
Dementia on the Retreat in the U.S. and Europe - bookofjoe
https://www.nytimes.com/2020/08/03/health/alzheimers-dementia-rates.html
======
subsubzero
Some things it could possibly be:

\- Lead gasoline stopped being sold(this is also theorized why crime dropped
alot from the 90's)

\- Pollution being down across the board due to better EPA standards and
electric vehicles.

\- Increased internet access and more games/puzzles with smart phones to
stimulate the mind.

\- Lead paint being taken very seriously as being detrimental to health.
having specialized crews dealing with removing it, also asbestos being removed
from society in the same way.

~~~
colordrops
Some other possibilities (guesses):

\- Banning of transfats

\- Better dietary and fitness practices in general

\- People getting on daily antivirals if they have HSV

~~~
GeoAtreides
>People getting on daily antivirals if they have HSV

That's not happening in Europe, only Americans are weird about HSV. Most
Europeans ignore it and don't make a big thing out of it.

~~~
MaximumYComb
Is that really a thing? I live in Australia and I'm really careful about who I
have sex with mainly due to not wanting to catch HSV-2. I'm an early 30's man
and I turn down more potential sexual partners than not. Condom use prevents
most STD's + unwanted pregnancy with a high degree of success but not HSV.

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bookofjoe
>Twenty-seven-year time trends in dementia incidence in Europe and the United
States — The Alzheimer Cohorts Consortium

[https://n.neurology.org/content/95/5/e519](https://n.neurology.org/content/95/5/e519)

~~~
phaemon
^^ This is the original paper and the full pdf is available. I recommend a
brief perusal before posting your "guesses". It's not very long and has pretty
graphs.

~~~
ghaff
Although in fairness, the paper mostly just speculates itself as to the
underlying cause--mostly better control of high cholesterol and blood
pressure, presumably primarily through drugs.

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zrail
Could this be related to lead exposure? Leaded gasoline was fully banned for
new vehicles in 1996.

~~~
spanhandler
My mom tells stories about pesticide trucks driving down the street, spraying
entire neighborhoods, when she was a kid. Says it happened pretty often. Kids
would chase them, playing in the "clouds". Talk about yikes.

I do wonder what we interact with regularly that future people would have to
be paid _very_ well to even be in the same room with, and will think we were
nuts for ever thinking was OK. I'm guessing "basically anything plastic,
especially if contact with food" is a likely candidate. Fire retardant
chemicals in construction materials and furniture, probably.

~~~
sandworm101
>>pesticide trucks driving down the street

That was DDT. Occassional exposures like that aren't linked to anything
horrible in humans. It was banned for its impacts on birds, specifically their
eggs. (Google "silent Spring".)

~~~
limomium
Sounds pretty horrible to me...:

> DDT is classified as "moderately toxic" by the US National Toxicology
> Program (NTP) and "moderately hazardous" by WHO

> studies document decreases in semen quality among men with high exposures
> (generally from indoor residual spraying)

> Indirect exposure of mothers through workers directly in contact with DDT is
> associated with an increase in spontaneous abortions

> studies found that DDT or DDE interfere with proper thyroid function in
> pregnancy and childhood

> Mothers with high levels of DDT circulating in their blood during pregnancy
> were found to be more likely to give birth to children who would go on to
> develop autism

~~~
perl4ever
Malaria used to be a serious problem in the US.

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omgwtfbyobbq
I wouldn't be surprised if some of the change is due to better recognition of
other neurological disorders that were lumped in with Dementia in the past.

------
iso8859-1
Why does the submission headline say "N. America" when the linked article
doesn't? The linked article does say have this ridiculous sentence though:
"One puzzling aspect of the decline is that it seems to be confined to Europe
and the United States — it was not seen in Asia, South America or, from
limited data, in Africa."

~~~
gnramires
"Methods This analysis was performed in aggregated data from individuals >65
years of age in 7 population-based cohort studies in the United States and
Europe from the Alzheimer Cohort Consortium. First, we calculated age- and
sex-specific incidence rates for all-cause dementia, and then defined
nonoverlapping 5-year epochs within each study to determine trends in
incidence. Estimates of change per 10-year interval were pooled and results
are presented combined and stratified by sex."

