Emily Oster

4 min Read Emily Oster

Emily Oster

Does Breastfeeding Increase the Risk of Colorectal Cancer?

Q&A on the latest panic headline

Emily Oster

4 min Read

I just read that a study was published that breastfeeding increases the risk of colorectal cancer?! Should I stop??

—Concerned exclusively-BF mom

We are all very used to panic headlines about the dangers of not breastfeeding. I spend a good deal of my time debunking these claims. The latest breastfeeding panic headline is the opposite — the claim in this paper is that breastfeeding increases the chance that a child later develops colon cancer. The authors are quick to note that this doesn’t mean you shouldn’t breastfeed, since there are other benefits. But the scare is there: did your choice to breastfeed actually make your child’s long-term health worse?

The paper in question is here. The analysis is relatively straightforward. The authors use data from a large, well-known study called the Nurses’ Health Study, which enrolled a large cohort of female nurses beginning in the 1990s. These women have been followed through at least 2015, with information collected about their health status over that period; this is how the researchers learn about colon cancer. Women in the study are also asked if they were breastfed and, if so, for how long.

The primary finding in the study is that the women who reported being breastfed were more likely to get colon cancer than others. The increase is about 20% to 40%, which sounds large but is small in absolute terms — in the data, they see 1,490 cases in 3.5 million person-years of follow-up.

Given the information the authors had available, this study is well-done (in my view). The sample is large, and the analysis makes sense. To the extent possible, the authors adjust for differences across the groups in terms of demographics.

Having said that, there are a few issues. One they highlight is that the breastfeeding data is self-reported by the individual, which introduces error. This is an example of something that seems like it could be a problem but I think isn’t very important — yes, there is statistical noise, but it’s not likely to impact the results.

A second issue is that there are important demographic differences between the moms who breastfed and those who did not; as in virtually all studies of this type, the breastfeeding mothers are better-educated and have more resources than the non-breastfeeding ones. The way that might impact the results is a little subtle. Generally, more resources are associated with better health, which would push against their findings. In this case, though, I worry a bit about variation in screening. If people with more resources are more likely to be screened, and then more likely to be diagnosed, we might see these results even if the actual incidence of cancer is the same. (This happens with breast cancer screening.)

There are some additional analyses that might be helpful here: a more complete look at screening behaviors, and maybe some placebo tests using other behaviors. At this point, I think this is the range of something to look into more, not something to take to the bank (a point I think the authors would agree with).

A final note: I cannot help but be struck in reading this paper and the commentary on it by how differently things are reported here, versus in similar papers where the finding is in favor of a benefit of breastfeeding. The authors here are tripping over themselves to say that this doesn’t indicate that breastfeeding has risks and to emphasize that this shouldn’t change breastfeeding behavior. In a sense, I do not disagree, given where the evidence is, but … it’s notable given the rhetoric I’d expect if the findings were the opposite.

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Milestones. We celebrate them in pregnancy, in parenting, and they’re a fun thing to celebrate at work too. Just a couple years ago I couldn’t have foreseen what this community would grow into. Today, there are over 400,000 of you here—asking questions, making others feel seen wherever they may be in their journey, and sharing information that supports data > panic. 

It has been a busy summer for the team at ParentData. I’d love to take a moment here to celebrate the 400k milestone. As I’ve said before, it’s more important than ever to put good data in the hands of parents. 

Share this post with a friend who could use a little more data, and a little less parenting overwhelm. 

📷 Me and my oldest, collaborating on “Expecting Better”

Milestones. We celebrate them in pregnancy, in parenting, and they’re a fun thing to celebrate at work too. Just a couple years ago I couldn’t have foreseen what this community would grow into. Today, there are over 400,000 of you here—asking questions, making others feel seen wherever they may be in their journey, and sharing information that supports data > panic.

It has been a busy summer for the team at ParentData. I’d love to take a moment here to celebrate the 400k milestone. As I’ve said before, it’s more important than ever to put good data in the hands of parents.

Share this post with a friend who could use a little more data, and a little less parenting overwhelm.

📷 Me and my oldest, collaborating on “Expecting Better”
...

I spend a lot of time talking people down after they read the latest panic headline. In most cases, these articles create an unnecessary amount of stress around pregnancy and parenting. This is my pro tip for understanding whether the risk presented is something you should really be worrying about.

Comment “link” for an article with other tools to help you navigate risk and uncertainty.

