BRAVE NEW NATURE
A Nation of Lab Rats
Is genetically engineered food bad for you? Maybe. Maybe not.
by Barbara Keeler
If it’s true that you are what you eat, now would be the time to start scrutinizing the fine print. Just five years after genetically engineered foods were quietly introduced into the marketplace, gene-manipulated soy, papaya, yellow-neck squash, canola, potatoes, tomatoes, and dairy and animal products are on the tables of consumers, with another hundred or so, including wheat, expected soon. According to most estimates, 60 to 70 percent of all processed foods contain genetically modified ingredients.
But there is no fine print. Food regulations in the United States don’t require segregation or labeling of genetically engineered products. The Food and Drug Administration presumes that genetically engineered foods are substantially the same as their unmodified counterparts. But Health Canada (the FDA’s Canadian equivalent), the UN Food Safety Agency, and the United Kingdom’s Ministry of Agriculture have all questioned the safety of certain genetically engineered foods, especially dairy products from cows treated with recombinant bovine growth hormone, or rBGH. Last year, the EU declined to approve Monsanto’s Roundup Ready corn for human consumption because of concern about potential allergic reactions. Roundup Ready corn and soybeans are ubiquitous in the U.S. food supply, despite Monsanto’s own study for the FDA, which revealed large differences in nutrients and allergens between its modified and unmodified soybeans.
To understand the potential problems, you first have to understand the process by which geneticists hope to imbue a living organism with new characteristics, such as herbicide resistance. Scientists pluck a gene from another species (a “transgene”) that carries the desired trait. But the transgene does not travel alone. It generally rides in on a “truck” of bacterial DNA, loaded with baggage and sometimes unsuspected stowaways. Even if the transgene comes from a related plant species, bacteria, virus, and antibiotic-resistant genes are usually packaged in as delivery systems, “on switches,” or markers.
Whether transgenes are introduced into a cell of a host plant using bacteria or a “gene gun” (a process in which gold or tungsten micro-particles are coated with transgenes and then fired into targeted cells or tissues), they cannot be directed to a specific location on the host chromosomes or even to a specific chromosome. Incorporation into the host DNA is more or less a crapshoot, and only a small percentage of cells end up with the transgenes. To figure out what’s ended up where, scientists link marker genes that are resistant to antibiotics or herbicides, then kill off all cells except those with the resistance markers and allow the transformed cells to grow into intact organisms. Voilà, a pest-resistant zucchini. Well, maybe--and maybe things unexpected as well.
Without segregation of genetically engineered products and post-market monitoring, the long-term impacts on human health of, for example, the cauliflower mosaic virus (a virus used to assist the process as a “promoter”) are impossible to monitor. But we’ve already had warnings of genetic engineering’s potential impact on antibiotics resistance, naturally occurring allergens, and healthy human cells, some of them from the FDA’s own literature. For example:
As long as genetically engineered foods remain largely unregulated and products unlabeled, the causes and effects of those abnormalities may remain a mystery. The only comprehensive experiments may be under way at your dinner table.
Barbara Keeler writes about health, environmental, and regulatory issues.Up to Top
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