[HN Gopher] Younger generations less likely to have dementia, st...
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Younger generations less likely to have dementia, study suggests
Author : robaato
Score : 51 points
Date : 2025-06-02 15:42 UTC (7 hours ago)
(HTM) web link (www.theguardian.com)
(TXT) w3m dump (www.theguardian.com)
| scroot wrote:
| Lead?
| gwbas1c wrote:
| Personally, I think it's some other pollutant.
|
| That being said, there's some remarkable correlations with bans
| on leaded gasoline.
| olddustytrail wrote:
| The man who invented leaded gasoline - Thomas Midgley Jr. -
| also invented CFCs.
|
| He's been referred to as a "one man environmental disaster".
| SoftTalker wrote:
| Two things we know for sure now, and probably knew pretty
| well even then, chlorinated hydrocarbons and heavy metals
| are not good for the environment. They have their
| industrial uses but need to be used with care.
| JumpCrisscross wrote:
| > _Lead?_
|
| Unclear. The cohort most exposed to atmospheric lead was born
| between 1951 and 1980 [1]. This study only measures those born
| before 1948.
|
| (To the extent the study supports a hypothesis, it's the null.
| Given atmospheric lead increased from 1890 onwards, until about
| the 1980s [2], if lead were the culprit we'd expect to see
| _more_ dementia among the study 's younger generations. Not
| less.)
|
| [1] https://www.pnas.org/doi/full/10.1073/pnas.2118631119
|
| [2]
| https://www.sciencedirect.com/science/article/abs/pii/S10406...
| Ifkaluva wrote:
| Would be a crazy plot twist if social media and doomscrolling
| were protective against dementia
| mentos wrote:
| Aren't puzzles recommended for the elderly to keep their minds
| active?
|
| Curious to see how a lifetime of nonstop digital interactive
| puzzles leaves us. (Video games)
| opan wrote:
| This would make for a neat study considering all the
| different genres of video games. I imagine they wouldn't all
| have an equal effect.
| lagniappe wrote:
| This is the most egregious rationalization of the Capcha
| dystopia I've ever seen.
| UncleOxidant wrote:
| somehow I suspect it's going to be the opposite.
| JumpCrisscross wrote:
| Study:
| https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
| pedalpete wrote:
| Interesting to see they are rating dementia as the 7th leading
| cause of death[1]. In Australia the common understanding is
| Alzheimer's is currently the 2nd and will likely claim the 1st
| spot in the next decade [2].
|
| The study seems to go against everything else I've seen which
| suggests that as people are living longer, the incidence are
| increasing, not decreasing. However, my understanding is that
| as we get better at curing cancers, reducing heart-disease, and
| generally increasing life-span, the longer a person lives, the
| more likely they are to get dementia.
|
| [1]https://www.who.int/news-room/fact-sheets/detail/dementia
| [2]https://www.abs.gov.au/media-centre/media-
| releases/australia...
| georgeburdell wrote:
| The article doesn't seem to posit one single cause, but
| anecdotally, the people in my family with dementia were women.
| One got it from smoking. Three others had Alzheimer's. The one
| who had it least bad was the one who had a job other than
| housewife
| gwbas1c wrote:
| How do you get dementia from _smoking_?
| JumpCrisscross wrote:
| "Smoking increases the risk of vascular problems (problems
| with the heart and blood vessels). These vascular problems
| are also linked to the two most common forms of dementia:
| Alzheimer's disease and vascular dementia.
|
| Toxins in cigarette smoke also cause inflammation and stress
| to cells, which have both been linked to Alzheimer's
| disease."
|
| https://www.alzheimers.org.uk/about-dementia/managing-the-
| ri...
| jjtheblunt wrote:
| thanks for this link: they're interesting to mid 50s me,
| who never smoked, but whose dad did smoke for decades, and
| his memory started failing late 80s, i'd never seen it.
| useful link.
| toast0 wrote:
| I don't know how you determine causality of dementia. But
| smoking leads to poor heart and lung health and function, and
| that's got to have follow on effects on brain health. And
| there's correlation linking smoking to dementia [1]. So, I
| think it's fair to say grandma smokes a lot who had dementia
| got it from smoking even without a specific link.
