Background/objectives: To examine the associations of dietary inflammatory index (DII) with bone mineral density (BMD) and fracture risk in adult Americans.Subjects/Method:The United States National Health and Nutrition Examination Survey participants during 2005-2010 were included if they had measured data on dietary intake and BMD. DII scores were calculated from estimated micro- and macronutrients from a single 24-h dietary recall. BMD was measured using dual-energy X-ray absorptiometry densitometers. Risk of fractures was obtained from participant self-report (ever) based on doctor information. Analyze of covariance and χ2-tests were employed, while accounting for the complex survey design.
Results: A total of 18 318 participants were included, with 51.3% (9397) being men. Age, sex, race, physical activity, smoking, C-reactive protein and body mass index-adjusted mean BMD (g/cm2) in different bodily sites significantly decreased across increasing quarters of the DII (all P<0.001). After further adjustment for calcium intake, the trend in BMD across DII quarters remained significant for total femur, femoral neck, trochanter and intertrochanter BMD (all P<0.001). Across increasing quarters of the DII, the proportion of fractures ranged from 1.1 to 1.5% for hip fracture (P=0.02), from 7.9 to 10.5% for wrist fracture (P<0.001) and from 2.2 to 2.7% for spine fracture (P=0.002. Prevalent wrist fractures significantly differed across DII quarters (P<0.0001), driven by high prevalence in the top quarter, while hip and spine fractures' prevalence did not vary significantly.
Conclusions: The current study provides evidence suggesting a potential adverse effect of pro-inflammatory diet on bone health; which may have implications for dietary approaches for those with history of abnormal bone health complications.