*[Factors That Can Protect Older Adults from Dementia]

Lifestyle Choices Can Moderate the Development of Alzheimer’s Symptoms

In my book, Aging or Alzheimer’s? readers will discover 31 personal choices that can slow or even prevent symptoms of Alzheimer’s disease. Check out Table 2 for “Potentially Modifiable Alzheimer’s Disease Risk Factors.” Most reflect the same healthy lifestyle choices we were urged to adopt long before becoming distressed by failing memory. Suggested lifestyle reforms range from shunning unhealthy diets and physical inactivity, to aiming for the 7-hour Sleep-duration “sweet spot”, while avoiding distressing dreams, social isolation, and noise pollution.

Genetics and Inherited Resilience

We have no choices available to us in this arena. Our personal wins and losses in the genetic lottery were locked in at conception and will be forwarded automatically to our progeny, and later to theirs.

 Genetic risks: We could be carrying the “Alzheimer’s Gene “. The strongest genetic risk factor for the common (late-onset) form of Alzheimer’s disease (AD) is the E4 allele of apolipoprotein E (APOE4). This gene contributes to the likelihood of developing AD and is present in 40%–60% of cases. 

Genetic benefits: Individuals vary in their “resilience,” a highly beneficial inherited trait that combines both resistance to expected age-related brain changes and protection from the effects of toxic accumulation of amyloid and tau proteins on cognition. Identified “resilient” people have avoided dementia despite extreme old age, even when their brains are indistinguishable from those of their peers with Alzheimer’s disease!

 Acquired Protection Through “Cognitive Reserve”

WHAT: Unlike lifestyle choices or inherited tendencies, “Cognitive Reserve” (CR) represents an individual’s unique acquired ability to maintain normal cognitive function despite the presence of brain disease or injury. It offers hope that we can act now to potentially protect our children, grandchildren, and ourselves from future decline. (See Chapter 4, Aging or Alzheimer’s?)

WHO: Cognitive Reserve is most often found in individuals with significant educational and occupational achievements and engagement in leisure and social activities.

HOW: Interference with connections between distant brain regions is a feature of Alzheimer’s disease. CR is attributed to acquired backup brain circuitry. Increased neural connections buffer the effects of losing brain cells and the links between them to AD. The greater the number of years of learning, the more dense the circuitry. Experts assume that if the original path is lost to Alzheimer’s, the brain can activate the backups. Thus, brains with added cognitive reserve can lose more cells and connections to AD without effect. Despite the same amount of amyloid, there is less cognitive decline!

Activities Generating Cognitive Reserve: “Common surrogates for CR include years of schooling, job complexity, vocabulary level, literacy, and integrity of social networks.” Each factor has been shown to reduce the degree of AD measured by quantitative biomarkers. Observers have linked CR to more successful aging and a decreased risk of dementia.

Schooling:  When compared with those with less schooling, persons with the highest levels of Education had a 40% decreased risk of Alzheimer’s disease. Half of the autopsied individuals identified as “resilient” had a college degree, compared with 32% for “non-resilient.”

The nature of one’s work: In a study of 107,896 participants, the risk of dementia in old age was lower in individuals with cognitively stimulating jobs than in those with non-stimulating jobs. This finding persisted with adjustments for education and established dementia risk factors. Job-related cognitive stimulation was also associated with lower levels of some blood proteins believed to increase dementia risk.

Exposure to Early-Life Cognitive Enrichment (ELCE): Investigators examined the brains elderly subjects who had previously detailed what “Early-Life Cognitive of Enrichment” they had experienced by ages six, eight, twelve, and eighteen. ELCE included socioeconomic status, parents’ education, number of siblings, cognitive resources in the home, reading and being read to, and early foreign language instruction. ELCE was associated with better late-life cognitive health, partly through fewer AD brain changes. Notably, these effects were independent of one’s late-life socioeconomic status and late-life reports of cognitive activity, suggesting that the benefits of early cognitive enrichment go beyond long-term changes in lifestyle or behavior.

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Cognitive Reserve – The Bottom Line:

Bravo for preschool and at-home enrichment programs!

By helping prevent or lessen the impact of dementia, such interventions have the demonstrated potential to extend their benefits a lifetime beyond their stated purpose of promoting “school readiness of infants, toddlers, and preschool-aged children.”