Wednesday, July 15, 2009

Free Range Kids Book Review

[One more post about Free Range Kids and I will get back to blogging my latest creative projects. Crafting has been slowed by work and my latest infection/inflammation cycle.]

Many people have asked me if I read Free-Range Kids: Giving Our Children the Freedom We Had Without Going Nuts with Worry by Lenore Skenazy.

Yes, I bought and read it when it first came out. No, I am not wild about it. It covers familiar territory, but it doesn't delve deeply IMHO. It read like she was rushing to press while she was still in the limelight.

For example, she dismisses the dangers of BPA. I don't think she spoke to enough scientists. I don't think she spoke to any scientists. Investigative journalist David Case of Fast Company, did dig deep and The Real Story Behind Bisphenol A is great investigative reporting. I am posting a few excerpts, but you should really read the whole thing.
BPA is dangerous to human health. Or it is not. That's according to two government reports in recent months that came to opposite conclusions. The National Toxicology Program (NTP), which is part of the National Institutes of Health, reported in September 2008 "some concern" that BPA harms the human brain and reproductive system, especially in babies and fetuses. Yet less than a month earlier, the U.S. Food and Drug Administration declared that "at current levels of exposure" BPA is safe. Even after the FDA's own science board questioned the rigor of this analysis in late October, the agency didn't change its position.

Let's take a moment to ponder this absurd dichotomy. How could our nation's health watchdogs reach such divergent conclusions? Are we being unnecessarily scared by the NTP? Or could the FDA be sugarcoating things? What exactly is going on?

We went on a journey to find out. What we learned was shocking. To some degree, the BPA controversy is a story about a scientific dispute. But even more, it's about a battle to protect a multibillion-dollar market from regulation. In the United States, industrial chemicals are presumed safe until proven otherwise. As a result, the vast majority of the 80,000 chemicals registered to be used in products have never undergone a government safety review. Companies are left largely to police themselves

....

Perhaps. But consider this: Of the more than 100 independently funded experiments on BPA, about 90% have found evidence of adverse health effects at levels similar to human exposure. On the other hand, every single industry-funded study ever conducted -- 14 in all -- has found no such effects.

...

It is the industry-funded studies that have held sway among regulators. This is thanks largely to a small group of "product defense" consultants -- also funded by the chemical industry -- who have worked to sow doubt about negative effects of BPA by using a playbook that borrows from the wars over tobacco, asbestos, and other public-health controversies....Yet as BPA products have made their way into every part of our lives, biologists have discovered evidence that very low doses may have a completely different set of effects -- on the endocrine system, which influences human development, metabolism, and behavior.

At first, these discoveries emerged by accident, when test tubes and petri dishes in laboratories were switched from glass to plastic. A group of Stanford researchers in 1993 found that breast-cancer cells it was studying reacted with a mysterious estrogen, which it traced to polycarbonate lab flasks. A few years later, Patricia Hunt, a geneticist at Case Western Reserve University, discovered abnormalities in the chromosomes of her lab mice. She eventually concluded that damaged polycarbonate cages were at fault.

Yes, the industry-funded studies had larger sample sizes; only industry has the deep pockets to afford such large sample sizes. But many scientists have found flaws in the experimental design in every the industry-funded study of BPA safety. A cynical person would conclude that is because those studies were designed to prove a foregone conclusion--BPA is safe. I'm betting my family's health on the independent, but smaller, studies.

10 comments:

  1. An interesting post.

    The government has deep enough pockets to do a big, well-designed study, if they were so inclined. The problem is that by the time they are so inclined, public opinion will be so entrenched that it won't matter what the studies say. Just look at what happened with the vaccine-autism thing. There are now really good, large studies showing no link, and still a sizeable percentage of parents just won't believe them.

    Another scientist mom and I did some reading on BPA back when our babies were still taking bottles at day care. We both came to the conclusion that given the way we were using the bottles, the risk was low. Of course, neither of us is an endocrinologist or toxicologist. We are both trained in biochemistry.

    To me, the biggest unresolved question is how much BPA actually leaches from the container under normal use. The studies we could find were either inconclusive or so amazingly bad that we couldn't take their findings seriously. In this case, the bad studies were funded by environmental working groups who wanted BPA removed from use. These "policy groups" can be as distorting in their use of science as industry groups.

    The other big question to me is: will the replacement be any better? What if it is worse? All the baby bottle manufacturers have replaced BPA now, because the big retailers said they wouldn't carry anything with BPA in it. In 10 years, what problems will we be reading that the replacement chemicals cause? I don't even know what was used as a replacement. I think the biggest problem is that we don't require any testing of chemicals used in containers like this. But then, I'm not sure how we'd design a system that would support such testing and not simultaneously make all our bottles cost $50.

    On a related note, you might find this survey of toxicologists interesting:
    http://stats.org/stories/2009/are_chemicals_killing_us.html

    They put BPA at a medium to low risk (see table 2).

    Another really interesting (to me) part of the survey is what the toxicologists thought of various sources of information about potential risks (see table 3). Wikipedia does surprisingly well.

