By Deborah Blum
Yesterday, John Timmer, the amazingly smart science editor at Ars Technica, posted this comment on Twitter:
@j_timmer Ugh. @grist, if your author doesn’t understand a science paper, maybe he shouldn’t make wild accusations based on it? http://t.co/4p5ezqsN
I don’t what it says about me but I immediately clicked on the link to discover this story about a study proposing that rising autism rates could be linked to consumption of high fructose corn syrup. And, again, I don’t what it says about me but my first reaction was not to check my pantry for such products but to think ‘Darn it (or words to that effect) didn’t I just write last week about studies linking autism to obesity during pregnancy?” Yes, and not in an entirely enthusiastic way.
Timmer then added this note:
@j_timmer That @grist article shows no indication of critical thinking skills whatsoever. Paper appealed to author’s biases, so he ran with it.
At this point, I took a more serious look at Tom Laskaway‘s Grist story, which states:
“The blaring headline version of the new study’s conclusion would read: “High-Fructose Corn Syrup Causes Autism. And while that may be a bit of an overstatement, it’s not off by much.”
Honestly, readers, I had to get up and kick a piece of furniture. Of course, some may feel that a better response would be to alert the Nobel committee that we are close (“not off by much”) to discovering the cause of autism and it appears to be something akin to a Theory of Corn Consumption. Or possibly obesity in pregnancy. Or could it be both, as Kristina Chew wondered over at the website Care2: “High Fructose Corn Syrup and Maternal Obesity: Autism Causes?” Or could it be…well, I’ll get to that later.
As I’ve already written about the obesity coverage, let me take a minute here to further discuss the realities of that corn syrup study. The study was published April 10 in the online, peer-reviewed journal Clinical Epigenetics in what the journal describes as provisional form. The lead author is Renee Dufault, a former toxicologist for the U.S. Food and Drug Administration (FDA) who is these days described as a government whistle blower.
According to the Government Accountability Project, she was forced out of the agency after discovering low-levels of mercury contamination in High Fructose Corn Syrup and refusing to follow an agency directive to conceal that. Her findings were included in a 2009 paper, published in the journal Behavioral and Brain Functions, titled “Mercury Exposure, Nutritional Deficiencies, and Metabolic Disruptions May Affect Learning in Children.” (It’s important to note here that Dufault does not include vaccines in this equation and does not consider them a contributor to autism.)
Her latest paper continues to focus on the possible link between trace mineral deficiencies and developmental disorders, in which high fructose corn syrup may play a role. The basic idea is this: a diet high in mercury-contaminated corn syrup tends to interfere with the way we metabolize trace nutrients, lowering zinc levels in the body and allowing a higher load of other heavy metals. This nutrient imbalance also interferes with production of enzymes that work to break down dangerous substances – from metals to pesticides – as they enter the body. Without this protection, these contaminants are allowed to wreak greater havoc, in particular, in pregnant women, they may affect the developing nervous system of an unborn child and – if all of this occurs as proposed – could possibly be a contributing factor in the Autism Spectrum Disorder.
Or as the authors put it in their 20-page paper (which is available for free download from the journal), this cascade of events, if occurring as described, can “lead to oxidative stress in the brain reducing neuronal plasticity.” In fact, this is, at least, an interesting idea and, I think, fits into our growing appreciation of the intricate dance between environment, biology, and behavior. Could it lead to a better understanding of such effects on developmental neurobiology? Yes. Eventually. Does it definitively establish corn syrup as a “cause” at this moment. No.
For one thing, other literature contradicts the idea that high fructose corn syrup always has a dramatic effect on mineral uptake, as, for instance, in this 1992 paper. For another, the authors point out in the paper that there are other dietary reasons that people may be low in certain minerals, such as “insufficient dietary intake of Ca (calcium), Mg (magnesium), and Zn (zinc.) The study compares populations in the US and Italy, where far less corn sweetener is used, but it’s fair to wonder about other dietary differences between these two cultures.
To be fair, there’s been a fair amount of cautionary health studies concerning an over-reliance on high fructose corn syrup as a sweetener. And to be fair again, Grist wasn’t the only publication to see the study as an opportunity to urge changes in the American diet. “Americans are screwed by the food we eat,” wrote Thom Hartman at The Talk Radio News Service. “The typical American diet may be linked to the epidemic of autism in children in the U.S.,” noted the Public News Service. “The typical American diet may fuel autism,” agreed Deborah Mitchell at the EmaxHealth website.
Maybe but let’s hold off after all on that phone call to Stockholm. I tend to prefer the analysis over at he lifestyle blog Bliss Tree, where Hanna Brooks-Olsen called the study disturbing but noted a number of research challenges to be overcome, including the fact that “it’s difficult to truly study something that most of the population is consistently being exposed to at low levels.”
And at the Autism Key blog, writer Gary Porter called it more of a food safety concern than necessarily an autism finding. “With autism rates now at a mind-blowing 1 in 88,” he added, “there are many who are desperately looking for a definitive cause and a silver bullet theory.
And this, I think may be the most important point here, a legitimate connection between last week’s obesity analysis and this week’s targeting of high fructose corn syrup. As Liz Szabo at USA Today noted in a savvy story earlier this month, the rising autism numbers are driving a new sense of urgency in understanding the causes of the disorder. In addition to long-standing genetic theories, she points out, researchers are now looking at everything from the risk of living too close to a highway to the risk of maternal use of antidepressants to the risk of aging parents.
I’m in favor of the big picture here, the one that puts all this research together and suggests that autism is a complicated story and that we’re likely to find an intricate web of influences that lead to it. I hope, in fact, that such awareness will result in a lessening of the anti-vaccine misinformation related to this disease. But if we jump on the bandwagon of every one of these alternative theories and ideas, we do neither our readers or the science itself much service. Instead, we may only add to misinformation. And that, readers, is why I chose to kick the furniture instead of making that long-awaited call to Stockholm.