Dementia is a looming problem amongst the ageing population. That is why a lot of research goes into investigating its causes and methods of prevention.
Dementia is the leading cause of death among Australian women according to the latest figures.
Previous studies have linked physical activity to improved cognitive functioning and a decreased risk for dementia. Aerobic exercises aimed at improving cardiovascular functioning has a moderate effect on cognitive function in healthy older adults according to previous studies.
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But most studies are conducted on people over 60 years of age and very few have a follow up of over 20 years.
Midlife has been suggested to be a sensitive period for the effect of cardiovascular risk factors on dementia.
To investigate whether greater cardiovascular fitness in midlife is associated with decreased dementia risk in women, scientists from the University of Gothenburg in Gothenburg, Sweden conducted a study on a population-based sample of 1,462 women.
The women who were aged between 38 to 60 years old were examined in 1968.
Out of these 191 women undertook a bicycle exercise test until they were exhausted to measure their peak cardiovascular capacity. The average peak workload was measured at 103 watts.
40 women reached peak capacity and were categorised for high fitness level at over 120 watts and over.
92 women were in the medium fitness level and 59 women were in low fitness category defined as 80 watts or less – or having their exercise stopped due to high blood pressure, chest pain or other cardiovascular problems.
Over the next 44 years the women were tested for dementia in 1974, 1980, 1992, 2000, 2005, and 2009.
During that time 44 women developed dementia. Five percent of the highly fit women developed dementia compared to 25 percent of the moderately fit women and 32 percent of the women with low fitness.
The scientists calculated that fit women were 88 percent less likely than moderately fit women to develop dementia.
Among the women who had stopped exercise due to problems, 45 percent developed dementia decades later.
When the highly fit women did develop dementia, they developed it is at an average of 11 years later that the women who were moderately fit – at an age of 90 years instead of at age 79 years.
Th study shows that negative cardiovascular processes in midlife result in early onset of dementia in later years in women.
The study does not show the cause and effect between cardiovascular fitness and dementia, but the discoveries are exciting as its possible to improve cardiovascular fitness in middle age to delay the risk of dementia.
Although further investigations are necessary, based on the findings cardiovascular fitness can be included in interventions used to mitigate dementia.
Source: Neurology
