Lactose is the chemical name for milk sugar, which you ingest any time you drink milk or consume most dairy products. To digest lactose, your body uses an enzyme called lactase, which is a beta-galactosidase. Some individuals can't produce lactase -- or produce it in insufficient quantities -- which leads to lactose intolerance.
Lactose
Lactose is a disaccharide, which means that it's made up of two smaller sugar units, explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry." It has the chemical formula C12H22O11, which is identical to the chemical formula of the very similar sugar sucrose, also called table sugar. The most common source of lactose in food is dairy, and it's found in both milk and dairy products. Though lactose is a sugar, it tastes much less sweet than other common sugars.
Beta-Galactosidase
Beta-galactosidase is the chemical name for a large class of enzymes, where enzymes are proteins that help reactions take place faster than they otherwise would. Lactase, the enzyme that humans and other organisms use to digest lactose, is a beta-galactosidase. However, not all beta-galactosidases can digest lactose; only lactase can operate in this capacity. Some publications and individuals mistakenly refer to lactase and beta-galactosidase interchangeably, but one is a specific enzyme and one is an enzyme class.
Lactase
To absorb lactose, you must first break it into its constituent smaller sugar units, namely glucose and galactose. Lactase, which you produce in your small intestine, accomplishes this digestive process, explains Dr. Lauralee Sherwood in her book "Human Physiology." Almost all humans produce sufficient quantities of lactase to digest lactose early in life -- juvenile lactose intolerance is relatively rare -- but lactase production can drop off as you age, leading to lactose intolerance.
Lactose Intolerance
If you find that you experience uncomfortable digestive symptoms -- including gas, cramping, and bloating -- upon consumption of dairy, you may have lactose intolerance. While aging is the main cause of lactose intolerance in adults, you can also become lactose intolerant as the result of an injury or illness in the intestine. Age-related lactose intolerance is typically permanent, while you can sometimes recover your ability to produce lactase if you've become lactose intolerant as the result of illness.
References
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
Member Comments