Associations between Dietary Fiber Intake and Bone Mineral Density in Adult Korean Population: Analysis of National Health and Nutrition Examination Survey in 2011

BACKGROUND: The correlations between the amount of daily fiber intake and bone mineral densities (BMDs) in Korean adult population were investigated in our study. METHODS: Utilizing the Korean National Health and Nutrition Examination Survey in 2011, multivariable linear regression was performed to explore the association between fiber consumption and BMD of lumbar vertebrae 1 to 4 (L1–4 total), L1, L2, L3, and L4 vertebrae, femur neck, femur total, and trochanter. All models were adjusted for age, body mass index, vitamin D level, smoking, physical activity, alcohol use, contraceptive use, hormonal replacement therapy, consumption of carbohydrate, protein, fat, calcium, phosphate, iron, thiamine, riboflavin, niacin, and vitamin C. RESULTS: In males aged between 18 and 45, fiber intake significantly increased BMDs of L1 (coefficient β=0.004, P=0.040) and L2 (β=0.004, P=0.038) while daily protein consumption significantly lowered BMDs of femur neck (β=−0.001, P=0.009), femur total (β=−0.001, P=0.008), and trochanter (β=−0.001, P=0.008). In males aged 65 and older, nutrient intake shows no significant correlations with BMDs except fat consumption was inversely associated with BMD of trochanter (β=−0.001, P=0.017). In females aged between 18 and 45, fiber intake shows no significant relationship with BMDs while daily fat consumption significantly increased BMDs of L1 (β=0.001, P=0.028), L2 (β=0.001, P=0.024), L3 (β=0.001, P=0.033), and L1–4 total (β=0.001, P=0.017). CONCLUSIONS: Fiber intake was a protective factor of lumbar spine (L1 and L2) BMD in male aged between 18 and 45 but not in female participants of any age groups.