In a hopeful sign for the health of the nation’s brains, the percentage of American seniors with dementia is dropping, a new study finds.

The downward trend has emerged despite something else the study shows: a rising tide of three factors that are thought to raise dementia risk by interfering with brain blood flow, namely diabetes, high blood pressure and obesity.

Those with the most years of education had the lowest chances of developing dementia, according to the findings published in JAMA Internal Medicine. This may help explain the larger trend, because today’s seniors are more likely to have at least a high school diploma than those in the same age range a decade ago.

The new results add to a growing number of recent studies in the United States and other countries that suggest a downward trend in dementia. These findings may help policy-makers and economic forecasters adjust their predictions for the total impact of Alzheimer’s disease and other conditions.

The researchers used data and cognitive test results from ISR’s long-term Health and Retirement Study to evaluate trends from 2000 to 2012 among a nationally representative sample of more than 21,000 people age 65 or over.

In all, 11.6 percent of those interviewed in 2000 met the criteria for dementia, while in 2012, only 8.8 percent did. Over that time, the average number of years of education a senior had increased by nearly an entire year, from 12 to 13.

Even as these new results come out, the research team is in the middle of another large study of dementia in the U.S. that will help refine the techniques for better understanding who has dementia in the American population, and allow them to be used in other countries around the world where HRS “sister studies” are also collecting data.

Paper: “A Comparison of the Prevalence of Dementia in the United States in 2000 and 2012”
Reprinted from materials provided by the University of Michigan.