Here we go again. A pseudoscience pushing website (which occasionally tosses in stories about real science) is trumpeting a primary research study (published 6 months ago) that may, or may not, indicate that plant DNA may survive intact in the digestive tract and show up in the bloodstream. You just know what they’re going to say next.
This will now be all about genetically modified foods.
In case you’ve ignored this area of pseudoscience, genetically modified crops are foods derived from genetically modified organisms (GMOs); of course, all types of agricultural breeding induces genetic modification, but in general, GMO usually implies actual manipulation of the genes. Based on some of the worst science available, anti-GMO cultists have condemned GMO foods as being dangerous. Of course, there is actually no science supporting the anti-GMO claim, and the vast scientific consensus says that GMO foods are safe to humans, animals and the environment.
A paper published in the online journal, PLoS One, seems to indicate that possible DNA fragments pass from the digestive tract into the blood. The authors, Spisak et al., concluded:
…based on the analysis of over 1000 human samples from four independent studies, we report evidence that meal-derived DNA fragments which are large enough to carry complete genes can avoid degradation and through an unknown mechanism enter the human circulation system.
Based on our knowledge of the digestive process, fats, DNA, carbohydrates, and proteins are broken down into their simplest components, and specialized transport systems move these simple components across the barrier between the digestive tract and blood. They have evolved to not transport full size molecules, partially because the blood is incapable of carrying large foreign molecules (and could induce an immune response). Moreover, small constituent molecules, like amino acids instead of the whole protein, or glucose instead of a long-chain carbohydrate, are more easily transported to locations in the body to be then used as fuel or building blocks for new proteins and DNA. We just have not seen a mechanism in the digestive tract that can move large molecules, like gene-length DNA fragments, into the bloodstream.
In fact, the authors admit that the mechanism is unknown . . .