Lactose is the natural carbohydrate in milk. Around 4.7 percent is contained in whole milk, and 4.8 percent in low-fat milk (1.5 percent fat). Milk sugar is broken down around four times more slowly and introduced into the metabolism as an energy supplier than household sugar. This is an advantage for many everyday situations, such as an office job, where a quick “energy shot” is rarely needed. What is more in demand are small sugar portions that are available as an energy supplier throughout the day.
Metabolism: processing of lactose in the body.
Milk sugar is a dual sugar and consists of glucose and galactose. The enzyme ß-galactosidase (lactase) breaks down lactose into its building blocks during intestinal transit. Glucose is fed directly into the energy metabolism. Not so galactose; it must first be broken down further into glucose. Then it is also used for energy production.
Lactase is much less active than the enzyme sucrosease, which breaks down the two-sugar sucrose (household sugar) into its building blocks. The slower breakdown is caused by the necessary further conversion of galactose and the lower enzyme activity of lactase. The protein and fat in the milk further delay the breakdown and the introduction of the sugar into the metabolism.
Milk as a sustainable energy supplier
This delayed breakdown of milk sugar has a positive consequence: milk provides energy over a longer period of time and hunger does not return until later.
By the way: milk or lactose also pay off as an energy supplier before or after sports. Energy is released in small portions, whether before training for the subsequent athletic performance or after training for regeneration.
Lactose for a healthy intestinal flora
Lactose causes a pH reduction in the intestine via its breakdown product lactic acid. This wards off germs and fungi, which thus have less chance of multiplying in the intestine.
Lactose helps to restore healthy intestinal flora after intestinal infections. It is positively associated with the immune system localized in the intestine. Bacteria are essential for healthy intestinal flora. Part of the lactose is not broken down, but serves as food for the bacteria of the large intestine. In particular, lactic acid bacteria, which are beneficial for intestinal flora, use lactose.
Lactose promotes calcium absorption
Lactose promotes the absorption of the important mineral calcium from the intestine. Lactic acid is probably responsible. It ensures a low pH value in the intestine. The acidic environment improves the availability and solubility of calcium.
Lactose for a regulated digestion
Lactose has long been known as a home remedy for regulated digestion. And it works like this: The lactic acid produced during bacterial breakdown binds water in the intestines. The effects are comparable to those of dietary fiber: The stool volume increases and the intestinal musculature is stimulated, so that the food pulp is conveyed on briskly.
Lactose – one man’s joy, another man’s sorrow
In some people, lactase activity decreases in the course of life; this is referred to as lactose malabsorption. About 15 percent of the German population is affected. Only when so much lactose reaches the large intestine undigested that symptoms such as painful flatulence or diarrhea occur is it called lactose intolerance.
Lactose intolerance does not mean that dairy products per se are no longer tolerated. Dairy products with a lower lactose content, for example sour milk products or hard cheese, can often be eaten without any problems. Tolerance varies from person to person and must be determined individually.