Lactose is a type of sugar found in milk. When ingested, lactose is broken down by the enzyme lactase into useable energy for the body. The majority of infants possess this enzyme in sufficient quantities, which is necessary for breast feeding, but a large portion of the adult population do not. For those lacking it, consuming milk or dairy products can be an uncomfortable experience.
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The ability to digest lactose into adulthood is actually not the norm. Amongst mammals, the genes that regulate the production of lactase are typically inactivated after infancy. This is because beyond breastfeeding, lactose does not continue to be part of an animal’s diet and the ability to digest it is unnecessary. A large population of humans can still drink milk into adulthood now, as the ability was developed over thousands of years of feeding on the cheese and milk of the cattle we raised. The majority of people world-wide have retained their lactose intolerance, at least to some extent, with only 1/4 of adults fully tolerant. The majority of lactose tolerant people are of a Northern European descent and this is thought to be due to the history of ancient agriculture amongst these populations.
Is Lactose Intolerance an allergy? When an individual with lactose intolerance drinks milk, they do not have a typical “allergic” reaction involving the immune system as is seen in other food allergies. While it is possible to be truly allergic to proteins found in milk, lactose intolerance operates through a different mechanism. The inability to break down lactose into a useful form of energy means it will pass undigested into the intestines. Here, the bacteria that reside in the colon are able to metabolize it, but produce large amounts of gas as a by-product. Along with the excess gas, the products of this reaction increase the flow of water into the intestines resulting in diarrhea. Lactose Intolerance is not an allergy.
The symptoms of lactose intolerance usually present within 30 minutes to 2 hours after the ingestion of milk or dairy products. They include flatulence, bloating, cramps, diarrhea, nausea, and vomiting. Even though the symptoms are uncomfortable, they are not thought to pose a long-term risk to the health of those affected. However, those with lactose intolerance need to be careful to supplement the calcium in their diets that would normally come from dairy with another source. Calcium is important for both healthy bones and the functioning of the heart and nerves.
For those afflicted, the easiest way to avoid discomfort is simply to avoid milk and dairy products. However, the level of the lactase enzyme varies between individuals and different people will have different tolerance thresholds. Products derived from milk, such as cheese and yogurt tend to have less lactose than milk itself and may be better tolerated. There are also a number of dairy products on the market such as lactose-free milk, yogurt and ice cream. Alternatively, it is now possible to supplement the lactase enzyme in the form of a pill or drop and regain the ability to digest dairy symptom-free.by