Lactose Intolerance is not mediated by the immune system.
· The symptoms of abdominal bloating and diarrhoea are the result of the malabsorption of the CHO-lactose.
· There are three major types – congenital, primary and secondary lactose intolerance (1).
· Seventy percent of lactose intolerance occurs over a period of many years and never before the ages of 2 -5 years up until adulthood.
· In secondary lactose intolerance, there is reduced lactase activity due to illness, viral gastroenteritis, giardiasis and celiac disease, which results in damage to the brush border of the small intestine (1).
· Lactose can usually be introduced several weeks after maintaining the lactose free diet (1).
· The diagnosis of lactose intolerance is by breath hydrogen breath test; the measurement of the rise in BGL after the consumption of dairy; to test for the evidence of reducing substances in the stool (1).
Individuals with lactose intolerance experience symptoms of diarrhoea, abdominal bloating and cramping. Read more about the symptoms of lactose intolerance.
These symptoms are a result of the malabsorption of lactose, which exhibits an osmotic load (1). This increased load increases the rate of intestinal transit time (1). Once, in the colon the lactose is acted upon by bacteria which produce Short Chain Fatty Acid (SC-FA) and gas which is what causes the bloating (1). Research reveals that 24- 27% of individuals with IBS have lactose Intolerance (1).
Management of lactose intolerance
The management of lactose intolerance is generally through a lactose free diet, encompassing lactose free milk and for the very sensitive individuals the avoidance all products containing dairy. There are a range of lactose free products including milk (Liddel`s and Parmalat milk), yoghurt, chocolate, and dairy free cakes and biscuits. Individuals can also use a lactase enzyme (Lactese), to digest the lactose in milk or a food product.
1. Tanya Wright and Rosan Meyer., Dietary Management of Milk and Eggs -Food Hypersensitivity: diagnosing and managing food allergies and intolerances – edited by Isabel Skypala, Carina Venter; Wiley and Blackwell 2009, Part 2, p 117- 128.
2. William B Smith, Dery Thompson, Margaret Kummerow, Patrick Quinn, Michael S Gold., A2 milk is allergenic., MJA2004;181(10):574.
Article submitted by Julie Albrecht.