Nutrition and cognitive deficit in the elderly: a population study.

OBJECTIVE: To investigate the association between a healthy diet indicator and the prevalence of cognitive impairment in the elderly. DESIGN: Cross-sectional study. SETTING: Population based. SUBJECTS: A total of 1651 subjects (560 men and 1091 women) including everybody aged 70 y or more, and a random sample of people (about 40%) aged 65-69 y resident in four rural towns in the province of Pavia, Italy in 1992-1993. INTERVENTIONS: The healthy diet indicator based on the WHO guidelines for the prevention of chronic diseases was calculated as reported by Huijbregts et al (1998; Eur. J. Clin. Nutr. 52, 826-831). Food intake was estimated by means of a 180-item food-frequency questionnaire and nutrient intake was calculated using the food composition database compiled for epidemiologic studies in Italy. The cognitive function was categorized into four levels-normal cognition, mild, moderate and severe cognitive deficit-according to the neuropsychological test score. The relationship between the dietary and the ordinal cognitive function variables was studied using the proportional-odds model. RESULTS: After adjustment for age, sex, education, total energy intake, cigarette smoking, alcohol consumption and physical activity, a better healthy diet score was associated with a lower prevalence of cognitive deficit. The cumulative odds ratio was 0.85 (95% CI 0.77-0.93). CONCLUSIONS: Our results suggest an association between a globally satisfactory diet and better cognitive performance in the elderly. However, the specific aspects of a 'healthy diet' for the elderly should be clarified.