Storing up a buffer – the power of cognitive reserve
Cognitive reserve is “a condition in which an individual has observed cognitive performance better than expected given their brain’s
High cognitive reserve ensures normal cognition despite structural atrophy on brain imaging. Proxy measures of cognitive reserve include premorbid intelligence, education attainment, linguistic ability (e.g. bilingualism). One additional year of education confers 13-18% reduction in likelihood of receiving an AD diagnosis within 1 year of death; high cognitive activity level confers 50% reduction in dementia risk in next five
Again, inconclusive studies abound, attributable to difficulties in accounting for a large variety of cognitive activities (e.g. reading, board game/card games, playing musical instruments), rating the intensity of these activities, and teasing out confounding effect of social stimulation or physical exertion inherent to these activities. As a dementia care specialist, patients often ask me about cognitive training “games”; I usually advise focusing on personal hobbies or leisure activities. My advice is borne out by studies showing that gains in targeted function (e.g. memory, processing speed) from cognitive training tasks do not transfer to untrained task or daily life activities, therefore lack ecological
Putting it all to the test in randomized controlled trials
Three large landmark RCTs were completed recently. FINGER was a 2-year study in Finland examining the effect of a combined brain-healthy diet, exercise, cognitive training, stimulating social activity, vascular risk monitoring in 2,654 individuals pre-selected for vascular risk factors.6 PreDIVA was a 6-year study in the Netherlands assessing the effect of a multidomain cardiovascular intervention program including individually tailored lifestyle advice and medication treatment for vascular risk factors in 2,635 individuals.7 MAPT was a 3-year study in France and Monaco examining the effect of a multidomain program including exercise, cognitive activities, nutrition and omega-3 polyunsaturated fatty acids (PUFA) supplementation in 1,680 individuals.8
Only FINGER showed positive results for the primary outcome – multidomain intervention improved or maintained cognition. The other two studies showed negative primary outcomes, but subgroup analyses revealed benefit of aggressive vascular risk control in individuals who had not yet been treated in PreDIVA, and protective effect of multidomain intervention and omega-3 PUFA supplementation in individuals with high vascular risk and positive amyloid PET scan (i.e. higher risk for developing AD) in MAPT. These findings suggest more promise in multidomain approaches and carefully matching intervention with specific patient characteristics.