This story makes a compelling case that pharma profits by overdiagnosis, with a current 600,000 early Alzheimer's patients receiving anti-amyloid drugs set to become 47 million "pre-clinical"...
This story makes a compelling case that pharma profits by overdiagnosis, with a current 600,000 early Alzheimer's patients receiving anti-amyloid drugs set to become 47 million "pre-clinical" healthy people who receive dangerous treatments because they test positive for amyloid buildup that is less than 20% likely to cause clinical symptoms.
This article is U.S.-centric, and American systemic incentives for care of elderly people through Medicare are closely aligned with drugmakers' priorities. However, it's my impression that other countries with national health systems are vulnerable to the same manipulative marketing for "preventative" Alzheimer's testing and treatment.
The "amyloid hypothesis" for Alzheimer's and related dementias has been called into question due to research misconduct, narrowly based research, and drug company biases. As the article illustrates, the risk/benefit ratio for the eye-wateringly expensive amyloid-busting drugs is very questionable.
There's growing evidence that herpesviruses, autoimmunity, and nutritional deficiency contribute to the development of symptomatic Alzheimer's dementia.
Disclosure: I have a personal stake in Alzheimer's research and prevention. I have rheumatoid arthritis, which used to carry a 40% increased risk of early dementia. I'm on a TNF-alpha inhibitor, and current research says this means I now have a 20% reduced risk of Alzheimer's compared to the general population. I've gotten my shingles vaccination. I've also started taking 1 mg lithium orotate daily, in part because I'm in a region with naturally low lithium content in water and soils. So yes, I'm biased against the single-cause amyloid hypothesis.
Apparently, the beta amyloid hypothesis is false: Also, saunas. Apparently, the key to dodging Alzheimer's is to spend more time in a sauna. Or out in the sun in hot weather. It is less convenient...
Apparently, the beta amyloid hypothesis is false:
The interesting thing about him is that Alzheimer's disease, not only the rare kind, but the kind that, you know, is much more widespread, has sort of two proteins that are hallmarks of the disease. One is called amyloid. That's the protein that clumps into plaques in brains of people with Alzheimer's, usually forms about 20 years before symptoms emerge. And the second protein is called Tau. And that's the thing that forms these kind of sticky tangles. And that's much more connected to kind of symptoms of cognitive decline.
So what they've learned about Doug Whitney is that he has a whole lot of amyloid in his brain. He has amyloid levels that should suggest that he would have Alzheimer's many years ago even, but he has very little tau. So something in his biology has interrupted that progression from amyloid protein to tau protein. And that's what they want to zero in on. From PBS
Also, saunas. Apparently, the key to dodging Alzheimer's is to spend more time in a sauna. Or out in the sun in hot weather. It is less convenient than a pill, but also far less expensive.
Assuming we can remember how to connect the ethernet ports with our Alzheimer ridden brains. But assuming we can, UT2004, Quake 3, Battlefield 1942 and Command & Conquer (Never was big on...
Assuming we can remember how to connect the ethernet ports with our Alzheimer ridden brains.
But assuming we can, UT2004, Quake 3, Battlefield 1942 and Command & Conquer (Never was big on Starcraft) all the way.
I am so looking forward to this. My parents are very well cared for and comfortable at their nursing home, but the TV is always on when I visit. What a waste! I'm sure I could get a good game of...
I am so looking forward to this. My parents are very well cared for and comfortable at their nursing home, but the TV is always on when I visit. What a waste! I'm sure I could get a good game of Noita going. I might not be able to do to well in Dwarf Fortress, but I didn't do to well when I used to play it in those happy care-free days of yore. Maybe Nethack will be too much for me to be able to ascend, but it's too much right now, so what's the difference? Maybe I'll finally be able to get an ascended play before... I... ascend for real.
It doesn’t sound like that article disproves the hypothesis. It sounds like the patient is unusual.
It doesn’t sound like that article disproves the hypothesis. It sounds like the patient is unusual.
Nearly 7 million Americans currently live with Alzheimer’s and by 2060, experts say that number could be as high as 14 million. Scientists are trying to find out how one man has been able to stave off Alzheimer's for 25 years, despite having a rare genetic mutation that, doctors say, essentially guaranteed he’d develop the disease. Pam Belluck of The New York Times joins Ali Rogin to discuss.
You don't have to take my word for it: I was speaking to the point in the article, that pharmaceutical treatments, mostly based around amyloid targets, have been dubious. Conversely, I was...
You don't have to take my word for it:
“You can’t look at brain tissue and believe beta amyloid has nothing to do with it. It’s absolutely everywhere. But we’ve got lots and lots of patients who have tons of amyloid … with normal cognition,” said Matthew Schrag, a Vanderbilt University neuroscientist who discovered the doctored images in the 2006 Nature paper while working independently of his employer. “Biology is trying to tell you that there’s clearly more to the story.” Stat News
I was speaking to the point in the article, that pharmaceutical treatments, mostly based around amyloid targets, have been dubious. Conversely, I was surprised to learn that the production of heat shock proteins from high temperature exposure is correlated with lowered Alzheimer's incidence.
