Lactose intolerance is a real and important clinical syndrome, but quantifying its public health burden is challenging. An NIH Consensus Development panel was convened this week to assess the available evidence on lactose intolerance and health across the age spectrum and across racial and ethnic groups.
The panel will hold a telebriefing to highlight their findings today at 2:00 p.m. EST. Reporters may participate by calling 888-428-7458 or visit http://consensus.nih.gov/2010/lactosemedia.htm for more information.
Many individuals with diagnosed or perceived lactose intolerance avoid dairy products, which constitute a readily accessible source of calcium, other nutrients, and vitamin D (when fortified). Inadequate consumfpaption of these nutrients may increase the risk for chronic health problems, including osteoporosis and decreased bone health.
The panel defined lactose intolerance as the onset of gastrointestinal symptoms-diarrhea, abdominal pain, flatulence, and/or bloating-after ingesting lactose-containing foods and beverages; this is due to deficient levels of lactase, an enzyme necessary to break down lactose. Lactose malabsorption occurs when lactose is incompletely broken down in the intestine, which may or may not result in gastrointestinal symptoms after eating dairy products. Reduction of lactase in humans occurs in childhood and persists through the lifespan in most individuals (lactase nonpersisters). These individuals may or may not have the gastrointestinal symptoms of lactose intolerance. Understanding the distinction and interplay between these conditions is important when considering ways to meet nutritional needs.
"A lot of people who think they have lactose intolerance don't," said panel and conference chairperson Dr. Frederick J. Suchy, chief of pediatric hepatology at Mount Sinai School of Medicine. "They may have other conditions, or they may just need to consume smaller amounts of dairy products. Whether they are truly lactose intolerant or not, it is important that they meet recommended intakes of calcium and other essential nutrients."
Many individuals mistakenly ascribe symptoms of a variety of intestinal disorders, including irritable bowel syndrome and inflammatory bowel disease, to lactose intolerance and avoid lactose-containing foods without undergoing testing. This misconception becomes intergenerational when self-diagnosed lactose-intolerant parents place their children on lactose-restricted diets in the mistaken belief that they will experience symptoms.