Are malnutrition and stress risk factors for accelerated cognitive decline? A prisoner of war study

We set out to test the hypothesis that severe malnutrition and stress experienced by prisoners of war (POWs) are associated with cognitive deficits later in life. We assessed 101 former Australian POWs of the Japanese and 108 veteran control subjects using a battery of neuropsychological tests, a depression scale, a clinical examination for dementia, and CT. We divided the POWs into high weight loss (>35%) and low weight loss groups (<35%). We found no significant differences in cognitive performance between the POWs and control subjects or between high and low weight loss groups on any of the tests or in the prevalence of dementia. Scores on the depression scale showed that the former POWs had more depressive symptoms than the control subjects a decade previous, but the difference had diminished over time. This study does not support the hypothesis that malnutrition is a risk factor for accelerated cognitive decline nor the theory that severe stress can lead to hippocampal neuronal loss and cognitive deficits. Cognitive deficits in earlier studies of former POWs may have been associated with concurrent depression.