A little too much knowledge is a dangerous thing *UPDATED*

I live in Marin County, which has a very high incidence of breast cancer.  A few years ago, Marin launched a very expensive investigation, asking each Marin woman to fill out a form documenting how often she eats hot dogs and bacon, and whether she lives near power lines.  I was unimpressed, although I dutifully entered the information.  One doesn’t need to spend tens of thousands of dollars to figure out why Marin has a high incidence of breast cancer.  The answers are obvious, and have to do with social and economic issues.

The social issues are that women in Marin delay childbearing (sometimes forever).  Aside from the fact that childbearing and nursing seem to have a positive impact on avoiding breast cancer, the same statistics about delayed childbearing also mean that many women have spent years on oral contraceptives, which may have a negative impact on avoiding breast cancer.  There are also a lot of Jewish women in Marin (not religiously affiliated, perhaps, but genetically affiliated), and we know that Ashkenazi Jews have a higher incidence of breast cancer.

Probably the biggest factor in Marin’s breast cancer numbers, though, is that this is a wealthy community, with people eating well, exercising often, and getting good medical care.  They avoid heart disease, diabetes and other common youthful killers, and live into a nice old age — and old women get breast cancer.  The older you are, the more likely you are to get it, so a population with a lot of older ladies (not as many as Miami, admittedly, but still a lot) is going to pop up with a lot of cancer patients.  Not only that, but the confluence of affluence and good medical care means that these cases are going to be diagnosed.

Diagnosis matters a lot when it comes to statistical anomalies.  I can’t track the story down, but unless I was hallucinating, I swear that several years ago, when I was still listening to NPR, I heard a story about clusters of brain tumors amongst children in a small Canadian town.  The usual panic ensued, with expensive testing of water supplies, soil, power lines, food, etc.  It finally turned out that the problem was caused by a new imaging machine at the local hospital.  In the old days, when children banged their heads (something children do a lot), the doctors diagnosed concussions by observation.  In the modern era, doctors stuck the kids into the MRI machine.  It was as a byproduct of these concussion tests that the brain tumors starting appearing.  In other words, the brain tumors were always there (apparently a lot of us have innocuous, anomalous growths in our brains), but no one had ever seen them before.

I thought of these two stories when I read today in the New York Times that a simple food allergy test is resulting in over-diagnosis of food allergies, with the resulting inconvenience and, in extreme cases, malnutrition:

Doctors say that misdiagnosed food allergies appear to be on the rise, and countless families are needlessly avoiding certain foods and spending hundreds of dollars on costly nonallergenic supplements. In extreme cases, misdiagnosed allergies have put children at risk for malnutrition.

And avoiding food in the mistaken fear of allergy may be making the overall problem worse — by making children more sensitive to certain foods when they finally do eat them.

More than 11 million Americans, including 3 million children, are estimated to have food allergies, most commonly to milk, eggs, peanuts and soy. The prevalence among children has risen 18 percent in the past decade, according to the Centers for Disease Control and Prevention. While the increase appears to be real, so does the increase in misdiagnosis.

The culprit appears to be the widespread use of simple blood tests for antibodies that could signal a reaction to food. The tests have emerged as a quick, convenient alternative to uncomfortable skin testing and time-consuming “food challenge” tests, which measure a child’s reaction to eating certain foods under a doctor’s supervision.

The problem in each of the examples above isn’t the absence of data, it’s too much data, or the misinterpretation (for reasons of ignorance or politics) of existing data.  It’s a cheap and easy shot to add here that the same phenomenon seems to be a part of the hysteria about global warming, but I’m going to do it anyway.

Just as the MRI in Canada, by revealing hitherto hidden, but perfectly normal information, caused a brain tumor panic, so too did the recent ability to take the earth’s temperature cause a panic.  And just as people were loath to admit that lifestyle and money could affect breast cancer, and instead tried to blame paranoid bugaboos such as water and power lines, so too have greenies been loath to admit that the earth has a cycle, and they are instead trying to blame American capitalism.  And just as we’re discovering that the wrong tests yield the wrong data about food allergies, we’re increasingly learning that the warmies have been messing with or misreading the data about the climate.

