A few days ago my health-conscious wife rushed downstairs from her computer, printed web site pages in hand. "My Boca Chik'n Burgers are made with a neurotoxin," she said, "They're going to kill me."
She wasn't 100% serious... about the killing part. But after some initial skeptical mutterings of that can't be from me, my Googling confirmed that hexane is indeed involved in the processing of lots of veggie burgers which contain non-organic soy protein.
This isn't new news. We just hadn't come across the hexane scare until now.
Back in April of this year, Mother Jones magazine kicked off a frenzy of concern among veggie burger-eating folks like us with a story, "Which Veggie Burgers Were Made With a Neurotoxin?"
Guaranteed to generate interest among those who like their burgers made from ingredients that didn't moo at one time. However, when I dug into the details of the story, the seeming health scare turned out to be more worthy of mild concern.
Hexane, a petroleum product, is used to make burgers more low-fat by separating soybean oil from the protein. It's toxicity is low, so to call it a "neurotoxin" is a stretch. A Slate article, "Is Your Veggie Burger Killing You?", was reassuring.
Many non-organic soy products may contain traces of the neurotoxin hexane, according to a report by a research group that supports organic and sustainable agriculture. How worried should soy foodies be?
Maybe a tiny bit, but only because of the lack of data. The FDA does not currently impose a ceiling on hexane residue in soy foods, but it does limit how much of the chemical can be left in fish protein isolate (5 parts per million), as well as in hop extract and spice resins (25 ppm). The study (PDF) that's now in the news found 21 ppm of hexane in soy meal—the defatted soy flakes that are used in products like energy bars and veggie burgers.
The authors of the study told the Explainer that more recent testing has found concentrations as high as 50 ppm. But that's no reason to throw your meatless breakfast links down the disposal. The hexane limits are precautionary. No study has ever tested how much hexane a person can safely eat over the course of a lifetime, but rodent studies suggest that your Thanksgiving tofurkey isn't going to kill you.
The research described in the Mother Jones story came from the Cornucopia Institute, which promotes organic foods and farming. Since hexane isn't found in organic products, the Institute has an obvious interest in tilting consumers away from non-organic soy veggie burgers.
I doubt, though, that the Cornucopia Institute report, "Behind the Bean," is scientifically biased. At least, not much. I couldn't find any out-and-out debunkings of the Institute's study.
Soy that's been processed with hexane is best avoided. My favorite veggie burger is the Amy's Kitchen Texas Burger (I have one for lunch most days). Fortunately, I found an April 2010 press release from the company that said:
Because of concerns around soy protein extracted with hexane, we have eliminated the use of any soy protein ingredient that uses hexane in its processing.
Good for you, Amy's Kitchen. Laurel wasn't so lucky.
When she phoned Boca Burger headquarters, she learned that the Chik'n Burger, and all other Boca soy products, I believe, are still made with hexane processed soybeans. (Factoid: Boca Burger is a subsidiary of Kraft, which is owned by Phillip Morris.)
I'm not going to freak out if I eat some soy that's been processed with hexane. It's still wise to avoid it when possible, though, which is why Laurel has switched to a different veggie burger. A follow-up Mother Jones story had this question and answer:
"Hexane's boiling point is well below grilling temperature (69C, about 157F). That's cooler than even a toaster. Is there any evidence that the slightest bit remains in a veggie burger?"
Vallaeys: "The evaporation argument is often used by the companies that make these products. But what happens to the food when you cook it with this neurotoxic compound? Does it react with other substances and create new compounds before it evaporates? That really has not been studied. We think there should be more testing done on what these substances do to the food.
So a cooked veggie burger may not contain any hexane at all. The Cornucopia Institute study was a useful eye-opener to a potential health problem, but the benefits of being a vegetarian are far out-weighed by any possible slight negative effects of hexane processed soy.
Thus saith "Hexane in veggie burgers: little science behind the claims."
It’s not difficult to avoid all food additives, of course, if you eat a diet based on whole plant foods—always the best choice for health. Paradoxically though, while focusing on a problem that isn’t known to exist, the Cornucopia Institute promotes animal food consumption, as long as the foods come from small-scale organic farms. But omnivore diets have their own set of health problems and always contribute to animal cruelty (no matter where the food comes from).
Prudence dictates that, to the extent possible, foods should be free of all contaminants. But if the occasional veggie burger can help people move toward a healthful and compassionate vegan diet, the benefits of consuming these foods in moderation are likely to outweigh any unproven risks.