|
| [1] https://www.heart.org/en/news/2021/07/06/smoking-harms-
| the-b...
| francisofascii wrote:
| The vascular damage seems to be the main suspect. But I also
| wonder if smoking causes poor sleep due to it being a
| stimulant. Poor sleep leads to dementia.
| vjvjvjvjghv wrote:
| In my family it's the other way around. It's very worrisome
| that both my father and grandfather had dementia.
| RyanOD wrote:
| Same here. It's like a specter always one step behind me.
| n1b0m wrote:
| "Women have a greater risk of developing dementia during their
| lifetime. The main reason for this is thought to be because
| women live longer than men. Age is the biggest risk factor for
| dementia so living longer means that the risk of developing it
| is greater."
|
| https://www.alzheimers.org.uk/blog/why-dementia-different-wo...
| pedalpete wrote:
| Women are twice as likely as men to get Alzheimer's.
|
| The two current prevailing theories are, both of which focus on
| the amyloid hypothesis are
|
| 1) menopause changes in grey matter reduce the glymphatic
| systems ability to flush metabolic waste from the brain
|
| 2) sleep loss during child-rearing and menopause result in
| increased amyloid load, which begins the cycle of reduced
| ability of the glymphatic system to remove waste from the
| brain.
|
| I know someone is going to come in complaining about the
| amyliod hypothesis, but it is unlikely to be "wrong", it is
| just incomplete. We are likely lumping multiple different
| diseases together under the label of Alzheimer's because we
| don't understand the disease well enough yet.
| gwbas1c wrote:
| A while back I read Silent Spring, and the author made an
| interesting note: Pesticides used in the 1960s were neurotoxins,
| and she feared that they could cause neurological disorders. We
| now use different pesticides.
| JumpCrisscross wrote:
| > _Pesticides used in the 1960s were neurotoxins, and she
| feared that they could cause neurological disorders. We now use
| different pesticides_
|
| The "younger generations" in this study were born between 1944
| and 1948. (Older, 1890 to 1913.) Pesticides don't explain why
| those born in the former have less dementia than those born
| between 1939 and 1943.
| cogman10 wrote:
| They do if the effects are cumulative.
|
| They additionally cite in the article that perhaps it's
| smoking that's changed, yet that also didn't really
| significantly change in public until the 90s.
|
| 40 additional years of pesticides/lead/smoking/etc will take
| their toll.
| dragonwriter wrote:
| > They additionally cite in the article that perhaps it's
| smoking that's changed, yet that also didn't really
| significantly change in public until the 90s.
|
| Prevalence of smoking in the US peaked at around 45% in the
| 1950s, and had dropped to around 25% by the 1990s.
| (Depending on your own age, this may _feel_ wrong because
| there was a surge in _youth_ smoking from the 80s peaking
| in the mid-1990s, so its easy for people in a certainnage
| range to _feel_ like smoking was very prevalent through the
| 1990s, and then dropped like a rock.)
| JumpCrisscross wrote:
| > _Prevalence of smoking in the US peaked at around 45%
| in the 1950s, and had dropped to around 25% by the 1990s_
|
| Wouldn't you expect to see more variation between the
| American and European cohorts if smoking were the
| culprit?
| AbstractH24 wrote:
| And while smoking has plummeted, nicotine usage is
| resurgent
|
| As is smoking of other things
| exe34 wrote:
| Very loose speculation as a non-biologist. Could it have been
| that most of the healthy males (e.g. good testosterone
| levels, and whatever else made virile young males) were away
| at war, and the men left to father children had some sort of
| deficiency which also correlates with better protection
| against dementia?
| nartho wrote:
| Probably not. you'd have to prove that people who were able
| bodied in their youth are less likely to have dementia than
| people with disabilities or bad physical health. To my
| knowledge there is no such link. Besides, a big part of
| this sample was from the US who didn't enter the war before
| the very end of 41 (December 7th so might as well be 1942).
| Occupied Europe also didn't really have it's men "away at
| war". Also, men at war, even during WW1, were able to go
| back home from time to time, so I don't think the argument
| holds.
