Fragile Bones a Risk for Girls Who Consider Themselves Lactose Intolerant

WEST LAFAYETTE, Ind., Sept. 12 -- Girls who think that milk gives them indigestion are likely to consume less calcium, and as a result are likely to have weaker bones, researchers said.

And while this perception of lactose intolerance, as determined by a questionnaire, had a direct effect on dietary calcium intake, the perception was wrong more than half the time, according to Leann Matlik, M.S., R.D., of Purdue University, here, and colleagues.

Their study, published in the September issue of Pediatrics, included 291 sixth grade girls who participated in a two-state (California and Indiana) substudy of the Adequate Calcium Today study, which was conducted at sites in six states.

Hydrogen breath testing to identify lactose maldigesters (breath hydrogen of >20 ppm) was completed by 230 girls and 246 girls completed perceived milk intolerance questionnaires.

Calcium intake was estimated from food frequency questionnaires and bone mineral content was measured with dual-energy absorptiometric measurements (total body, spine L2-L4, hip, and hip femoral neck).

The girls' mean age was 12 and 47 of the girls who completed milk intolerance questionnaires identified themselves as milk intolerant. Of those, 40 completed breath tests. Of the total 230 girls who completed breath tests, 91 were determined to have lactose maldigestion.

Among the other findings:

• Asian girls had the highest rate of breath-test confirmed lactose intolerance (67.7%) followed by Hispanic girls (47.4%), versus non-Hispanic white girls (12.4%, P