Tag Archives: child health

Chesterton’s fence in health

[Epistemic status: mostly informed guesswork.]

I started writing down some beliefs I have about health, and realized most of them kind of echo Chesterton’s fence:

There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, “I don’t see the use of this; let us clear it away.” To which the more intelligent type of reformer will do well to answer: “If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.”
– G. K. Chesterton

In terms of health, my belief is something like: don’t mess with bodies too much, because they probably function best under conditions that existed well before the 20th century. I certainly also have beliefs that don’t fit this pattern (C-sections and formula are literally lifesavers if you need them!) A lot of these ended up being about child health, because apparently that’s what I read a lot about right now.

Specific beliefs:

Shoes are a pretty new development for the human body. Community Paediatrics Committee: “Children’s feet should be left alone as much as possible.”

Most modern advice is to use shoes sparingly for kids, and to use lightweight flexible shoes when needed. We’ve found that Robeez, Pediped, and See Kai Run are brands with nice bendy soles. Here’s a more complete list.

I’m not as sold on the barefoot running thing for most adults. Jeff used to have a lot of knee problems and also used to walk with a strong heel-strike, which is only viable in padded shoes. He found that walking barefoot or in minimalist shoes for a while changed the way he walked, and that combined with some other changes (stretches and exercises, not walking pigeon-toed) has resolved his knee pain. Now he’s fine in normal shoes. Unless you have a problem, I think sensible shoes for adults are probably fine.

Then there are high heels. I don’t want to do the thing where we shame women for engaging in (and enjoying) behaviors that society rewards them for doing, but I do think people (and particularly young people) should understand what heels can do to your body.

Moving throughout the day
People seem to agree that sitting down all day is bad for you. Having short movement breaks throughout the day (“nutritious movement”) might be better than working straight through and doing one longer workout. Katy Bowman‘s work on this seems 40% woo, 60% solid.

Set up your life to make this easy: wear clothes you can move in. Have a quick workout app on your phone, weights or a pull-up bar out where you see them and they’re easy to grab. Work in different positions: standing, sitting in different postures. (I realize this is much easier said than done unless you work from home, but a lot of us spend plenty of time sitting at home too.)


Use it or lose it
By the time you get old and stiff, it’s a lot harder to develop habits that improve flexibility and balance. I try to include motions that I want to be able to do throughout life: our bed is on the floor and we don’t have a baby changing table, so Jeff and I are up and down from floor-level many times a day. I can do a pretty good squat now, too. Early parenthood (after your body has recovered some from pregnancy) is a good time to work on this stuff because there’s so much bending, lifting, and getting down on the ground.

Vestibular input
Children’s vestibular (balance) systems need stimulation to develop. They need to rock, bounce, roll, tip, and spin. An overview. I think it’s likely that a lot of modern kids aren’t getting enough physical play.

Toys like swings, seesaws, rocking horses, balance beams, bicycles, hammocks, big exercise balls, jump-ropes, trampolines, office chairs, obstacle courses, tunnels, and balance boards, as well as lots of other activities, encourage motion in all different directions.

There’s some evidence that people with clinical anxiety are disproportionately likely to have vestibular problems (they literally feel off-balance and insecure!), and that balance exercises can help with anxiety.

I suspect that giving children plenty of opportunity for lots of kinds of motion helps them be more at ease, less fidgety, and better able to focus.

Back pain is really common and really debilitating. I think helping your spine be in the right shape is important, and I’m pretty sold on Esther Gohkhale’s book 8 Steps to a Pain-free Back. She draws on posture from historical images and pre-industrial societies to argue that humans are designed to stand, sit, and bend differently than we now do (though she could be cherry-picking and I would have no way of knowing).


More picture comparisons of S-shaped vs. J-shaped posture.

Reviews I’ve seen basically indicate that at worst this method is probably harmless, since it doesn’t advise special treatment or gear or doing any time-consuming exercises, just moving differently during your normal activities.

The major part of the book that I disagree with is about lifting from the back rather than the knees: I believe that people who’ve been lifting from the back all their lives can do it fine, but starting abruptly seems like a bad idea. I try to do straight-back bending while emptying the dishwasher and so forth when not bearing extra weight.


Baby formula is pretty good now (and to be clear, it’s absolutely a blessing when breastfeeding isn’t cutting it for whatever reason). There are a few randomized controlled trials of breastfeeding vs. formula feeding which indicate advantages to breastmilk, but they were from before we started putting DHA (a fatty acid thought to be good for brain development) in formula in 2002, so it’s possible they’re more similar now. But given that after 100 years of commercial formula they’re still trying to improve the recipe, I’m guessing it’s probably still not as good as the original.

Light and vision
Children who sleep with night lights are more likely to be short-sighted, and sleeping with a normal light on is worse. Apparently you need actual darkness in early childhood for your eyes to develop properlyb.