We all know the line that a little knowledge can be a dangerous thing.  It turns out that in our modern, politically driven, somewhat paranoid era, a lot of knowledge, misinterpreted or messed with, can be a damn dangerous thing too.

UPDATE:  I can’t resist adding this little story, about hitherto unknown animal species coming to light in the rainforest.  We bemoan the decrease in population of animals that we know exist, but we still have the hubris to think we’re aware of all animals.  In the cycle of life, species come and species go, and we don’t know everything about all of them.

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  • suek

    Heh. I had breast cancer at age 48. My first child was born when I was 23, and I breastfed 5 babies, 4 of them for about 6 months each (one for only a month – he was colicky, though it turned out later that he had a colon polyp, which may or may not have been the cause). I have never used oral contraceptives in my lifetime. I don’t live near any power lines, though this one is a bit tricky, as I’ve lived in a lot of different places, and may not remember about this one or that – but I don’t remember ever living near power lines. I’m not Jewish in any family lines that I’m aware of – though who knows! Life plays odd tricks! I discovered the lump myself, not as the result of a medical check up.
    I can’t remember the last time I had a hot dog, though I have bacon probably 3-4 times a month (I use it more often for a casserole than for a breakfast meat).

    I had a mastectomy plus chemo, and so far have not had a re-occurrence.

    so.

    Where does that fit….I’m just lucky???

  • http://photoncourier.blogspot.com David Foster

    Everyone who goes to college should learn a little bit about statistical inference…it is useful in virtually all careers, plus is important in thinking coherently about public policy. Journalists, in particular, would benefit from some knowledge here.

  • http://OgBlog.net Earl

    There’s another risk factor that gets ignored a lot. Check out:
    http://www.abortionbreastcancer.com/

    The first line when you actually enter the site is this:

    “It cannot be said that all women who have breast cancer have had abortions. Similarly, not all women who have had abortions will get breast cancer. Nevertheless, abortion is the most preventable risk factor for breast cancer.”

    At the very least, people ought to be aware that there is more credible evidence of this link than there is connecting second-hand smoke to anything at all in people who don’t live full-time with a smoker in the house.

    And yes, I’ve read the statements from government agencies, as well as others….this is an enormous political issue. One wants to be alert to misuse of data from whatever source. But, the biological rationale for the link is sound, and there’s enough smoke in the air that careful people ought to at least be keeping an eye out for a bit of fire.

  • suek

    >>“It cannot be said that all women who have breast cancer have had abortions….>>

    Good thing…I didn’t have those either.

    Maybe I should start buying lottery tickets…!

  • Tiresias

    Aging is an interesting dynamic, and of course exposes us to a lot of stuff our bodies are really sort of surprised to be exposed to: we weren’t designed to live so long. As we do, we diagnose a lot better. It’s an old question: is the disease more prevalent these days, or are we just better at spotting it?

    It’s also interesting to come to grips with the knowledge that though we know a hell of a lot more than we used to, it isn’t much. For example, a particularly fascinating (I find it so, anyway) fact that’s come to light in the last couple of decades is how little of us is us. Think of the human body as a galaxy, only instead of stars, you’re made up of about 100 trillion cells: one hundred million million separate units of living matter.

    That’s impressive, but what’s even more impressive is that only about 10 trillion of the cells that make up you, are you. The other 90 trillion cells are bacteria, parasites, viruses, fungi, and other miscellaneous riff-raff. Inside your own body you are badly outnumbered by other species, about 9 to 1.

    I only bring that up in the context of this post to point out that your entire life and relationship with this stuff is an ongoing balancing act, and the 1 being able to keep down the 9 inside you is the result of a variety of complex interconnected systems that (hopefully) keep functioning.

