If you want to avoid a society-wide epidemic of Alzheimer's, target the less well-educated for mental stimulation
Participants [in the new study out of the Mayo Clinic, published in JAMA Neurology] underwent a “neuropsychological battery of tests,” evaluating the executive, language, memory, and visuospatial performance of their brains. The researchers found that “the protective effect of intellectual enrichment is primarily manifested as a relatively consistent higher cognitive performance over time.” Higher education levels, and more occupational and cognitive activity were independently associated with a lower risk of dementia as well.
Mental stimulation throughout a person’s life helped decrease the risk more than if they started cognitive activities in mid-life, but those with lower education levels benefitted more from mid and late life activity than those with higher education levels.
“Doing cognitive activities at least three times a week was highly protective,” says Dr. Prashanthi Vemuri, an assistant professor of radiology at the Mayo Clinic and lead author on the study.
The difference was measured in years. Those who had more education got at least five years of protection; mid and late life cognitive activity provided about three years of protection on average for APOE4 gene carriers and about seven years for non-carriers. The overall effect of “lifetime intellectual enrichment”—all these factors taken together—was strong. Those who ranked in the 75th percentile could delay the onset of cognitive impairment by more than eight years, compared to those with low lifetime intellectual achievement (the 25th percentile).
“If you start early, your brain is probably sharper than starting later,” [Dr. Prashanthi Vemuri, an assistant professor of radiology at the Mayo Clinic and lead author on the study] says, “But it’s never too late, that’s one strong message from the study.”
You could call it "Late Start" instead of "Head Start."
Of course, we can take education levels as a reasonable proxy for class. And the very last thing our society wants to do is have working people using their heads. Anyhow, dementia is profitable. So forget it.