Malnutrition is associated with faster functional loss but not cognitive decline in older adults with dementia, suggests new research led by King’s College London and Stavanger University Hospital.
Published in the Journal of Alzheimer’s Disease, the study is one of the first to analyse the association between malnutrition and the course of cognitive and functional decline in people living with dementia.
The researchers accessed a long-term cohort study called the Dementia Study of Western Norway, drawing on data from 202 patients diagnosed with mild dementia, including Alzheimer’s disease (AD; n = 103), Lewy body dementia (LBD; n = 74) and other dementias (n = 25).
Cognition was assessed with the Mini-Mental State Examination and functional decline through the activities of daily living included in the Rapid Disability Rating Scale. The Global Leadership Initiative on Malnutrition Index, which measures body weight, thinness and muscle mass, was used to determine nutritional status. Associations of nutritional status with cognitive and functional decline were evaluated through adjusted linear mixed models.
At baseline, the prevalence of general malnutrition was 28.7 per cent; 17.3 per cent were classified as moderate malnutrition and 11.38 per cent as severe malnutrition (there were no significant differences between AD and LBD).
Malnutrition at diagnosis and over five-year follow-up was a significant predictor of faster functional-decline, but not of cognitive decline.
A more comprehensive dementia approach including nutritional assessments could improve prognosis, the study concluded.
Study author Prof Dag Aarsland, King’s College London’s Institute of Psychiatry, Psychology & Neuroscience, said: “We think malnutrition worsens function through its impact on the body’s muscles and immune system, mood, mobility and other aspects of physical and mental health. However, this relationship is likely to go in both directions – for example, functional loss generates barriers to food access and cooking, which could exacerbate malnutrition.”