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.
Humans and insects have a lot in common, genetically. If miRNA can in fact survive the gut then it's entirely possible that miRNA intended to influence insect gene regulation could also affect humans.
Monsanto's claim that human toxicology tests are unwarranted is based on the doctrine of "substantial equivalence." According to substantial equivalence, comparisons between GM and non-GM crops need only investigate the end products of DNA expression. New DNA is not considered a threat in any other way.
"So long as the introduced protein is determined to be safe, food from GM crops determined to be substantially equivalent is not expected to pose any health risks," reads Monsanto's website.
In other words, as long as the final product -- the pizza, as it were -- is non-toxic, the introduced DNA isn't any different and doesn't pose a problem. For what it's worth, if that principle were applied to intellectual property law, many of Monsanto's patents would probably be null and void.
Chen-Yu Zhang, the lead researcher on the Chinese RNA study, has made no comment regarding the implications of his work for the debate over the safety of GM food. Nonetheless, these discoveries help give shape to concerns about substantial equivalence that have been raised for years from within the scientific community.
一批科学家1999年就向著名的《自然》杂志写过一封信，题为《在实质性等同的背后》。埃里克 米尔斯通等人在这封信中指出：“ 实质性等同 是一个 伪科学概念 ，在本质上是反对科学的，因为把它提出来只是为不做生物化学检验或毒理学检验找了个借口。”
In 1999, a group of scientists wrote a letter titled "Beyond Substantial Equivalence" to the prestigious journal Nature. In the letter, Erik Millstone et. al. called substantial equivalence "a pseudo-scientific concept" that is "inherently anti-scientific because it was created primarily to provide an excuse for not requiring biochemical or toxicological tests."
对于科学家的指控，孟山都公司是这样回应的：“在1991年的时候， 实质等同性原则 这一概念在一个由 经济合作与发展组织(OECD) 所召开的国际科学专家会议上制定了细节。那是早在生物工程产品还没有上市之前的事情了。”
To these charges, Monsanto responded: "The concept of substantial equivalence was elaborated by international scientific and regulatory experts convened by the Organization for Economic Co-operation and Development (OECD) in 1991, well before any biotechnology products were ready for market."
This response is less a rebuttal than a testimonial to Monsanto's prowess at handling regulatory affairs. Of course the term was established before any products were ready for the market. Doing so was a prerequisite to the global commercialization of GM crops. It created a legal framework for selling GM foods anywhere in the world that substantial equivalence was accepted. By the time substantial equivalence was adopted, Monsanto had already developed numerous GM crops and was actively grooming them for market.
The OECD's 34 member nations could be described as largely rich, white, developed, and sympathetic to big business. The group's current mission is to spread economic development to the rest of the world. And while the mission has yet to be accomplished, OECD has helped Monsanto spread substantial equivalence globally.
Many GM fans will point out that if we do toxicity tests on GM foods, we should also have to do toxicity testing on every other kind of food in the world.
But we've already done the testing on the existing plants. We tested them the hard way, by eating strange things and dying, or almost dying, over thousands of years. That's how we've figured out which plants are poisonous. And over the course of each of our lifetimes we've learned which foods we're allergic to.
All of the non-GM breeds and hybrid species that we eat have been shaped by the genetic variability offered by parents whose genes were similar enough that they could mate, graft, or test tube baby their way to an offspring that resembled them.
A tomato with fish genes? Not so much. That, to me, is a new plant and it should be tested. We shouldn't have to figure out if it's poisonous or allergenic the old fashioned way, especially in light of how new-fangled the science is.
It's time to re-write the rules to acknowledge how much more complicated genetic systems are than the legal regulations -- and the corporations that have written them -- give credit.
Monsanto isn't doing itself any PR favors by claiming "no need for, or value in testing the safety of GM foods in humans." Admittedly, such testing can be difficult to construct -- who really wants to volunteer to eat a bunch of GM corn just to see what happens? At the same time, if companies like Monsanto want to use processes like RNA interference to make plants that can kill insects via genetic pathways that might resemble our own, some kind of testing has to happen.
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 website, 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.
Given what we know, that stance is arrogant. Time will tell if it's reckless.