US Dementia Rates Drop 24%, New Study Finds (cnn.com)

A new study involving more than 21,000 people across the country finds that dementia rates in people over age 65 fell from 11.6 percent in 2000 to 8.8 percent in 2012 -- a decline of 24 percent. CNN reports: The decline in dementia rates translates to about one million fewer Americans suffering from the condition, said John Haaga, director of behavioral and social research at the National Institute on Aging, part of the National Institutes of Health, which funded the new study. Dementia is a general term for a loss of memory or other mental abilities that's severe enough to interfere with daily life. Alzheimer's disease, which is believed to be caused by a buildup of plaques and tangles in the brain, is the most common type of dementia. Vascular dementia is the second most common type of dementia and occurs after a stroke. The study, which began in 1992, focuses on people over age 50, collecting data every two years. Researchers conduct detailed interviews with participants about their health, income, cognitive ability and life circumstances. The interviews also include physical tests, body measurements and blood and saliva samples. Although researchers can't definitively explain why dementia rates are decreasing, Langa said doctors may be doing a better job controlling high blood pressure and diabetes, which can both boost the risk of age-related memory problems. High blood pressure and diabetes both increase the risk of strokes, which kill brain cells, increasing the risk of vascular dementia. Authors of the study found that senior citizens today are better educated than even half a generation ago. The population studied in 2012 stayed in school 13 years, while the seniors studied in 2000 had about 12 years of education, according to the study. People who are better educated may have more intellectually stimulating jobs and hobbies that help exercise their brains, Langa said. The study has been published Monday in JAMA Internal Medicine.

Comments

Lead?

[Anonymous Coward]

I wonder if it is part of the theorized behavioral wave resultant from banning Tetraethyllead.
https://en.wikipedia.org/wiki/...
The ban is correlated with the lead free generation of young adults having a greatly reduced threshold for criminal violence and murder.

Falling smoking rates?

[Anonymous Coward]

As the main modifiable risk factor, it's almost certain that cigarette smoking factors in there.

the cause of this sudden decline

[Mysund]

First thing that jump into my mind: Can this be caused by the removal of lead from petrol/gasoline and other consumer products?

Re:the cause of this sudden decline

[Anonymous Coward]

The first thing that jumps to my mind is this:

figures released Tuesday by the Alzheimer's Association show that deaths from the disease increased by 68 percent between 2000 and 2010.

"It's an epidemic, it's on the rise, and currently [there is] no way to delay it, prevent it or cure it," says Maria Carrillo, a neuroscientist with the Alzheimer's Association. More than 5 million people in the U.S. have the disease, she says, and that number could reach nearly 14 million by 2050. -- NPR 2013

So the studies cover comparable time spans and come to widely diverging results -- unless there is some unknown factor that has made Alzheimer's less detectable and more lethal. Before that is explained I would not draw any conclusions.

Re:the cause of this sudden decline

[Anonymous Coward]

Alzheimer's is a subset of dementia. The study in the article also looked at a particular age cohort, whereas for the study from the Alzheimer's Association you are seeing figures from all ages for a subset of conditions referenced in the article.

The two studies are not necessarily at odds with each other.

Re:Statistical anomaly?

[hey!]

Well, getting really good public health data is hard, because it's expensive to do it in a way that gives you something you can go on, as opposed to something to purely speculate about. For all the limitations of something like the Framingham Heart Study or the Nurses Health Study, they're probably the gold standard when it comes to picking out statistical correlations that might be worth further investigation.

I think, though, if there were an increase in the death rate of dementia patients that was big enough to explain at 24% decline in twelve years we'd probably know it. Either the sampling was wildly biased at one or both ends of that period, or there's something going on. Management of diabetes and high blood pressure is definitely a plausible cause for such a decline because they're both correlated to vascular dementia and stroke.

On a personal note I know what you're going through. My Mom was really intelligent woman, but she had both hypertension and diabetes. The last ten years of her life she had progressive dementia, and it every time I saw her it was like a little bit more of her had slipped away. It encouraged me to get my act together -- without my mind I don't have much to live for, certainly not my looks. I dropped my blood pressure over several years 128/86 to 105/64 through diet and exercise.