Frequently Asked Questions About GMOs
Jack Kittredge, NOFA/Mass policy director
Although NOFA/Mass is committed to organic methods, we feel that transgenic technology is such a threat to organic farming that we are happy to encourage the purchase of conventionally grown non-GMO products when organic options are not available or not practical. The following questions and answers may help you understand how to wisely select non-GMO products.
How can I determine if a product contains GMO ingredients?
If you are in doubt about a product, the surest way to find out is to have it tested. Testing destroys the material tested, thus if you test the entire product you have nothing left. So normally testing is done on a representative sample of the product.
Is there any way I, as a consumer, can get my food tested for GMOs?
There is a non-profit organization, called the Non-GMO Project, which has been set up by major natural food manufacturers and retailers for exactly this purpose. If a product bears the "Non-GMO Project Verified" label then:
- If the product contains ingredients for which there are commercialized GMO varieties (corn, soy, canola, cotton, etc.) those ingredients will have been tested and less than 0.9% of them come from GMOs, and
- If the product does not contain such ingredients then documentation and supply-chain verification has been done for what it does contain.
The Project does not itself do the testing. There are a number of ISO (International Organization for Standardization) certified labs which do that, and the sampler can select any they want.
What are the tests and how do they work?
There are currently two main types of tests. A PCR test (polymerase chain reaction) examines the actual DNA of the tested material, looking for indications of transgenic manipulation. An ELISA test (enzyme-linked immunosorbent assay) looks for the specific proteins that are the means by which the altered DNA carries out the effects the alteration seeks.
The PCR is right now more complex and expensive than the ELISA, but it is also more sensitive (it can detect GMOs down to 0.01% of material) and can be used to test for "any GMOs", It is able to do this because there are several markers that are used in almost all genetic engineering. Califlower mosaic virus is an example. It is used as a promoter and its marker is called 35S. If this is present, it is an engineered crop. Just as there are promoters for a gene sequence, there are also terminators that are generally used. These also are flags of GE. Kentucky blue grass, however, which was recently released, does not use 35S. (Test labs are trying to learn how it was engineered, which is public information, so it is available.)
ELISA tests are much easier to administer (some "strips" have been developed for common engineered proteins that can be used on-site by farmers or processors. Since ELISA tests require knowing the structure of the specific protein you are testing for, however, you cannot use this method to test for new, proprietary, or uncommon proteins. Testing is rapidly evolving, of course, and becoming more and more accurate and less expensive.
How large a batch of material is needed for a statistically valid result?
Generally, a PCR test can be valid for up to about 500 metric tons of corn, or 1000 metric tons of soy. Say a producer got a load of 1000 metric tons of masa flour from a miller who used 2000 metric tons of corn to produce that batch. In that case 4 tests would be necessary of different samples to statistically arrive at a 95% certainty (4 because there were 4 loads of 500 metric tons or corn kernels input. The actual sample size for such a test would be about 200 grams of masa flour.)
500 metric tons is a large amount for a small producer to buy at one time, so perhaps the miller would test the whole load with 4 samples and then store the flour in a fashion which can keep the identity of it protected and sell smaller batches with the paperwork showing it is tested.
Does batch size change with kind of material (e.g. seed versus ground meal), or type of source (e.g. corn vs. soy)?
Most types of crops would be valid to the 500 metric tons level, except soy, which is valid to 1000 m.t.
How is the sample taken, and how it is treated before testing?
There are careful protocols for this. It is usually taken by the person owning the batch at that point, but the Non-GMO Project, for example, requires the person be trained in sampling and storing and shipping the sample.
Once a product has been verified, what, if anything, might trigger retesting it later?
If there were any indication, either from previous dealings with that supplier or new information that such a procedure is suggested, new testing can be done. The Non-GMO Project does have a surveillance program, and random off-the-shelf samples are taken of products as well.
What are the costs involved for current PCR testing?
It costs between $200 and $400 to $500 a test, depending on details, such as whether it is a qualitative (yes/no meets thresholds) or quantitative (x% was found) test.
How long does it take from sampling the batch to determining the results?
Normally 3 to 5 days.
Much of the current end use of GMO corn and soy is as animal feed. Can GMO feeding be detected in the final meat, milk, eggs, fiber, etc?
