Lactose Intolerance

Lactose intolerance is the inability to digest significant amounts of lactose, the major sugar found in milk.

Normally upon the consumption of lactose, it is hydrolyzed by the intestinal brush-border enzyme, lactase, into absorbable sugars, namely glucose and galactose. Lactase is found in the small intestine and localized to the tips of the villi, a factor of clinical importance when considering the effect of diarrheal illness on the ability to tolerate milk.

Deficiency of lactase due to primary or secondary causes results in clinical symptoms. Lactase nonpersistence results in incomplete digestion of an ingested load of lactose; hence lactose is malabsorbed and reaches the colon. If sufficient lactose enters the colon, the subject may experience symptoms of abdominal pain, bloating, excess flatulence, and diarrhea, a condition known as lactose intolerance

There are 4 main causes of lactase deficiency:
*Primary Lactase Deficiency
It is the most common cause of lactase deficiency, also known as lactose non­persistence. There is a gradual decline in lactase enzyme activity with increasing age. Most people will not notice symptoms until they are much older.

*Secondary Lactase Deficiency
Secondary Lactase Deficiency occurs when injury to intestinal mucosa due to several infectious, inflammatory or other diseases can cause secondary lactase deficiency. These diseases include celiac disease, inflammatory bowel disease, and Crohn’s disease.

*Congenital Lactase Deficiency
Some people are born with a likelihood of developing primary lactase deficiency because it has been passed to them genetically.

*Developmental Lactase Deficiency
It is seen in premature infants born at 28 to 37 weeks of gestation. The intestine of the infant is underdeveloped resulting in an inability to hydrolyze lactose.

Common symptoms, which range from mild to severe, include nausea, cramps, bloating, gas, and diarrhea. Symptoms begin about 30 minutes to 2 hours after eating or drinking foods containing lactose.
Lactose Intolerance

What is meant by lactose intolerance?

The most common types of food sensitivities include lactose intolerance and celiac disease.

A common intolerance, lactose is a principle carbohydrate found in milk and other dairy products. Deficient enzyme lactase in the lower intestine or other intestinal injury interferes with lactose absorption and produces unpleasant symptoms.

When a person with lactose intolerance consumes milk or other dairy products, some or all of the lactose they contain remains undigested, retains fluid and ferments in the colon, resulting in abdominal cramps, bloating, diarrhea and gas.

Symptoms usually begin between thirty minutes and two hours after consumption of dairy foods.

Lactose intolerance in varying forms of severity may affect all segments of the population. It can occur up to 90 percent of some ethic groups, such as Greeks, Arabs, Jews, black Americans, Japanese, Thai, Formosans, and Filipinos.

Anthropological study has demonstrated that lactose intolerance is most common in regions of the world where adults do not drink milk.
What is meant by lactose intolerance?

Carbohydrates

Carbohydrates
Unlike proteins, the carbohydrates in the body contribute nothing to the structure of tissue and although they contribute to the regulation of metabolism, they do not control individual molecular events as the enzymes (proteins) do. Their major function is the provision of energy to a variety of tissues, especially to the brain and nervous system which cannot utilize other nutrients for energy.

The carbohydrates in a typical breakfast – toast and tea with milk and sugar – are roughly representative of the distribution of carbohydrate in the average diet: starch from bread, potatoes, rice, pasta: sucrose from sugar: and lactose from milk. Starch is large molecule made up of many glucose units joined together, all glucose units being of similar structure. It is rapidly digested to its basic glucose units which are readily absorbed.

Lactose and sucrose are by contrast very much small molecules, each of which is digested to become effectively (in the liver) two units. The enzymes responsible for their digestion are, respectively, lactase and sucrase. There is rarely a problem is the digestion of sucrose but a great number of number people encounter problems with lactose digestion, most of which are associated with and inadequate supply of lactase.

Undigested lactose passes from small intestine, where digestion and absorption of its glucose units should occur, into the large intestine, where bacteria (a normal non pathogenic population of microbes) ferment the lactose and cause digestive upsets and diarrhea. The bulk of the population of Africa, Southern Europe, and the near East develop lactose intolerance during later childhood and adult life.

Under normal conditions, however the great majority of carbohydrates in our typical meal are digested and absorbed as glucose, if you measured blood glucose levels before such a meal and at half hourly intervals thereafter, you would see a rise in blood glucose, peaking at about the half hour mark and returning to fasting levels almost as quickly. If you were to abstain from carbohydrates for a considerable period say a week, your blood glucose levels would still be normal in spite of a minimal or zero intake, the body’s capacity to maintain blood glucose within specific limits is achieved by a variety of hormones, the two most important of which are insulin and glucagon. Both are secreted by the pancreas into bloodstream, as required.
Carbohydrates