During processing, sugar is added to food to enhance flavor, texture, shelf life or other properties.
Added sugar is usually a mixture of simple sugars such as glucose, fructose or sucrose. Other types, such as galactose, lactose and maltose, are less common.
Unfortunately, food manufacturers often hide the total amount of sugar by listing it under several different names on ingredients lists.
In short, yes. Glucose and fructose — even though they’re very common and often found together — have very different effects on the body.
Glucose can be metabolized by nearly every cell in the body, while fructose is metabolized almost entirely in the liver.
Studies have repeatedly demonstrated the harmful effects of high fructose consumption.
These include insulin resistance, metabolic syndrome, fatty liver, and type 2 diabetes.
Although eating any extra sugar should be avoided, it is especially important to minimize your intake of added sugars that are high in fructose.
Sucrose is the most common type of sugar.
Often called “table sugar,” it is a naturally occurring carbohydrate found in many fruits and plants.
Table sugar is usually extracted from sugar cane or sugar beets. It consists of 50% glucose and 50% fructose, bound together.
Sucrose is found in many foods, including ice cream, candy, pastries, cookies, soda, fruit juices, canned fruit, processed meat, breakfast cereals and ketchup, to name a few.
BOTTOM LINE: Sucrose is also known as table sugar. It occurs naturally in many fruits and plants and is added to all sorts of processed foods. It consists of 50% glucose and 50% fructose.
High-fructose corn syrup is a widely used sweetener, especially in the US.
It is produced from corn starch via an industrial process and consists of both fructose and glucose.
There are several different types of HFCS, which contain varying amounts of fructose.
Two notable varieties are:
- HFCS 55: This is the most common type of HFCS. It contains 55% fructose and 45% glucose, which makes it similar to sucrose in composition.
- HFCS 90: This form contains 90% fructose.
High-fructose corn syrup is found in many foods, especially in the US. These include soda, breads, cookies, candy, ice cream, cakes, cereal bars and many others.
BOTTOM LINE: High-fructose corn syrup is produced from corn starch. It consists of varying amounts of fructose and glucose, but the most common type contains 55% fructose and 45% glucose.
Agave nectar, also called agave syrup, is a very popular sweetener produced from the agave plant.
It is commonly used as a “healthy” alternative to sugar because it doesn’t spike blood sugar levels as much as many other sugar varieties.
However, agave nectar contains about 70–90% fructose, and 10–30% glucose.
Given the harmful health effects of excess fructose consumption, agave nectar may be even worse for metabolic health than regular sugar.
It is used in many “health foods,” such as fruit bars, sweetened yogurts and cereal bars.
BOTTOM LINE: Agave nectar or syrup is produced from the agave plant. It contains 70–90% fructose and 10–30% glucose. It may be even more harmful for health than regular sugar.
Most added sugars and sweeteners contain both glucose and fructose.
Here are a few examples:
- Beet sugar
- Blackstrap molasses
- Brown sugar
- Buttered syrup
- Cane juice crystals
- Cane sugar
- Carob syrup
- Castor sugar
- Coconut sugar
- Confectioner’s sugar (powdered sugar)
- Date sugar
- Demerara sugar
- Evaporated cane juice
- Florida crystals
- Fruit juice
- Fruit juice concentrate
- Golden sugar
- Golden syrup
- Grape sugar
- Icing sugar
- Invert sugar
- Maple syrup
- Muscovado sugar
- Panela sugar
- Raw sugar
- Refiner’s syrup
- Sorghum syrup
- Treacle sugar
- Turbinado sugar
- Yellow sugar
BOTTOM LINE: These sugars all contain varying amounts of both glucose and fructose.
These sweeteners contain glucose, either pure or combined with sugars other than fructose (such as other glucose units or galactose):
- Barley malt
- Brown rice syrup
- Corn syrup
- Corn syrup solids
- Diastatic malt
- Ethyl maltol
- Glucose solids
- Malt syrup
- Rice syrup
BOTTOM LINE: These sugars are comprised of glucose, either on its own or with sugars other than fructose.
These two sweeteners contain only fructose:
- Crystalline fructose
BOTTOM LINE: Pure fructose is simply called fructose or crystalline fructose.
There are a few added sugars that contain neither glucose nor fructose. They are less sweet and less common, but are sometimes used as sweeteners:
BOTTOM LINE: D-ribose and galactose are not as sweet as glucose and fructose but are also used as sweeteners.
Barley malt syrup
Cane juice crystals
Coconut palm sugar
Corn syrup solids
Dehydrated cane juice
Evaporated cane juice
Free-flowing brown sugars
Fruit juice concentrate
HFCS (High-Fructose Corn Syrup)