Potential confounder: maybe short-sighted parents are more likely to leave the lights on, and also more likely to have short-sighted kids. But I’d expect it to be more based on dark vision. Jeff can see ok in conditions where I can’t see at all; I do night feedings entirely by memory, touch, and echolocation (luckily it’s not that hard to find a crying baby in the dark).

Several studies also suggest that kids who spend more time outdoors are less likely to be short-sighted, maybe because of brighter light, different spectrum of light, or higher vitamin D. Could be confounded of course if short-sighted kids don’t enjoy outdoor play as much because they can’t see as well.

Gut health
In 20 years I think this will be a much more mainstream component of how we think about health.

We know that antibiotics mess up gut flora, particularly in young children.

(I was about to write that early antibiotic use makes children more prone to asthma, but apparently that’s not likely. It does seem to increase risk of food allergies, though.)

About 1/3 of mothers in the US and UK are given IV antibiotics during labor to prevent group B strep infections in their babies. Right now the reasoning seems to be that antibiotics are pretty harmless, so why not give them? But I hope we’ll develop better ways of targeting which children most need the antibiotics. In think we may also see a trend toward narrow-spectrum antibiotics for shorter periods of time.

During pregnancy and breastfeeding, I also try to be extra-careful about hand-washing, keeping cuts covered, and so forth to reduce the chance that I’ll need antibiotics. Mastitis is a common reason breastfeeding moms take antibiotics, and knowing how to deal with it before it gets bad can help avoid the need for medication.

Babies are born with a sterile intestinal tract, and they get colonized with their mother’s microflora during and after birth. There’s growing interest in how to facilitate this for babies born by cesarian section, for example by swabbing babies with fluids from the birth canal. I can imagine that this will catch on, but it might also end up being more risky than it’s worth because of group B strep, herpes, etc which you don’t want colonizing your baby.

I think water birth looks worse for this reason — you don’t want to be washing babies as soon as their born.

Right now we don’t know much about how exactly to help gut health once something is wrong, and how to add and nurture the specific microflora that you want for specific problems. The best we can do is eat fiber (prebiotics) which serves as food for the good bacteria (probiotics), and maybe eat foods with live cultures like yogurt and kimchi. These seem like a good idea, since they’re basically what people have been doing for thousands of years. Packaged commercial probiotic supplements seem generally safe, including for kids, though I think in 20 years we’ll know a lot more about which strains you want.

I think we’ll learn things we don’t currently know about ways that plastics are bad for us. In college, before they decided BPA was bad, I used to microwave my lunch in my Nalgene bottle every day. It’s not clear that what they’re using instead is much better, we might just not have as much evidence about it. I expect it’s just a matter of time until they find long-term effects from things we haven’t been using very long. I don’t put hot food in plastic containers anymore. We use Pyrex glass containers for most food.

Preventing child sexual abuse

Content: nothing graphic. Discussion of adults not believing children.
I think this is a good thing for non-parents to read too, since neighbors, teachers, and family friends may be in a position to notice something is happening.

A while ago a relative expressed worry about the possibility that her child might be sexually abused in the future. Other adults in the family assured her that children are very safe nowadays and that there was almost no risk.

As someone who works with sex offenders, and as the parent of a little girl, this question interests me a lot.

I think it’s important to know the actual risks, because in the past programs have been aimed at preventing risks that weren’t particularly likely: stranger rapes by “predators.” You don’t want to frighten people about events that are very unlikely, but you also don’t want to ignore more likely risks.

How common is it?

  • It’s notoriously hard to collect good data on this, but a metastudy concluded that the sexual abuse prevalence rate for girls in the US is 10.7% to 17.4% and the rate for boys is 3.8% to 4.6%. This is for contact abuse only (abuse that involved touching, not something like an adult showing their genitals to a child).
  • Sexual abuse rates seem to be declining, probably because of greater public awareness and less tolerance of abuse.

Characteristics of children at risk:

  • Risk factors, in order of magnitude: being a girl, having low socioeconomic status, and not living with both biological parents (foster children are most at risk). There are racial differences but they all disappear when you control for class and family structure (source). Other risk factors include being socially isolated, not having someone to confide in, having a mother who is dead or mentally ill, and having parents with alcoholism (source).
  • Boys are most at risk as very young children (peaking around age 4), and less at risk as they get older. Girls’ risk peaks once around 4 but rises to a higher peak around 14. Screenshot 2015-07-26 at 11.23.25 AM(source)

Characteristics of perpetrators:

  • Perpetrators are usually a family friend, neighbor, or babysitter. Family members are next most likely, with strangers being fairly unlikely (14%).
  • Different sources estimate that 87% to 95% of perpetrators are male. (source, other source)
  • About a quarter of the time, the perpetrator is under age 18. 14 again seems to be a particularly risky age. I’m not sure how much of this pattern is 14-year-olds assaulting other 14-year-olds (or how much the 14-year-olds would consider consensual, or how much a 14-year-old can consent).

Screenshot 2015-07-26 at 11.28.51 AM(source)

How do you find out?

