Who’s Got the Science? An Answer to Mike and Ewan.

Before we can go further, I have to answer the multiple objections to the whole Alzheimer’s scenario raised by my two most faithful commentators, Mike W. and Ewan R. (sorry you continue to lurk behind screen names instead of putting yourselves squarely behind your remarks, but if you don’t mind the implications of that, it’s your choice).  Only when the issues they raise have been fully and thoroughly dealt with can I go on to connect the dots and show direct links between glyphosate and the mechanisms that underlie Alzheimer’s (AD).

Let’s begin with what seems at first sight the most damaging evidence: the apparent absence of any time-lag between the steep rise of glyphosate use/GE R-R crops and AD statistics.  Ewan himself inadvertently gave me the answer to that:

“Herbicide use on corn in the years prior to HT corn (1998 being year of release) 1994 - 170,221,000 lbs 1995 - 167,642,000 lbs 1996 - 186,977,000 lbs 1997 - 164,051,000 lbs 1998 - 177,012000 lbs.”  In other words, massive use of herbicides predated the emergence of glyphosate as the major herbicide.

When did I ever claim that glyphosate was the only herbicide that caused chronic disease?  Neither Swanson nor I did this.  Indeed Swanson specifically states that “We do not imply that all of these diseases have a single cause as there are many toxic substances and pathogens that can contribute to chronic disease.” We focused on glyphosate because of its present-day ubiquity, but there’s no reason to doubt that similar chemicals used in a similar way would have had similar effects.  So the steep rise in levels of AD and other chronic diseases in the 1990s reflects mostly exposure to previously-used pesticides, from 1970 (when Roundup was introduced) to the ’90s when it became dominant, giving just the predictable time-lag for AD.  After all, even industry representatives were congratulating themselves (and still do) on having substituted glyphosate (“the pesticide of the century”, as GMO advocate called it) for the more dangerous pesticides that preceded it.

As for attributing chronic diseases to obesity, that fails on a number of grounds.  For instance Hawaii, which has a shot at most-sprayed-state-in-the-union status, has a chronic kidney disease rate 30% higher than the natural average, yet in 2013 had the second-lowest incidence of obesity.  Moreover, as will be shown in subsequent posts, the mechanisms that cause obesity are the same as those involved in the etiology of chronic disease.  One thing we’ve learned (or should have) in the last few years is that the old one-size-fits-all medical model is hopelessly at variance with the facts.  People are vulnerable in different ways, simply because we all differ in our genetic make-up, so the same chemical (whether cure or poison) may have quite different effects on different people.  What effect a pesticide might have will then tend to vary from person to person, although a cascade effect is likely in some cases—pesticide-triggered hormonal dysfunctions precipitating obesity which in turn leads to diabetes, which in turn leads to AD, and so on.  But it follows too that at some stage a saturation point will be reached—only a certain proportion of the population will be likely candidates for obesity, and once that point is reached you’ll see the kind of leveling off you’d like to seize on to show that glyphosate is not what’s doing the harm.

Note that the same argument I made about the supposed “AD time-lag” applies equally to the 80’s rise in obesity that began before massive glyphosate use—other pesticides could have started what glyphosate, for all the touting of its “safety”, simply continued.  I’m not claiming that the Swanson case might not have been more effective if this point had been seen and emphasized. But obviously something in the environment started to change in the last quarter of last century.  If not pesticides, then what?  Change in lifestyles?  People don’t want to be obese.  If they did, how could the weight-loss industry be as big as it is?  How could new fad diets emerge almost daily?  You’d think all this publicity (even including TV shows like “The Biggest Loser”) would send rates plummeting. And if better diet and more exercise could cure it, you’d surely think they would.  But they don’t.  Obesity rates creep on up no matter what people do.

But there are much broader issues involved in Mike’s and Ewan’s remarks.  For instance, Ewan made a big deal of the fact that atrazine, contrary to what I suggested, is a selective pesticide.  I would have thanked him for this—no-one is readier than me to admit when I’m wrong or more grateful for any addition to my knowledge—if he had not started so immodestly crowing over it.  The fact that I got this wrong was to him a clear indication that I could not even grasp “the simple stuff” and was therefore clearly incapable when it came to “the hard stuff”.

Sorry, Ewan, that’s not how science works.  It may be how science education works, by slowly accumulating factoids into solid chunks of what currently passes for knowledge, but I suspect that’s exactly why science education in the U.S. is so ineffective.  Science isn’t like that.  First of all it advances through argument.  If you retracted from science journals all the papers that weren’t arguing one opinion against another, those journals would be two-thirds empty.  So contrary to normal practice in pro-GMO circles, you do not treat your opponents as ignorant idiots (or “fear-mongers”, if it comes to that).   Second of all, you don’t need to learn “the simple stuff” in order to learn “the hard stuff”--especially if, as in this case, the simple stuff is in one branch of science and the hard stuff is in a quite different branch.

