The Effect of Isoflavone Supplementation by Soymilk on Bone Mineral Density in Underweight College Women

Sung, Chung Ja; Kim, So Yeon; Kim, Mi Hyun; Kim, Eun Young

Abstract

The purpose of this study was to investigate the effect of isoflavone supplementation using soymilk on bone mineral density in underweight college women aged 19-22 years with lower than average bone mass. The bone mineral density (BMD) of the lumbar spine and femoral neck of a number of underweight (BMI<20) college women was measured. From this group, 33 subjects whose T-score value was below -1 were selected. Anthropometric measurements, dietary recall and BMD were measured before the study began and at the end of the 10th week. The 33 subjects were given 400 ml of soymilk containing 60 mg of isoflavones daily for 10 weeks. After 12 weeks at the end of 10 weeks treatment, the BMD of the subjects was reassessed. The average age of the subjects was 21.1 yrs. At the baseline, average height, weight, and BMI of the subjects were 161 cm, 49.1 kg, 18.8 kg/m2, respectively. Mean daily intake of energy and protein was 1637.2 kcal and 61.2 g, respectively. Mean dietary isoflavone intake was 17.4 mg. Despite the 400 ml soymilk supplementation, there was no significant change in nutrient intake after the 10-week treatment. However, there were significant increases in lumbar spine and femoral neck BMD. After the study, the BMD of the subjects' spine and femoral neck was lower than that before the study. In conclusion, soymilk intake was associated with a significant increase in the BMD of the lumbar spine and femoral neck in underweight college women with lower than average bone mass.