GMO foods and ingested RNA gene blockers
For those interested in GMO (genetically modified organisms) here is a summation and a link to an interesting story concerning how the introduction of DNA and RNA fragments into food which is then consumed by people can actually have some important possible side effects. As the author of the piece points out, normally, throughout history, people have discovered that some food was toxic by making the mistake of eating it, and given that GMOs are not tested or regulated, it would appear that if it ever happens that troublesome RNA enters the food chain, people will find out after the fact, and even then, no doubt there will be a long period of controversy over the true cause, much like decades were spent quarrelling about such products as cigarettes.
Chinese researchers have found small pieces of rice ribonucleic acid (RNA) in the blood and organs of humans who eat rice. The Nanjing University-based team showed that this genetic material will bind to receptors in human liver cells and influence the uptake of cholesterol from the blood.
microRNA (abbreviated to miRNA) due to its small size. MiRNAs have been studied extensively since their discovery ten years ago, and have been implicated as players in several human diseases including cancer, Alzheimer's, and diabetes. They usually function by turning down or shutting down certain genes. The Chinese research provides the first in vivo example of ingested plant miRNA surviving digestion and influencing human cell function in this way.
(MiRNA may also play a role in) cross-species communication, co-evolution, and predator-prey relationships.
In a technique called RNA interference, or RNA knockdown, these small bits of RNA are used to turn off, or "knock down," certain genes.
RNA knockdown was first used commercially in 1994 to create the Flavor Savr, a tomato with increased shelf life. In 2007, several research teams began reporting success at engineering plant RNA to kill insect predators, by knocking down certain genes.
..cotton plants that silence a gene that allows cotton bollworms to process the toxin gossypol, which occurs naturally in cotton. Bollworms that eat the genetically engineered cotton can't make their toxin-processing proteins, and they die.
Researchers at Monsanto and Devgen, a Belgian company, made corn plants that silence a gene essential for energy production in corn rootworms; ingestion wipes out the worms within 12 days.
A good place to start would be the testing of introduced DNA for other effects -- miRNA-mediated or otherwise -- beyond the specific proteins they code for. But the status quo, according to Monsanto's web page, is,
There is no need to test the safety of DNA introduced into GM crops. DNA (and resulting RNA) is present in almost all foods. DNA is non-toxic and the presence of DNA, in and of itself, presents no hazard.
There are computational methods of investigating whether unintended RNAs are likely to be knocking down any human genes. But thanks to this position, the best we can do is hope they're using them. Given it's opposition to the labeling of GM foods as well, it seems clear that Monsanto wants you to close your eyes, open your mouth, and swallow.
It's time for Monsanto to acknowledge that there's more to DNA than the proteins it codes for -- even if it's for no other reason than the fact that RNA alone is a lot more complicated that Watson and Crick could ever have imagined.
link to www.alternet.org