But where would the profit motive be in generating an Alzheimer's epidemic if the treatment were just several sessions a sauna each week?
I think a lot of people are conflating "there's more to the story than just B amyloid" (certainly true) with "the amyloid hypothesis is debunked!" (probably overstated). More specifically, that's...
I think a lot of people are conflating "there's more to the story than just B amyloid" (certainly true) with "the amyloid hypothesis is debunked!" (probably overstated).
Conversely, I was surprised to learn that the production of heat shock proteins from high temperature exposure is correlated with lowered Alzheimer's incidence.
More specifically, that's a theoretical mechanism. What we can actually say is that saunaing (among certain populations, etc etc) is correlated with lower AD incidence, and HSP is a reasonably plausible theory suggesting why. But exercise is also linked to lower AD incidence, and so the benefit of sauna might just be the elevated heart rate and have nothing to do with HSP at all. The evidence supporting the B amyloid hypothesis - even accounting for the questionable stuff - is much, much stronger than the evidence supporting the "it's all HSP!" hypothesis.
I know you were being a bit glib, but if the treatment for AD was just "sauna!" we would've already figured it out, because nobody in all of Finland would have AD. And they do. Ironically, in fact, Finns suffer from AD at disproportionately high rates - the highest mortality rate from AD in the world.
Finland has relatively high rates of alcoholism and depression, which are both Alzheimer's risks. The population is somewhat genetically homogenous as well, which might have concentrated...
Finland has relatively high rates of alcoholism and depression, which are both Alzheimer's risks. The population is somewhat genetically homogenous as well, which might have concentrated predisposing genetic risk factors. Finally, it's a relatively prosperous nation where many people live to the age range in which Alzheimer's can be a cause of death, and they dont die so frequently of other preventable causes.
Yes, of course. I'm not trying to disprove the HSP hypothesis. My point is that it's more complicated than "the B amyloid hypothesis is false... But we've figured it out how to fix it! It's saunaing!"
Yes, of course. I'm not trying to disprove the HSP hypothesis. My point is that it's more complicated than "the B amyloid hypothesis is false... But we've figured it out how to fix it! It's saunaing!"
Apologies - I wasn't trying to argue with your point about the HSP hypothesis, it was more about generalizing any specific population's risk profile without looking at potential confounders....
Apologies - I wasn't trying to argue with your point about the HSP hypothesis, it was more about generalizing any specific population's risk profile without looking at potential confounders. Public health research review habits...
It's funny you should mention Finland, because Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged Finnish men. They found that, "in this male population,...
Now, lifestyle changes are, of course, really important. But if regular exposure to high temperatures creates abundant heat shock protein in the spinal fluid that prevents the conditions that lead to Alzheimer's, then it might be one particularly desirable lifestyle change.
I'm not trying to disprove the HSP hypothesis. My point is that you're committing the exact same error that you criticize in the B amyloid theory: oversimplifying, coming up with theoretical...
I'm not trying to disprove the HSP hypothesis. My point is that you're committing the exact same error that you criticize in the B amyloid theory: oversimplifying, coming up with theoretical causal mechanisms to explain an observational effect, and generalizing from quite limited studies. The HSP theory may well have elements of truth, but if so it needs to be experimentally tested and we need to be able to answer why there's so much Alzheimer's in populations that already sauna heavily, in exactly the same way that the B amyloid theory needs to be able to answer why some people have huge amounts of B amyloid buildup but no Alzheimer's.
I was surprised by how many studies are published on HSP and Alzheimer's, around 100 if Google Scholar is to be believed. They are both case control studies and murine model, even c. elegans,...
I was surprised by how many studies are published on HSP and Alzheimer's, around 100 if Google Scholar is to be believed. They are both case control studies and murine model, even c. elegans, going back at least to the '90s. I just found out about this yesterday.
As for Finland, if you tell me that heat shock protien has a protective effect against Alzheimer's and that one of the coldest countries on earth has a high rate of Alzheimer's, I will believe you. However, if you tell me that, in that country, the people who frequent the sauna the most have a significantly decreased rate of Alzheimer's, I will still believe you. Now, if you go and add that, coincidentally, the people who live in the hottest places on earth happen to have the lowest rates of Alzheimer's, that I will also believe. If you told me that the one guy, who was basically guaranteed to get Alzheimer's, somehow didn't get it, perhaps because he spent 20 years working in the hottest rooms on earth, I will believe you.
However, maybe there is more to the story. Maybe this is just something that, upon further inspection, will turn out to be a mirage in the desert, if you will. The human mind is adept at making sense out of that which is later realized to be false, and many errors have been made in this fashion. But the hypothesis has marvelous explanatory power, no?
