Younger generations less likely to have dementia, study suggests

Definitely feels like that effect is more likely to be explained by the Great Depression and World War II than anything else.

> Nearly everyone outside of US/UK in the younger generation speaks at least two languages pretty well, while the older ones often don't.

Interestingly, the opposite seems to have been happening in Malaysia. The older generation tend to be able to speak a ton of languages (Malay, English, Chinese, Cantonese, Hokkien, maybe more), my generation has mostly settled on just English. I have gone out of my way to learn Japanese but even then, I can only understand 4 languages and speak 2 vs the 5 languages my parents/grandparents are essentially native speakers of.

> your grandparents probably read for entertainment instead of tiktok

It's not trivial to say that our grandparents read more than us. Paper books, newspapers and magazines are less common but we have ebooks, substacks and online newspapers now.

> your grandparents were more physically active

Perhaps at work, but my access to exercise during leisure time is much greater.

> your grandparents didn't eat ultra processed food because it hadn't been invented yet

I don't have hard data on this, but I think it's fair to say their generation's overall exposure to toxins was much greater. DEET, smoking, leaded petrol, asbestos and coal power stations seem much worse than the occasional McFlurry.

>your grandparents probably read for entertainment instead of tiktok

This is a reach... Have you met old people? They vegetate in front of the TV channel surfing- their version of TikTok- never questioning the content or researching topics further on their own. And after 40 years of this activity still don't know how to operate the remote.

> your grandparents probably read for entertainment instead of tiktok

We still do? Tiktok/shorts are that on the toilet/in bed activity. I still spend I'd guess on average at least 8 hours a day reading. Not necessarily books but diverse articles, game guides, work stuff..

> your grandparents were more physically active - brain and body are connected

More physically active but not more active in skillful tasks. I've seen correlation between less/later dementia and things like playing musical instruments but I've not heard of construction workers being dementia resistant.

> your grandparents didn't eat ultra processed food because it hadn't been invented yet...once again, brain and body are connected

Mine ate whatever was available. Many unleavened flour+water flatbreads baked on the woodfire oven used for heating, rice and lots of lye in winter. Lots of fruits and veggies when available.

Now we mostly eat much better. You have every single fruit/vegetable/meat available 365 days a week, very clean food.. Only gotta stop yourself from overindulging.

We also have better medicine, better cleaning products, better understanding of what's toxic and bans based on that..

>your grandparents probably read for entertainment instead of tiktok

I strongly disagree. Reading books as activity, maybe. It depends on the person too. But reading itself? In this time and age, we are constantly reading, either in your phone ( even most tiktok videos these days have subs for everything ), browsing the web is a constant reading activity, work/email/essays/whatsapp/telegram, completely outweights the amount of text we read/write now comparing it with our older generation.

>your grandparents probably read for entertainment instead of tiktok

I'm not actually sure my grandparents were able to read, let alone for entertainment. Not in the US fwiw.

It could but you need a body of evidence for it, plus credible pathways to explain it. So far the greater weight seems to be behind "use it or lose it".

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.

I dread to think what diseases the even 'younger generations' are going to get with all the microplastics in just about everything we eat, drink, and in some cases breathe.

>Pesticides don't explain why those born in the former have less dementia than those born between 1939 and 1943

If only there was something big in the world happening from 1939 to 1945 ...

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?

My personal experience is your immune system is sharp on both sides. You hope whatever antibodies and immune response gets triggered doesn't cross react with self.

I have some friends that had Hashimoto's disease. Type 1 diabetes. Friends with lupus. 4-5 friends that had Guillain-Barre syndrome. My mom died of ITP. I have sarcoidosis. I have friends who for unexplained reasons are 'unwell'

ITP is an interesting one. The antibodies target an enzyme that's needed to keep your blood platelets from binding together in your blood. Thus the idea that you can have autoimmune syndromes that can mess with thousands of different enzymes and proteins. Or stimulate inappropriately. Seriously why not.

I can totally believe that infection with childhood diseases of yore could lead to dementia later in life.

The author made it very clear that she believed the problem was indiscriminate use of, and overuse of pesticides. She explained this at the end.

Did anyone report on reductions in sleep apnea due to GLP-1s ? I would imagine that the introduction of effective weight loss meds en masse might change the trajectory of more than a few sleep apnea sufferers

Respectfully... how do you work in the field, while being so wrong?

Oxygen desaturation correlates with long-term metabolic outcomes, but correlates very poorly to day-to-day symptoms.

The actual primary cause of symptoms in SDB is microarousals resulting from increased respiratory effort, and sleep studies using 3%-or-arousal criteria report MUCH higher OSA rates than the commonly used hypoxia+reduction in flow criteria, while also having a much higher correlation with symptoms(>60% vs ~17% for AHI), and the problem is not over, but under- diagnosis since people with relatively few apneas(e.g. UARS patients) are rarely diagnosed correctly.

