COW CONUNDRUM the science behind lactose intolerance BY Dana Morcillo
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e’ve all heard those words before - lactose intolerant. You, a close friend, or even a random stranger at dhall mutters those words and with it comes the inability to eat milk, cheese, and ice cream. But what does being lactose intolerant actually mean? Besides special access to that one refrigerator in dhall you’ve always wondered about, lactose intolerance means that you lack a special enzyme needed to digest lactose - a sugar present in many of your favorite foods. What is lactose and its purpose in the body? Lactose is a disaccharide, or sugar, made up of glucose and galactose. In order to be broken down into its monosaccharides, it requires a specific enzyme called lactase. Everyone is born with an abundance of lactase in order to break down the lactose present in your mother’s milk into needed energy. This lactase resides in the inner lining of your small intestine. It can then break down lactose before it passes into your large intestine. Through this process, glucose and galactose - the resulting sugars - can then enter the small intestine and be absorbed into the bloodstream to be converted or used for energy. If the body contains little or no lactase, it loses the ability to digest lactose in the small intestine. This results in lactose being passed through the large intestine and into the colon where it’s broken down by bacterial fermentation. This process of digestion is called lactose malabsorption. However, lactose malabsorption doesn’t always lead to lactose intolerance. That transition can depend on different factors such as how much lactose was consumed, and an individual’s colonic flora and sensitivity to lactose fermentation products. What is lactose intolerance?
Lactose intolerance is a condition in which an individual experiences irregular digestives symptoms such as diarrhea, abdominal pain, or bloating after consuming any food or drink that contains lactose.1 These painful symptoms are the result of lactose malabsorption and can manifest at three different levels. The most common type is primary lactose intolerance. Primary lactose intolerance is caused by a dropoff in the production of lactase seen in adulthood. This type of intolerance is genetically determined and seen most frequently in individuals of African, Asian or Hispanic ancestry.2 Secondary lactose intolerance is a decrease in lactase production caused by damage to the small intestine whether it’s through illness, injury or surgery. The last is developmental lactose intolerance. Those with this heritable condition are born without any lactase or lactase activity.
