Adherence to Mediterranean Diet In Relation to Bbone Mineral Density and Risk of Fracture: Accumulative Evidence From a Systematic Review and Meta-Analysis of Epidemiological Sstudies

Given the conflicting findings and lack of systematically reviewed publication of previous studies, this study aimed to systematically review available data on the association between adherences to Mediterranean diet (MD) and bone mineral density (BMD) as well as risk of fractures through a meta-analysis.
Previous studies in the field of adherence to MD in relation to BMD and risk of fracture were selected through searching PubMed, Scopus, ISI Web of Science and Google Scholar databases prior to June, 2016 by using Mesh and non-Mesh relevant keywords. Observational studies that conducted on humans, examined the relationship between adherence to MD and BMD and risk of fractures, reported odds ratios (ORs) or hazards ratios (HRs) along with 95% confidence intervals for fracture or BMD or reported BMD ҆s mean ± standard deviations (SDs) across categories of MD score were included.
Considering inclusion criteria and aim of the study, 13 papers were included for the systematic review and 7 papers included for meta-analysis. In the meta-analysis of 6 effect sizes, obtained from 4 studies, we found that adherence to MD was associated with a 34% reduced risk of hip fracture [overall RR: 0.66; 95% CIs: 0.51 to 0.85]; however, a significant between-study heterogeneity was found (I2=74.2%, Pheterogeneity=0.002). Study design was the main source of between-study heterogeneity; the inverse association remained significant for both cohort [RR=0.79; 0.72-0.87] and case-control studies [RR =0.26; 0.51-0.85]. Adherence to MD was positively associated with lumber spine’s [mean difference of BMD comparing highest and lowest categories of MD score: 0.12; 95% CI: 0.06-0.19 g/cm2], femoral neck [0.10; 0.06-0.15 g/cm2] and total hip [0.11; 0.09-0.14 g/cm2] BMD.
Adherence to MD was associated with a reduced risk of fracture as well as with a higher mean BMD.