Lactose is a type of sugar found naturally in dairy products such as milk and milk byproducts. Lactose makes up approximately 8 percent of the solids in milk. Normally, enzymes in your body break down lactose and absorb it into your bloodstream. However, if you are lactose intolerant, you can not digest milk sugars because your body cannot produce the enzymes needed to digest the lactose.

Breaking Down Lactose

As you age, you are more likely to lose the ability to break down lactose. However, in most cases, you continue to produce the enzymes needed to digest lactose throughout your life. However, individuals with lactose intolerance no longer can produce enzymes necessary to digest milk sugars 2. This makes it impossible for lactose intolerant individuals to consume any milk and milk byproducts after the onset of the lactose intolerance 2.

Cattle Domestication

According to “Nelson Textbook of Pediatrics,” before the domestication of cattle approximately 8,000 years ago, humans only consumed lactose from breast milk while nursing. Therefore, as you aged, your body would naturally stop producing the enzyme needed to digest lactose. However, after domesticating cattle, humans started to drink milk throughout their lives. This caused a mutation in most individuals that allowed the human body to continue producing the enzyme needed to digest lactose after childhood.

Foods and Lactose

Manufacturers typically add lactose to prepared foods as a coating to prevent caking. Additionally, food producers use lactose as a filler in bread and other baked goods such as pancakes, cereals and cookies. Since lactose does not have any flavor, using lactose as a food additive does not change the flavor of food. Additionally, you can find lactose in frozen and canned vegetables because it also helps prevent discoloration of foods. Powdered food products such as soups, dehydrated potatoes and meal-replacement supplements typically contain lactose. Further, non-dairy foods, such as coffee creamers, may also contain lactose in the form of dry milk solids or whey.

Pills and Lactose

You can also find lactose as a coating or filler in in many prescription and over-the-counter drugs including birth control pills, antacids and throat lozenges. Usually, drugs have a very low level of lactose that will not affect most people. However, if you have a severe allergy to lactose, you should speak with your doctor before starting any new prescription or over-the-counter medication. Further, diabetics should limit or control lactose intake as lactose is a type of sugar.