Adherence to the Mediterranean Diet and the Risk of Frailty in Old People: A Systematic Review and Meta-Analysis

Frailty is a common geriatric syndrome in old people. It remains controversial whether Mediterranean diet could prevent old people from developing into frailty. The aim of this study is to summarize the relevant studies and assess the effectiveness of adherence to Mediterranean diet on frailty in old people. A systematic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials was conducted to identify all relevant studies up to Oct 2017. We included studies regarding the associations between adherence to Mediterranean diet and risk of frailty among elders. A meta-analysis was performed to explore the effects of Mediterranean diet on frailty. Six studies matched the inclusion criteria, of which five were prospective and one was cross-sectional. A total of 10,210 participants from the five prospective cohort studies were included to perform the meta-analyses. In comparison with lowest adherence to Mediterranean diet, elders with highest adherence to Mediterranean diet were significantly associated with lower risk of frailty in the future (RR= 0.56, 95% CI=0.36-0.89, p=0.015). Furthermore, the pooled estimates from four studies performed among participants in western countries (European and North American) showed that higher adherence to Mediterranean diet was associated with a 52% reduced risk of frailty (RR= 0.48, 95% CI=0.32-0.72, p < 0.001). However, one study showed no association between Mediterranean diet and frailty among Asian elders (RR=1.06, 95% CI=0.83-1.36, p=0.638). A higher adherence to Mediterranean diet is associated with a lower risk of frailty in old people. Meanwhile, the benefits may be more obvious among elders from western countries.