In the latest online issue of the journal Stroke a European research consortium, which also includes a German group (Department of Neurology, University of Heidelberg, Klinikum Mannheim), could again demonstrate that even very modest physical activity significantly reduces the risk of developing dementia (Verdelho et al., Stroke 2012, in press).
The LADIS (Leukoaraiosis and Disability) study prospectively investigates the role of CT or MRI white matter changes for later development of disability. Leukoaraiosis describes diffuse white matter abnormalities, as they are often observed in CT or MRI scans as incidental findings in healthy individuals. In recent years it has become increasingly clear that such changes frequently occur in people with vascular risk factors and that they appear to have some significance for the development of cerebrovascular diseases and dementia .
In the paper just published 639 older people with a mean age of 74.1 years who were living independently at the beginning of the observation period (but certainly could already be cognitively impaired) were observed over a period of three years. All subjects were tested annually for their cognitive performance and asked about their physical activity. An MRI was performed at baseline and at the end of the three-year observation period. All subjects presented with white matter changes at baseline (44% mild, 31% moderate, 25% severe). 30% had previously had a cerebral ischemia at least once, 15% suffered from diabetes mellitus. 64% of the subjects were physically active at the beginning of the study. For the assessment of physical activity, the criterion of the American Heart Association (AHA) was used. According to the AHA, a person is considered physically active, if she or he exercises at least three times a week for at least 30 minutes.
At the end of the observation period 90 people were diagnosed with dementia (vascular dementia: 54; Alzheimer’s dementia with vascular component: 34; frontotemporal dementia: 2). In 147 persons cognitive impairment without dementia was present. Subjects who were physically active at baseline had a lower risk of being diagnosed with dementia after three years by approximately 40%. The risk of suffering from cognitive impairment was reduced by about 60% by physical activity. The risk reduction was independent of the presence of diabetes mellitus. Likewise, no correlation with the severity of white matter changes at baseline or age or educational level of the subjects was found.
Earlier reports on results from the LADIS study had already shown that pronounced white matter changes are associated with poor motor performance and with an increased risk for falls. They also increase the risk for the development of cognitive impairment and vascular dementia. These newly published results suggest that such developments can be delayed with physical activity.
In the meanwhile, many studies have been performed and published on the link between physical activity and cognitive performance in old age and the risk of developing dementia. I will deal with this important issue in future posts.
This post is also available in: German