The association between dietary inflammatory index and bone health in US adolescents: Analysis of the NHANES data.

Introduction: Adolescents with a lower peak bone mineral density (BMD) and bone mineral content (BMC) have an elevated risk of osteoporosis in adulthood. The impact of diet on bone health, particularly its role in managing inflammation, which is a key factor in bone health, is gaining wider recognition. Despite evidence that anti-inflammatory diets can enhance bone health, the link between the dietary inflammatory index (DII) and bone health among US adolescents has not been thoroughly investigated. This study aimed to evaluate the correlation between DII score and bone health in this population.

Methods: This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) of US adolescents aged 12-18 years, spanning surveys from 2001 to 2018. The DII was derived from dietary recall data obtained through questionnaire interviews. Bone health was assessed through total body less head (TBLH) BMD and BMC z-scores and lumbar spine bone mineral apparent density for age (BMAD).

Results: The study comprised 8773 adolescents with a mean age of 14.94 ± 1.97 years, 52.2 % were male. Multivariate linear regression analysis revealed a negative correlation between DII and lumbar spine BMAD (β = -0.000003, 95 % confidence interval [CI], -0.000005 to -0.000001;  = 0.001).This significant association remained robust when DII was treated as a categorical variable. Compared with individuals in quartile 1(Q1) DII scores (-3.71 to 1.04), those in Q4 (3.37 to 5.04) had lower BMAD, with a regression coefficient of -0.00002 (95 % CI, -0.00003 to -0.000007,  < 0.001). DII was negatively correlated with TBLH BMC z-scores; however, the difference was not statistically significant. Subgroup analyses showed that DII was associated with lumbar spine BMAD and TBLH BMC z-scores in participants who were male, non-black, with a higher educational level, with a high family income, and underweight to normal weight. We found no significant association between DII and TBLH BMD z-scores.

Conclusion: The findings from this cross-sectional analysis indicate a significant association between the DII and bone health among adolescents in the US, with a notable impact in males and non-black. These insights underscore the importance of adopting dietary patterns to mitigate inflammation and to support optimal bone health and metabolism.