A new US study suggests that brain health is improving among older Americans as demonstrated by a decline in thinking and memory problems in this group. The
researchers said improved cardiovascular care, better education, and being financially better off could be the main reasons.
The research paper is published in the online issue of the journal Alzheimer's and Dementia and is the work of two doctors from the Ann Arbor based University of Michigan Medical School, and their colleagues.
The nationally representative study found there was a downward trend among people aged 70 and over in the rate of what the authors called "cognitive impairment" a term used by scientists to describe a range of conditions from memory loss to dementia and Alzheimer's disease.
Using data from the National Institute on Aging funded Health and Retirement Study (HRS), the researchers found that between 1993 and 2002, the prevalence of cognitive impairment among Americans aged 70 and over went down 3.5 per cent (from 12.2 to 8.7 per cent over the decade). This translates to a reduction of impairment in hundreds of thousands of US seniors.
The reasons for this decline are not clear, said the researchers, but they suggest older Americans today are more likely to be in receipt of improved care for neurological risk factors such as high blood pressure, smoking and high cholesterol; and more likely to have had more years of formal education and reached a higher economic status compared to their counterparts of a decade earlier.
The results showed that among the 11,000 people in the study, those who had been in education longer and had greater personal wealth were also the ones who were less likely to be experiencing cognitive problems.
A key interesting finding was that the more-educated seniors with cognitive problems were also more likely to die within two years of symptoms showing.
And this is where it would be easy to leap from "linked with" to "caused", a mistake that is made too often in reports of studies like this.
The authors were careful to draw attention to this by saying that this finding could also be due to the more educated elderly having a greater "cognitive reserve" which helped their brains sustain more damage before showing any cognitive impairment.
Lead author Dr Kenneth Langa, an associate professor of internal medicine and who also holds other appointments, said the results were good news for today's elderly Americans, and in line with new ideas about protecting and preserving brain health.
"Brain health among older Americans seems to have improved," said Langa, and suggested "education and wealth may be a big piece of the puzzle".
Mental stimulation affects how the brain is "wired", and education in early life appears to help people build up cognitive reserve, explained Langa.
"We also know cardiovascular health has a close link with brain health", he said, "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".
The researchers found that:
- About 40 per cent of the decrease in cognitive impairment over the decade ending in 2002 was likely due to increases in education and personal wealth. They found this by comparing two groups of seniors, one at the start of the decade and one at the end.
- School attendance requirements, graduation rates in high school, enrollment rates in college or technical school, all went up in the period when the adults in the study were children and young adults.
- 72 per cent of people aged over 65 living in 2003 had a high school diploma compared with 53 per cent in 1990.
- The proportion of college-educated elderly also went up during that time, from 11 to 17 per cent.
However, the gains made in the 1990s and early 2000s could be offset by the potential damage of a rising type 2 diabetes epidemic among the elderly, and the unhealthy life style and eating habits of young and middle aged Americans.
Also, although the proportion of older Americans with cognitive impairment might go down, we can't take our eye off the ball, because the actual number could go up, because the population is aging.
Co-author of the study and assistant professor of internal medicine at the University of Michigan, Dr Allison Rosen, said:
"This demographic reality will continue to make combating Alzheimer's disease and other types of dementia a top public health priority."
The researchers said older Americans should continue to pursue activities that keep their brain sharp and their cardiovascular risk low. These include doing crossword puzzles, volunteering, and making sure they take their blood pressure medication, as well keeping fit through physical exercises like walking.
As Langa explained, more and more evidence appears to show 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."
Click here for Alzheimer's and Dementia journal online.
Source: University of Michigan Health System press release.
Written by: Catharine Paddock, PhD