In nutrition, isomaltulose is a source of
food energy, providing the same amount of energy as sucrose. Like sucrose, isomaltulose provides sweetness to foods, but isomaltulose is only about half as sweet as sucrose. When eaten by humans, isomaltulose is digested completely and absorbed. Its intestinal digestion involves the enzyme
isomaltase, which is located at the surface of the
brush border lining the inner wall of the small intestine. This enzyme is otherwise involved in the digestion of α-1,6 linkages present in starch. The products of isomaltulose digestion are glucose and fructose, which are absorbed and enter the bloodstream. Once absorbed, the glucose and fructose follow the same
metabolic pathways through the body as if they were derived from sucrose. the
food energy value of isomaltulose is identical to that of sucrose. For both, it is 4 kcal/g (17 kJ/g), a value that is used in food labelling or dietary planning.
Slow and sustained release of carbohydrate and energy Isomaltulose is slow to be digested and absorbed, and is therefore gradually released as glucose and fructose into the bloodstream. After ingestion, the enzymatic digestion of sucrose and isomaltulose occur on the same
sucrase-isomaltase enzyme complex, which is located in the small intestine. Several studies show that this complex breaks down isomaltulose more slowly than sucrose. The
maximum rate at which
isomaltase can process isomaltulose (Vmax) is 4.5 times lower than that of
sucrase for sucrose. As a result of its slow digestion, isomaltulose travels further through the human small intestine than sucrose does, as evidenced by the difference in
incretin responses they elicit. Compared to sucrose, isomaltulose leads to lower secretion of the incretin hormone GIP (
glucose-dependent insulinotropic polypeptide), which is released from the upper (proximal) part of the small intestine. In contrast, it triggers higher secretion of the incretin hormone GLP-1 (
glucagon-like peptide-1), which is released from the lower (distal) part of the small intestine. Compared with sucrose, the absorption of energy as carbohydrate from isomaltulose is prolonged. compared to 67 for sucrose and 100 for glucose, making isomaltulose a particularly low-GI carbohydrate (GI<55). Confirmation of a low glycaemic response to isomaltulose is provided in numerous studies for different population groups including healthy people, overweight or obese persons, prediabetic persons, and type 1 or type 2 diabetes patients. Among these studies, all show the lower blood glucose response of isomaltulose and where tested also show the associated reduction in the blood insulin response. A significant role for the incretin hormone GLP-1 has been established, which is secreted in response to distal carbohydrate absorption and limits the rise in blood glucose concentration after a meal. following the publication of a positive opinion from the
European Food Safety Authority. In the long term, when eating a diet including carbohydrate, avoiding undesirably high concentrations of glucose in blood and the associated demand for insulin, is supportive of the prevention and management of
diabetes mellitus,
cardiovascular disease, and possibly
overweight and
obesity—as indicated by the International Carbohydrate Quality Consortium consensus of expert nutrition scientists. Continuous monitoring of 24-h blood glucose concentration following diets including isomaltulose instead of sucrose lowers the blood glucose profile over the day, as a result of a lower blood glucose response to individual meals. A lower glycemic diet can be achieved by choosing foods with low or reduced glycemic properties, more specifically by choosing lower GI foods from within each
food group (fruit, vegetable, whole grains, etc.). The use of Isomaltulose in place of sucrose and other carbohydrates allows for the production of foods with reduced GI. Several studies provide evidence of improvements in both blood glucose control and
lipid metabolism in both diabetic and non-diabetic persons upon regular consumption of isomaltulose when compared with other carbohydrates such as sucrose, maltodextrin, or glucose.
Effect on fat oxidation Compared to other carbohydrates, isomaltulose ingestion is associated with higher rates of fat oxidation and lower rates of fat storage. First, isomaltulose "dives" under the enzymatic "radar" surpassing the GIP producing upper part of the small intestine. It finds the degrading enzyme deep down in the GLP part of the intestine. GLP/GIP balance favors late insulin secretion, and shuts down glucagon secretion. Thus the release or new production of liver glucose is slowed down. Mechanistically this involves a lower blood glucose concentration with reduced insulin secretion, which in turn allows more fatty acids to be released from
adipose tissue for oxidation as an energy source. The lower insulin concentration also decreases carbohydrate oxidation, allowing more fatty acids to be oxidized. A lower insulin concentration also lowers the rate of liver free fatty acid recycling via plasma VLDL
triglycerides and reduces the storage of triglycerides in adipose tissue. Practical implications include higher rates of fat oxidation after ingestion of isomaltulose than higher glycaemic carbohydrates. This has been shown in many studies with different areas of focus:
Weight management and body composition Studies have looked at the effects on fat oxidation and other metabolic responses when replacing sugars with isomaltulose in meals (or drinks) taken by healthy or overweight to obese adults, with or without impaired glucose tolerance, while largely sedentary. These studies have shown isomaltulose to have a role in reducing adiposity, at least central obesity. Abdominal fat decreases when consuming isomaltulose instead of sucrose (sugar replacement) or instead of breakfast calories (largely carbohydrate replacement).
Physical activity and sports nutrition Others studies have examined the potential benefits of slow and sustained release of carbohydrate during physical activity. Using isomaltulose in place of other ingested carbohydrates, higher rates of fat oxidation also occur during endurance activities, where preserving glycogen is important. In addition, trials using a recovery protein drink have shown that incorporating isomaltulose and a nutritional supplement (
β-hydroxy- β-methylbutyrate ) may help recovery from resistance exercise—so reducing of muscle damage and improving athletic performance.
Type 1 diabetes patients engaging in physical activity In people with
type 1 diabetes, taking isomaltulose instead of glucose during moderate
carbohydrate loading before exercise improves blood glucose control and protects against hypoglycemia while maintaining running performance. The reduced risk of exercise-induced hypoglycemia arises in part from a lower requirement for insulin by injection (50% lower) when using isomaltulose and in part from the higher contribution of fat oxidation to energy metabolism, which preserves glycogen stores, further reducing the risk of hypoglycemia.
Cognitive performance (mood and memory) The rate of glucose supply from dietary carbohydrates can affect cognitive performance, with effects on
mood and
memory having been shown in several studies that compared isomaltulose with higher glycaemic carbohydrates taken at breakfast, showing improvements in mood and memory in healthy children, middle-aged adults, and aged adults.
Oral health Isomaltulose is ‘kind to teeth’. Fermentation of carbohydrates by bacteria in the mouth (especially on the teeth) is responsible for the formation of
dental plaque and oral acids. The acid initiates tooth demineralisation and
tooth decay (dental caries). Isomaltulose largely resists fermentation by oral bacteria and is the first carbohydrate of its kind with negligible acid production on teeth, as shown by pH telemetry. The evidence is strong and provides the basis for ‘kind to teeth’ claims approved by both the
Food and Drug Administration in the USA and European authorities following a positive opinion from the
European Food Safety Authority. == Production and assays ==