Atrazine and its properties form part of weed science.  As I’m the first to admit, I don’t know weed science, and I’m sure Ewan does.  But weed science is just a small branch on the great tree of biology, and if you’ve been following that over the last decade or two you’ll know that there’ve been great changes—changes that produced whole new biological fields such as evo-devo and niche construction theory.  These changes have already turned biology into something a lot less friendly to the whole GMO/pesticide nexus than the “one gene = one protein = one trait”, “genes rule”, “genes are like Lego blocks” biology of the Dawkins era.  Now we know that genes are pleiotropic as well as collaborative, so that to talk about “the gene for X” where X is any behavioural trait is at best misleading.  GMO researchers had to find this out the hard way; what they seldom admit is that “implanting the gene for X” fails far more often than it succeeds.  (Occasionally even the staunchest GMO advocate can let this slip out:  “There are probably fifty different genes that have been engineered into citrus trees, most of them don't work or show little promise”—Kevin Folta.)  Far from genetic engineering being a precise and well-understood process, its procedures are just hit-and-miss trial and (mostly) error.

With the new biology we know the ease with which, especially given the ideal circumstances, resistance to any threat can evolve.  GMO enthusiasts have provided those ideal circumstances.  “Ecological theory predicts that the large-scale landscape homogenization with transgenic crops will exacerbate the ecological problems already associated with monoculture agriculture.”  Artificially breed resistance to a particular herbicide in a crop, grow that crop over as large an area as possible, use that herbicide over that whole area, and you are just doing evolution’s job at a faster rate.  You are actively selecting for herbicide-resistant weeds, because you are killing off all their competition--the non-resistant weeds--and leaving a vacuum for the “superweeds” to fill (just like the asteroid strike cleared the field for us mammals 65 million years ago).  Monsanto didn’t know this—their propaganda in the nineties said there was little likelihood that glyphosate would create resistance—but anyone with up-to-date scientific knowledge could have predicted it.

Now we further know that environmental inputs can have massive effects on development from foetus to adult, modifying gene expression, upregulating or downregulating proteins, guiding not only individual development but the future evolution of species.  This new knowledge has already proved fatal to the canon on which all GMO undertakings are based—“The dose is the poison”, the dictum of a sixteenth-century alchemist/astrologer, and surely the last piece of sixteenth-century science to survive into the twenty-first century.  All pesticide safety testing is aimed at detecting acute effects, whereas the main dangers from pesticides are chronic effects that can be caused by much lower doses, but only become apparent after long periods.  (Don’t forget how they told you for years that smoking was safe, and to be sure, nobody ever collapsed as a consequence of smoking a pack.)  Chemicals can no longer be assumed to have monotonic dose-response curves, leading the Endocrine Society (who should surely know about toxicity, if anyone does) to call for a complete change is safety-testing methods.

That is what I meant and will continue to mean by the “hard stuff” that GMO advocates refuse to deal with.  I can only assume it’s because there’s no way they could.  And this explains why they have to pounce every time a GMO opponent misstates some trivial factoid about pesticides--it's the only way they can maintain the myth that they know science and the other side doesn't.  It also explains why, when I began quite recently to learn about GMOs, my first reaction was “There’s no way, in the second decade of the twenty-first century, that anyone could call this stuff scientific!”

Alzheimer's I: No It's NOT Just Because There's More Old People!

Since there has been so much fuss over the correlations in Swanson et al., I thought, why not take the dodgiest-looking of those correlations and look into it a little more closely.  For instance, what about their correlation between glyphosate/GMO increases and the growth of Alzheimer’s, suggesting that one could cause the other?  Surely that’s a no-brainer!  As commentators on pro-GMO blogs have already noted, Alzheimer’s is a disease of old age, older Americans are increasing, so naturally there’s an increase in Alzheimer’s—isn’t there?

But wait.  If a growing number of aged was sole or even main cause, then the increase in numbers of old folk should equal (or not much increase) the increase in the number of Alzheimer’s deaths.  If however there turned out to be a discrepancy, with the second figure substantially higher than the first, then some new factor or factors must be causing that increase.

I took age 65 as the cutoff point, partly because it’s a division found in census data but mainly because 98% of Alzheimer’s deaths occur after 65.  And the conclusions were stunning.  From 2000 to 2010, the over-65s increased by 13.1%.  But in the same period, deaths from Alzheimer’s increased by 39.1!   In other words, Alzheimer’s deaths increased three times as much as would have been predicted by a mere increase in the elderly population.

Clearly, some environmental factor that is both new and widely-distributed must be causing that increase.  But why should glyphosate be blamed?  There are several good reasons.

