The generous participants in the 20+ year Rush Memory and Aging Project were recruited from Chicago community-based settings and studied on average for 7 years with wide-ranging cognitive assessments. Of the people in this study, 24% were ApoE 4 carriers.
The key question was whether early cognitive enrichment (factors such as being read to at a young age, reading books at age 8 and above and studying a foreign language before age 18), were associated directly with cognitive health in old age (as has been suggested in previous studies) and ALSO indirectly associated with cognitive health due to less Alzheimer's brain pathology.
Here are the results, in excerpts:
This will reassure some of us lucky enough to have had these experiences. It also makes a compelling argument that ALL children should have rich cognitive experiences starting in preschool, with Head Start, UPK and high quality literacy support. Even with children who speak a home language other than English, teaching parents how to read to and with their preschoolers leads to strong English literacy later on. We help our future elder population when we help our youngest population.From January 1, 1997, through June 30, 2019, 2044 participants enrolled, of whom 1018 died. Postmortem data were leveraged from 813 participants. Data were analyzed from April 12, 2019, to February 20, 2020...
ELCE [Early Childhood Cognitive Enrichment] was associated with better late-life cognitive health, in part through an association with fewer AD pathological changes...An indirect effect through AD pathological changes constituted 20% of the association between ELCE and the rate of late-life cognitive decline, and 80% was a direct association... The effect size associated with a 1-unit increase in the ELCE was equivalent to the effect size associated with being 8 years younger...Addition of a term for possession of an APOE ε4 allele did not affect results (eTable 4 in the Supplement), indicating that the association of ELCE with AD pathological changes was not confounded by APOE ε4 genotype.