I thought it could be related to demographics, but they calculated using age-
specific rates. Still, if the age bins are not small enough there could be
some leftover bias (more older people in each bin for older countries). But
that's for between-country comparison. The age distribution within the US
itself might not have changed enough to account for the reduction.

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kodablah
> One puzzling aspect of the decline is that it seems to be confined to Europe
> and the United States [...] One leading hypothesis for the decline in the
> United States and Europe is improved control of cardiovascular risk factors,
> especially blood pressure and cholesterol.

My completely-devoid-of-evidence hypothesis is that over the past 25 years,
increased globalization has reduced the number of menial jobs/tasks in those
two continents, thereby increasing overall day-to-day mental exercise. This
coupled with the rise of the internet gives citizens a needed mental outlet.
The article mentions improved education as a possible reason, but not in the
form of late-age mental exercise.

~~~
melling
Claude Shannon had Alzheimer’s so I’m not sure if being really smart with a
playful mind protects you.

“Shannon developed Alzheimer's disease and spent the last few years of his
life in a nursing home; he died in 2001”

~~~
jrott
It wouldn't protect you completely but doing intellectually stimulating things
is supposed to reduce your risk of Alzheimer's.

~~~
Barrin92
I've always wondered if this simply isn't a case of having the causality
wrong, that is to say people in old age who don't have alzheimer symptoms are
more intellectually engaged.

~~~
phaemon
Well today is your lucky day, because you can cease your wondering! The answer
is "no".

In fact, any question you have that relies on thousands of doctors and
professors in the field missing something obvious is always "no" (cf "never a
compiler error").

~~~
perl4ever
It's not clear to me precisely what you are intending to communicate.

Are you scoffing at the idea that Alzheimer's symptoms could reduce
intellectual engagement?

Or just at the idea that experts could have missed it in favor of the opposite
relationship?

~~~
phaemon
The latter of course. Everyone who has given more than 10 seconds of thought
to the issue has considered the opposite relationship because it's _so
obvious._

------
Gatsky
Sigh, biology. We spend years working on the disease with no progress, and
don’t manage to work out the cause before it starts going away by itself
magically...

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remote_phone
I have 3 best friends I’ve known for over 40 years. 3 out of 4 of us have a
parent with dementia, including my mom. I know 3 other close friends whose
parents have dementia as well. I know this is anecdotal but to me it looks
like a crisis.

~~~
JamesBarney
Dementia rates per capita rates are soaring due to an aging population and
better medicine(we're able to keep sick people alive for longer who are at
much higher risk of dementia). But dementia rates age groups are dropping.

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throwaway6000
1) Smoking is not as widespread compared to 10-20 yrs ago.

2) Less indoor/outdoor pollution ie. less lead/asbestos/pestecides/etc.

3) People exercising more

4) More activities ie. Internet, movies, iPhones, gaming, etc.

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riffic
everyone is just dying off of social diseases instead (addiction, murder,
PTSD, war, suicide, et cetera)

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sparrish
My guess is the decrease in using aluminium cookware can explain this. Those
areas that didn't see the dementia reduction are also likely poorer areas
where they still cook using aluminium.

~~~
mr_overalls
Studies have not provided strong evidence of aluminum being a risk factor for
the development of dementia.

[https://alzheimer.ca/en/Home/About-dementia/Alzheimer-s-
dise...](https://alzheimer.ca/en/Home/About-dementia/Alzheimer-s-disease/Risk-
factors/Aluminum)

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ManuelKiessling
Not directly related to the article, but tangential: sometimes I wonder “how
do I know that right now, I’m _not_ in fact sitting in a wheelchair in an
elderly’s home, with final stage dementia, and my dementia-ridden mind telling
me I’m writing this comment on Hacker News as a healthy 40-something?”

~~~
tspiteri
Because dementia is forgetting, not hallucinating.

~~~
SamReidHughes
That's what it wants you to think.

