Lactose, a disaccharide composed of glucose and galactose, is the principal sugar of mammalian milk and the principal carbohydrate energy source for infants and children. Lactose has formula C121H22O11. Thus galactose plays a main metabolic role in human nutrition. Lactose is hydrolyzed in the intestine into glucose and galactose, which together with other sources of these monosaccharides are absorbed and metabolized and used as energy. Lactose consists of one glucose molecule and one galactose molecule. In fact human breast milk has more lactose than cow’s milk does, making human breast milk taste sweeter. The name is derived from Latin word lac which means milk and suffix –ose refers to sugars.

History

Lactose was first isolated by Italian physician Fabrizio Bartoletti (1576-1630) which was published in 1633. In 1700, Lodovico Testi, a Venetian pharmacist published a booklet of testimonials to power of milk sugar to provide relief from other ailments and arthritis symptoms. In 1715, Antonio Vallisneri published Testi’s procedure to make milk sugar. Then lactose was known as sugar by Carl Wilhelm Scheele in 1780. Heinrich Vogel, in 1812 recognized that glucose was a product of hydrolyzing lactose. Louis Pasteur, in 1856, crystallized other component of lactose, galactose. Emil Fischer established configurations of component sugars by 1894. Lactose was named by ean Baptiste Anedre Dumas, a French chemist in 1843.

Food Sources

Food name	Weight (g)	Lactose (g)
Ice Cream with milk chocolate candies	348	21.68
Eggnog	254	19.91
Ice Cream with cookie	337	18.94
Chocolate milk	250	9.57
Kefir	247	7.98
Coffee	262	7.65
Vanilla ice cream	120	6.71
Egg custards	141	6.53
Greek yogurt	200	5.84
Lasagna classico	422	5.15
Hotcakes	149	4.98
Cottage cheese	113	4.37
Rice puddings	113	3.88
Cream	120	3.50
Cottage cheese	113	3.02
Queso fresco cheese	122	2.83
Mozzarella cheese	228	2.67
Strawberry ice cream	58	2.57
Spinach souffle	136	2.05
Queso blanco cheese	118	1.18

Health Benefits of Lactose

Low calories

Lactose is regarded as natural and low calorie sweetener. Lactose is a natural sugar which does not have detrimental effects on the body. It is less sweet and provides more energy in comparison to granulated sugar. In comparison to other sugars, it has less significant metabolic effects. Lactose has low glycemic index number than glucose. Lactose is beneficial for diabetic people as well as it provide low impact on blood sugar. Less impact shows that lactose causes less health problems than other sugars.

Acts as a prebiotic

Lactose enhances the growth of micro flora in intestinal tract to maintain healthy digestive tract. To break down lactose in digestive system, body produces an enzyme known as lactase. As people ages, the ability of the body to produce this enzyme declines. When body does not break down all lactose, it passes through digestive system. In digestive system, good bacteria will take advantage of this undigested sugar and use it as energy to grow and flourish. Lactose helps to maintain healthy micro flora in gut.