Dozens of review studies carried out by academic researchers have backed that view. Opponents of genetically modified foods point to a handful of studies indicating possible safety problems. But reviewers have dismantled almost all of those reports. But the potato was not intended for human consumption—it was, in fact, designed to be toxic for research purposes.
The Rowett Institute later deemed the experiment so sloppy that it refuted the findings and charged Pusztai with misconduct. Similar stories abound. After a review, the European Food Safety Authority dismissed the study's findings. Several other European agencies came to the same conclusion. Some scientists say the objections to GM food stem from politics rather than science—that they are motivated by an objection to large multinational corporations having enormous influence over the food supply; invoking risks from genetic modification just provides a convenient way of whipping up the masses against industrial agriculture.
Not all objections to genetically modified foods are so easily dismissed, however. Long-term health effects can be subtle and nearly impossible to link to specific changes in the environment. Scientists have long believed that Alzheimer's disease and many cancers have environmental components, but few would argue we have identified all of them.
And opponents say that it is not true that the GM process is less likely to cause problems simply because fewer, more clearly identified genes are replaced.
And as U. True, the number of genes affected in a GM plant most likely will be far, far smaller than in conventional breeding techniques. Yet opponents maintain that because the wholesale swapping or alteration of entire packages of genes is a natural process that has been happening in plants for half a billion years, it tends to produce few scary surprises today. Changing a single gene, on the other hand, might turn out to be a more subversive action, with unexpected ripple effects, including the production of new proteins that might be toxins or allergens.
Opponents also point out that the kinds of alterations caused by the insertion of genes from other species might be more impactful, more complex or more subtle than those caused by the intraspecies gene swapping of conventional breeding. And just because there is no evidence to date that genetic material from an altered crop can make it into the genome of people who eat it does not mean such a transfer will never happen—or that it has not already happened and we have yet to spot it.
These changes might be difficult to catch; their impact on the production of proteins might not even turn up in testing. It is also true that many pro-GM scientists in the field are unduly harsh—even unscientific—in their treatment of critics.
GM proponents sometimes lump every scientist who raises safety questions together with activists and discredited researchers. Most of them are nonscientists, or retired researchers from obscure institutions, or nonbiologist scientists, but the Salk Institute's Schubert also insists the study was unfairly dismissed.
Schubert joins Williams as one of a handful of biologists from respected institutions who are willing to sharply challenge the GM-foods-are-safe majority. Both charge that more scientists would speak up against genetic modification if doing so did not invariably lead to being excoriated in journals and the media. These attacks, they argue, are motivated by the fear that airing doubts could lead to less funding for the field.
Both scientists say that after publishing comments in respected journals questioning the safety of GM foods, they became the victims of coordinated attacks on their reputations. Schubert even charges that researchers who turn up results that might raise safety questions avoid publishing their findings out of fear of repercussions.
There is evidence to support that charge. The paper showed that GM corn seemed to be finding its way from farms into nearby streams and that it might pose a risk to some insects there because, according to the researchers' lab studies, caddis flies appeared to suffer on diets of pollen from GM corn. Many scientists immediately attacked the study, some of them suggesting the researchers were sloppy to the point of misconduct.
There is a middle ground in this debate. Many moderate voices call for continuing the distribution of GM foods while maintaining or even stepping up safety testing on new GM crops.
They advocate keeping a close eye on the health and environmental impact of existing ones. But they do not single out GM crops for special scrutiny, the Center for Science in the Public Interest's Jaffe notes: all crops could use more testing. Even Schubert agrees. In spite of his concerns, he believes future GM crops can be introduced safely if testing is improved. Stepped-up testing would pose a burden for GM researchers, and it could slow down the introduction of new crops.
That is a fair question. But with governments and consumers increasingly coming down against GM crops altogether, additional testing may be the compromise that enables the human race to benefit from those crops' significant advantages.
