One of the ways in which general health practices - such as exercise and fitness - steer cognitive health is through the state of the blood vessels in your brain: if they are deteriorating more rapidly, then more microinfarcts will occur, destroying more of the function of the brain, one tiny piece at a time. This is a mechanism quite distinct from the root causes of dementias like Alzheimer's disease, as this study illustrates: "This study was untaken to investigate the association of micro brain infarcts (MBIs) with antemortem global cognitive function (CF). ... Subjects were 436 well-characterized male decedents from the Honolulu Asia Aging Autopsy Study. Brain pathology was ascertained with standardized methods, CF was measured by the Cognitive Abilities Screening Instrument, and data were analyzed using formal mediation analyses, adjusted for age at death, time between last CF measure and death, education, and head size. Based on antemortem diagnoses, demented and nondemented subjects were examined together and separately. ... In those with no dementia, MBIs were strongly associated with the last antemortem CF score ... This suggests that microinfarct pathology is a significant and independent factor contributing to brain atrophy and cognitive impairment, particularly before dementia is clinically evident. The role of vascular damage as initiator, stimulator, or additive contributor to neurodegeneration may differ depending on when in the trajectory toward dementia the lesions develop."

Link: http://www.ncbi.nlm.nih.gov/pubmed/22162060

Source:
http://www.longevitymeme.org/newsletter/latest_rss_feed.cfm