No, it can't be detected with current methods. The best way to avoid GMO use in animal products you purchase is to look for verification done on the basis of documentation (how much feed did the farmer raise or purchase in the last year, how was it produced, is there evidence that enough non-GMO feed was raised or purchased to account for all the meat, eggs, milk, fiber, etc. the farm is marketing) and verifying this information by checking back up the supply chain. This is the kind of inspection and verification that takes place on certified organic farms, which are prohibited from using GMO inputs.
What innovations are happening in the science or engineering of GMO testing and what options might they open up?
There is a lot of interest in pushing the testing technology to be able to detect the fragments of DNA left in meat and milk and refined oils. That is possible, but the science is just are not there yet. Another problem is the use of stacked traits in crops. These are seeds that bear several different modifications at the same time. Each trait uses promoters and terminators and that confuses the situation if you are looking for a quantitative test result. A small percent of GMO ingredient, for instance, if containing a stack of 5 traits, might show a percent of GMO 5 times larger than is real.
What products does the Non-GMO Project verify?
It will consider any agricultural product for verification. This includes foods, animal and pet feed, natural fiber clothing, packaging material, biofuels, some personal care products, etc. There has been a surge in interest in verifying packaging, dinnerware, cosmetics, restaurant meals, etc. The Project's standards board is trying to come up with decisions on which thresholds to use for some of these items.
They are also getting a lot of interest from non-North American companies (South African, Italian, other European) interested in exporting to the US and Canada.
What foods can I buy without worrying about GMO ingredients?
Most fruits and vegetables in their natural state are still GMO-free. This is because no commercial GMO varieties have been developed for them yet, so there is no danger of contamination via pollen exchange, mislabeled seed, accidental mixing of seed at the farm, etc. Thus you can make salads, stir fries, soups, etc. starting with raw fruits and vegetables without worry. The primary exception to this is corn. Both sweet corn and field corn (cow corn) - but not popcorn -- have been engineered, and so the above kinds of contamination can occur. Other exceptions are papaya, zucchini, and summer squash (which have a few commercialized GMO varieties.)
The Non-GMO Project has tested "natural" products, believe to be from non-GMO seed, which came out 100% GMO. Organic crops generally test out at 1% or less, but they have found some much higher. Organic production still is a strong barrier to GMOs, according to the Project. With careful attention to control (large borders, seed testing, cleaning equipment rigorously, perhaps different treatment of crops from edge rows than inner rows), they feel that GMOs can be contained. If the seed is clean, less than 1% of contamination is likely to occur from wind pollination.
About 90% of all corn and soy grown in this country is now genetically engineered, however, and virtually all processed products involving several ingredients (frozen dinners, baked goods, beverages, snacks, etc.) have some amount of corn or soy as oils, sweeteners, or serving other functions. Unless the product is organic or Non-GMO verified, that corn and soy is almost certainly GMO.
Is organic certification a guarantee against GMOs?
GMOs are prohibited in organic production. Inspectors both visit the farm and pour over farm records to make sure they have not been used.
For plants, however, should non-GMO seed be planted and then during the flowering stage some GMO pollen blow in, the resulting seed (not stalks, leaves, roots, etc.) might thus have some GMO content. Corn, soy and canola are the best examples of this possibility. For products containing corn, soy or canola, thus, GMO testing is the best indicator of GMO presence or absence.
For animal products, testing is not available. Thus the work of organic inspectors in ascertaining that organic feed was used is your best guarantee that the resulting meat, milk, eggs, or fiber is GMO-free. Animal products labeled with the Non-GMO Verified logo also undergo careful inspection.
Where can I get products that don't contain GMOs?
Of course your surest and least expensive option is to get unprocessed foods. Your own garden, local farms, farmers markets, CSAs, and retailers carrying fresh produce are the best sources. If you want to buy processed foods, you need to find sources that carry either organic foods, or ones that are Non-GMO verified. Demand for both organic and Non-GMO verified food is rapidly growing and many stores now carry both.
Some natural and whole foods retailers are encouraging all the vendors in their stores to move to either organic certification or Non-GMO verification. As you begin to look for these foods you will be adding your own purchasing power to that of others and making such foods even easier to find over time.
How about feed for my pets or livestock?
There is a lively market for organic pet and livestock feed. You can find brands at many feed stores as well as natural food retailers. Or you can order organic feed on the internet if no one near you carries it. The market for Non-GMO animal feed is not as well developed yet. Undoubtedly some brands will be getting verified, but as of now your best choice is to find an organic brand you like.
This page was last modified on October 03, 2011 at 9:02:25 AM.
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