#emilyoster #parentdata #riskmanagement #parentstruggles #parentingstruggles

I spend a lot of time talking people down after they read the latest panic headline. In most cases, these articles create an unnecessary amount of stress around pregnancy and parenting. This is my pro tip for understanding whether the risk presented is something you should really be worrying about.

Comment “link” for an article with other tools to help you navigate risk and uncertainty.

#emilyoster #parentdata #riskmanagement #parentstruggles #parentingstruggles
...

Here’s why I think you don’t have to throw away your baby bottles.

Here’s why I think you don’t have to throw away your baby bottles. ...

Drop your toddlers favorite thing right now in the comments—then grab some popcorn.

Original thread source: Reddit @croc_docs

Drop your toddlers favorite thing right now in the comments—then grab some popcorn.

Original thread source: Reddit @croc_docs
...

Just keep wiping.

Just keep wiping. ...

Dr. Gillian Goddard sums up what she learned from the Hot Flash  S e x  Survey! Here are some key data takeaways:

🌶️ Among respondents, the most common s e x u a l frequency was 1 to 2 times per month, followed closely by 1 to 2 times per week
🌶️ 37% have found their sweet spot and are happy with the frequency of s e x they are having
🌶️ About 64% of respondents were very or somewhat satisfied with the quality of the s e x they are having

Do any of these findings surprise you? Let us know in the comments!

#hotflash #intimacy #midlifepleasure #parentdata #relationships

Dr. Gillian Goddard sums up what she learned from the Hot Flash S e x Survey! Here are some key data takeaways:

🌶️ Among respondents, the most common s e x u a l frequency was 1 to 2 times per month, followed closely by 1 to 2 times per week
🌶️ 37% have found their sweet spot and are happy with the frequency of s e x they are having
🌶️ About 64% of respondents were very or somewhat satisfied with the quality of the s e x they are having

Do any of these findings surprise you? Let us know in the comments!

#hotflash #intimacy #midlifepleasure #parentdata #relationships
...

Should your kid be in a car seat on the plane? The AAP recommends that you put kids under 40 pounds into a car seat on airplanes. However, airlines don’t require car seats.

Here’s what we know from a data standpoint:
✈️ The risk of injury to a child on a plane without a carseat is very small (about 1 in 250,000)
✈️ A JAMA Pediatrics paper estimates about 0.4 child air crash deaths per year might be prevented in the U.S. with car seats 
✈️ Cars are far more dangerous than airplanes! The same JAMA paper suggests that if 5% to 10% of families switched to driving, then we would expect more total deaths as a result of this policy. 

If you want to buy a seat for your lap infant, or bring a car seat for an older child, by all means do so! But the additional protection based on the numbers is extremely small.

#parentdata #emilyoster #flyingwithkids #flyingwithbaby #carseats #carseatsafety

Should your kid be in a car seat on the plane? The AAP recommends that you put kids under 40 pounds into a car seat on airplanes. However, airlines don’t require car seats.

Here’s what we know from a data standpoint:
✈️ The risk of injury to a child on a plane without a carseat is very small (about 1 in 250,000)
✈️ A JAMA Pediatrics paper estimates about 0.4 child air crash deaths per year might be prevented in the U.S. with car seats
✈️ Cars are far more dangerous than airplanes! The same JAMA paper suggests that if 5% to 10% of families switched to driving, then we would expect more total deaths as a result of this policy.

If you want to buy a seat for your lap infant, or bring a car seat for an older child, by all means do so! But the additional protection based on the numbers is extremely small.

#parentdata #emilyoster #flyingwithkids #flyingwithbaby #carseats #carseatsafety
...

SLEEP DATA 💤 PART 2: Let’s talk about naps. Comment “Link” for an article on what we learned about daytime sleep!

The first three months of life are a chaotic combination of irregular napping, many naps, and a few brave or lucky souls who appear to have already arrived at a two-to-three nap schedule. Over the next few months, the naps consolidate to three and then to two. By the 10-to-12-month period, a very large share of kids are napping a consistent two naps per day. Over the period between 12 and 18 months, this shifts toward one nap. And then sometime in the range of 3 to 5 years, naps are dropped. What I think is perhaps most useful about this graph is it gives a lot of color to the average napping ages that we often hear. 

Note: Survey data came from the ParentData audience and users of the Nanit sleep monitor system. Both audiences skew higher-education and higher-income than the average, and mostly have younger children. The final sample is 14,919 children. For more insights on our respondents, read the full article.

SLEEP DATA 💤 PART 2: Let’s talk about naps. Comment “Link” for an article on what we learned about daytime sleep!