Also, (optimally) healthy people DO breathe 100% of the time during sleep- breathing during sleep is controlled by a different system while awake, and is extremely regular during NREM sleep, with REM merely introducing noise to breath amplitude. Any and all pauses in breathing are caused by sleep disruption.

The only reason why it seems like apnea-based criteria are oversensitive is because obese, older men often DON'T wake up from airway collapse and may be fine at 5, 10, or even 15 AHI. For everyone else, it's possible to have debilitating symptoms at 4 because the actual Respiratory Disturbance Index is 20+.

Goddammit man. People like you are why so many go their entire lives unable to find treatment. If you're working in the field, educate yourself about it. Ugh.

When I did my sleep study they monitored my o2 saturation. it's true that there's no ongoing monitoring during treatment though.

Slightly off-topic, but as someone in the field, what is your opinion of the apnea-detecting functionality of smart watches?

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.

It 100% will. Interestingly zepbound does more than merely lower weight and thus reduce sleep apnea as a secondary result, it seems to actually help directly from the preliminary studies I've read, much like we're seeing in other domains where GLP-1 drugs actually reduce e.g. fatty liver disease more than the same amount of weight loss alone.

I wonder if we'll discover that there's actually an endemic deficiency in endogenous GLP-1 production due to some other cause? The usual suspects of environmental contamination or subclinical infection, perhaps.

There is also a reverse causality that's often overlooked - People getting obese because they develop sleep apnea. Happened to a relative. Developed allergy-related sleep apnea resulting in significantly reduced sleep quality and quality of life. Was often awake until after midnight due to trouble falling asleep from breathing issues that occured when nose and throat would start to relax. After about two years of this, he let himself go and gain 15kg over the coarse of a single year.

GLP-1 drugs mean that peek obesity is already passed.

yes, but in one case we're talking about OSA causing dementia and in the other we're talking about obesity causing OSA

I think being around explosions actually IS linked to Alzheimer's. It wouldn't surprise me to find a link to dementia as well.

But generally, bullets, disease, and malnutrition don't cause the same sort of brain trauma.

https://newsroom.uw.edu/news-releases/blast-related-concussi...

You had me wondering if wind-playing itself has unfortunate cognitive effects. (This seems just barely plausible, since you spend a lot of time breathing funny if you play a wind instrument.)

4.7 years. Also, no evidence that it reduces the risk of getting it, the benefit is purely delayed onset. Still, I'd take an extra 5 years of working brain, if only I could learn a second language (does Python count?).

https://pmc.ncbi.nlm.nih.gov/articles/PMC7089902/

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.

Sometimes. Not reliably. I've seen studies correlating antibiotic therapy with reduced dementia rates in the next 5 or 10 years or something, but you can just as well wipe your gut microbiome and open it up to opportunistic pathogens.

>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).

Excuse me?

The vast majority of millennials did not receive the chicken pox vaccine as it was not FDA approved until 1995. The youngest millennials were born in 1996. The oldest millennials were already in high school by 1995.

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.

This is the most egregious rationalization of the Capcha dystopia I've ever seen.

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.

Not a chance that idly scrolling through videos is better than trying to figure out why a PR is breaking the compiler.

Unfortunately my mom developed dementia in her late 60s. Not exactly old. I’ve wondered if covid triggered the onset. Her husband was/is a covid denier though he had it three times and almost died once. My mom never had a bad case of Covid, but was exposed many times.

Interestingly, research, including UK biobank data with massive sample sizes, has proven many times that childless women are at considerably higher risk for dementia and Alzheimer's than women with 1-4 children.

> sleep loss during child-rearing and menopause

The prevalence of obstructive sleep apnea is much larger in men than in women. If sleep loss were the only factor we probably would see greater dementia incidence in men, due to long-term chronic sleep loss from OSA.

Do you have anything that shows the link to sleep disorders and menopause? And if you happen to know, does that apply to artificial menopause, where the organs have been removed, and then you go through menopause directly afterward?

Same here. It's like a specter always one step behind me.

Not just air pollution at large but specifically we are practically sunsetting diesel engines in most developed urban centres.

I can't find a quote but one trivia bit from 'diesel gate' is that the execs were aware of the neurotoxicity of NO2 and other substances that were found in higher concentration in diesel exhaust.

"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...

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...

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.

Have you heard of Ozempic?

Cars only fully replaced horses after WW2, so they were the first universally exposed generation, if anything.

The man who invented leaded gasoline - Thomas Midgley Jr. - also invented CFCs.

He's been referred to as a "one man environmental disaster".