Older, But Not Alzheimer
The percentage of over-70-year-old Americans with cognitive impairment (Alzheimer’s and related conditions) declined over a decade from 12.2 to 8.7 percent of the population interviewed by researchers in a study released this week. The authors, who conducted surveys in 1993 and 2002 using a special database, attribute the improvement to better education and the use of cholesterol-lowering drugs, blood pressure medications and other drugs and strategies that have reduced the incidence of vascular dementia, which can be caused by strokes and clogged arteries.
The people interviewed in both years were living independently–people in nursing homes were excluded from the study. Which means that if more senile adults live in nursing homes today–a question that isn’t addressed in the study–the numbers might not hold up in the general population.
The number of people age 65 and older who had a high school diploma increased from 53 percent to 72 percent between 1990 and 2003 in the survey of 11,000 seniors. The rates of college education also rose, from 11 percent to 17 percent. More mental stimulation has been shown to ward of Alzheimer’s disease. Smarter people tend to get Alzheimer’s later, a fact attributed to “cognitive reserve”–the idea that if you’ve got more tools in the shed, you can still work with them as they start to get dull. Once people with higher IQs develop Alzheimer’s, however, they decline faster.