Of all toxic chemicals, glyphosate is the one whose use has increased most dramatically over the last quarter-century.  GMO advocates often state that the growing of GMO crops has reduced the quantity of pesticide sprayed.  That is a half-truth, and, as in every half-truth, the part that isn’t true is false.  “Pesticide” is a blanket term for herbicides, insecticides and fungicides.  It is true that insecticide use has been reduced.  But that is not true for herbicides.  You can make plants toxic to insects, but you can’t make them toxic to weeds.  All you can do is make them resistant to herbicides and then spray indiscriminately, crops along with the weeds.  And that process eventually produces herbicide-resistant weeds, so you have to spray more.  Not to mention the recently-introduced practice of spraying crops, GMOs and non-GMOs alike, with pesticide (mostly glyphosate) so as to dry them out immediately before harvest.  The lie that GMO crops have reduced pesticide use is repeated ad nauseam on GMO sites, but in fact any reduction in insecticide use is more than offset by the increase in herbicide use.  Here’s the truth:

“Herbicide-resistant crop technology has led to a 239 million kilogram (527 million pound) increase in herbicide use in the United States between 1996 and 2011, while Bt crops have reduced insecticide applications by 56 million kilograms (123 million pounds). Overall, pesticide use increased by an estimated 183 million kgs (404 million pounds), or about 7%.”  Glyphosate is by far the commonest herbicide because it was the first for which crop-resistance was originally engineered.  In the U.S. the use of glyphosate went from 27 million pounds in 1996 to 250 million pounds in 2009.

Of all toxic chemicals, glyphosate is perhaps the most multivectorial.   It can enter the human body via air, water, or food.  Since the vast majority of corn, soy and sugar-beet are now glyphosate-resistant, most processed food will carry residues of glyphosate, which--however infinitesimal each one may be—can accumulate over time in the human body.  It follows that there are very few people in the US who have not ingested glyphosate, a fact that makes epidemiological studies difficult, for the following reason.

The best way to perform an epidemiological study is by dividing populations into two groups: those that have been affected by the presumed pathogen and those that haven’t.  Tobacco was a classic case.  There were people who smoked and people who didn’t.  If tobacco caused lung cancer, you should find significantly more cases in the second group than in the first.  And you could refine the search—those groups that smoked more should have more cancers than those who smoked less, and the same with lifelong smokers versus those who gave it up.  That’s because smoking a cigarette is a conscious, deliberate choice.

But because there are so many vectors and because none of them involves a conscious decision (in the absence of labeling laws, we have no idea whether what we’re eating has been sprayed with glyphosate or not, whatever our attitude towards GMOs), it’s not possible to determine which sections of the population might be affected and which might not.  But what about areas where there’s been spraying against those where there hasn’t?   Surely there should be some difference between these, if glyphosate was involved.  

There are two good reasons why there shouldn’t be.  One, spraying isn’t just farmers in rural areas—it’s golf courses in suburbs, and municipalities in parks, and householders in their own yards.  Two, even if the rural-urban distinction could be made, there’s no reason to believe—contra the facts of tobacco-smoking—that greater exposure to glyphosate would correlate with higher incidence of Alzheimer’s.  Glyphosate is an endocrine-disrupting chemical (EDC), and as I showed in ‘Unsafe at Any Dose?” EDCs can cause damage at doses as small as one part in a billion.  Moreover, an EDC harmful at these levels may be completely harmless at far heavier doses.  The reason’s simple: chemicals can harm you in more ways than one, at more levels than one, and the two different effects can occur at very different dose levels.

That’s why Swanson et al. could deal with the glyphosate/ Alzheimer’s correlation only by taking figures for the whole population.  Which is what leads pro-GMO folk to think that they can explain away the data by repeating their mantra “Correlation is not causation” and drawing phony graphs between rising diseases and any other factor that happens to have gone up in the last couple of decades.  Like this, for example:

“There’s a plethora of items whose prevalence or use has increased during the past 20 years: the number of electronics we own, the number of pedicures women get, the amount of coffee we drink, etc., and each would make an equally convincing graph…” 

So says Layla Katiraee, “a Senior Scientist in Product Development at a biotech company in California”.  A similar-looking graph, sure.  But “equally convincing”?  To “a Senior Scientist”?  I doubt if anyone with an IQ above room temperature would think that something meant to beautify your feet would be as likely a cause of death as something designed to kill living organisms. 
  

But how could glyphosate hurt us, when its makers assure us that “Glyphosate inhibits an enzyme that is essential to plant growth; this enzyme is not found in humans or other animals, contributing to the low risk to human health.”  That’s another GMO lie, and it’s already the subject of a California lawsuit.  More on this next week, when I’ll write about the only link still missing from our chain of causal evidence connecting glyphosate to Alzheimer’s: exactly what glyphosate can do to humans, and how it can do it.