Objectives: To investigate the association between nutritional status and general and specific (fluid and crystallized) cognitive functioning in a group of older people living in a rural area in Bangladesh.
Design: Cross-sectional study.
Setting: Matlab, Bangladesh.
Participants: Four hundred fifty-seven randomly selected persons aged 60 and older (mean age 69.5 +/- 6.8), 55% female.
Measurements: Nutritional status was evaluated using a modified form of the Mini Nutritional Assessment (MNA). General cognitive function was assessed using the Bangla Adaptation of the Mini-Mental State Examination, and a word synonym test was used to test semantic memory function (a crystallized ability). To assess cognitive processing speed (a fluid ability), "cross balls" and "complete boxes" tests (scores/time unit) were used. Clinical diagnoses were registered. Structured questionnaires were used to assess demographic and socioeconomic status of the participants.
Results: Twenty-six percent of the participants were undernourished, and 62% were at risk of malnutrition according to the MNA. The MNA scores were significantly lower in women than in men (P=.01). Women performed worse than men in all three cognitive tasks (P<.001). Poorer cognitive performance was independently associated with older age, female sex, illiteracy, visual impairment, severity of disease, and depressive symptoms. There were significant associations between better nutritional status and better cognitive performance tests of general ability and processing speed, whereas semantic memory appeared to be less affected.
Conclusion: The association between nutritional status and cognitive function involves general and specific cognitive abilities, with fluid ability seeming to be affected but crystalized functions being relatively spared.