TABLE 1.

Consumer knowledge of GMOs¹

Reference	Population	Sample size2	Main findings
Hallman et al., 2004 (12)	US consumers	N = 1201	• 48% know that GMOs were available in supermarkets
			• 31% believe that they have most likely consumed a GM product
		n = 600	• Limited self-rated knowledge about GMOs
			• 48% know very little
			• 16% know nothing at all
			• 30% know a fair amount
			• 5% know a great deal
Hallman et al., 2013 (13)	US consumers	N = 1148	• 43% know GM products are sold in supermarkets
			• 26% believe they have probably eaten a GM food
			• 54% know very little or nothing at all about GMOs
			• 25% have never heard of GMOs
		n = 491	• 59% know that GM soybeans are sold in US supermarkets
			• 56% mistakenly believe that GM tomatoes are sold
			• 55% mistakenly believe that GM wheat is sold
			• 50% mistakenly believe that GM chicken is sold
Aleksejeva, 2014 (14)	Latvian consumers	(not reported)	• 50.0% believe that an ordinary tomato does not contain genes, but a GM tomato does.
			• 68.2% believe that GM food genes can get into human generative cells and can be passed to future generations
			• 40.9% believe that by eating a GM tomato, a person’s genes could also be changed
			• 90.0% know that insertion of a fish gene would not make a tomato taste fishy
			• 95.5% know that both non-GM and GM foods could cause toxic or allergic reactions
			• 22.7% self-rate their knowledge as 6 out of 10
			• 77.3% self-rate their knowledge as 5 out of 10 or lower
Turker et al., 2013 (15)	Turkish nursing students	N = 346	• 32.4% correctly identified soy, corn, and cotton as the most cultivated GMOs
			• 58.4% incorrectly identified tomatoes, peppers, and zucchini as the most cultivated GMOs
			• 5.5% incorrectly identified potatoes, wheat, and eggplant as the most cultivated GMOs
			• 77.7% believe that production of GM food is risky for all living things
			• 72.8% believe that it could be dangerous to consume GMOs
			• 82.9% felt that society was not adequately informed about GMOs
			• 16.8% felt that they themselves had sufficient knowledge about GMOs
Jurkiewicz et al., 2014 (16)	Polish students	N = 500	• 57.4% of participants doubted that studies of GMO health effects are reliable
			• 64.1% stated that media reports on GMOs are untrustworthy
			• 59.9% had negative opinions of GM plants in the food production system
			• Self-reported knowledge regarding genetic modification is as follows:
			• 81.4% report either, “I know very little about it” or “unlikely I know”
			• 16.8% report knowing rather a lot
			• 1.8% report knowing a lot
McGarry et al., 2012 (17)	US, Italian, and Japanese food shoppers	N = 550 US consumers, 200 Italian consumers, and 128 Japanese consumers	• 40.9% of US consumers were somewhat or very familiar with GMOs
			• 28.0% of Italian consumers were somewhat or very familiar with GMOs
			• 33.3% of Japanese consumers were somewhat or very familiar with GMOs
			• Cultures varied in their ranking the most desirable characteristics of foods:
			• US consumers rated “GMO-free” as the 17th most important characteristic on their list
			• Italian consumers listed “GMO-free” as the 5th most important characteristic
			• Japanese consumers listed “GMO-free” as the 7th most important characteristic

¹GM, genetically modified; GMO, genetically modified organism.

²N = total sample; n = question-specific sample.