally arrives, there are some foods which come right back on the menu (turkey sandwiches, for example).

But breastfeeding brings its own set of questions, which really come in two types.

When it’s about breastfeeding, though, the questions are much more predictable and really come in two types.

First, there are the questions about whether your eating during breastfeeding impacts your baby and, more pointedly, whether it makes them act like a jerk. Babies cry a lot, and in our search for meaning, the question of whether what we eat matters often comes up.

Second, there are the recreational questions. Specifically: Can I have alcohol or marijuana? These reflect, I think in part, the desire to return to something like “normal” post-pregnancy. Also, sometimes you just want a glass of wine.

Today I’m going to dive into three breastfeeding diet topics. First: What are the links between the foods you eat and infant colic? Mostly I’ll talk about dairy. Second: Can you have alcohol and, if so, how much? Third: What about marijuana?

(There are many other questions about breastfeeding diet. Like coffee. Or whether what you eat influences your child’s taste for varying flavors later. There’s much more on this in Cribsheet, and I’m sure we’ll revisit it here sometime too.)

Diet and behavior: allergens and milk

Does what you eat as a breastfeeding mother affect your baby’s mood? This is a hard question to answer, because babies are unpredictable. As an adult, we often have a good sense of which foods agree with us or not. For example, I love nachos, but I know that I cannot eat them. That knowledge is based on a combination of experience and experimentation. With a baby, the overall variation in behavior can leave us looking for meaning where there is none. If I eat cabbage today and my baby farts a lot tomorrow, there is a temptation to link cabbage and gas. But honestly, babies fart a lot.

What this means is that there’s a strong imperative for experimentation in this space. Where this has been somewhat explored is in the possible link between colic and allergenic foods. In particular, one possible treatment for infantile colic (excessive crying) is to try cutting out common allergens from the breastfeeding diet or by switching to a low-allergen formula.

There is one randomized trial, from 1995, that evaluated this type of intervention. It took 38 formula-fed and 77 breastfed babies and randomized them into a typical diet or a low-allergen diet, either using a low-allergen formula or (for nursing mothers) eliminating nuts, wheat, dairy, and eggs from the diet. Needless to say, this is extremely restrictive. The paper found a reduction in parent-reported infant distress eight days after adopting the new formula or diet (39% of the treatment group reported less distress relative to 16% of the control).

This is only one study, though, and the combination of the fact that parents knew if they were in the treatment group and the outcome was self-reported leads us to some concern about reporting bias. And, indeed, a larger review of this question notes that in general the evidence for or against the role of diet in infant colic is sparse.

Low-allergen diets focus on many allergens, but the question that seems to come up most often in public discourse is milk allergy. People raise the concern that maternal consumption of dairy products is a common cause of infant fussiness or discomfort. This could occur if the infant has an allergy to cow’s milk (sometimes just referred to as CMPA, for cow’s milk protein allergy).

CMPA has two types — IgE- and non-IgE-mediated. IgE-mediated allergy shows up with more standard allergy symptoms: fast onset after consumption, vomiting, lethargy, respiratory illness. Diagnosis of this type of allergy is typically straightforward, and it will respond to dietary changes.

It is much harder to diagnose non-IgE-mediated allergy to cow’s milk because the symptoms are much less specific. In some cases, there are bloody stools (a strong signal of intolerance), but this allergy is also blamed for a more general set of symptoms — crying, diarrhea, vomiting — that happen a lot anyway. There’s no test, so the diagnosis is based on symptoms and on the infant reaction to changes in diet.

There is some controversy, then, over the question of whether this intolerance is overdiagnosed. In 2020, there was an absolutely scathing article in JAMA arguing, effectively, that a huge share of these cases are simply overdiagnosis. The authors write that the actual prevalence of CMPA in the population is probably 1% to 2%, with most of that being the easier-to-diagnose IgE form. They note, though, that something like 14% of parents say their child has this sensitivity.

The paper goes on to say that the concentration of cow’s-milk proteins in breast milk is low and unlikely to trigger a response in infants. Their overall claim is that this is dramatically overdiagnosed, leading to more reaction among parents than is necessary and to unrealistic, or at least annoying, changes in diet. They blame, in part, influence from formula manufacturers and their desire to sell specialized formulas.