  • Sexually abused children usually don’t tell anyone during childhood (source).
  •  If children disclose abuse, they are most likely to tell their mothers and adolescents are most likely to tell a friend. Teachers are third most likely. (source) To me, this points to the importance of having a relationship where your children trust you. I’ve heard horror stories from clients about not being believed, or even being beaten, when they told their parents they were being molested. This made no sense to me until I reflected that the abuser was usually a respected person like the mother’s brother or the parish priest. I also think parents are sometimes so overwhelmed by horror at the thought of this happening to their child that they refuse to believe it.
  • Rather than giving one complete disclosure, children often drop a hint, see what the reaction is, and then decide whether to drop more hints. To me, this again underscores the importance of paying attention to what children say and responding sensitively.
  • It’s fairly common for children to recant or change stories after disclosing abuse, presumably because the memories are difficult to deal with or because it’s causing a stressful situation. (Imagine a child who discloses first to a sibling, then to her mother, then to the child protective worker, then to the police investigator, then a taped deposition for the court—she may recant just to make it all stop. Some families choose not to press charges for this reason.) Memory lapses are also a post-traumatic symptom, and it’s possible some children genuinely don’t remember. I have no idea how you tell the difference between the retraction of a false story and a true one, but it’s considered very unlikely that a child would make this up.
  • Sexual drawings and age-inappropriate sexual behavior may be an indication that something has happened.

Protecting children:

These are my personal guesses, not proven strategies. Some other ideas here.

  • Listen to children. Pay attention to their fears and concerns.
  • Drop in unexpectedly when children are alone with an adult or an older child. Offenders are rarely caught in the act but are often caught pushing boundaries.
  • Notice your child’s mood after they have been alone with an adult or older child.
  • If your child seems uncomfortable around someone, err on the side of keeping them apart even if you haven’t gotten to the bottom of the situation.
  • Make clear to children that they will not be blamed for disclosing and that sexual abuse is never children’s fault.
  • Respond with support and love if they disclose something. Let the child know you appreciate their bravery in telling, and that it is now your job to handle the situation. More good tips here and here.
  • If you hear a disclosure, you will probably experience shock, rage, and sadness. Try to stay calm around the child—let them see that you can handle hearing this. Find an adult you can vent to, so the child does not have to take care of your emotions.
  • Respect children’s boundaries. Don’t make them hug or kiss people they don’t want to, even if grandma is expecting it. In a discussion on boundaries at a Quaker community where I lived, one woman recounted that when she asked a six-year-old girl in the community for a hug, the girl answered, “I only hug people in my family.” The woman held this up as healthy development to be celebrated. Teaching children phrases like this, or a simple “No, thanks,” teaches children that it’s fine to refuse unwanted attention.
  • Unfortunately it’s unclear how well any of this works.

Reducing schizophrenia risk

Schizophrenia affects about 1% of the population. It usually develops during or after adolescence and involves losing your grip on reality in a way that people find really debilitating and unpleasant.

I started researching this because I knew some people (like those with a family history) have elevated risk, meaning above 1%. If some people’s risk is higher than 1%, and the population averages 1%, people without risk factors must have lower than 1% risk. My plan was to reassure myself that my kids were unlikely to get schizophrenia, but it turns out reading a lot about schizophrenia was not a good way to put myself at ease.

If you find this topic interesting and not nervous-making, go ahead. If not, I really didn’t find anything very actionable, so feel free to stop reading.

Schizophrenia.com has a very complete list of factors that may increase schizophrenia risk. I started reading these with the intent of actually doing things differently to reduce my kids’ risk, but a lot of the suggestions either seem spurious or things you were going to do anyway (“try not to have traumatic experiences,” “don’t drink during pregnancy.”) Some of the recommendations were based on pretty ridiculous evidence, like the ones on dental x-rays and dry cleaning.

Here are the ones I found interesting.


The radiation thing hinges on two studies. One is that people whose mothers got dental x-rays during pregnancy have higher schizophrenia risk. But the level of radiation you get from dental x-rays is really low, less than you get in a normal day from things like sunshine. I think the actual explanation is that they won’t give you x-rays if you tell them you’re pregnant, so the only people who get dental x-rays during pregnancy are women who don’t know they’re pregnant (and are probably still drinking or doing other things that aren’t good for fetuses).

Second, there’s a study that 8 rhesus monkeys exposed to high amounts of radiation in utero developed cognitive symptoms including hallucinations once they hit adolescence (not sure how you tell if a monkey is hallucinating). This made me worried about flying until I realized the low dose in this study was roughly equivalent to flying across the US 2000 times in ten days. That helped me decide I was okay with a few flights.

