|Van Loan, Marta|
Submitted to: Pediatrics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2006
Publication Date: 9/3/2007
Citation: Matlik, L., Savaiano, D., Mccabe, G., Van Loan, M.D., Blue, C.L., Boushey, C.J. 2007. Perceived milk intolerance is related to bone mineral content in 10-13 year-old female adolescents. Pediatrics. 120:699-677.
Interpretive Summary: Milk consumption during adolescences is critical to healthy bone development. However, not all people tolerate the sugar in milk, known as lactose. Intolerance to lactose may result in significant gastrointestinal discomfort and thus an avoidance of milk products. Some racial and ethnic groups appear to be intolerant to lactose, however, a systematic examination of this has not been done. We assessed lactose intolerance in 291 Asian, Hispanic and Caucasian adolescent girls. Each girl drank a set amount of milk after which breath samples were collected and analyzed for the amount of hydrogen in the breath. Hydrogen is a by-product of lactose metabolism. We also questioned each girl as to her perception of milk intolerance (PMI). Only 19.1% of the girls believed themselves to be intolerant of milk lactose and therefore consumed less millk. However, using the breath hydrogen test 43.5% of the girls were classified as lactose intolerant. Girls with PMI also had lower bone density at the spine. Our results suggest that as young 11 years of age, girls that believe they are milk intolerant restrict their milk intake and have lower bone density – all of which may have long term consequences for bone health during later years.
Technical Abstract: Objective: The purpose of this study was to determine associations among lactose maldigestion status, perceived milk intolerance (PMI), dietary calcium intake and bone mineral content in early adolescent females. Methodology: Subjects were 291 girls who participated in a sub-study of the multiple-site project, Adequate Calcium Today (ACT). Lactose maldigestion status was determined by hydrogen breath testing and questionnaires were used to assess PMI. Dietary calcium was estimated from a semi-quantitative food frequency questionnaire. Anthropometric and DXA (Lunar Prodigy) measurements (total body, spine L2-L4, total hip, and hip femoral neck) were standardized across sites. Results: Of the 230 girls completing the breath hydrogen test, 65 were Asian, 76 were Hispanic, and 89 were non-Hispanic White. A total of 100 girls (43.5%) experienced a rise in breath hydrogen >20 ppm and were classified as lactose maldigesters. Of the 246 participants who completed useable PMI questionnaires, 47 (19.1%) believed themselves to be milk intolerant. Of these 47 girls self-reporting with PMI, 40 completed breath hydrogen testing and 22 (55%) were not maldigesters. Girls with PMI consumed an average of 212 mg total food calcium per day less than girls without PMI (P=0.023). Spine bone mineral content (BMC) was significantly lower in the girls with PMI than the girls without PMI (P=0.009). When girls with lactose maldigestion were compared to girls without lactose maldigestion there were no significant differences in calcium intakes or bone measures. Conclusions: These results suggest that starting as early as 11 years of age, a self-imposed restriction of dairy foods due to perceived milk intolerance is associated with lower spinal BMC values. The long term influence of these behaviors may contribute to later risk for osteoporosis.