This article has a blistering tone that is rare in an academic paper, making it an entertaining read. But it also has a potentially reasonable point, one I have heard echoed from many pediatricians (including my own). Namely, we shouldn’t jump to dairy elimination with a baby who is just fussy. Changing diet in this way may make sense with more direct evidence — bloody poop, for example — but it shouldn’t be the first line. Definitely talk to your pediatrician before you make any big changes in either diet or formula choice.

If you do want to try making a change, be a little patient. Based on what we know about protein elimination from the bloodstream, you’d want to give it a couple of weeks.

Alcohol

Not dissimilar to the case of Botox, which I discussed recently, evaluating the possible impact of alcohol during breastfeeding is somewhat easier than evaluating the impacts during pregnancy. This is because you can directly measure the alcohol in breast milk. At a minimum, this can give a sense of the plausible exposure.

When you drink, the alcohol level in your milk reflects the alcohol level in your bloodstream. This ends up meaning that even if you drink a large amount, the amount of alcohol passing through the breast milk is quite low. In one paper, researchers calculated that even if you have four drinks extremely quickly and then breastfeed at the maximum blood-alcohol level, the exposure for the baby is still extremely low.

There is some suggestion that chronic, heavy alcohol use can impact infants in the short term, but these studies generally have very limited samples and a poor ability to control for other differences across families. Randomized studies of mothers consuming small amounts of alcohol show very limited effects. There is no good evidence of any long-term developmental effects of alcohol in breastfeeding.

The LactMed database reports: Casual use of alcohol (such as 1 glass of wine or beer per day) is unlikely to cause either short- or long-term problems in the nursing infant. 

So, good news! And if you want to be extremely cautious, or you’re thinking of a big party night out and worried about the impacts of heavier drinking, this document has a helpful reference for how long you’d need to wait to be sure that the alcohol was out of your system. For a 150-pound woman, it’s about two hours for one drink, four hours for two drinks. If you have nine drinks, it could take almost a day (but also, don’t do that).

Final side note: There is no benefit to pumping and dumping. You would only want to do so if you’ve decided to wait to nurse and you need to pump to either keep up supply or for comfort reasons.

Marijuana

The evidence on marijuana is much more complicated.

Let’s start with what we do know. Like alcohol, THC (an active ingredient in marijuana) passes into breast milk. The concentrations are lower than what the mother is exposed to, but possibly higher than the level in her bloodstream. Unlike alcohol, THC takes a long time to leave the body — days or weeks, rather than hours. The approach of waiting for the substance to eliminate from your system before nursing is not feasible.

Where things are much harder is when we turn to ask whether this low-level exposure has any impacts on infants or children. In animal models (mice, rats), researchers have seen evidence of neurological and developmental issues from maternal exposure to THC. However, findings in humans are mixed — there are some studies that show worse developmental outcomes, and others that do not.

Regardless of the result, these studies are very hard to reliably interpret, given the differences across groups of mothers. The fact that until recently, marijuana has been illegal in most of the U.S. makes this problem more extreme than it would be in the case of, for example, alcohol or cigarettes. There is also the problem that use during breastfeeding is related to use during pregnancy, which could also carry similar risks.

Bottom line: We just do not know enough to be sure either way. It seems unlikely that there are very large negative effects, since we’d be able to pick them up more easily if there were. On the other hand, we are definitely not in a position to rule out some risks, especially with heavier usage. Because marijuana is now more widely legal, usage is increasing; this makes it easier to study and also more relevant to more people. So one may hope for better data coming.

People often ask about CBD. It passes through to breast milk like THC, so the same basic concerns appear. There is little or no evidence directly on CBD from animal models. In human data it is difficult to separate the two compounds, because analysis tends to focus on marijuana overall, not individual components. Given the tremendous rise in the use of CBD for anxiety and a million other things, I would really hope we’d get better data on this one.

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Looking for Memorial Day Weekend plans? Might be the perfect time to give potty training a shot. Potty training is notoriously difficult, and we unfortunately don’t have a lot of evidence-based guidance on what works best. So I asked the ParentData community to fill out a survey and share their knowledge — about 6,000 people responded.

👉Comment “Link” for a DM to an article that summarizes all of the best potty training advice we collected. 

Remember, you are not alone in the potty training struggle! It can be incredibly challenging, so please give yourself some grace.

