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Mystbuster: GMOs and antinutrients

The term anti-nutrients seems to come up a lot when considering ancestral diets, and for those trying to eat a diet more in line with this concept. For one, I don't think antinutrients is truly the best of describing these plants compounds - calling phytic acid or lectins 'antinutrients' automatically assumes that they are bad in all forms and all concentrations.

You'll hear me say this a lot - Nutrition is Toxicology. There is nothing that is inherently bad for you, in and of itself. It depends on the quality, quantity, and form. Don't get me wrong, phytic acid may be something you want to consider, especially if you're a vegetarian with low iron, but it's also been looked at as having anti carinogenic effects (1) - there is definitely not enough of a body of research to draw any overwhelming clinical significance out of this, but there's at least a hint that it's not all bad (phytic acid will probably get its own post later).

Anywho, let's get to the myth I mention in the title: I've seen a lot of people saying that we've bred modern wheat, and genetically modified it, to be higher in protein and that some of these 'antinutrients' are protein, so presumably, ancestral grains and modern grains have differing levels of these. This sounds fine in theory, as does a lot of nutrition theory. The problem is that not all physiology can be reasoned out, and as I've posted about before, evolutionary theory can't really help you derive what is most healthy for you.

So naturally, to solve this issue, I went to the literature. A paper out of Food and Chemical Toxicology (2) looked at some of these 'antinutrients' in rapeseeds, maize, potatoes, soybeans, and tomatoes. Some of the 'antinutrients' analyzed were phytates, glucosinolates, lectins, oxalates, solanine, protease-inhibitors and isoflavones. The study found a lot of variability in the content of these foods, GMO or not. This does not surprise me - a lot of these compounds are plant defense systems: depending on the environment and the specific oppressive environmental agents acting on the plant, they would presumably respond by increasing their concentrations of these specific components to meet their defensive needs. The article notes that drought stress was able to more than double glucosinolate concentrations (sulfur containing, largely found in cruciferous veg, goitrogenic compound but also potentially anti-cancerous effects [3]) in both parental and GMO versions of rape seed plant compared to standard concentrations. The study concludes that the modified versions of plants' toxins were in the range of parental versions.

What I hope you can take away from this is that any forum that make definitive statements need to back these up with definitive facts. I can think of a few other reasons that I don't like GMOs, but spreading untruths regarding antinutrient content of GMO foods does not help advance science. Also, if lectins are a big concern for you, understanding that the environment that the food was grown in appears to be the major factor regarding concentration is something to keep in mind - it's pretty difficult in the modern food environment to be that concerned with antinutrients since all of our food is grown in a number of different environments with a lot of different predatory factors that plants may respond to.

More on this topic of plant defenses/toxins to come!

(1). Shamsuddin, A. M. (2002), Anti-cancer function of phytic acid. International Journal of Food Science & Technology, 37: 769–782. doi: 10.1046/j.1365-2621.2002.00620.x

(2). Novak, W.K., Haslberger, A.G. 2000. Substantial equivalence of antinutrients and inherent plant toxins in genetically modified novel foods. Food and Chemical Toxicology.

(3). http://www.ansci.cornell.edu/plants/toxicagents/glucosin.html

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