Greater physical activity and cardiorespiratory fitness are associated with reduced age-related cognitive decline and lower risk for dementia. However, significant gaps remain in the understanding of how physical activity and fitness protect the brain from adverse effects of brain aging.
Cardiorespiratory fitness is a physiological attribute defined as the ability for circulatory and respiratory systems to deliver oxygen.
Cardiorespiratory fitness has a positive relationship with functional connectivity of several cortical networks associated with age-related decline. Furthermore it can occur independent of habitual physical activity.
A 2017 article found evidence for a shared mechanism underlying a favourable cardiovascular fitness profile and ALS susceptibility. The scientists did expose three hypothesis but this one had their favors: A genetic predisposition, for example metabolism, could lead to an increased risk of ALS and a beneficial cardiovascular risk profile. But they were unable to find evidence supporting it.
The scientists in this new publication on contrary found no association between common vascular risk factors and cognitive impairment in patients with Amyotrophic Lateral Sclerosis.
In their cohorte 870 patients, 266 had cognitive impairment. yet no cognitive burden from vascular risk factors was found in patients with Amyotrophic Lateral Sclerosis. On the contrary (and as found in many other studies), the authors first observed that type 2 diabetes mellitus and hyperlipidemia showed protective effects against cognitive decline in Amyotrophic Lateral Sclerosis.
Sensitivity analyses of gender did not substantially reverse the risk estimates. : T2DM and hyperlipidemia decrease the risk of cognitive impairment in patients with Amyotrophic Lateral Sclerosis.
So the fitness hypothesis in Amyotrophic Lateral Sclerosis seems less probable or more complex than initially stated.