Rh incompatibility

Speaking of rhesus monkeys, Rh incompatibility increases schizophrenia risk, but the study came out in the year before Rhogam, so these were untreated pregnancies. Fun fact about pregnancy: if you have an Rh-negative blood type and your baby is Rh-positive, if you’re exposed to their blood (often during birth), you essentially develop an allergy to your baby. The first baby is usually okay, but after you develop the reaction your blood recognizes and attacks the blood of subsequent Rh-incompatible babies. This is one explanation for why Henry VIII had live births from his wives’ first pregnancies but so many miscarriages thereafter—he may have had an Rh-positive blood type and the wives had Rh-negative blood.

Fortunately, Rhogam (Rho(D) immune globulin) is one of the miracles of modern medicine and means that Rh-negative women like me can have healthy pregnancies, because it prevents us from developing the reaction to your baby’s blood. I assume that if you get the treatment in time, your child’s schizophrenia risk is not elevated.

Birth interval

This part is just weird. For a second child born a short time after their older sibling, the risk is fairly low. The risk increases if you’re spaced 15-26 months apart (with 18-20 months being the worst). Then risk decreases again with longer intervals, being the lowest after 45 months of space between siblings. They think it might be related to folatepregnancy and breastfeeding deplete your folate, so your second child might not get enough if your body is still recovering from the first pregnancy. That explains why a long interval is best, but why is a short interval better than a medium one? You can only have Irish twins if you’re not breastfeeding much (since breastfeeding suppresses the return of ovulation). So perhaps mothers who don’t breastfeed are able to replenish their folate faster than mothers who do.

But even the worst-off second children have about the same rates as only children. So the folate thing doesn’t make a lot of sense. Unless first-time mothers aren’t taking prenatal vitamins at the time of conception, but start taking them and are still taking them at the time they conceive their second child, since you’re supposed to take them after birth and the whole time you’re lactating? But the study started with children born 1950-1983, and for at least part of that period I don’t think folic acid supplements were a thing.

Rather than folate, it might also have to do with an older sibling bringing home germs from daycare, or how stressed your mother is about being pregnant while minding a toddler. This all seems inexplicable enough that I decided not to take it too seriously.

Paternal age

Older fathers are more likely to have schizophrenic children. This seems like one of those that would be nice to plan around if you can, but I don’t know who really makes major life decisions based on a slight shift in likelihood of something that’s already unlikely.

Birth season

Children born in late winter in un-sunny places have higher schizophrenia risk. Some people think taking extra vitamin D is a good idea. But these are big population studies that don’t control for things like maternal infection (the other obvious difference between winter and summer babies), because checking the birthday of people with schizophrenia is much easier than finding out whether their mothers got the flu during third trimester.

(Also dredged up during this part: lesbians and baseball players are more likely to be born at the end of summer; gay men are more likely to be born six months opposite.)

Dry cleaning

Schizophrenia.com recommends recommends avoiding dry cleaning chemicals during pregnancy, but this turns out to be based on 4 people with schizophrenia whose parents were professional dry cleaners. And the Last Psychiatrist points out that 3 of these 4 dry-cleaner parents were fathers. It’s plausible that their sperm were affected, or that they contaminated their homes and wives enough to have an effect. But this doesn’t seem like a very strong basis for advice to avoid dry cleaned clothes during pregnancy. More like “avoid having babies with professional dry cleaners.” Or perhaps they should be advising men, not pregnant women, to avoid the chemicals before conception.

Marijuana/street drugs

Schizophrenia.com is very anti-drug, unsurprisingly. Slate Star Codex addresses the topic in a post on marijuana. (It’s a long post; search for “psychosis.”) There are lots of studies that show a correlation between using drugs like marijuana, LSD, and ecstasy and later being diagnosed with a psychotic disorder like schizophrenia. But it’s not clear whether marijuana and other drugs like LSD, meth, and ecstasy actually increase risk, or if teens in the early stages of developing psychosis are more drawn to drug use. I plan to tell my kids that we don’t know which way the causality goes here, and the risk is something they should consider.

There also seem to be certain genetic mutations that make this effect, if there is one, more likely for some people.


A British study found that women who used painkillers during the second trimester of pregnancy were several times more likely to have children with schizophrenia (and yes, they controlled for viral infections, which could be a cause both of taking painkillers and of damage to the fetus). This study looks weird to me, though, because fewer than 2% of participants reported taking painkillers during any given trimester, which seems awfully low given that about 20% of people use over-the-counter painkillers in a given week.

Other stuff

Pretty much everything else on the list can be described as good prenatal, physical, and mental health. Everything you’re supposed to do during pregnancy (eat vegetables and omega-3s, exercise, take your vitamins, try not to get sick, avoid alcohol, avoid toxins) helps reduce the child’s risk of schizophrenia. After birth, a nurturing, low-stress environment (caring for your own mental health, breastfeeding, giving the baby plenty of touch, living in less urban environments, not yelling, helping children handle stress in healthy ways) also helps. Other bad things during childhood: head injuries, emigration, psychological trauma.

How much should you protect your child?

Before I got pregnant, I read Scott Alexander’s excellent Biodeterminist’s Guide to Parenting and was so excited to have this knowledge. I thought how lucky my child would be to have parents who knew and cared about how to protect her from things that would damage her brain.