This article was originally published with the title "Are Engineered Foods Evil? Food, Inc. Peter Pringle. Tough Lessons from Golden Rice. Martin Enserink in Science , Vol. Natasha Gilbert in Nature , Vol. Watch a video on how genetically modified crops are made at ScientificAmerican. David H. According to the companies and scientists who design new GMO crops, this new technology is harmless to humans, better for the environment, and is the only way to feed an ever-growing population [2].
On the other hand, anti-GMO groups claim that GMOs cause health problems for both humans and animals, destroy the environment, and only benefit large corporations. So, why did scientists develop these new organisms?
Crop scientists and engineers want to come up with solutions to problems facing the world, like decreased yields due to pests and weeds. For example, Roundup Ready corn was supposed to be better for the environment by decreasing the amount of herbicide farmers needed to use on their crops.
Scientists also make GMOs to address health problems in the developing world. For instance, Golden Rice was developed to prevent Vitamin-A deficiency in the children of developing countries.
In both of these examples, the scientists had a socially-responsible motive for creating a GMO see Fig. However, it can be difficult to predict all the effects both good and bad of a new technological advancement. In order to decide for ourselves what the effects of GMO use have been, we need to look at the most unbiased source of information—the scientific literature.
Figure 1. The good and bad of two genetically modified organisms. Image by Hannah Somheygi. Herbicides are chemicals, often highly toxic, that are sprayed on weeds in order to kill them so that they do not compete with the desired crop for space and nutrients.
Some are selective for certain kinds of plants. Others, including Roundup, are nonselective, and if they are sprayed on both weeds and crops, they will kill both. Scientists thought that if the crops were resistant to Roundup, use of the herbicide would be more effective.
Spraying the whole field with Roundup would take less time and actually use less Roundup than spraying the weeds one by one. Using less herbicide in this way would be better for the environment as well. For these reasons, Roundup Ready corn and soybeans were created to be resistant to Roundup.
The chemical in Roundup that kills plants is called glyphosate. Glyphosate works by inhibiting the plant enzyme that helps make some of the amino acids protein building blocks that the plant needs to survive [3]. Roundup Ready crops contain a different version of this enzyme that is not blocked by glyphosate. Use of glyphosate-resistant crops was supposed to decrease herbicide use because less herbicide would be needed to kill the weeds, and to some extent, it has.
Based on national pesticide usage data and other previously published pesticide use data from a number a sources in the scientific literature, it seems that herbicide use has decreased. From to , use of herbicide-tolerant cotton reduced herbicide use by 6.
However, the liberal use of herbicides by farmers who grow herbicide-resistant crops has catalyzed the evolution of herbicide-resistant weeds. Since Roundup Ready crops were introduced in , at least sixty-four weed species have evolved resistance [5]. Because of herbicide-resistant weeds, farmers will now have to increase herbicide use, so the recent decreases will not last.
From these experiences, scientists have learned that engineering plants to be resistant to herbicides is not an effective long-term solution.
There is always room for improvement when new technologies are introduced, and GMOs are no different. One of the problems with selective breeding is that it can also result in traits that are not desired. Genetic engineering allows scientists to select one specific gene to implant.
This avoids introducing other genes with undesirable traits. Genetic engineering also helps speed up the process of creating new foods with desired traits. These concerns have thus far been unfounded. None of the GE foods used today have caused any of these problems.
They assess the safety of GE foods to humans, animals, plants, and the environment. Cotton, corn, and soybeans are the main GE crops grown in the United States. Most of these are used to make ingredients for other foods, such as:. The World Health Organization, the National Academy of Science, and several other major science organizations across the globe have reviewed research on GE foods and have found no evidence that they are harmful.
There are no reports of illness, injury, or environmental harm due to GE foods. Genetically engineered foods are just as safe as conventional foods. The US Department of Agriculture has recently started requiring food manufacturers to disclose information about bioengineered foods and their ingredients.
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