By Reed Vawter, M.S.
Brigham and Women's Hospital
Consumers may not be aware that genetically modified foods are part of the U.S. food supply. Many experts predict this will change as people become more aware of the economic, environmental and health consequences of these crops. Here's more about the science behind them so you can make an informed decision about what to put on your family's plate.
What Are Genetically Modified Foods?
Genetically modified foods come from organisms that scientists have created by injecting foreign genes into them. They are called GMOs or genetically modified organisms. (They are also known as biotech, bioengineered and genetically engineered organisms.) By changing their genetic material, scientists give plants or animals new characteristics.
Examples of genetically modified plants include soybeans, corn, cottonseed oil and canola oil. They are typically modified to tolerate herbicides and pesticides, be more resistant to pests or even produce their own insecticides.
Many other countries have been cautious about allowing GMOs into the food supply and require them to be labeled. The U.S. Food and Drug Administration, however, does not require that food from genetically modified animals or plants be labeled as such, despite studies showing that 89% of Americans are in favor of labeling GMO-containing foods.
Biotechnology companies argue that GMOs are the future of food, suggesting they will help feed a hungry world, are better for the environment and are no different than natural foods. But recent studies are questioning some of these claims.
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Do GMOs Increase Crop Yields?
Many GMOs were created with the intent of growing more food per acre. But a recent review by the Union of Concerned Scientists concluded that "after more than 20 years of research and 13 years of commercialization in the United States ... genetic engineering has done little to increase overall crop yield." Instead, the report says, traditional plant breeding and other improvements in farming have proven far more effective.
GMOs may even put crops at risk for greater catastrophic failure. They encourage monocropping, the practice of growing the same crop year after year on the same land, without rotating other crops through. This reduces biodiversity, which can leave crops more vulnerable to particular pests and diseases. This occurred with genetically modified corn in Africa and cotton in India. Traditional farming practices promote biodiversity, which strengthens the overall crop.
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Are GMOs Better for the Environment?
GMOs were originally expected to need fewer chemicals to grow. But a recent report from The Organic Center shows that GMO crops actually have increased herbicide and pesticide use. In fact, "an additional 318 million pounds of pesticides were applied due to the planting of genetically engineered crops from 1996 to 2008." According to the data, GMOs are actually worse when it comes to releasing chemicals into our environment.
It is also difficult to predict the effect of these newly introduced genes from GMOs on the larger environment. Pollination from neighboring crops makes it difficult, if not impossible, to keep non-GMO crops free from contamination. The modified DNA can also be transferred through organisms in the soil. A recent Canadian study found bioengineered genes present in many bacteria and organisms living in fields planted with genetically engineered corn. While the long-term effects of this are unknown, there is concern that we may be unintentionally transferring DNA to other species.
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Are They Safe To Eat?
The biotechnology industry points to over a decade of humans eating GMOs with no direct link to negative health effects. But opponents cite mounting evidence against GMOs along with the fact that there is no well-designed, long-term safety testing. This is what is needed to truly ensure safety.
A recent study published in the International Journal of Biological Sciences highlights this concern. The authors concluded that consumption of GMO corn by rats was associated with increased organ failure. They found "a clear negative impact" on the kidneys and livers of rats that consumed genetically modified corn for just 90 days.
The American Academy of Environmental Medicine (AAEM) has also taken an aggressive position against genetically modified foods. It states that they "pose a serious health risk in the areas of toxicology, allergy and immune function, reproductive health, and metabolic, physiologic and genetic health and are without benefit." The AAEM recommends that people avoid genetically modified foods, that they are labeled, and that studies are done to establish their long-term safety.
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So What's a Consumer To Do?
With all this information, it can be confusing to decide what to eat. The biotech industry paints a glowing picture of their products. But we should be skeptical, especially considering reports that scientists are not being given unrestricted access to seeds for independent research.
Luckily, there are steps you can take to fill your plate with truly natural foods that do not contain genetically modified ingredients.
- Choose organic – Organic products are the only regulated label that prohibits the use of genetically modified foods. Selecting 100% organic items is the surest way to avoid genetically modified products in the United States.
- Choose 100% grass-fed beef – Most beef is raised eating GMO feed. Choosing 100% grass-fed beef ensures that you are not indirectly consuming GMOs from the meat you eat.
- Look for foods that don't use GMOs – Labeling foods as containing genetically modified ingredients is voluntary and uncommon. However, some manufacturers include information on their labels to indicate that they actively avoid genetically modified ingredients. Choosing foods from these companies can send the message that GMO-free food is important to you. Look for "non-GMO," "Made without genetically modified ingredients," or some other statement on the label that there are no ingredients that were produced using biotechnology or bioengineering.
- Learn how to identify the most commonly used genetically modified ingredients in processed foods: corn, soy, cottonseed and canola oils. Use the Non-GMO Shopping Guide to help you shop smarter.
- Buy fresh and local – Local foods come from small farmers who are less likely to use GMOs. If you purchase from a farmer's market, you'll even have the chance to ask them!
Ultimately, you have the right to choose the food you want to eat. Biotechnology corporations and agricultural giants have quietly placed GMOs in many products in your shopping cart, without your input. It's time for that to change. By becoming more aware of GMOs, you will be able to make smart choices about what you put on your family's dinner table.
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Reed Vawter is currently a dietetic intern at Brigham and Women's Hospital. He received his M.S. in Nutrition from Bastyr University.