Angry Toxicologist

A study in Neurology came out today ($ required) that found that those with better reading skills had 2.5 times less cognitive brain damage due to lead! Reading ability is one of the best ways to measure cognitive reserve (CR), the ability to maintain good cognitive performance despite disease or injury. It is also related to head size, education, linguistic ability, and occupational achievement but reading is really the best indicator (achievement under very controled settings is better but it’s really hard to control for opportunity in medium size studies). Those in the study are occupationally exposed to lead and were divided into categories depending on their reading ability and administered 14 neuropsyc tests. Among similar exposures, those with better CR did better on the tests.

What strikes me after reading this article (after I get over how facinating I find the brain and neuropsyc) is how “the rich get richer” applies to more than finances. For those with a low CR, one could expect to not read as well, not do a well in school or in a job, and to top it off, now that said person is stratified to the lower level, when exposed to neurotoxicants, they’re more likely to get wacked than their more cerebral friends. However, not all evidence supports such a fateful view. A study published in Brain about 3 years ago (I wrote recently and then looked at the date. Sheesh, time flies) used childhood intelligence (among other things) to control for CR and found that after using this score, education still had an impact. So, that suggests that learning can help with your CR. So keep reading!

Caveats: Education and reading may only help significantly until around sexual maturation based on some monkey studies but hey, it can’t hurt! It’s like the crosswords to prevent senility, does it help or do people with better CR just like crosswords. Also, cognitive ability is very small part of ability to succeed in the world and certainly not a part of being an all-around great person.


  1. #1 Jim Lemire
    July 31, 2007

    Confused about a couple of things:
    1) can you explain more about the neuropsych tests?
    2) were these workers assessed for brain disease/injury?
    3) you say: “Among similar exposures, those with better CR did better on the tests.” – but does exposure necessarily translate into real damage?

    Basically, all these questions add up to – how do they know that higher CR “protects” against brain injury vs. brain injury leads to lower CR?

  2. #2 bacopa
    August 1, 2007

    Didn’t Jesse jackson make some excellent comments on the lead-exposure/achievement-gap hypothesis back in the seventies?. That whole “If we can run faster, jump higher, shoot a basketball straighter…” thing?

    Don’t get me wrong. Lead exposure is bad, and I believe we would have been better off using carcinogenic benzene as an antiknock agent rather than tetra ethyl lead. However, I think racism, classism, and poor education have a far greater effect than incidental environmental contaminents,

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