Nutrient intake and psychological health in an elderly Chinese population

BACKGROUND: Associations between nutrition and cognitive impairment, and nutrition and depression, have been observed. Elderly people are at risk of under nutrition, and also have higher prevalence of cognitive impairment and depression. OBJECTIVE: To examine the relationship between nutrient intake and psychological health in the elderly, adjusting for confounding factors. SUBJECTS: Three thousand nine hundred and ninety-nine men and women aged 65 years and over living in the community, with approximately equal numbers in three age groups: 65-69, 70-74, 75+ years. METHODS: Dietary intake was assessed using a 7-day food frequency questionnaire. Cognitive function was assessed by the cognitive part of the Community Screening Instrument for Dementia (CSID). Depression was assessed using the Geriatric Depression Scale (GDS). Information was also collected for confounding factors: demographics, educational level, socioeconomic status, medical history, smoking, alcohol intake, and physical activity. Logistic regression analyses were carried out to examine associations between lifestyle and dietary variables, and CSID and GDS, controlling for confounders. RESULTS: Both CSID and GDS scores were associated with co-morbidity, demographic and socioeconomic factors. Few associations between lifestyle factors and CSID score were observed. Dietary factors inversely associated with GDS score include total fat intake, vitamins A, B2, B3, C, fibre, and vegetables. In terms of nutrient density, iron and isoflavone intake were additional factors. CONCLUSION: Association exists between intake of various nutrients and psychological health independent of other confounding factors in the elderly population. A follow-up study of this cohort or interventional studies are needed to elucidate cause effect relationship.