The first three months of life are a chaotic combination of irregular napping, many naps, and a few brave or lucky souls who appear to have already arrived at a two-to-three nap schedule. Over the next few months, the naps consolidate to three and then to two. By the 10-to-12-month period, a very large share of kids are napping a consistent two naps per day. Over the period between 12 and 18 months, this shifts toward one nap. And then sometime in the range of 3 to 5 years, naps are dropped. What I think is perhaps most useful about this graph is it gives a lot of color to the average napping ages that we often hear.

Note: Survey data came from the ParentData audience and users of the Nanit sleep monitor system. Both audiences skew higher-education and higher-income than the average, and mostly have younger children. The final sample is 14,919 children. For more insights on our respondents, read the full article.
...

Happy Father’s Day to the Fathers and Father figures in our ParentData community! 

Tag a Dad who this holiday may be tricky for. We’re sending you love. 💛

Happy Father’s Day to the Fathers and Father figures in our ParentData community!

Tag a Dad who this holiday may be tricky for. We’re sending you love. 💛
...

“Whilst googling things like ‘new dad sad’ and ‘why am I crying new dad,’ I came across an article written by a doctor who had trouble connecting with his second child. I read the symptoms and felt an odd sense of relief.” Today we’re bringing back an essay by Kevin Maguire of @newfatherhood about his experience with paternal postpartum depression. We need to demystify these issues in order to change things for the better. Comment “Link” for a DM to read his full essay.

#parentdata #postpartum #postpartumdepression #paternalmentalhealth #newparents #emilyoster

“Whilst googling things like ‘new dad sad’ and ‘why am I crying new dad,’ I came across an article written by a doctor who had trouble connecting with his second child. I read the symptoms and felt an odd sense of relief.” Today we’re bringing back an essay by Kevin Maguire of @newfatherhood about his experience with paternal postpartum depression. We need to demystify these issues in order to change things for the better. Comment “Link” for a DM to read his full essay.

#parentdata #postpartum #postpartumdepression #paternalmentalhealth #newparents #emilyoster
...

What does the data say about children who look more like one parent? Do they also inherit more character traits and mannerisms from that parent? Let’s talk about it 🔎

#emilyoster #parentdata #parentingcommunity #lookslikedaddy #lookslikemommy

What does the data say about children who look more like one parent? Do they also inherit more character traits and mannerisms from that parent? Let’s talk about it 🔎

#emilyoster #parentdata #parentingcommunity #lookslikedaddy #lookslikemommy
...

SLEEP DATA 💤 We asked you all about your kids’ sleep—and got nearly 15,000 survey responses to better understand kids’ sleep patterns. Comment “Link” for an article that breaks down our findings!

This graph shows sleeping location by age. You’ll notice that for the first three months, most kids are in their own sleeping location in a parent’s room. Then, over the first year, this switches toward their own room. As kids age, sharing a room with a sibling becomes more common. 

Head to the newsletter for more and stay tuned for part two next week on naps! 🌙

#parentdata #emilyoster #childsleep #babysleep #parentingcommunity

SLEEP DATA 💤 We asked you all about your kids’ sleep—and got nearly 15,000 survey responses to better understand kids’ sleep patterns. Comment “Link” for an article that breaks down our findings!

This graph shows sleeping location by age. You’ll notice that for the first three months, most kids are in their own sleeping location in a parent’s room. Then, over the first year, this switches toward their own room. As kids age, sharing a room with a sibling becomes more common.

Head to the newsletter for more and stay tuned for part two next week on naps! 🌙

#parentdata #emilyoster #childsleep #babysleep #parentingcommunity
...

Weekends are good for extra cups of ☕️ and listening to podcasts. I asked our team how they pod—most people said on walks or during chores. What about you?

Comment “Link” to subscribe to ParentData with Emily Oster, joined by some excellent guests.

#parentdata #parentdatapodcast #parentingpodcast #parentingtips #emilyoster

Weekends are good for extra cups of ☕️ and listening to podcasts. I asked our team how they pod—most people said on walks or during chores. What about you?

Comment “Link” to subscribe to ParentData with Emily Oster, joined by some excellent guests.

#parentdata #parentdatapodcast #parentingpodcast #parentingtips #emilyoster
...

Humility. That’s why. That’s the whole reason.

#emilyoster #secondbaby #parentingjokes #parentinghumor

Humility. That’s why. That’s the whole reason.

#emilyoster #secondbaby #parentingjokes #parentinghumor
...

Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET 
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray

Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray
...