Notice is hereby given by the National Institutes of Health (NIH) of the “NIH Consensus Development Conference: Lactose Intolerance and Health” to be held February 22-24, 2010, in the NIH N
Notice is hereby given by the National Institutes of Health (NIH) of the “NIH Consensus Development Conference: Lactose Intolerance and Health” to be held February 22-24, 2010, in the NIH Natcher Conference Center, 45 Center Drive, Bethesda, Maryland 20892. The conference will begin at 8:30 a.m. on February 22 and 23 and at 9 a.m. on February 24, and it will be open to the public.
Lactose intolerance is the inability to digest significant amounts of lactose, a sugar found in milk and other dairy products. Lactose intolerance is caused by a shortage of the enzyme lactase, which is produced by expression of the lactase-phlorizin hydrolase gene by the cells that line the small intestine. Lactase breaks milk sugar down into two simpler forms of sugar called glucose and galactose, which are then absorbed into the bloodstream. Infants of every racial and ethnic group worldwide produce lactase and successfully digest lactose provided by human milk or by infant formulas. However, by the time many of the world's children reach the age of 3-4 years, expression of intestinal lactase ceases. Most affected individuals, referred to as lactase nonpersisters, in the United States belong to minority groups, especially Asians, African Americans, Hispanics, Native Americans, Alaskan Natives, and Pacific Islanders.
Consumption of lactose-containing products by lactase nonpersisters may cause gas production, bloating, abdominal pain, and diarrhea. These symptoms of lactose intolerance are caused by intestinal bacteria's fermentation of undigested lactose and often cause individuals to avoid lactose-containing products. Lactose intolerance can be diagnosed by drinking one to two large glasses of milk after fasting and measuring breath hydrogen levels a few hours later. Other diagnostic tools include analyzing an intestinal biopsy sample or determining the genetic makeup of the chromosomal region coding for lactase. However, many individuals mistakenly ascribe symptoms of a variety of intestinal disorders to lactose intolerance without undergoing testing. This becomes intergenerational when self-diagnosed lactose-intolerant parents place their children on lactose-restricted diets in the belief that the condition is hereditary.
Healthcare providers are concerned that many lactose-intolerant individuals are avoiding dairy products, which constitute a readily accessible source of calcium and are fortified with vitamin D and other nutrients. Therefore, these individuals may not be meeting recommended intakes of these essential nutrients. Insufficient intakes of calcium carry a risk of decreased bone mineral density. This may have effects on bone health and increase the risk of fracture throughout the lifecycle, especially in Start Printed Page 2552postmenopausal women. Very low intake of vitamin D can lead to the development of rickets, especially in those of African descent and other highly pigmented individuals. Although milk alternative products are typically fortified with vitamin D and other nutrients, they are often more expensive and less widely available than conventional products.
The public health burden from deficiencies attributable to lactose intolerance is difficult to quantify. Additionally, it is challenging to identify and manage lactase nonpersisters. Questions remain as to the amount, if any, of lactose that can be tolerated by lactose nonpersisters and how best to assist these individuals in meeting recommended intakes. To examine these important issues, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Office of Medical Applications of Research of the National Institutes of Health will convene a Consensus Development Conference from February 22 to 24, 2010, to assess the available scientific evidence related to the following questions:
- What is the prevalence of lactose intolerance, and how does this prevalence differ by race, ethnicity, and age?
- What are the health outcomes of dairy exclusion diets?
- What amount of daily lactose intake is tolerable in subjects with diagnosed lactose intolerance?
- What strateg