Cardiorespiratory fitness, the ability of the circulatory and respiratory systems to supply oxygen to the musclesdecreases more and more with age as skeletal muscles weaken. It is estimated that cardiorespiratory fitness decreases by approximately 3 to 6% per decade between the ages of 20 and 30, but this decline accelerates to reach more than 20% per decade after the age of 70.
Low cardiorespiratory fitness is a predictor of cardiovascular events
such as strokes and heart attacks, and all-cause mortality. This research reveals that it is also a predictive factor of dementia.
Conversely, good cardiorespiratory fitness is associated with better cognitive function, less cognitive decline and a lower risk of dementia in the long term, with important precision: including in people with a genetic predisposition to dementia.
The study follows more than 60,000 participants, free of dementia at baseline, aged 39 to 70 at baseline, registered with the UK Biobank and followed for a minimum of 12 years. At enrollment, participants’ cardiorespiratory fitness was assessed with a stationary bike test and their cognitive function using neuropsychological testing. Their genetic predisposition to dementia was estimated using the Alzheimer’s disease polygenic risk score. The analysis finds that:
- over the 12-year follow-up period, 0.9% of participants were diagnosed with dementia;
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compared to participants with low cardiorespiratory fitness, for participants with high cardiorespiratory fitness, the risk of all dementias is reduced by 40%;
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the onset of dementia is delayed by 1.5 years on average;
- Good cardiorespiratory fitness is also associated with a 35% reduction in participants with moderate or high polygenic risk scores.
Although this is an observational study which therefore does not demonstrate the cause and effect relationship, it reveals a solid association, over a large sample and an extended age spectrum, between good cardiorespiratory health and a reduction in the risk of dementia.
Improve your cardiorespiratory condition by practicing a suitable exerciseconstitutes a prevention strategy, effective at all ages, against the development of dementia, and even for people with a strong genetic predisposition to Alzheimer’s disease.