    The longer you stay alive, the better the chance that somewhere a leak may spring. This is what takes down most of us – though that being said I went to a service not long ago for my neighbor’s grand-daughter, who had had most of her insides removed by the age of four and didn’t quite make it to a month after her fifth birthday. Age, one suspects, didn’t have much to do with that.

    And aging itself is also interesting. Had lunch and far-ranging conversation a few days ago here in the sun with a bio-geneticist (or something, I’ve already forgotten both his name and proper title) from a large university on the mainland who posed a very simple question: why do we age and die?

    A child’s question, you might think, but he meant it in a somewhat different sense. As follows:

    It was only in the last hundred years, out of the three million plus years or so of human history, that the human lifespan got past being about 45 years, on average. Before that, it was even younger.

    So. Your DNA directs your genes to tell your cells and thus your body what to do. If, as we think is the case; for the first 3 million years of human existence hardly anyone lived past the age of about 25, (everybody got killed fighting or hunting or in childbirth): where’d your DNA learn about aging? The cells in someone of 70 reproduce and are constructed vastly differently than in someone of 15. Why? Where – and when – in the human experience on this planet did your genes learn about being 70? 70 has only become common enough to make a noticeable difference within the last hundred years – nowhere near long enough to affect mutation on the genetic scale.

    This also had the potential to become a philosophical/religious discussion. (Sorry, Book, gone very far afield here, but maybe it’s interesting.) The philosophical component is: we apparently have an “aging” gene. It’s built in, right on Day 1, original equipment. Unused, unnoticed – but there. And there it sat, not turned on, for something in excess of 3 million years. It’s only within the last 100 years, as life-spans got long enough to activate it that it activated; and so we age, and can die of age. In the first 3 million years there probably weren’t 3,000 people who lived long enough to activate it (so he said) – but it was always there, with no genetic mutation reason in the world for it to be there.

    Where’d it come from? And where this becomes weirdly Intelligent Design-y is the corollary question – if you like – of not simply whence it came from, but: who put it there?

  • Dennis Elliott

    Years ago (in the mid to late 60’s) I was a young forester in southern Oregon. In that country, after a timber stand is cut and the resulting debris eliminated (usually through burning), the site is taken over by Alder. This robust, thickly growing shrubby tree will drastically reduce the early growth of conifers, that growth being very important to the efficient start of a new stand. It was the practice at the time to retard the growth of Alder by spraying the herbicide 2-4D. In due time (remember these were the days of Agent Orange scares) there erupted a hue and cry concerning the increased incidence of teratomas (sp?) in babies being born to local mothers. The result, of course, was the elimination of spraying, the acceptance of the retardation of conifer growth, and decreased efficiency of the forest management efforts on State, Federal and industry lands, not just in southwestern Oregon, but on most timberlands in the West that dealt with a shrub invasion problem. A decade later, after numerous studies by Oregon State University, it was discovered that the increased incidence of tumors in babies was the result not of 2-4D, but the fact that there was a much higher than normal population of young women of child-bearing age owing largely to the back-to-nature movement popular then. When studies controlled for this demographic anomaly, the incidence of teratomas was less than in a normal population.

  • suek

    >>This also had the potential to become a philosophical/religious discussion. >>

    Indeed…

    When you consider the efforts made to increase abortions while at the same time increasing life span.

    What a wonderful world some want to create when the average age is about 50! or whatever. Much older than it is today, in any case.

    Well, understandable – when you get that much older, who wants to be chasing around after those 100% energized little bunnies! And of course, by then we’re probably expecting that new babies will all be grown in test tubes. Frankly, I know pregnancy is difficult for some women, and maybe hampers their life style, but it’s _after_ they’re born that they really create havoc. Now if they’d just invent a capsule for the kids until they’re full fledged adults – about 28 or so…!