A new nationally representative study by physicians at the University of Michigan shows a downward trend in the rate of "cognitive impairment" -- the umbrella term for everything from significant memory loss to dementia and Alzheimer's disease -- among people aged 70 and older.
While the prevalence of cognitive impairment these older adults went down by only 3.5 percentage points between 1993 and 2002 (from 12.2 percent to 8.7 percent) , that figure represents a difference of hundreds of thousands of people.
What Causes Cognitive Impairment Rates to Go Down?
The reasons for this decline aren't yet fully known, but the authors point to influences that may help slow the rate of cognitive impairment decline:
- More formal education and more money Among 11,000 people in the study, those with more formal education and personal wealth were less likely to have cognitive problems.
The research team's analysis suggests that about 40 percent of the decrease in cognitive impairment over the decade was likely due to the increase in education levels and personal wealth between the two groups of seniors studied at the two time points.
Researchers note that school attendance requirements, high school graduation rates and college or technical school enrollment rates all increased during the years when the adults in the study were children and young adults. In recent years, research has suggested that the more education a person receives early in life, the more his or her brain will be able to stay sharp later.
Interestingly, the more-educated seniors who had cognitive impairment were more likely to die within two years. But the researchers say this may actually result from a protective effect of better education on a person's "cognitive reserve" -- their ability to sustain more insults to their brain before significant thinking problems arise.
- Better health care – Study participants received better care for risk factors such as high blood pressure, high cholesterol and smoking that can jeopardize their brains. The use of cholesterol-lowering drugs, blood pressure medications and other preventive cardiovascular medications and strategies increased dramatically in the 1990s. Researchers believe that these factors may have helped protect seniors' brain function by decreasing the incidence of vascular dementia -- cognitive problems brought on by mini-strokes, strokes and decreased blood flow to and within the brain due to "hardened" or clogged arteries.
Good News for Seniors
Kenneth Langa, M.D., Ph.D., and study lead author, calls the findings good news for today's seniors, noting that the new data support recent theories of how brains can be protected and preserved.
"From these results, we can say that brain health among older Americans seems to have improved in the decade studied, and that education and wealth may be a big piece of the puzzle," Langa says.
The Keys to Cognitive Health? Mental Stimulation and Cardiovascular Health
"We know mental stimulation has an impact on the way a person's brain is 'wired,' and that education early in life likely helps build up a person's cognitive reserve," Langa said.
"We also know cardiovascular health has a close link with brain health," he continues. "So what we may be seeing here is the accumulated effects of better education and better cardiovascular prevention among the people who were over age 70 in 2002, compared with those who were over age 70 in 1993."
…But Type 2 Diabetes is On the Rise
While the new study shows a decline in cognitive impairment rates over time, the researchers say that gains made in the 1990s and early 2000s might be offset by the damage that could result if the current epidemic of type 2 diabetes keeps growing among the elderly, and if current middle-aged and younger people stick with unhealthy eating and exercise habits that lead to unhealthy weights and blood pressures.
Total of Adults with Cognitive Impairments Will Rise as Boomers Age
Even if the proportion of older adults with cognitive impairments keeps declining, the total number of older adults with cognitive impairments and dementia are expected to increase significantly as more baby boomers reach age 65.
"This demographic reality will continue to make combating Alzheimer's disease and other types of dementia a top public health priority," said Allison Rosen, M.D., Sc.D., and co-author of the study.
What You Can Do to Reduce Your Risk of Cognitive Impairment
The study authors recommend that today's older Americans resist the urge to rest on their laurels, and instead pursue activities that can keep their minds sharp and their cardiovascular risk low. which can reduce their risk factors for cognitive impairment. From crossword puzzles and volunteer activities to blood pressure medications, today's seniors can work to boost their brain health now and prevent decline later. The authors also suggest that walking and other types of physical activity are important for preventing cognitive and memory decline.
"The evidence seems to be showing that staying mentally engaged with the world in any fashion -- reading, talking with friends, going to church, going to movies -- is also likely to help reduce your risk down the road," Langa says.