Real life, of course, got more complicated. It’s one thing to intend to avoid neurotoxins, but another to arrive at the grandparents’ house and find they’ve just had ant poison sprayed. What do you do then?

Here are some tradeoffs Jeff and I have made between things that are good for children in one way but bad in another, or things that are good for children but really difficult or expensive.

Germs and parasites

The hygiene hypothesis states that lack of exposure to germs and parasites increases risk of auto-immune disease. Our pediatrician recommended letting Lily playing in the dirt for this reason.

While exposure to animal dander and pollution increase asthma later in life, it seems that being exposed to these in the first year of life actually protects against asthma. Apparently if you’re going to live in a house with roaches, you should do it in the first year or not at all.

Except some stuff in dirt is actually bad for you.

Scott writes:

Parasite-infestedness of an area correlates with national IQ at about r = -0.82. The same is true of US states, with a slightly reduced correlation coefficient of -0.67 (p<0.0001). . . . When an area eliminates parasites (like the US did for malaria and hookworm in the early 1900s) the IQ for the area goes up at about the right time.

Living with cats as a child seems to increase risk of schizophrenia, apparently via toxoplasmosis. But in order to catch toxoplasmosis from a cat, you have to eat its feces during the two weeks after it first becomes infected (which it’s most likely to do by eating birds or rodents carrying the disease). This makes me guess that most kids get it through tasting a handful of cat litter, dirt from the yard, or sand from the sandbox rather than simply through cat ownership. We live with indoor cats who don’t seem to be mousers, so I’m not concerned about them giving anyone toxoplasmosis. If we build Lily a sandbox, we’ll keep it covered when not in use.

The evidence is mixed about whether infections like colds during the first year of life increase or decrease your risk of asthma later. After the newborn period, we defaulted to being pretty casual about germ exposure.

Toxins in buildings

Our experiences with lead (and lessons learned about how to reduce risk). Our experiences with mercury.

In some areas, it’s not that feasible to live in a house with zero lead. We live in Boston, where 87% of the housing was built before lead paint was banned. Even in a new building, we’d need to go far out of town before reaching soil that wasn’t near where a lead-painted building had been.

It is possible to do some renovations without exposing kids to lead. Jeff recently did some demolition of walls with lead paint, very carefully sealed off and cleaned up, while Lily and I spent the day elsewhere. Afterwards her lead level was no higher than it had been.

But Jeff got serious lead poisoning as a toddler while his parents did major renovations on their old house. If I didn’t think I could keep the child away from the dust, I wouldn’t renovate.

Recently a house across the street from us was gutted, with workers throwing debris out the windows and creating big plumes of dust (presumably lead-laden) that blew all down the street. Later I realized I should have called city building inspection services, which would have at least made them carry the debris into the dumpster instead of throwing it from the second story.

Floor varnish releases formaldehyde and other nasties as it cures. We kept Lily out of the house for a few weeks after Jeff redid the floors. We found it worthwhile to pay rent at our previous house in order to not have to live in the new house while this kind of work was happening.

Pressure-treated wood was treated with arsenic and chromium until around 2004 in the US. It often has a greenish tint, though it may not be obvious after fading or staining. Playing on playsets or decks made of such wood increases children’s cancer risk. It should not be used for furniture (I thought this would be obvious, but apparently it wasn’t to some of my handyman relatives).

I found it difficult to know how to deal with fresh paint and other fumes in my building at work while I was pregnant. Women of reproductive age have a heightened sense of smell, and many pregnant women have heightened aversion to smells, so you can literally smell things some of your coworkers can’t (or don’t mind). The most critical period of development is during the first trimester, when most women aren’t telling the world they’re pregnant (because it’s also the time when a miscarriage is most likely, and if you do lose the pregnancy you might not want to have to tell everyone). During that period, I found it difficult to explain why I was concerned about the fumes from the roofing adhesive being used in our building. I didn’t want to seem like a princess who thought she was too good to work in conditions that everybody else found acceptable. (After I told them I was pregnant, my coworkers were very understanding about such things.)


Recommendations usually focus on what you should eat during pregnancy, but obviously children’s brain development doesn’t stop there. I’ve opted to take precautions with the food Lily and I eat for as long as I’m nursing her.

Claims that pesticide residues are poisoning children scare me, although most scientists seem to think the paper cited is overblown. Other sources say the levels of pesticides in conventionally grown produce are fine. We buy organic produce at home but eat whatever we’re served elsewhere.

I would love to see a study with families randomly selected to receive organic produce for the first 8 years of the kids’ lives, then looking at IQ and hyperactivity. But no one’s going to do that study because of how expensive 8 years of organic produce would be.
The Biodeterminist’s Guide doesn’t mention PCBs in the section on fish, but fish (particularly farmed salmon) are a major source of these pollutants. They don’t seem to be as bad as mercury, but are neurotoxic. Unfortunately their half-life in the body is around 14 years, so if you have even a vague idea of getting pregnant ever in your life you shouldn’t be eating much farmed salmon (or Atlantic/farmed salmon, bluefish, wild striped bass, white and Atlantic croaker, blackback or winter flounder, summer flounder, or blue crab).