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlertips

Looking for Memorial Day Weekend plans? Might be the perfect time to give potty training a shot. Potty training is notoriously difficult, and we unfortunately don’t have a lot of evidence-based guidance on what works best. So I asked the ParentData community to fill out a survey and share their knowledge — about 6,000 people responded.

👉Comment “Link” for a DM to an article that summarizes all of the best potty training advice we collected.

Remember, you are not alone in the potty training struggle! It can be incredibly challenging, so please give yourself some grace.

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlertips
...

We’re hiring an Associate Editor at ParentData! More details at my link in bio. Please share with the great writers and data-loving people in your network. 📊💻

We’re hiring an Associate Editor at ParentData! More details at my link in bio. Please share with the great writers and data-loving people in your network. 📊💻 ...

Do you brand things a certain way to get your kid to accept it? Like calling carrots “rabbit popsicles”? Or telling them to put on their “super speed socks” in the morning? Share your rebrands in the comments below! You never know who you might be helping out 👇

#emilyoster #funnytweets #relatabletweets #parentingjokes #kidssaythedarndestthings

Do you brand things a certain way to get your kid to accept it? Like calling carrots “rabbit popsicles”? Or telling them to put on their “super speed socks” in the morning? Share your rebrands in the comments below! You never know who you might be helping out 👇

#emilyoster #funnytweets #relatabletweets #parentingjokes #kidssaythedarndestthings
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Have you ever panic-googled a parenting question when everyone else is asleep? If so, you’re not alone. 

Today is the first episode of a new biweekly series on my podcast: Late-Night Panic Google. On these mini-episodes, you’ll hear from some familiar names about the questions keeping them up at night, and how data can help. First up: @claireholt!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #emilyoster #claireholt #parentingstruggles #parentingtips #latenightpanicgoogle

Have you ever panic-googled a parenting question when everyone else is asleep? If so, you’re not alone.

Today is the first episode of a new biweekly series on my podcast: Late-Night Panic Google. On these mini-episodes, you’ll hear from some familiar names about the questions keeping them up at night, and how data can help. First up: @claireholt!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #emilyoster #claireholt #parentingstruggles #parentingtips #latenightpanicgoogle
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Sun safety is a must for all ages, especially babies! Here are my tips for keeping your littlest ones protected in the sunshine:
☀️ Most importantly, limit their time out in hot weather. (They get hotter than you do!)
☀️ Keep them in the shade as much as possible when you’re out.
☀️ Long-sleeve but lightweight clothing is your friend, especially on the beach, where even in the shade you can get sunlight reflecting off different surfaces.
☀️ If you want to add a little sunscreen on their hands and feet? Go for it! But be mindful as baby skin tends to more prone to irritation.

Comment “Link” for a DM to an article on the data around sun and heat exposure for babies.

#sunsafety #babysunscreen #babyhealth #parentdata #emilyoster

Sun safety is a must for all ages, especially babies! Here are my tips for keeping your littlest ones protected in the sunshine:
☀️ Most importantly, limit their time out in hot weather. (They get hotter than you do!)
☀️ Keep them in the shade as much as possible when you’re out.
☀️ Long-sleeve but lightweight clothing is your friend, especially on the beach, where even in the shade you can get sunlight reflecting off different surfaces.
☀️ If you want to add a little sunscreen on their hands and feet? Go for it! But be mindful as baby skin tends to more prone to irritation.

Comment “Link” for a DM to an article on the data around sun and heat exposure for babies.

#sunsafety #babysunscreen #babyhealth #parentdata #emilyoster
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I’m calling on you today to share your story. I know that many of you have experienced complications during pregnancy, birth, or postpartum. It’s not something we want to talk about, but it’s important that we do. Not just for awareness, but to help people going through it feel a little less alone.

That’s why I’m asking you to post a story, photo, or reel this week with #MyUnexpectedStory and tag me. I’ll re-share as many as I can to amplify. Let’s fill our feeds with these important stories and lift each other up. Our voices can create change. And your story matters. 💙

#theunexpected #emilyoster #pregnancycomplications #pregnancystory

I’m calling on you today to share your story. I know that many of you have experienced complications during pregnancy, birth, or postpartum. It’s not something we want to talk about, but it’s important that we do. Not just for awareness, but to help people going through it feel a little less alone.