| JumpCrisscross wrote:
| > _a big part of this sample was from the US who didn 't
| enter the war before the very end of 41 (December 7th so
| might as well be 1942). Occupied Europe also didn't
| really have it's men "away at war"_
|
| The nail in the coffin for the hypothesis is the lack of
| significant variation between the US and European
| cohorts. Europeans were killed indiscriminately. Our men
| were selectively slaughtered. If there was a selection
| effect, you'd expect that to present in the American
| cohorts and not European ones; that is not observed.
| mullingitover wrote:
| It's gonna be, at least in part, vaccines[1]. If we invented
| drugs today that did what routine vaccinations did for
| Alzheimer's prevention, it would be hailed as a medical miracle.
|
| > Patients who received the Tdap/Td vaccine were 30% less likely
| than their unvaccinated peers to develop Alzheimer's disease
| (7.2% of vaccinated patients versus 10.2% of unvaccinated
| patients developed the disease). Similarly, HZ vaccination was
| associated with a 25% reduced risk of developing Alzheimer's
| disease (8.1% of vaccinated patients versus 10.7% of unvaccinated
| patients). For the pneumococcal vaccine, there was an associated
| 27% reduced risk of developing the disease (7.92% of vaccinated
| patients versus 10.9% of unvaccinated patients).
|
| [1] https://www.uth.edu/news/story/several-vaccines-
| associated-w...
| pinkmuffinere wrote:
| That's super interesting! From the first line I thought this
| comment was going to go the other way, lol...
| SoftTalker wrote:
| Still hard to draw conclusions. It could be that people who
| get all the recommended vaccines are just in general more
| health-conscious and this has some relationship to dementia
| risk.
| JumpCrisscross wrote:
| > _could be that people who get all the recommended
| vaccines are just in general more health-conscious and this
| has some relationship to dementia risk_
|
| Huh, it looks deeper than mere correlation [1][2].
|
| The simple explanation is inflammation. The intriguing
| potential is the vaccines train the immune system to clear
| something harmful.
|
| EDIT: It looks like some HSV antibodies also attack various
| Alzheimer's-related compounds, including "Ass protein, tau
| protein, presenilin, rabaptin-5, b-NGF, BDNF, mTG, and
| enteric nerve" [3]. Wild. I wonder if there is a link
| between the vaccination status of a mother and childhood
| dementia presentation.
|
| [1] https://www.nature.com/articles/s41591-024-03201-5
|
| [2] https://pubmed.ncbi.nlm.nih.gov/33856020/
|
| [3] https://pmc.ncbi.nlm.nih.gov/articles/PMC6032666/
| mullingitover wrote:
| The shingles vaccine is another promising one[1]
|
| > Researchers found that compared to those who didn't get
| the shingles vaccination, those who received it...
|
| > were 3.5% less likely to develop dementia over seven
| years (a 20% reduction)
|
| These types of findings are problematic for anti-vaxxers,
| however they seem likely to overcome this through their
| wholesale butchery of US research.
|
| [1] https://www.health.harvard.edu/blog/can-a-routine-
| vaccine-pr...
| somenameforme wrote:
| The interesting thing about dementia is that it is not
| normally distributed whatsoever. Pick basically any
| characteristic imaginable - environmental, behavioral, or
| genetic, and you're going to find a difference, often
| very significant, between groups.
|
| Everything from your occupation, to your diet, to martial
| status, to hobbies, and much more have been shown to have
| significant relationships with dementia rates. The
| problem you obviously run into here is that a person's
| approach towards healthcare is itself a _major_
| behavioral characteristic and so seeing varying rates of
| dementia based on this characteristic alone would be very
| unsurprising.
| JumpCrisscross wrote:
| > _seeing varying rates of dementia based on this
| characteristic alone would be very unsurprising_
|
| Sure. That's why the antibody cross-reactivity is
| intriguing.
| _DeadFred_ wrote:
| Random thought. Do antibiotics kill any sort of permanent
| seemingly benign outside bacteria in the body? Did we
| historically have more ongoing internal invaders than we do now
| because we now have antibiotics? I guess I'm asking did we used
| to have persistent, ongoing infections that now get wiped out
| every so often as a side effect of taking antibiotics?