I had the best intentions of eating lots of the right kind of high-omega-3, low-pollutant fish during and after pregnancy. Unfortunately, fish was the only food I developed an aversion to. Now that Lily is eating food on her own, we tried several sources of omega-3 and found that kippered herring was the only success. Lesson: it’s hard to predict what foods kids will eat, so keep trying.
Postscript, 2016: Based on this review, we’ve been giving her a fish-oil supplement which she loves (“More fishy pill!”)

In terms of hassle, I underestimated how long I would be “eating for two” in the sense that anything I put in my body ends up in my child’s body. Counting pre-pregnancy (because mercury has a half-life of around 50 days in the body, so sushi you eat before getting pregnant could still affect your child), pregnancy, breastfeeding, and presuming a second pregnancy, I’ll probably spend about 5 solid years feeding another person via my body, sometimes two children at once. That’s a long time in which you have to consider the effect of every medication, every cup of coffee, every glass of wine on your child. There are hardly any medications considered completely safe during pregnancy and lactation—most things are in Category C, meaning there’s some evidence from animal trials that they may be bad for human children.


Too much fluoride is bad for children’s brains. The CDC recently recommended lowering fluoride levels in municipal water (though apparently because of concerns about tooth discoloration more than neurotoxicity). Around the same time, the American Dental Association began recommending the use of fluoride toothpaste as soon as babies have teeth, rather than waiting until they can rinse and spit.

Cavities are actually a serious problem even in baby teeth, because of the pain and possible infection they cause children. Pulling them messes up the alignment of adult teeth. Drilling on children too young to hold still requires full anesthesia, which is dangerous itself.

But Lily isn’t particularly at risk for cavities. 20% of children get a cavity by age six, and they are disproportionately poor, African-American, and particularly Mexican-American children (presumably because of different diet and less ability to afford dentists). 75% of cavities in children under 5 occur in 8% of the population.

We decided to have Lily brush without toothpaste, avoid juice and other sugary drinks, and see the dentist regularly. We also use a $20 water filter that removes fluoride (we verified with lab tests; I recommend the Maine state lab if you need this kind of thing). Fluoride basically doesn’t pass into breastmilk, but I used it while I was pregnant and will use it when the kids start drinking water instead of mostly milk.

Home pesticides

One of the most commonly applied insecticides makes kids less smart. This isn’t too surprising, given that it kills insects by disabling their nervous system. But it’s not something you can observe on a small scale, so it’s not surprising that the exterminator I talked to brushed off my questions with “I’ve never heard of a problem!”

If you get carpenter ants in your house, you basically have to choose between poisoning them or letting them structurally damage the house. We’ve only seen a few so far, but if the problem progresses, we plan to:

1) remove any rotting wood in the yard where they could be nesting

2) have the perimeter of the building sprayed

3) place gel bait in areas kids can’t access

4) only then spray poison inside the house.

If we have mice we’ll plan to use mechanical traps rather than poison.

Flame retardants

Since the 1970s, California required a high degree of flame-resistance from furniture. This basically meant that US manufacturers sprayed flame retardant chemicals on anything made of polyurethane foam, such as sofas, rug pads, nursing pillows, and baby mattresses.

The law recently changed, due to growing acknowledgement that the carcinogenic and neurotoxic chemicals were more dangerous than the fires they were supposed to be preventing. Even firefighters opposed the use of the flame retardants, because when people die in fires it’s usually from smoke inhalation rather than burns, and firefighters don’t want to breathe the smoke from your toxic sofa (which will eventually catch fire even with the flame retardants).

We’ve opted to use furniture from companies that have stopped using flame retardants (like Ikea and others listed here). Apparently futons are okay if they’re stuffed with cotton rather than foam. We also have some pre-1970s furniture that tested clean for flame retardants. You can get foam samples tested for free.

The main vehicle for children ingesting the flame retardants is that it settles into dust on the floor, and children crawl around in the dust. If you don’t want to get rid of your furniture, frequent damp-mopping would probably help.

The standards for mattresses are so stringent that the chemical sprays aren’t generally used, and instead most mattresses are wrapped in a flame-resistant barrier which apparently isn’t toxic. I contacted the companies that made our mattresses, and they’re fine.

Ratings for chemical safety of children’s car seats here.

Thoughts on IQ

A lot of people, when I start talking like this, say things like “Well, I lived in a house with lead paint/played with mercury/etc. and I’m still alive.” And yes, I played with mercury as a child, and Jeff is still one of the smartest people I know even after getting acute lead poisoning as a child.

