Association of dietary diversity with frailty and pre-frailty in a general Japanese population: the Hisayama Study

Frailty and pre-frailty are characterized by a decline in life functions, including physical and mental vitality, for which dietary habits play an important role. This study aimed to examine the association of dietary diversity with frailty and pre-frailty in a community-dwelling older Japanese population. Food intake was assessed using a food frequency questionnaire, and the dietary diversity score (DDS) was calculated based on the number of days per week that each of the 12 food groups was consumed. A total of 1,388 participants (628 men and 760 women) aged 65 and older were divided into five groups according to the quintile of DDS. Frailty status was assessed according to the revised Japanese version of the Cardiovascular Health Study criteria. A multinomial logistic regression analysis was used to estimate odds ratios with 95% confidence intervals (CIs) for having frailty and pre-frailty according to the DDS. The overall prevalence rates were 6.7% ( n = 93) with frailty and 47.5% ( n = 659) with pre-frailty. Higher DDS was significantly associated with a lower likelihood of frailty and pre-frailty. The multivariable-adjusted odds ratio for having frailty and pre-frailty in individuals in the highest quintile of DDS was 0.36 (95% CI, 0.16–0.81) for frailty, and 0.53 (95% CI, 0.35–0.81) for pre-frailty. Further adjustment for intakes of energy, protein, and calcium found that 60.2% and 33.5% of the association of DDS with frailty and pre-frailty could be explained by these factors. Dietary diversity is associated with a lower likelihood of having frailty and pre-frailty, which may be partly attributable to the intake of energy, protein, and calcium.