Lactose intolerance is a common digestive disorder in which the affected person cannot properly break down a sugar called lactose, which is found in milk and dairy products. Although public health authorities agree it is a genuine and important clinical ailment, much myth and hyperbole surround the subject. For example, a National Institutes of Health report suggests that the public, especially minority communities, could benefit from more consumer education on the subject, but doctors likewise need more training on how to give dietary advice in light of public concerns over lactose intolerance.
Lactose Intolerance Facts
Lactose intolerance is caused by a deficiency of the enzyme lactase that breaks down the sugar known as lactose in milk and milk products. It's a digestive disorder, not a milk allergy, which is when your immune system reacts to the proteins found in milk. The Western United Dairymen, a dairy industry group, reports that people lose some ability to digest lactose as they age, but the National Digestive Disorders Information Clearinghouse states that lactose intolerance has a higher incidence among blacks, Hispanics, American Indians, Asians, as well as premature infants. The NDDIC says lactose intolerance is least common among Americans of northern European descent. The Eunice Kennedy Schriver National Institute of Child Health & Development states that an estimated 30 to 50 million American adults are lactose intolerant.
Symptoms and Treatment
The disorder is marked by mild to severe symptoms, including abdominal pain, bloating, nausea, gas and diarrhea. Although most people who are lactose intolerant can handle a small amount of lactose-containing food, the condition is managed by replacing some foods with lactase-free foods and other changes to diet. More serious cases can involve medication. If your child has symptoms of lactose intolerance, you should see his pediatrician, who might prescribe a special nutrition plan, to ensure he gets the needed amount of calcium and vitamin D for his growing bones.
Major Public Health Reports
In February 2010, the National Institutes of Health convened a consensus development conference on "Lactose Intolerance and Health" to provide answers and update general knowledge on the subject. NIH consensus meetings generally involve "state-of-the-science" statements prepared by independent panels of health professionals and public representatives. The 2010 meeting aimed to answer outstanding questions about the prevalence of lactose intolerance, the effectiveness of diets that exclude dairy, how much lactose a lactose-intolerant person can safely consume, what the science says about effectively managing the condition and what questions about the condition remain unresolved. While acknowledging the real and clinical significance of lactose intolerance, the consensus was that true estimations of its prevalence need to be obtained. Often, people "diagnose" themselves or take a test in which they know they are consuming a lactose-containing food. The consensus was also that many people confuse lactose absorption issues with lactose intolerance.
Public Misperception
A major thrust of the NIH consensus development meeting also focused on the fact that people who think they are lactose intolerant tend to avoid dairy and get too little calcium and vitamin D, which may predispose them to osteoporosis and other negative health outcomes. These findings were echoed months later by a spring 2010 report from the Dairy Council of California Functional Foods Task Force. The task force said people also stop regular dairy when infants have unexplained colic or at the first sign of any gastrointestinal upset in adults. Babies, they say, then grow up largely without dairy because of the perception that they are better off without it. The task force recommended broad "culturally sensitive" education for the public and doctors to turn around this perception. The NIH meeting concluded more study is needed to advise people on how to get enough of important nutrients with and without dairy foods and supplementation.
Contributor to Health Disparities
Two researchers from the National Dairy Council published an article in the February 2002 "Journal of the National Medical Association" stating that broad patterns of avoiding dairy because of lactose intolerance may contribute to the health disparities among minorities in the United States. For example, they suggest that many chronic diseases that disproportionately affect blacks, such as high blood pressure, stroke, colon cancer and obesity, may be intensified by their chronically low intake of dairy. They said the average intake of calcium and dairy among blacks, Hispanics and Asians hovers near the threshold point, below which bone loss and hypertension is normally seen. While acknowledging that lactose intolerance may play a role, they place more blame on "culturally determined food preferences" and eating habits learned early in life. They also say public health reports on the prevalence of lactose intolerance among minority groups "grossly overestimates the number of people who will experience intolerance symptoms."
References
- National Digestive Disorders Information Clearinghouse; Lactose Intolerance; June 2009
- Eunice Kennedy Schriver National Institute of Child Health & Development: Lactose Intolerance: Information for Health Care Providers
- NIH Consensus Development Conference: Lactose Intolerance and Health; February 2010
- Dairy Council of California; Functional Foods Task Force Report; Spring 2010
- "Journal of the National Medical Association"; Overcoming the Barrier of Lactose Intolerance to Reduce Health Disparities; Judith K. Jarvis and Gregory D. Miller; February 2002
- "American Family Physician"; Lactose Intolerance; Daniel Swagerty et al.; May 2002
