A new study in the US suggests memory loss and other aspects of cognitive impairment are becoming less common among older Americans. Cognitive impairment is the umbrella term for everything from major memory loss to dementia and Alzheimer's disease. The study was published online Feb. 20 in Alzheimer's & Dementia.
The national study of 11,000 people aged 70 and older found that cognitive impairment declined from 12.2 percent to 8.7 percent between 1993 and 2002. The research team first studied 7,406 people who, at age 70 and older, took a standard test of memory and thinking ability in 1993. The team found 12.2% of the group had serious memory problems and possibly Alzheimer's.
The team then studied 7,104 people who reached the age of 70 almost a decade later in 2002. They found only 8.7% of these seniors scored as low on the memory test.
"We found a clear relationship. The more education people had, the better they performed on cognitive tests," said Dr. Ken Langa of the University of Michigan, who led the study.
The analysis conducted by Langa and colleagues suggests that about 40 percent of the 3.5 percent decrease in cognitive impairment between 1993 and 2002 was the result of increased education and personal wealth.
"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 said in a prepared statement.
"We know that 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. We also know cardiovascular health has a close link with brain health," he noted. "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."
Langa said the results might also reflect better cardiovascular health, which can reduce strokes or other injuries that affect brain function.
But what is gained through education could be lost through diabetes, say the researchers. Langa and other experts such as William Thies of the Alzheimer's Association say the USA can still expect a massive upturn in Alzheimer's cases.
Obesity and diabetes could accelerate the risk of Alzheimer's in old age. Overweight adults and children often suffer from Type 2 diabetes and clogged arteries, and those health problems almost certainly will add to an increased risk of cognitive impairment.