    I have this survey on my list of things to blog about, but haven't gotten around to it.

    And finally, if studies do find that BPA is the likely cause of the earlier puberty we're seeing in girls, will people stop freaking out about the use of bovine growth hormone in dairy cows? We currently can't have a sane discussion about the costs and benefits of that practice- any attempt gets bogged down in the accusations about early puberty, which have never made any sense to me.

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  2. Cloud, those are very good points.

    The way I was using BPA was definitely not safe. My water bottle in my car gets much hotter than the 100-105F that is deemed absolutely safe. And I was microwaving in Tupperware Rock n Saves, which were supposed to go from freezer to microwave. I still use them, but not w/ hot foods. I also try to avoid sticking melamine in the microwave.

    I eat lunch sometimes w/ a couple with PhDs in environmental engineering and chemistry. I asked what they do. They use Pyrex or Corningware. At the very least, they said to transfer to glass or porcelain for microwaving.

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  3. How much early puberty is related to obesity in general? Has anyone done a controlled study?

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  4. Interesting about the microwaving. We do most of ours in the "disposable" tubs, which never had BPA (they aren't hard enough plastic) or on the plate we're going to eat off of. We switched to the disposable tubs mostly because they stack nicely in the freezer.

    On the puberty thing- I am not aware of a controlled study. But yeah, my money is on obesity. And also just on general better nutrition- I don't think we actually know when humans are "supposed" to hit puberty. I think it has been getting steadily earlier as we get better fed. But I don't have a reference for that, either.

    I will be really, really surprised if bovine growth hormone turns out to have anything to do with it.

    The parent part of me understands why it is so hard to have rational public discussions about these things. But it drives that scientist part of me nuts.

    I'm reading "The End of Food" now. Finally, I may have found the food book I wanted. Lots of research cited, seems even handed and not out to "prove" a specific agenda... So far, I'm impressed. (I WILL get around to setting up a Goodreads account soon, I promise...)

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  5. There are two books named The End of Food. Which one are you reading?

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  6. Funny. I didn't realize that. I'm reading the one by Paul Roberts.

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  7. http://pubs.acs.org/cen/news/87/i29/8729news3.html

    From today's C&E News

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  8. Marianne, how timely and interesting. Our governator has been accused of packing panels (e.g. the coastal commission) with pro-business people. I wonder about the doctors he picked.

    I read that one reason teen pregnancies are down is that sperm counts are down for teens. I don't recall where I read that.

    Cloud, I don't know the culprit for younger puberty in girls and lower sperm counts in boys, but I do feel uneasy that we have embarked on a huge biological experiment on ourselves. I would like to see more research and more reasoned debate.

    My lymphocytes are unclear on their job description, even on my best days. I do suspect that many chemicals that are safe for others are not safe for genetically susceptible people like myself. I witnessed a huge variability in people's tolerances for VOCs in organic chemistry lab. That is why I switched to computational chemistry. I figured that out even before the gene test that confirmed my suspicions.

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  9. The reason I'd be surprised if bovine growth hormone in milk has anything to do with early puberty is that it is a protein, so even if it is passes into the cow's milk, it is almost certainly degraded into amino acids in our stomachs. Almost all proteins and peptides are- this is why protein and peptide drugs have to be injected.

    If you have a subscription to Science, you can read the summary of why the FDA approved the use of bovine growth hormone in cows: http://www.sciencemag.org/cgi/reprint/249/4971/875.pdf

    Quoting from the article:
    "The evaluation of the human food safety of bGH was based on several factors: bGH is biologically inactive in humans, rbGH is orally inactive, and rbGH and bGH are biologically indistinguishable."

    There was some concern about the fact that growth hormone treatment elevates levels of a protein called insulin-like growth factor (IGF) in milk. However, that protein also does not seem to be active when ingested. Also, the levels found in the milk of treated cows seemed to be within the range found in human breast milk.

    Now, it may be that we should be concerned about the use of bovine growth hormone from an animal welfare/use of antibiotics standpoint, because I have seen some data indicating that cows getting growth hormone have a higher incidence of mastitis. But that's a separate issue.

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  10. Cloud, until you mentioned it, I didn't realize that hormones can be macromolecules like proteins. I am more familiar with the smaller molecules that we ingest, such as estrogen and progesterone.

    I looked it up
    http://www.medterms.com/script/main/art.asp?articlekey=3783
    and
    http://dictionary.reference.com/browse/hormone .

    I have a BS in Chemistry and never realized (before you pointed it out) that *some* hormones are proteins, and thus unlikely to survive digestion.

    No wonder the public is so confused about bovine growth hormone. If we can produce more milk with less cows, without harming the cows or the environment, wouldn't that be a good thing? That is, we could feed the same amount of people with less energy, space and damage to the environment.

    OTOH, if the cows get mastitis from taking it, then I would vote nay. I remember suffering from mastitis while breastfeeding, and I wouldn't inflict it upon anyone else.

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