But I do wonder if my mind would work a little better without the mercury exposure, and if Jeff would have had an easier time in school without the hyperactivity (a symptom of lead exposure). Given the choice between a brain that works a little better and one that works a little worse, who wouldn’t choose the one that works better?

We’ll never know how an individual’s nervous system might have been different with a different childhood. But we can see population-level effects. The Environmental Protection Agency, for example, is fine with calculating the expected benefit of making coal plants stop releasing mercury by looking at the expected gains in terms of children’s IQ and increased earnings.

Scott writes:

A 15 to 20 point rise in IQ, which is a little more than you get from supplementing iodine in an iodine-deficient region, is associated with half the chance of living in poverty, going to prison, or being on welfare, and with only one-fifth the chance of dropping out of high-school (“associated with” does not mean “causes”).

Salkever concludes that for each lost IQ point, males experience a 1.93% decrease in lifetime earnings and females experience a 3.23% decrease. If Lily would earn about what I do, saving her one IQ point would save her $1600 a year or $64000 over her career. (And that’s not counting the other benefits she and others will reap from her having a better-functioning mind!) I use that for perspective when making decisions. $64000 would buy a lot of the posh prenatal vitamins that actually contain iodine, or organic food, or alternate housing while we’re fixing up the new house.


There are times when Jeff and I prioritize social relationships over protecting Lily from everything that might harm her physical development. It’s awkward to refuse to go to someone’s house because of the chemicals they use, or to refuse to eat food we’re offered. Social interactions are good for children’s development, and we value those as well as physical safety. And there are times when I’ve had to stop being so careful because I was getting paralyzed by anxiety (literally perched in the rocker with the baby trying not to touch anything after my in-laws scraped lead paint off the outside of the house).

But we also prioritize neurological development more than most parents, and we hope that will have good outcomes for Lily.

Adventures in toxicology

Last week Jeff discovered a horrifyingly large mercury spill behind a closet wall in our new house (about a pint, the amount in 10,000 mercury thermometers). Apparently it had been part of an early 20th century heating system, had been spilled during renovations in the 1970s, and someone decided to just wall it up instead of cleaning it up properly.

The good news is that none of us seem to have been exposed in any dangerous way, since we weren’t using the room and were evacuated quickly after the mercury was opened up to the air.

Lessons learned:

Don’t use a vacuum cleaner to clean up mercury! It vaporizes and gets everywhere. Brooms are also not a good idea, as they break it up into little droplets that scatter. Don’t walk around in shoes or socks that might be contaminated. Don’t pour mercury down a drain or wash mercury-contaminated clothes in a washer, as the metal will get contaminated. Further instructions here.

This document was the most helpful thing I found, being candid thoughts on how mercury is spilled and spread in houses and how to clean it up, by an environmental toxicologist. The one thing that seems to have changed since it was written is that there’s now a meter capable of measuring smaller quantities of mercury vapor in air (which is good, because the most conservative air vapor limit is an order of magnitude lower than the commonly-used Jerome meter can even measure).

When you’re being evacuated from your home, assume it will be for at least several days. When the fire department told us to leave, I took the baby, her carrier, my purse, my shoes, my phone, and a few diapers (thinking we would be in the front yard for an hour or two). That was a week ago and we still don’t know when we’ll be back. Luckily we have family nearby we can stay with, and Jeff was able to go back to get some clothes.

Obviously if there’s immediate danger you should get out as quickly as possible. But if it’s the kind of situation where you can take 10 minutes to pack medications, a phone charger, some changes of clothes, etc. — take a few minutes to pack a bag! With the caveat that if there’s something dangerous spilled in the house, you really don’t want to track it. Better and cheaper to buy more of whatever you need from the back room than spread the spill.

Previous adventures and lessons learned in lead paint.

What should toddlers drink?

Now that Lily’s had a birthday, I’m trying to figure out what the evidence says on what children should drink after age 1.

If you’re just breastfeeding, it’s not that complicated about when to do what. The WHO recommends breastfeeding for at least 2 years, although I can’t even find numbers on how many women actually do that. (Around 1/3 of American babies are at least partly breastfed at 12 months). Their recommendations for non-breastfed children assume that people aren’t continuing formula past 6 months, I guess because most of the world can’t afford formula for a long time.

The American Academy of Pediatrics, on the other hand, says to stick with formula or breastmilk for 12 months and then…it gets kind of vague. Every “how to feed your child” guide handed out at the doctor’s office will tell you that after 12 months, you give them cow’s milk. I imagine most parents take this with a sigh of relief that they can start paying $3/gallon for whole milk instead of $24/gallon for formula.

But something doesn’t make sense here. If the WHO recommends breastfeeding for 2 years, and if formula is intended as artificial breastmilk, why stop formula at 12 months?

(One theory is that the WHO guidelines are meant for people living in countries with poor water sanitation, and breastmilk is recommended partly because it’s cleaner and safer than bottles or cups).

