Maltose is a sugar made out of two glucose molecules bound together.
It’s created in seeds and other parts of plants as they break down their stored energy in order to sprout. Thus, foods like cereals, certain fruits and sweet potatoes contain naturally high amounts of this sugar.
Even though maltose is less sweet than table sugar and fructose, it has long been used in hard candy and frozen desserts because of its unique tolerance to heat and cold.
Thanks to growing public awareness about the negative health effects of high-fructose corn syrup and other sweeteners containing fructose, many food companies are switching to maltose, which contains no fructose.
This article addresses how maltose affects your body, where it comes from and whether it's healthy or unhealthy.
Most sugars are short chains made up of smaller sugar molecules that act as building blocks. Maltose is made of two glucose units. Table sugar, also known as sucrose, is made of one glucose and one fructose.
Maltose can be made by the breakdown of starch, a long chain of many glucose units. Enzymes in your gut break these chains of glucose down into maltose (1).
Plant seeds also produce enzymes to release sugar from starch as they sprout.
People have long taken advantage of this natural process for food production.
For example, in the process of malting, grains are sprouted in water then dried. This activates the enzymes in the grains to release maltose and other sugars and proteins.
The sugars and proteins in malt are very nourishing for yeast, so malt has become important in brewing beer, whisky and malt vinegar.
Malted grains are also used in candies and desserts as sweeteners.
Maltose can be purchased as dry crystals where brewing supplies are sold or as a syrup sold alongside baking supplies. The syrup is usually corn-based, but it’s not to be mistaken for high-fructose corn syrup.
You can use maltose in recipes as a 1:1 substitute for other sugars. Maltose is not as sweet as sucrose or fructose, so in some recipes, slightly more than 1:1 may be needed to produce the desired flavor.
Summary: Maltose is created by the breakdown of starch. This happens in your gut after you eat starch and also in seeds and other plants as they begin to sprout. This sugar is important in brewing and as a sweetener.
Several foods naturally contain maltose (2).
You can find it in wheat, cornmeal, barley and several ancient grains. Many breakfast cereals also use malted grains to add natural sweetness.
Fruits are another common source of maltose in the diet, especially peaches and pears. Sweet potatoes contain more maltose than most other foods, accounting for their sweet flavor.
Most syrups get their sweetness from maltose. High-maltose corn syrup provides 50% or more of its sugar in the form of maltose. It is useful in making hard candies and an inexpensive sweetener.
Summary: Maltose is found in starchy grains, vegetables and fruits. It is useful as a low-cost sugar source in the form of high-maltose corn syrup.
People commonly use sucrose, also known as table sugar, for cooking and sweetening foods. It’s another short, two-sugar chain made of one glucose molecule linked to one fructose molecule.
Because sucrose delivers both these sugars, its health effects are likely somewhere in between those of glucose and fructose.
However, fructose has more severe health implications and is metabolized differently than glucose.
Consuming a high-fructose diet may cause a quicker onset of obesity, insulin resistance and diabetes (3).
Since maltose is made up of just glucose, not fructose, it might be slightly healthier than table sugar. However, no research has investigated the effects of substituting fructose for maltose, and more research is needed.
Summary: Maltose does not contain fructose like table sugar does. So replacing table sugar with maltose in your diet will help you avoid the known health implications of too much fructose. However, the effects of maltose on health have not been studied well.
Some people think that table sugar is healthier than the often-demonized high-fructose corn syrup.
But actually, their fructose content is very similar. Table sugar is exactly 50% glucose and 50% fructose, while high-fructose corn syrup is about 55% fructose and 45% glucose.
This small difference makes table sugar essentially no healthier than high-fructose corn syrup (4).
Food companies have attempted to avoid the increasing negative public perception of fructose by replacing high-fructose corn syrup with high-maltose corn syrup.
And they may be right in doing so. If maltose is used to replace the same amount of fructose, gram-for-gram, it may be a slightly healthier option.
Generally, high-maltose and high-fructose corn syrups may be substituted for each other in a 1:1 ratio, but individual products may vary.
Just because fructose may be a little bit worse for you doesn’t necessarily make maltose healthy. Keep in mind that maltose is still sugar, and it should be used in moderation.
Summary: Replacing high-fructose corn syrup with high-maltose corn syrup might have a small health benefit since it would reduce your fructose intake. However, no conclusive research is available, so more is needed.
Almost no research exists on the health effects of maltose in the diet.
Because most maltose is broken down into glucose when digested, its health effects are probably similar to other sources of glucose (5).
Nutritionally, maltose provides the same number of calories as starches and other sugars.
Your muscles, liver and brain can convert glucose into energy. In fact, the brain gets its energy almost exclusively from glucose. Once these energy needs are met, any remaining glucose in your bloodstream is converted into lipids and stored as fat (6).
However, if you consume maltose in excess, it can lead to obesity, diabetes and heart and kidney disease, just like other sugars (3).
For maltose, as for most nutrients, it’s the dose that makes the poison.
Summary: Research is limited, but the health effects of maltose are likely similar to those of other sugars. Thus, the moderate consumption of maltose does not cause harm.
Maltose is a sugar that tastes less sweet than table sugar. It contains no fructose and is used as a substitute for high-fructose corn syrup.
Like any sugar, maltose may be harmful if consumed in excess, leading to obesity, diabetes and heart disease (3).
Instead, use fruits and berries as sweeteners. This will help you reduce added sugars in your diet. Also, while they do contain small amounts of sugar, they also offer additional nutrients like fiber, vitamins and antioxidants.
Maltose might be preferable to sugars that contain fructose. However, it’s still sugar, so consume it sparingly.