Glucose syrup is commonly referred to in the US as corn syrup, due to corn being the major ingredient used as starch in its production. It's employed mostly as a sweetener or thickener, which is why it's one of the principal ingredients found in candy and other unhealthy treats. But did you also know that it's particularly common for corn to be grown by means of genetic engineering? Re: It's totally unnatural and won't do your body any favors.