Fructose is a simple sugar, or monosaccharide, commonly referred to as “fruit sugar.” It is found in various plant sources, including fruits, vegetables, and honey, and is also a component of sucrose (common table sugar). The body metabolizes fructose differently than glucose, with the bulk processed exclusively by the liver. Excessive consumption, particularly from added sugars, is linked to concerns like increased de novo lipogenesis (fat creation), elevated triglyceride levels, non-alcoholic fatty liver disease, and insulin resistance.
Identifying Fructose on Nutrition Labels
Successfully avoiding fructose begins with scrutinizing ingredient lists, as the sugar hides under many different names. Any ingredient ending in the suffix “-ose” is a type of sugar, and several contain fructose or are converted to it. Sucrose, or common table sugar, is 50% fructose by composition. Also look for dextrose, maltose, and lactose, as these indicate sugar content.
The most notorious source is high-fructose corn syrup (HFCS), created by converting corn starch into a liquid sweetener. HFCS is typically found in two main compositions: HFCS 42 (about 42% fructose) and HFCS 55 (roughly 55% fructose). Also watch for crystalline fructose, which is a highly concentrated, purified form.
Beyond corn-derived products, many seemingly natural sweeteners are high in fructose and must be avoided. These include agave nectar (up to 90% fructose) and honey (approximately 40% fructose). Maple syrup is primarily sucrose and therefore contains a significant amount of fructose. Other aliases to watch for are concentrated sources of the sugar:
- Fruit juice concentrates
- Brown rice syrup
- Evaporated cane juice
Eliminating High-Fructose Industrial Sources
The most effective step in reducing fructose intake is purging the diet of industrial food products where it is heavily added. Sugar-sweetened beverages are the largest single source of added fructose for many people, primarily as HFCS 55. A single 12-ounce can of soda can easily contain over 20 grams of fructose.
Fruit juices, even those labeled as “100% juice,” are concentrated sources of natural fructose without the fiber that slows absorption, and many are also fortified with added high-fructose sweeteners. Processed baked goods like packaged cookies, cakes, and breakfast pastries frequently use HFCS and crystalline fructose for sweetness and texture. Many breakfast cereals, particularly those marketed toward children, contain HFCS 42 as a primary sweetener.
Fructose also permeates savory packaged foods. Common condiments, such as ketchup, barbecue sauce, and certain salad dressings, often rely on high-fructose corn syrup for flavor and shelf stability. Even items like flavored yogurts and prepared sauces, such as pasta sauce, frequently include added sugars containing fructose to balance acidity or improve palatability. Eliminating these highly concentrated sources provides the most immediate reduction in dietary fructose load.
Managing Natural Fructose Intake
Fructose is naturally present in whole foods, and managing this intake requires selection and portion control rather than complete elimination for most people. The fiber in whole fruit acts as a buffer, slowing the rate at which fructose is absorbed in the small intestine compared to the rapid absorption from liquids.
Certain fruits contain significantly higher amounts of fructose than others and should be limited on a strict avoidance plan. High-fructose fruits include:
- Mangoes
- Grapes
- Pears
- Apples
- Cherries
Dried fruits, such as raisins and dates, are extremely high in fructose because the water has been removed, concentrating the sugar content.
To minimize natural fructose, select lower-sugar fruits, such as berries, avocados, and citrus fruits (lemons and limes). When consuming fruit, eat it in its whole form to retain the fiber. Root vegetables like sweet potatoes and carrots also contain some fructose and should be consumed in moderation, especially when managing fructose malabsorption.
Fructose-Free Sweetener Alternatives
Once concentrated fructose sources have been removed, several alternatives can be used to sweeten foods and beverages. Stevia is a zero-calorie sweetener derived from the Stevia rebaudiana plant that does not contain fructose and is well-tolerated. Monk fruit extract is another natural, zero-calorie option that achieves its sweetness from compounds called mogrosides.
Sugar alcohols, such as erythritol and xylitol, are common bulk sweeteners that are not metabolized into fructose. Erythritol is popular because it provides a similar mouthfeel to sugar with almost no calories. However, excessive consumption of sugar alcohols can lead to digestive discomfort, including gas and bloating, because they are not completely absorbed in the small intestine.
A warning applies to sorbitol, another sugar alcohol often found in sugar-free gums and candies. Sorbitol can be converted into fructose in the liver, which may negate the benefit of avoidance. Therefore, for strict fructose avoidance, non-fructose sweeteners like Stevia and Monk Fruit extract are the most reliable choices.