What Are GMO Foods, and Are They Dangerous?

Are genetically modified "Frankenfoods" harmful to consumers or do they help build our food supply? Expert Chris Woolston weighs in on the food fight.

By Chris Woolston
Also published in Reader's Digest Magazine January 2014

cornAdam Voorhes

The loudest public food fight right now is about GMOs, or genetically modified organisms. Scientists add genes to corn, soybeans, and other plants, usually to protect the crops from insects or herbicides.

Proponents say the genetic tinkering makes crops easier to grow and cheaper. But many consumers and food-safety watchdogs worry that GMOs pose an unnatural threat to our health and the environment. Opponents say that GMOs have been linked to depression, allergies, infertility, and even cancer.

Although GMOs have been in our food supply for 20 years, the controversy has moved to center stage. Recent documentaries and experts on The Doctor Oz Show have fanned the flames. About 75 percent of consumers say they are concerned about the safety of genetically modified foods, according to a New York Times survey. Maine and Connecticut recently passed bills requiring labeling of all foods made with GMOs; many other states are considering mandatory labeling. The European Union already requires labeling, and several countries, including France, have banned the planting of genetically modified crops. So are GMOs safe—or should you avoid them at all costs? Here, a look at the evidence.

What You’ve Heard
Roughly 90 percent of the corn, canola, soybeans, and sugar beets grown in this country have bits of DNA that originally came from a lab. The soy in some multigrain breads, the canola in margarine, and the corn syrup in everything from ketchup to soda are likely genetically modified. Unless you’ve been eating only foods labeled 100 percent organic—which must be GMO-free—you probably have GMOs in your system now.

In a big red-flag–raising study, French researchers reported last year in Food and Chemical Toxicology that rats developed huge tumors after living on genetically modified corn for two years. “Genetic engineering can have unintended consequences,” says Bill Freese, science policy analyst for the Center for Food Safety. Artificial genes force plants to produce unnatural proteins, he says, and no one knows how those may affect human health.

… But Not So Fast
Scientists immediately criticized the French study (and it was ultimately retracted by the journal in November 2013.) For one thing, the types of rats used in the study were highly prone to cancer, so it was predictable that some would develop tumors after eating GMOs, notes Nina Fedoroff, a professor of biology and life sciences at Penn State University. She adds, “We’ve eaten these foods for 20 years and aren’t walking around with giant tumors.”

Hundreds of other studies have found no trouble with GMOs, says Ruth MacDonald, professor and chair of food science at Iowa State University. After looking at more than 130 research projects—including animal studies and searches for known toxins or allergens in GMO foods—the European Union concluded that there’s nothing especially risky about them.

In September, the editors of Scientific American denounced the efforts to label GMO foods, stating that there’s no proof that so-called Frankenfoods can endanger people’s health. Adding genes to crops isn’t any more dangerous than traditional breeding, which farmers have done for thousands of years, the American Association for the Advancement of Science declared in 2012. Old methods of modifying crops mixed tens of thousands of genes with unpredictable results. The fact that scientists can now insert single genes into corn or soybeans shouldn’t raise any new alarms, says Fedoroff.

The Bottom Line
There doesn’t appear to be a scientific reason to ban GMO foods from your pantry to protect your health. But it is healthy to limit your intake of the processed foods that often contain them. And don’t assume that GMO-free packaged food is necessarily healthy. Organic cookies can still contain too much sugar or salt.

  • Your Comments

    • concerned food eater

      yeah, and lead in gas was a great idea and glass in macadam was going to make roads last forever. I like the long road to progressive food production – they also still have hundreds of chemicals in foods that are hurting many people sensitive to them, or just the general population in general – kinda like margarine being forced on everyone, esp doctors. now we have nano technology invading our food chain, sometimes just to make yogurt and milk products whiter!!! metals are being incorporated into our foods, and once again, most the population is ignorant of this added step in our foods! plus, making GMO impervious to pesticides means a produce bathed in pesticides is being consumed by the population – the arrogance and ignorance of making the population lab rats in a food experiment for profit is obscene and unforgivable. I want full disclosure on all the food ingredients and processes used – I trust no manufacturer, and even fresh produce any longer. We are all chumps if we do not demand full disclosure, and preserve our right to be fully informed as well as preserving our right to choose with our dollars and daily health concerns. welcome to the 21st century and men who love playing gods for profit. Food is sacred and pure – stop screwing with mother nature in such an unnatural way – have we learned nothing from all the other follies? Are all our rights and dignities to be trampled on in such a covert and manipulative way? We all will be responsible for being irresponsible, one way or another.

    • Karl Kuhlmann

      I worked with Sprague-Dawley rats when I was working in toxicology. They seem to get cancer by walking across the room. I have seen data where dimes apparently gave them cancer, as did distilled water. I wouldn’t trust any cancer data from studies that used Sprague-Dawley rate.

      Mary Shelley, James Whale, and the Hammer brothers have a lot to answer for.

    • Benz

      It is misleading to label GMOs as synthetic because there is nothing synthetic about the genes being inserted or its product/s. These genes are specifically selected and targeted for insertion from another same or different organism because prior knowledge of their biological importance is known. It would help to know that more than 8% of human genome consists of viral DNA, accumulated over millions of years of evolution enabling us to exist, yet we don’t feel so synthetic. GMOs are made to serve mankind, not to harm. So, scientifically validated GMOs, esp. crops, should not be persecuted based on mere prognostic fears.

    • Morwalk

      I love it when they say “there’s no proof” that something is dangerous. They have not convinced me that it isn’t dangerous.

      • Karl Kuhlmann

        You probably don’t know enough formal logic to realize it is impossible to prove a positive. To prove a negative, all you need is one case. To prove a positive, you need to prove any and all possible cases. So, you need to buy only “organic” food, or imagine that what you see at the grocers is not GMO.

    • DonnaSC

      If the GMO corn were grown without Roundup, that would be fine. But the Roundup is sprayed on the corn and gets in the kernels. The corn might be okay, but the Roundup in it is poison.