Prevalence of lactose intolerance may be far lower than previously estimated, according to a study in the latest issue of Nutrition Today. The study, which uses data from a national sample of three ethnic groups, reveals that the overall prevalence rate of self-reported lactose intolerance is 12 percent - with 7.72 percent of European Americans, 10.05 percent of Hispanic Americans and 19.5 percent of African Americans who consider themselves lactose intolerant.

These new findings indicate that previous estimates of lactose intolerance incidence - based on the incidence of lactose maldigestion - may be overestimated by wide margins. Previous studies have found lactose maldigestion, or low lactase activity in the gut, to occur in approximately 15 percent of European Americans, 50 percent of Mexican Americans and 80 percent of African Americans. The new study shows that lactose intolerance, based on self-reported data, may actually occur far less frequently than presumed.

"There's so much confusion surrounding lactose intolerance," said Theresa Nicklas, DrPH, of the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine and lead study author. "By getting a better handle on the true number of people who deal with this condition every day, the nutrition community can be better equipped to educate and provide dietary guidance for Americans, including strategies to help meet dairy food recommendations for those who self-report lactose intolerance…