Dietary glycaemic load associated with cognitive performance in elderly subjects.

PURPOSE
Ageing is associated with loss of cognitive function and an increased risk of dementia which is expected to place growing demands on health and long-term care providers. Among multiple causative factors, evidence suggests that cognitive impairment in older subjects may be influenced by diet. The objective of this study was to examine the association between dietary patterns, dietary glycaemic load (GL) and cognition in older Irish adults.

METHODS
Community-dwelling subjects (n 208; 94 males and 114 females; aged 64-93 years) were analysed. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Cognitive capacity was tested using the Mini-Mental State Examination (MMSE). The data were clustered to derive patterns of dietary intake. Multivariable-adjusted logistic and Poisson regression models were used to examine the relationship between dietary GL and MMSE score.

RESULTS
Elderly subjects consuming 'prudent' dietary patterns (high in fruit, vegetables, fish, low-fat dairy and salad dressings and low in red meat and white bread) had higher MMSE scores (better cognitive function) than those consuming 'Western' dietary pattern (high in red meat and white bread and low in fruit and vegetables; P < 0.05). Logistic and Poisson regression analyses both indicated that the MMSE score was inversely associated with the GL of the diet (P < 0.05) even after adjusting for age, gender, diabetes, hypertension, healthy food diversity, nutritional status, residential property price, cardiovascular medications and energy intake.

CONCLUSION
In this community-dwelling elderly Irish cohort, consumption of a high glycaemic diet is associated with poorer cognitive performance as assessed by the MMSE.