Nutritional parameters could influence self-perceived health and functional status of older adults.
We prospectively determined the association between diet quality and quality of life and activities of daily living.
This was an observational cohort study in which total diet scores, reflecting adherence to dietary guidelines, were determined. Dietary intakes were assessed using a food frequency questionnaire at baseline. Total diet scores were allocated for intake of selected food groups and nutrients for each participant as described in the Australian Guide to Healthy Eating. Higher scores indicated closer adherence to dietary guidelines.
In Sydney, Australia, 1,305 and 895 participants (aged ≥55 years) with complete data were examined over 5 and 10 years, respectively.
Main outcome variables
The 36-Item Short-Form Survey assesses quality of life and has eight subscales representing dimensions of health and well-being; higher scores reflect better quality of life. Functional status was determined once at the 10-year follow-up by the Older Americans Resources and Services activities of daily living scale. This scale has 14 items: seven items assess basic activities of daily living (eg, eating and walking) and seven items assess instrumental activities of daily living (eg, shopping or housework).
Statistical analyses performed
Normalized 36-Item Short-Form Survey component scores were used in analysis of covariance to calculate multivariable adjusted mean scores. Logistic regression analysis was used to calculate adjusted odds ratios and 95% CIs to demonstrate the association between total diet score with the 5-year incidence of impaired activities of daily living.
Participants in the highest vs lowest quartile of baseline total diet scores had adjusted mean scores 5.6, 4.0, 5.3, and 2.6 units higher in these 36-Item Short-Form Survey domains 5 years later: physical function (Ptrend=0.003), general health (Ptrend=0.02), vitality (Ptrend=0.001), and physical composite score (Ptrend=0.003), respectively. Participants in the highest vs lowest quartile of baseline total diet scores had 50% reduced risk of impaired instrumental activites of daily living at follow-up (multivariable-adjusted Ptrend=0.03).
Higher diet quality was prospectively associated with better quality of life and functional ability.