Food labeling is a hot topic, especially the pros, cons, and ethics of labeling items that contain genetically modified organisms (GMOs).

Citing a lack of evidence about the adverse effects of GMOs, The American Medical Association has sided with the U.S. Food and Drug Administration, saying that labeling GMOs is unnecessary. They say they've found no “material differences” between the bioengineered food and traditionally grown plants. Both organizations favor voluntary, rather than mandatory, GMO labeling.

While food labeling in the U.S. is primarily determined on a state-by-state basis, Whole Foods Market—the seventh largest grocery store chain in the country—recently stated that its suppliers must label all foods containing GMO ingredients by 2018.

So, how much does food labeling affect a person’s buying and eating habits? 

For the majority of people, not very much; it’s mostly in our heads until it’s time to pull out our wallets.

‘Organic’ Foods and the Health Halo

Researchers at Cornell University’s Food and Brand Lab wanted to test the “health halo effect,” or how much people overestimate the health advantages of a food based on its label. 

They recruited 115 mall shoppers in Ithaca, N.Y., to evaluate six food samples: two kinds each of cookies, potato chips, and yogurt. Some were labeled “organic” while others were labeled “regular,” even though all of the foods were identical and all were organic.

The majority of participants said that the foods labeled "organic" were more nutritious, lower in fat, and higher in fiber than the "regular" foods. Participants also said they were willing to pay up to 23.4 percent more for the food labeled "organic."

However, people who often buy organic foods, read food labels carefully, and recycle more were less likely to be swayed by the halo effect.

“This underscores the idea that the health halo effect is primarily driven by automatic processing based on heuristics (experience-based learning),” researchers wrote. Their study was published this week in the journal Food Quality and Preference.

People Buy ‘Frankenstein Food’ Even When They Say They Won’t

While most people say they prefer organic foods to GMOs, what they say they’ll buy and what they actually purchase can differ, especially when price is a factor.

A New Zealand study published in 2011 in the journal Science Communication examined the buying habits of people in six countries: Belgium, France, Germany, New Zealand, Sweden, and the U.K.

Europeans, by and large, are more skeptical of GMOs, and the E.U. has strict regulations on food products, including mandatory labeling of GMO items, according to the Council on Foreign Relations. The European press often refers to GMOs as “Frankenstein foods,” and some countries ban GMOs entirely.

Street-side fruit stalls were set up in each country and researchers gave people the option to choose among organic, low residue, and GMO items. Researchers also sent out paper surveys to see what options participants said they would buy.

On paper, New Zealand and Swedish customers preferred organic produce, even if the cost was 15 percent higher. However, at the food stalls, they bought GM-labeled fruit more often. Overall, GMO fruits were the first or second most popular choice in three of the five European countries, despite being least popular in the surveys.

After buying the fruit, 100 participants were immediately surveyed again and told researchers that price was an issue that affected their decisions. When it came down to the bottom line, many customers checked their moral reservations at the door.

Social Influence Affects Shopping Choices

“A person may be more likely to choose a cheaper, GM product if they believe no one is watching, but in a survey situation, there is a greater desire to make a socially acceptable choice,” the New Zealand researchers concluded.

Scientists said that GMO foods can be made more socially acceptable, so long as their advantages—lower prices and lack of pesticide residue—are clearly labeled and explained.

In the U.S., and elsewhere, the debate rages on.

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