That’s why I’m asking you to post a story, photo, or reel this week with #MyUnexpectedStory and tag me. I’ll re-share as many as I can to amplify. Let’s fill our feeds with these important stories and lift each other up. Our voices can create change. And your story matters. 💙

#theunexpected #emilyoster #pregnancycomplications #pregnancystory
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OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

Is side sleeping important during pregnancy? Comment “Link” for a DM to an article on whether sleep position affects pregnancy outcomes.

Being pregnant makes you tired, and as time goes by, it gets increasingly hard to get comfortable. You were probably instructed to sleep on your side and not your back, but it turns out that advice is not based on very good data.

We now have much better data on this, and the bulk of the evidence seems to reject the link between sleep position and stillbirth or other negative outcomes. So go ahead and get some sleep however you are most comfortable. 💤

Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76. 

#emilyoster #pregnancy #pregnancytips #sleepingposition #pregnantlife

Is side sleeping important during pregnancy? Comment “Link” for a DM to an article on whether sleep position affects pregnancy outcomes.

Being pregnant makes you tired, and as time goes by, it gets increasingly hard to get comfortable. You were probably instructed to sleep on your side and not your back, but it turns out that advice is not based on very good data.

We now have much better data on this, and the bulk of the evidence seems to reject the link between sleep position and stillbirth or other negative outcomes. So go ahead and get some sleep however you are most comfortable. 💤

Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76.

#emilyoster #pregnancy #pregnancytips #sleepingposition #pregnantlife
...

My new book, “The Unexpected: Navigating Pregnancy During and After Complications” is available for preorder at the link in my bio!

I co-wrote #TheUnexpected with my friend and maternal fetal medicine specialist, Dr. Nathan Fox. The unfortunate reality is that about half of pregnancies include complications such as preeclampsia, miscarriage, preterm birth, and postpartum depression. Because these are things not talked about enough, it can not only be an isolating experience, but it can also make treatment harder to access.

The book lays out the data on recurrence and delves into treatment options shown to lower risk for these conditions in subsequent pregnancies. It also guides you through how to have productive conversations and make shared decisions with your doctor. I hope none of you need this book, but if you do, it’ll be here for you 💛

#pregnancy #pregnancycomplications #pregnancyjourney #preeclampsiaawareness #postpartumjourney #emilyoster

My new book, “The Unexpected: Navigating Pregnancy During and After Complications” is available for preorder at the link in my bio!

I co-wrote #TheUnexpected with my friend and maternal fetal medicine specialist, Dr. Nathan Fox. The unfortunate reality is that about half of pregnancies include complications such as preeclampsia, miscarriage, preterm birth, and postpartum depression. Because these are things not talked about enough, it can not only be an isolating experience, but it can also make treatment harder to access.

The book lays out the data on recurrence and delves into treatment options shown to lower risk for these conditions in subsequent pregnancies. It also guides you through how to have productive conversations and make shared decisions with your doctor. I hope none of you need this book, but if you do, it’ll be here for you 💛

#pregnancy #pregnancycomplications #pregnancyjourney #preeclampsiaawareness #postpartumjourney #emilyoster
...

We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy. 

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙

We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy.

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙
...

Exciting news! We have new, high-quality data that says it’s safe to take Tylenol during pregnancy and there is no link between Tylenol exposure and neurodevelopmental issues in kids. Comment “Link” for a DM to an article exploring this groundbreaking study.

While doctors have long said Tylenol was safe, confusing studies, panic headlines, and even a lawsuit have continually stoked fears in parents. As a result, many pregnant women have chosen not to take it, even if it would help them.

This is why good data is so important! When we can trust the data, we can trust our choices. And this study shows there is no blame to be placed on pregnant women here. So if you have a migraine or fever, please take your Tylenol.

#tylenol #pregnancy #pregnancyhealth #pregnancytips #parentdata #emilyoster

Exciting news! We have new, high-quality data that says it’s safe to take Tylenol during pregnancy and there is no link between Tylenol exposure and neurodevelopmental issues in kids. Comment “Link” for a DM to an article exploring this groundbreaking study.

While doctors have long said Tylenol was safe, confusing studies, panic headlines, and even a lawsuit have continually stoked fears in parents. As a result, many pregnant women have chosen not to take it, even if it would help them.

This is why good data is so important! When we can trust the data, we can trust our choices. And this study shows there is no blame to be placed on pregnant women here. So if you have a migraine or fever, please take your Tylenol.

#tylenol #pregnancy #pregnancyhealth #pregnancytips #parentdata #emilyoster
...