Dementia rates decline in U.S., researchers unsure why

> results showing the number of dementia diagnoses in Europe has stabilized during the last 20 years

Diagnosis changes seem a possible contributing factor to me. We pick new names for things and recategorize them.

Could this have something to do with the nutrition science community's reversal of a decades old vilification of saturated fats, which tended to get replaced with much worse trans fats? Saturated fats are absolutely necessary for brain function, and for a long while the standard recommendation was to avoid them like the plague.

Reduction in vascular contributions to dementia due to the same technologies that have greatly reduced cardiovascular mortality over the past 40 years seems like a reasonable hypothesis.

A lot of the damage to your brain is due to deterioration of blood vessels, leading to a continual series of tiny unseen strokes, in effect, silently destroying tiny areas of brain tissue. The level to which that is present in an individual has been shown to correlate pretty well with cognitive impairment.

Who knows. May be it's because the next aging generation is more mentally and physically active. Maybe is for the leaded gasoline.

The problem with syndromes correlated with human behavior is they're vague enough they could have 4-5 causative factors. The same is true of potential causative factors in autism, sexual preferences or depression. It's even true of very acute syndromes like Parkinsons disease (or cancer). We found one direct cause of Parkinsons; fentanyl impurities -there might be 100 of these.

We want to use science to explain things, and of course, we should try, but teasing out complex causes that may have multiple components over a lifetime is extremely difficult.

DDT?

In Silent Spring, the author predicts that DDT will cause brain problems very similar to dementia. There is also a statistically-significant increase of DDT in some patients with alzheimer's.

Ubiquitous Internet access keeps the elderly better engaged with the world.

A few problems with the article's flow and coherence. First off, the article conflates, "rate of dementia," with, "total incidence of dementia," which is like confusing gallons of gas with miles per gallon. Secondly, the article conflates, "dementia," with "Alzheimers," but - those are highly correlated since Alzheimer's is the overwhelming cause of dementia, so we'll let that one slide. The article starts off with a paragraph that states effectively that, "They have been predicting there will be tons of dementia for years, but now they are wrong!" Well Stephen Feller (author of the article), no, there is a clearly demonstrated increase in the incidence of dementia that will occur in the United States due to the baby boom population, which will increase the incidence of dementia per total US population (call that IncDem/USPop), and no one argues against that, in fact you even later state that in your article. What this study shows, as your article states, is that among predominantly white populations, in an above average income town (Framingham, MA), there has been a decrease in dementia controlled by age-related factors, (call that LocalDem/FramPop). So Dr. Sudha Seshadri, referenced in the story, likely knows many of the mechanisms of why this happens, it's not like researchers are totally clueless, which the article seems to open to interpretation by using the article title modifier, "...Researchers Unsure Why." No, they are pretty sure of some of the reasons why LocalDem/FramPop is decreasing: basically, Framingham, being a somewhat higher than average income town, has more exposure to healthcare education and practices, particularly to alzheimer's reducing drugs such as Donenzepil, which delays symptoms of Alzheimer's for an average of around 5 years if adhered to properly. There are other health and psychological factors which tend to trace diet and well-being...so a poor southern town, one can pretty easily imagine, might not have had such a considerable decrease in their LocalDem/FramPop as Framingham, Mass over the last 40 years. Also, just because one town had a lower LocalDem/FramPop does not mean that there is a total decrease in the rate of increase of IncDem/USPop, in fact that rate could be accelerating due to our poor diets and expensive healthcare access. So perhaps a better title for the article could have been, "Can a Mass. Town's Lower Dementia Rate Point to a Better Path for the Looming US Dementia Problem?"

When someone writes a new article on the above improved analysis, you can credit me and link back here. What we get with articles that have a lack of rigor, like what Stephen Feller wrote, are people in the comments section saying, "Well maybe it's because people smoke more weed," even though they may well have read the whole article, the title and flow frames the discussion up incorrectly.