Answers to Your 7 Biggest GMO Questions

Get the facts before you join this controversial food fight.
Get the facts before you join this controversial food fight.

News flash: Your food might have been hacked. Back in 1994, the first genetically modified tomato hit supermarkets, and ever since, lab-altered food has been creeping onto America's plates. We get vegetable oils from plants tailored to produce pest-killing toxins, meat from animals raised on modified feed, and ice cream sweetened with pesticide-proof beet sugar. These days, about 70% of processed food on grocery store shelves contains at least one genetically modified ingredient.

You might or might not have realized you were so exposed to genetically modified organisms (GMOs), as the foods are known. If you haven't, it isn't surprising: Until very recently, there were no requirements for them to be identified in the U.S. But in May, Vermont became the first state to require labeling of GMO foods, and a couple of other states have passed preliminary measures.

Three out of four Americans would like GMO foods to be clearly labeled, reports a Rutgers University survey, even though 54% admit we know little or nothing about the technology. So let's figure out the real issues surrounding these so-called "Frankenfoods," and you can decide for yourself.

Related: What Do Organic Labels Really Mean?

1. What is a GMO?
Any food that's been engineered with DNA from another plant, animal, insect, or even bacterium. This can be done to food itself -- e.g., corn on the cob -- or to an ingredient in food, such as the corn in tortilla chips or cornstarch. Scientists implant useful genes from one living thing into another, usually with the goal of helping it resist threats. Some GMO corn, for example, contains a bacterial toxin that kills a voracious caterpillar known as the European corn borer. Ever heard of the weed spray Roundup? Scientists have created "Roundup Ready" soybeans, sugar beets, corn, cottonseed, alfalfa, and canola: The plants can tolerate high doses of the spray, allowing farmers to control weeds without killing crops.

Right now, GMO technology is used primarily in plants. Poultry and red meat may come from animals raised on genetically modified feed, but as of yet you won't find GMO animals for sale at your local butcher shop. (But salmon with an extra growth hormone gene may soon appear at the seafood counter. The fish reach full size in about half the time of unaltered salmon.)

2. Can GMO foods harm my health?
This is a contentious issue, but so far there's no conclusive evidence of harm -- though there have been few long-term studies on safety. While one, a 2012 French study, suggested that certain GMOs caused cancer in rats, it was later retracted by Food and Chemical Toxicology, the journal that had originally published it; after further review, the editors decided the research was inconclusive. In another high-profile case, a report claimed that GMO foods could lead to sensitivity and intolerance to gluten, but the Celiac Disease Foundation counters that there's no scientific evidence for a link between GMOs and gluten-related disorders (gluten intolerance is a hallmark of celiac disease).

3. What about food allergies?
Another topic of debate concerns whether or not GMOs will trigger allergies. "There's not a shred of proof," says Michael F. Jacobson, Ph.D., executive director of the Washington, DC-based Center for Science in the Public Interest (CSPI), a nonprofit independent watchdog that focuses on food safety, health, and nutrition issues. The group, a frequent critic of the food industry, doesn't see any reason to worry about current GMO foods. "The crops are tested for possible allergenicity before they're marketed," explains Jacobson. "The tests are not perfect, but they would identify most allergens."

Related: Here's What Would Happen to Your Groceries if Bees Went Extinct

4. So is there any reason to worry about GMOs?
Yes. Plenty of reasonable scientists feel that the safety of GMOs has not been established, and better long-term research needs to be done. Even CSPI thinks the U.S. government's regulation of GMOs could be improved. "The process is not as rigorous or independent as it should be. The FDA often does not get all the data to perform a fully informed safety review," noted Gregory Jaffe, director of the CSPI Biotechnology Project, in a 2012 report.

"The jury's still out on GMOs," says Miriam Arond, director of the Good Housekeeping Research Institute. "The health effects of their use in agriculture haven't been sufficiently studied."

Even the issue of allergies remains an open question for some. "There have not been adequate studies to put to rest all the concerns," says Rebecca Spector, West Coast director of the nonprofit Center for Food Safety. "With no labeling, there's really no way to track whether people are experiencing adverse effects."

5. How can I avoid GMO foods?
Right now, the only labels you can trust either say "Organic" or feature the "Verified" seal from a nonprofit group called the Non-GMO Project. (You might see "GMO-Free" and "Non-GMO" labels on products, but these terms do not have an agreed-upon definition or standard.) Recently, Whole Foods announced plans to label GMO products; Chipotle and Ben & Jerry's are in the process of eliminating GMOs from their offerings, and Target is removing them from its Simply Balanced brand. Of course, you can find plenty of foods that aren't GMOs, but knowing what's what can be tricky. (Strawberries, bell peppers, and tomatoes? Non-GMO for now -- those modified tomatoes were taken off the market. Papayas and zucchini? Possibly GMO.)

Related: Pesticide Alert: Your Guide to Shopping the Produce Aisle

6. How do GMOs affect the environment?
There's ongoing, intense debate over whether GMOs are harmful or helpful. One ominous sign: A recent Washington State University study found that weeds are developing resistance to Roundup, and farmers have had to up their use of weed killers by 25% per year. Meanwhile, Western corn rootworm -- a major pest -- is becoming resistant to some GMO corn. "With the increased use of pesticides, there's potential for water contamination and residues on foods," notes Rebecca Spector, West Coast director of the Center for Food Safety."GMOs were touted as a way to reduce pesticide use, but they really haven't."

7. Is there a way to know if foods have GMOs?
Food labeled "Organic" contains no GMO ingredients, but how can you tell if food has GMOs? You can't: While GMO foods must be clearly marked in 64 countries, the U.S. isn't among those, even though about 40% of GMO crops are grown here. Vermont's mandatory-labeling law is set to start in 2016. At press time, only Connecticut and Maine had similar laws; theirs go into effect only if surrounding states follow suit.

"In an age of transparency, consumers want to know how and where products are manufactured. It's not necessarily that GMOs are bad for you, but people are entitled to make informed decisions," says Miriam Arond, director of the Good Housekeeping Research Institute. Good Housekeeping supports labeling of genetically modified foods and hopes the growing focus on GMOs will spark more research about their effects.

-Sari Harrar

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