Behavioral Disturbances, Not Cognitive Deterioration, Are Associated With Altered Food Selection in Seniors With Alzheimer's Disease

Abstract

We previously reported alterations in circadian patterns of food intake that are associated with measures of functional and cognitive deterioration in seniors with probable Alzheimer's disease (AD). This study further explored disturbed eating patterns in AD, focusing on alterations in macronutrient (protein, carbohydrate, and fat) selection, and their association with measures of functional and behavioral losses. Forty-nine days of food intake collections were conducted on 32 residents (26 females, 6 males; age = 88.4 +/- 4.1 years; body mass index = 24.1 +/- 4.0 kg/m(2)) with probable AD residing at a nursing home (a fully accredited geriatric teaching facility affiliated with the University of Toronto's Medical School). All residents ate their meals independently. The relationships between patterns of habitual food consumption and measures of cognitive function (Severe Impairment Battery), behavioral disturbances (Neuropsychiatric Inventory-Nursing Home Version) and behavioral function (London Psychogeriatric Rating Scale) were examined, cross-sectionally. Consistent with our previous studies, breakfast intakes were not predicted by any of the measures of behavioral, cognitive, or functional deterioration, although those residents with greater functional deterioration, especially disengagement, attained lower 24-hour energy intakes. The presence of "psychomotor disturbances," including irritability, agitation, and disinhibition, were strongly associated with shifts in eating patterns toward carbohydrate and away from protein, placing individuals with these conditions at increased risk for inadequate protein intakes. Between-individual differences in intake patterns could not be explained by the use of either anorexic or orexigenic medications. Behavioral, not cognitive, deterioration is associated with appetite modifications that increase risk of poor protein intake, perhaps indicating a common monoaminergic involvement.