Glucose syrup and corn syrup are naturally derived added sweeteners. Corn syrup can be a type of glucose syrup, but not all glucose syrup is made from corn. Liquid glucose can be derived from many plants, but is typically made from either corn or wheat.
Natural Versus Added Sweeteners
Sugars are everywhere. These carbohydrates occur in a variety of foods, including fruits, vegetables, dairy, juices, desserts and beverages. Commonly consumed sugars include fructose, galactose, glucose, sucrose, lactose and maltose.
Of course, sugars aren't all the same — some are natural, while some are added. While the sugars in your fruits, vegetables and most dairy products are likely to be natural, most desserts, candies and drinks (including many juices) contain added sugars.
Although naturally occurring sugars are considered healthy, added sugar consumption should be limited. The Food and Drug Administration recommends consuming no more than 10 percent of your daily calories (the equivalent of about 200 calories) from added sugars, but other authorities recommend less. The American Heart Association says that men shouldn't consume more than 36 grams (150 calories) of sugar per day, while women should not exceed 25 grams (100 calories).
Added sugars, like glucose syrup, corn syrup, dextrose, honey, malt syrup, maple syrup and molasses, are all examples of the types of sweeteners you need to avoid. Excessive consumption of added sugars can contribute to weight gain. According to the Mayo Clinic, excessive sugar consumption can also increase your triglyceride levels and risk of cavities.
Read more: The 10 Best Foods to Beat Your Sugar Cravings
What Is Glucose Syrup?
Glucose syrups can come from a wide range of fruits and vegetables. For example, high-glucose foods include grapes, apricots, cranberries, jackfruit and plantains, according to the USDA. Technically, glucose syrup could be produced from any of these foods. However, the average glucose syrup product in your supermarket is more likely to be made from corn or wheat.
Making glucose syrup requires the production of starch first, regardless of your starting material. The starch needs to be broken down and the water evaporated off before you can obtain glucose syrup.
As a liquid, glucose is used in a variety of products. You can find it in many baked goods, candies, jams and ice creams. Glucose is even used in certain pharmaceutical products, like cough drops.
Glucose syrup can improve a variety of culinary properties in foods, like texture and volume. It can also improve the gloss and shine of your macaroon or icing. However, it isn't sweet enough to act as a stand-alone sweetener. Liquid glucose is most often used alongside sugar.
Although it may seem strange to combine different sweeteners, glucose syrup can be very useful. It's able to prevent baked goods from drying out and ice creams or jams from crystallizing, thereby improving foods and their shelf lives.
Corn Syrup Versus Glucose Syrup
Like other fruits and vegetables, corn has naturally occurring sugars. Corn syrup is considered a natural sweetener, but it is not a naturally occurring sugar. This product is an added sugar that's made from corn starch, according to the Food and Drug Administration (FDA).
Corn starch is essentially made from giant chains of glucose. When broken down into individual glucose molecules, the resulting product is liquid corn syrup. Since starch is glucose, corn syrup is 100 percent glucose, too. Consequently, some glucose syrup products may actually just be corn syrup.
You're likely also familiar with products like high-fructose corn syrup. This product is a combination of both glucose and fructose. According to the FDA, high-fructose corn syrup products contain either 42 or 55 percent fructose. The remainder of these products is still just glucose and water. Notably, high-fructose corn syrup is not considered the same as glucose syrup.
Read more: The Ultimate Guide to Natural Sweeteners
Corn and Glucose Syrup Consumption
A standard serving of corn or glucose syrup is about a tablespoon (19 to 20 grams). Despite the difference in sugar content between corn syrup and high-fructose syrup, there's not much difference in their calories or sugar content. The USDA reports that a tablespoon of corn syrup has 57 calories and 15.5 grams of sugar, while a tablespoon of high-fructose corn syrup has 53 calories and 14.4 grams of sugar.
Although glucose syrup products may be made from corn, these products don't always have the same calories or sugar content as corn syrup. In fact, glucose syrup may have a lot more variability. For example, a tablespoon of Queen glucose syrup has 318 calories and 28 grams of sugar.
Most people could consume about 2 tablespoons of corn syrup products in a day and still be within their recommended maximum consumption for sugar. However, given the variability of these products, always check the nutrition facts first. A tablespoon of Queen glucose syrup would be far more than the maximum amount of sugar you should consume on a daily basis.
Safety of Glucose Versus Fructose
However, as an added sugar, fructose products have been associated with a wide range of negative health effects. According to a June 2015 study in the American Journal of Clinical Nutrition, products with high-fructose corn syrup can increase your risk of cardiovascular disease.
A May 2018 review in the Journal of Hepatology also stated that products like high-fructose corn syrup can increase the risk of liver problems, resulting in conditions like non-alcoholic fatty liver disease and non-alcoholic steatohepatitis.
A March 2013 review in the journal Advances in Nutrition reported that many of the detrimental effects associated with added sugars are due to fructose, rather than glucose. This means that when you're choosing between glucose syrup, corn syrup and high-fructose corn syrup, either glucose syrup or pure corn syrup are healthier choices.
That said, all added sugars are bad in excess. An April 2014 study in JAMA Internal Medicine reported that regardless of their form, excessive consumption of added sugars can increase the risk of obesity, Type 2 diabetes, hypertension and cardiovascular disease.
- Advances in Nutrition: "Energy and Fructose From Beverages Sweetened With Sugar or High-Fructose Corn Syrup Pose a Health Risk for Some People"
- JAMA Internal Medicine: "Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults"
- Journal of Hepatology: "Fructose and Sugar: A Major Mediator of Non-Alcoholic Fatty Liver Disease"
- American Journal of Clinical Nutrition: "A Dose-Response Study of Consuming High-Fructose Corn Syrup–Sweetened Beverages on Lipid/Lipoprotein Risk Factors for Cardiovascular Disease in Young Adults"
- Queen: "Glucose Syrup 500g"
- USDA: "Basic Report: 19351, Syrups, Corn, High-Fructose"
- USDA: "Full Report (All Nutrients): 19349, Syrups, Corn, Dark"
- U.S. Food and Drug Administration: "High Fructose Corn Syrup Questions and Answers"
- Starch Europe: "Glucose Syrup"
- MyFoodData: "200 Vegetarian Foods Highest in Glucose"
- Mayo Clinic: "Added Sugars: Don't Get Sabotaged by Sweeteners"
- American Heart Association: "Added Sugars"