Abstract
AIM: This study aimed to investigate the association between dietary phytate intake and the incidence of bone fractures among adults aged over 50 years. METHODS: Particpants of the third (2006-2008) and fourth (2009-2011) phases of the Tehran Lipid and Glucose Study (n = 1917, mean age 59.1 ± 7.1 years, and 50.1% men) who had completed dietary data were included and followed through March 2018 for the incidence of any fracture requiring inpatient care. Cox proportional hazards models were conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident fractures across tertile categories (< 1770, 1770-2598, and > 2598 mg/d) and per each 500 mg/d increase in dietary phytate intake. RESULTS: During a median follow-up period of 11.5 years (interquartile range: 10.5-12.4 years), 4.4% of participants experienced a new incident fracture. Mean ± standard deviation of dietary phytate intake was 2313 ± 1061 mg/d. In the presence of the potential confounders (i.e., age, sex, use steroids, metabolic syndrome score, energy intake, dietary fiber and calcium, use of calcium and vitamin D3 supplement, smoking, and physical activity), participants in the highest tertile of dietary phytate intake (> 2598 mg/d) had a significantly lower risk of fracture (HR = 0.40, 95% CI = 0.21-0.775, P = 0.006). Each 500 mg/d increase in dietary phytate intake was associated with a 14% reduction in fracture risk (HR = 0.86, 95% CI = 0.75-0.98, P = 0.027). CONCLUSION: Higher dietary phytate intake was independently associated with a lower risk of incident fractures, suggesting a potential protective role against fracture in middle-aged and older adults.