Students having a snack, drinking a soda or eating a cheeseburger are likely consuming genetically modified products, whether they know it or not.

Genetically modified organisms, or GMOs, are produced by manipulating the DNA of a plant or animal in some way. An example is transferring a gene from one organism to another to produce favorable traits, such as insect resistance and longer shelf life.

As students guzzle down soft drinks, many don’t realize soda, like many processed foods and beverages, may contain ingredients that have been genetically modified.

“Some colas are made with high-fructose corn syrup that can contain genetically modified corn,” said Clark Ford, associate professor of food science and human nutrition.

Studies done by the Grocery Manufacturers of America estimate as much as 80 percent of processed food in the United States contains genetically modified ingredients.

“The vast majority of processed foods do contain some ingredients derived from soy and corn. Much of our soy and corn is genetically modified,” Ford said.

Foods containing corn or soy oils have a high likelihood of containing genetically modified ingredients, Ford said.

Diane Birt, chairwoman of food science and human nutrition, said soy products are very common in processed foods. Studies conducted in the food science and human nutrition department found it is difficult to keep soy products out of one’s diet because of their high prevalence in the marketplace, she said.

Genetically modified food: not just corn and soybeans

Corn and soybeans aren’t the only sources of genetically modified ingredients. Other genetically modified crops grown in the United States include cotton, canola, squash and papaya.

Genetic modification does not stop at crops, said Pat Murphy, university professor of food science and human nutrition. Murphy said the enzyme chymosin used to make cheese has been genetically modified since the early 1990s.

“People have been eating that kind of GMO, if they eat cheese, for a long time,” Murphy said.

She said many consumers do not realize products such as cheese contain genetically modified ingredients.

The enzyme used to make cheese that is now genetically modified can also be found in the stomachs of calves.

“It’s either kill the baby cow, or use the genetically engineered chymosin to make your cheese,” Murphy said.

Ford said it is difficult to detect which products contain genetically modified ingredients and to what extent the GMO ingredients were used.

“Food processors generally don’t distinguish between GMO and non-GMO corn and soybeans,” he said.

Birt said consumer detection of genetically modified ingredients in foods is not always feasible because ingredients that are genetically engineered are not “significantly different” from foods produced through traditional methods. However, some companies choose not to use biotechnology crops in their processing and take special measures to avoid using these products, she said.

“The company would have to pay farmers a premium to grow non-GMOs and keep [crops] segregated,” Murphy said.

It is difficult and costly for companies to avoid genetically modified crops, she said. Eating organic foods is one of the only ways to consume foods without genetically modified ingredients; organic food associations define these products as GMO-free, Murphy said.

So how do non-organic consumers know if what they are eating has been genetically modified? Chances are, they don’t.

GMO foods: more than you would expect

The Food and Drug Administration currently does not require labeling of genetically modified foods and ingredients, according to the Biotechnology Information Series. Labeling that states whether a product contains GMO ingredients can be done voluntarily by the company.

Due to the high usage of corn and soy ingredients in processed foods and the absence of labeling and tracking regulations for genetically modified ingredients, people regularly consume genetically modified foods and may not realize it.

For example, the long-time collegiate staple food, frozen pizza, contains corn syrup, corn oil, soybean oil and cottonseed oil, all of which may be produced from genetically modified crops.

Ingredients such as soybean oil and corn oil are found on ingredient labels for a host of other processed foods such as potato chips, cereal, some fruit juices and Campbell’s Soup. Even the legendary peanut butter and jelly sandwich is not GMO-free. In fact, all the basic elements of this lunchbox classic could be genetically modified at some level. Some bread contains both corn syrup and soybean oil, which may be produced with genetically engineered crops. Peanut butter also contains soybean oil and jelly is made using high fructose corn syrup.

After making it through a long day of class, thanks to their trusty caffeine-loaded, genetically modified soda, students may feel the need to unwind at their favorite drinking establishment. However, a trip down Welch Avenue will not necessarily be GMO-free either. Many companies use corn in beer brewing. According to the Miller Brewing Company, this is done to give the beer a “milder and lighter-bodied flavor.”

Students who unknowingly consume genetically engineered foods are not alone. A poll conducted by the Pew Initiative found only 24 percent of those surveyed believed they had eaten genetically modified food. In the same poll, 50 percent of respondents said it was “unlikely” that they would eat genetically modified foods.

Steve Sapp, professor of sociology, said Americans may be oblivious to the prevalence of genetically modified ingredients because there has not been great public controversy in the United States concerning GMOs.

“Students would probably be more aware that [GMOs are] out there because they hear about it in their classes,” Sapp said.

Tyler Lewis, sophomore in horticulture, said he knew he had eaten foods with genetically modified ingredients.

He said he did not feel there were any immediate, negative health effects caused by eating GMOs but he was unsure of long-term effects.

“I don’t think GMOs have been around long enough to know if there’s a possibility of carcinogenic effects,” Lewis said.

Murphy said the FDA recently ruled that cloned animals could be used as a meat source as long as they were healthy. These products have not yet hit the shelves, but she said she expects the introduction of these meats to be one of the hot topics among activist groups.