Relation between Milk Consumption and Bone Mineral Density of Female College Students in Korea

ABSTRACT

The purpose of our study was to evaluate an association between milk consumption and bone mineral density (BMD) of female college students in Korea. The dietary data of 1,410 Korean college students living in the vicinity of Seoul area were collected through the Food Frequency Questionnaire. The mean age, height, weight and BMI of the subjects were 20.4 years, 162.1 cm, 52.7 kg, and 20.0 kg/m2 respectively. The mean intakes of energy, protein, and phosphorus were 2,398.7 kcal, 95.2 g, and 1,302.9 mg respectively, which were above their EER or Recommended Intake (RI), but the mean intake of calcium was 657.8 mg which was below its RI, and 44.0% of the subjects did not meet Estimated Average Requirement (EAR) of calcium. The daily milk consumption was 131.1 g, and the total consumption of milk and dairy product was 228.7 g. Forty five percent of the subjects consumed 50 ~200 g of milk or dairy products. After the analysis of their dietary intakes, the subjects were divided into quintiles of total consumption of milk and dairy product, which were considered as major source of dietary calcium. Ninety two subjects from the upper quintile (UQ) and 85 subjects from the lower quintile (LQ) were selected and their bone mineral densities (BMD) of lumbar spine (L1-L4) and the femur were examined by the dual energy X-ray absorptiometry. The BMD (g/cm2) of L1, L2, L3, and average of femur were 1.065, 1.150, 1.187, and 0.988 for the UQ subjects, which were significantly higher than those of the LQ subjects, 1.010, 1.090, 1.146, and 0.942 respectively. Moreover, the T-scores of the UQ were significantly higher than those of the LQ. The prevalence rates of osteopenia classified according to WHO's criterion were 12.0% in the UQ, and 20.0% in the LQ group which showed non significant. Blood levels of calcium, and phosphorus of UQ and LQ group were both within the normal range, and were not significantly different. Our results showed that UQ group presented the better status of bone mineral density and bone health. Therfore our results suggest that continuous consumption of more than one and a half cups of milk per day, which corresponds to the least amount of UQ group's consumption, would affect positively on the bone health of Korean adults.