Lactose Intolerance Defined
Lactose intolerance — often referred to as LI — concerns the digestion of dairy products in your daily diet. Sometimes LI is referred to as lactase deficiency; the terms mean the same thing, and in the medical community the condition is referred to as “primary lactose intolerance.”
LI is a very common condition that often goes undiagnosed. Many individuals are living in unnecessary discomfort, and simple diet changes could easily make a huge difference. There is no magic wand to cure LI and no medical procedure that will correct it. Your comfort zone in living with LI depends on what you put in your mouth.
Lactose intolerance is completely different from milk allergy. Milk allergy is an allergic reaction triggered by the immune system to protein components in milk. Lactose intolerance is related to the digestive system and the inability to break down milk sugar (lactose). In addition, LI is not a contagious disease, and even though LI's symptoms are distressing and sometimes uncomfortable, they do not cause damage to the intestine.
Lactose and Lactase
Lactose is a primary simple sugar found in milk and dairy. In order to digest lactose, the digestive enzyme lactase must be present in the small intestine. Lactase breaks down the milk sugar into two simpler forms of sugar, glucose and galactose, which allows absorption into the bloodstream. The following definitions may be of help to you in your understanding of lactose intolerance.
Lactase: The enzyme present in the lining of the small intestine that is needed to digest lactose (milk sugar) in order for it to be absorbed by the body and used as nourishment.
Lactose: The sugar that is found naturally in the milk of all mammals, which the human body breaks down into galactose and glucose. Lactose is not found anywhere else in nature.
Lactase Deficiency: The lack of the enzyme lactase, which is the cause of lactose intolerance.
Lactose Intolerance: Being unable to digest the sugar in milk (lactose), which occurs because the body doesn't produce enough of the lactase enzyme.
Symptoms of LI
If there's a shortage of lactase in the small intestine, lactose carries additional fluid as it moves down to the colon. Fermentation of lactose in the colon begins to take place, and gases form. (Think of the fermentation process of fine wines and champagne.) The gas bubbles can be very uncomfortable, causing gastrointestinal symptoms such as cramping, flatulence, nausea, diarrhea, and abdominal bloating.
When toddlers are around age two, their bodies begin to produce less lactase. The symptoms of the lessening of lactase production may not be realized until a person is much older. In some cases it can be as late as the senior years.
Symptoms can range from severe pain to mild discomfort, depending on each individual's degree of lactase deficiency and the amount of lactose that's been consumed. It's common for symptoms to begin anywhere from thirty minutes to three hours after eating or drinking food containing lactose.
Who Is Lactose Intolerant?
As many as 75 percent of all adults worldwide are lactose intolerant, and more than 50 million Americans suffer from some degree of lactose intolerance. While 85 percent of children outgrow their intolerance, adults are not so lucky. Genetics can be a contributing factor, and LI can also be common among individuals who are alcoholic or ingest an abnormal amount of alcohol.
The numbers and percentages of lactose intolerant individuals are staggering. In fact, lactose tolerance is rarer than lactose intolerance. The National Institutes for Health reports that between 80–100 percent of Asian Americans and Native Americans are lactose intolerant, and up to 80 percent of African Americans are lactose intolerant. On the bright side, LI is not life threatening. It can be easily controlled by diet, and it's not an all-or-nothing situation.
Ongoing research is conclusive in illustrating a genetic link to lactose intolerance. This may be useful in developing a genetic test to identify potential lactose intolerance in people whose parents are lactose intolerant.
Secondary Lactase Deficiency
Secondary lactase deficiency is caused by certain digestive disorders that damage the small intestine. The damage inhibits the body's ability to produce lactase and process lactose. Crohn's disease, celiac disease, and inflammatory bowel disease can all lead to secondary lactase deficiency.
Testing, Testing
Medical tests can be performed with your doctor's advice to accurately diagnose lactose intolerance. It's important that you confirm the discomfort that you're experiencing after eating a meal or a snack is not a more serious digestive disorder than lactose intolerance. Consult your physician for advice on what testing needs to be done to narrow your diagnosis so that you can get on with enjoying your life.
In medically testing and measuring the absorption of lactose in the digestive system, common measures include a stool acidity test, a lactose tolerance test, and a hydrogen breath test. Let your doctor be your guide because every LI case is unique to the individual.
One very simple test can be performed at home. Avoid all milk products for several consecutive days. On a weekend when you plan to be at home, don't eat any breakfast but instead drink two large glasses of milk. During the next four to five hours, if you experience LI symptoms you are a prime candidate for being lactose intolerant. At this point, see a doctor for confirmation of your symptoms.