But let’s assume that there’s a nutritional component as well as a sanitation one. There’s hardly anything out there about the use of formula after 12 months. There’s one study (funded by a formula company) saying that formula-fed 3-4 year olds have fewer respiratory infections. There’s this theory that brain differences between breastfed and milk-fed toddlers might be decreased if toddlers got formula instead (but just a theory, no study). You can buy “toddler formula”, and while doctors seem to regard it as ok, I can’t find anyone who feels strongly about it.

I’m surprised at the lack of research here – it seems like it should be easy to find parents who would want to participate in a study where you gave them free formula. And if formula companies would love to point to studies in their favor. Possibly this means that some research was done and quietly discarded if it wasn’t in formula’s favor.

To me, the most obvious difference between formula and cow’s milk is that formula has added DHA. DHA and other long-chain polyunsaturated fatty acids seem to be important for brain development, and are found in breastmilk (particularly if mother is eating fish or fish-oil supplements). Cow’s milk does not have much of it, because cow’s milk is optimized for calves, which need to grow a lot of bulk and not a lot of brain.

They only started adding DHA to American formula in 2002, earlier in Europe. I suspect this is part of the reason that older trials, even ones that controlled for things like socio-economic status, found better cognitive outcomes in breastfed children. But in general supplements seem to work less well than actual food, and Cochrane says DHA supplements for babies don’t help.

So I guess I should keep trying to give Lily salmon, though she’s not keen on it right now.

Optimizing vs. satisficing in parenting

I was surprised to see a friend say that “One of the key points of the rationalist community is to learn to “optimize” rather than “satisfice” things.”

For me, the take-away from the optimize/satisfice concept was to optimize fewer things. It helped me start satisficing on unimportant things that I used to spend lots of time on, like sorting the recycling (and worse, sorting other people’s recycling, which can take basically infinite amounts of time). It was a big relief to realize that it was okay not to try to optimize everything.

One of the major problems for me in parenting has been figuring out when to optimize and when to satisfice. Having a toe in the waters of the rationality movement has swayed me in both directions. On the one hand, there is this strong drive to optimize the important things—and surely your child is important. On the other hand, people point to the research that children’s outcomes are mostly determined by genes and non-parental environment (their friends, teachers, etc.) So trying to optimize your child, instead of just trying to do a good job, is likely to be a waste of effort.

The child psychology field has been fighting this battle for a long time. From the Wikipedia entry on D. W. Winnicott’s concept of the “good enough parent“:

The idea of the good enough parent was designed on the one hand to defend the ordinary mother and father against what Winnicott saw as the growing threat of intrusion into the family from professional expertise; and on the other to offset the dangers of idealisation built into Kleinian articulations of the ‘good object’ and ‘good mother’, by stressing instead the actual nurturing environment provided by the parents for the child.

The idea is that a too-perfect parent will shield the child from all difficulty and frustration, setting them up for failure when they encounter the real world. I’m not sure how this could ever be a problem, given that the most attentive parents still can’t prevent their child from suffering from indigestion and so forth. All babies get upset and cry, no matter how well you care for them. But I still appreciate Winnicott standing up for “the sound instincts of normal parents,” as he put it.

I thought it was going to be great raising a child in a household that includes two social workers, a medical student, a midwife, and an early intervention specialist. Actually, it turns out to be pretty stressful being surrounded by experts. I envy people who get to parent without knowing or caring that their child should already be saying ‘m’ and ‘b’ sounds in her babbling.

I thought I could accept any amount of information and advice for my daughter’s sake, but actually I get as defensive as the next mother. Someone else trying to optimize your child is really hard to take.

I’m also really questioning the status of the expertise out there. Child care books by different pediatricians cite different expectations for developmental milestones like smiling and crawling, and none of them cite their sources. (The pediatrician/author my parents swear by, Dr. Spock, doesn’t even put one of those tables in his book because he says it just makes parents anxious.)

I’m also aware of the research that a lot of this stuff is genetically pre-programmed. Intensive developmental interventions do speed up children’s progress – for a while. Children who grow up in neglectful environments and then get adopted into nurturing families can catch up on their development to a large extent. But it’s generally considered that the heritability of IQ increases with age. In other words, a baby or young child’s IQ depends mostly on her environment (quality of parenting, preschool, nutrition, etc.) But by age 18 your IQ is much more correlated with your biological parents’ IQ (even if you were raised by someone else).

I wonder about this with milestones. Yes, I can see that if your child isn’t speaking or interacting at an age when almost all children are doing that, they should get professional help. But is it worth getting worried if your child is a month late in rolling over? Is there any adult with some kind of disability whose parents lament not getting help with her rolling-over skills at six months? I know children and adults who are pretty clumsy, and they might well have been physically uncoordinated as babies, but it’s hard to imagine that early intervention would have actually changed any kind of long-term outcome.

My take-away message from this week’s tribulations in child development is that my daughter’s development matters, but my sanity also matters. I should save my optimizing for the cases where it can actually make a significant difference. The rest of the time, we can relax and have fun together.