| Vrondi wrote:
| Not just antibiotics to consider along this line of thought.
| We historically had a higher load of parasites. Far more of
| the population had some amount of parasites more of the time.
| Things like sewer systems/sanitation/clean drinking
| water/bathing and personal hygiene/wearing shoes/not having
| piles of animal feces all over the streets. That all changed
| the amount of exposure to parasites for the common person. We
| know it affected our immune systems (overall rates of
| allergies increased). We do not know how it affected our
| brains. Makes intuitive sense that it must apply to bacteria
| as well. Before foods were pasteurized (and before
| refrigeration), for example, we were exposed to more dietary
| sources for bacteria, both beneficial and non-beneficial.
| sylens wrote:
| I am actually very interested to see the data play out with the
| first generation of people who received the chickenpox vaccine
| as kids (millennials). If you have chickenpox, then you're at
| risk for shingles later in life, which seems to be a
| contributing factor to dementia in some individuals. But if an
| entire generation isn't at risk of shingles, we would probably
| expect to see a statistically significant drop in dementia as
| well.
| reverendsteveii wrote:
| https://www.michiganmedicine.org/health-lab/sleep-apnea-cont...
|
| While we're speculating as to causes obstructive sleep apnea is
| associated with dementia, estimates are that 30 million people
| have it, and we only invented CPAPs in 1980.
| jajko wrote:
| Dude, global estimate for OSA is in the range of 1 _billion_ ,
| its a global pandemic
| bhouston wrote:
| Are cpaps that widely used to have that significant of an
| effect?
|
| For CPAP to be primarily responsible, we would need a very
| sizeable portion of the population to be using them, but I
| think the numbers are less than 3% right?
|
| From the article as to the effect size:
|
| "For example, in the US, among people aged 81 to 85, 25.1% of
| those born between 1890-1913 had dementia, compared to 15.5% of
| those born between 1939-1943,"
|
| I'm not saying that CPAPs don't contribute, but they are not
| likely the main contributors.
| alargemoose wrote:
| I think you have this backwards. OP is saying sleep apnea is
| common, but we've only had CPAP machines to compensate for
| it, since the 80s. I don't see them trying to implicate CPAP
| as the cause of an increase in dementia.
| aantix wrote:
| I wonder if sleep apnea diagnoses will decrease with the
| increasing use of GLP-1s?
|
| Zepbound is FDA-approved for OSA.
| mike-the-mikado wrote:
| Isn't sleep apnea associated with obesity, which undoubtedly
| has been increasing?
| reverendsteveii wrote:
| yes, but in one case we're talking about OSA causing dementia
| and in the other we're talking about obesity causing OSA
| pedalpete wrote:
| The prevalence of apnea is likely highly over-estimated. ResMed
| and Philips, who both make billions off of CPAP, push these
| high figures.
|
| Measures of OSA (Obstructive sleep apnea) are somewhat poor,
| more focused on the amount of pauses in breathing, rather than
| oxygen desaturation, which is the secondary measure. Note, you
| don't breath 100% of the time when you're awake either.
|
| I work in sleep and neurotech, and at a large sleep conference
| last year, a talk was given about better methods to measure
| apnea. It was clear these measures would have significant
| challenges in being adopted because it would result in less
| people being diagnosed as needing CPAP.
|
| Lastly, the impact of CPAP in improving cognitive function is
| inconclusive [1]. Not that it doesn't have an affect. It does
| in some people, but not in others.
|
| [1]
| https://www.sciencedirect.com/science/article/abs/pii/S13899...
| mike-the-mikado wrote:
| I think that head injuries are a known cause of dementia (my
| father suffered a serious head injury and developed dementia a
| few years later at the age of about 70). It has been implicated
| in connection with sports injuries (boxing, rugby, heading a
| ball).
|
| I wonder if the risk of head injury has reduced with time?
| JumpCrisscross wrote:
| > _head injuries are a known cause of dementia_
|
| Almost 2x more likely [1].
|
| > _wonder if the risk of head injury has reduced with time?_
|
| The lack of spikes from the world wars would suggest otherwise.
|
| [1] https://karger.com/ned/article-
| pdf/56/1/4/3752570/000520966....
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