The most dangerous theories always seem to have marvelous explanatory power on the surface, but often fall apart at closer examination. For example, it would be easy to assume that the Bolivian...
Now, if you go and add that, coincidentally, the people who live in the hottest places on earth happen to have the lowest rates of Alzheimer's, that I will also believe.
The human mind is adept at making sense out of that which is later realized to be false, and many errors have been made in this fashion. But the hypothesis has marvelous explanatory power, no?
The most dangerous theories always seem to have marvelous explanatory power on the surface, but often fall apart at closer examination. For example, it would be easy to assume that the Bolivian rainforest is hot because that would seem to fit our theory so nicely. But I might suggest you Google the average temperatures in the Bolivian rainforest. Not even close to the hottest place on earth and in fact it's kind of chilly through winter. Texas is much hotter. Southern Spain is much hotter. Southern Italy. Most of Pakistan. All of the middle east. Etc etc. All of these places are much hotter and yet have vastly more Alzheimer's than the tribes in Bolivia.
Same thing with the guy who worked in the engine room. Sure, it seems to fit, but what if his engine room history is completely unrelated and it just sounds good? What if he's got some sort of genetic mutation that's the actual cause of his resistance? It's the same potentially with the saunaing Finns, and basically everything else.
To make things even more complicated, the hottest places on Earth tend to have the highest relative food scarcity per person. Caloric restriction is known to contribute to longevity and cognitive...
To make things even more complicated, the hottest places on Earth tend to have the highest relative food scarcity per person. Caloric restriction is known to contribute to longevity and cognitive health...
Multicenter (277 medical research centers/hospitals in 8 countries), randomized, double-blind, placebo-controlled, 18-month phase 3 trial that enrolled 1736 participants with early symptomatic Alzheimer disease (mild cognitive impairment/mild dementia) with amyloid and low/medium or high tau pathology based on positron emission tomography imaging from June 2020 to November 2021 (last patient visit for primary outcome in April 2023).
Sounds pretty legit, and
Among participants with early symptomatic Alzheimer disease and amyloid and tau pathology, donanemab significantly slowed clinical progression at 76 weeks in those with low/medium tau and in the combined low/medium and high tau pathology population.
Donanemab, another anti-Alzheimer's drug with risk and uncertain benefit It is clear that there isn't consensus here: Efficacy, safety, and ARIA risk of anti–β-amyloid antibodies in early...
We believe that these findings are subject to misinterpretation and statistical bias. Donanemab is claimed to cause removal of up to 86 % of cerebral amyloid and 36 % delay in cognitive decline compared to placebo. In reality, these are very small changes on an absolute scale and arguably less than what can be achieved with cholinesterase inhibitor/memantine therapy. Moreover, the "removal" of amyloid, based on the reduced accumulation of amyloid-PET tracer, most likely also reflects therapy-related tissue damage. This would also correlate with the minimal clinical effect, the increased frequency of amyloid-related imaging abnormalities, and the accelerated loss of brain volume in treated compared to placebo patients observed with these antibodies.
In early AD, anti–β-amyloid monoclonal antibodies are associated with modest slowing of decline accompanied by increased ARIA risk and unfavorable structural brain changes, limiting clinical applicability.
Most evidence I've seen points to the beta amyloid hypothesis being likely true despite the research misconduct, just more complicated. There were some articles I think last year about a new drug...
Most evidence I've seen points to the beta amyloid hypothesis being likely true despite the research misconduct, just more complicated.
There were some articles I think last year about a new drug being tested that supposedly isolated the mechanism of why some people with lots of beta amyloid plaques are still doing fine, with great success in animals so far. That would be an incredible breakthrough, but the proposed explanation is in tune of "beta amyloid buildup is definitely a problem, but we can activate some protective mechanisms that seem to negate it".
The reason why drugs targeting beta amyloid plaque buildup do not work very well may easily just be because the ones used so far don't cross the blood-brain barrier well, and so the patient needs to take high doses to get an effect, which increases side effects. Next generations of drugs that try to solve this difficult problem are being worked on and could solve the issue.
So I've gotten into Nordic saunas, too - it's an easy way to get some of the benefits of cardiovascular exercise without the joint pounding, raises body temperature enough to reduce infectious...
So I've gotten into Nordic saunas, too - it's an easy way to get some of the benefits of cardiovascular exercise without the joint pounding, raises body temperature enough to reduce infectious disease risk, and you've just provided evidence of yet another benefit. Plus a sauna just feels ecstatically good when it's January, -20 °C outside, and the sun has been invisible for months.
I'm not a great example because I can't tolerate the traditional cold water plunge to bounce back into the heat. It's how I found out the hard way that I've got cold-induced urticaria... That...
I'm not a great example because I can't tolerate the traditional cold water plunge to bounce back into the heat. It's how I found out the hard way that I've got cold-induced urticaria... That being said, I normally take 3 or 4 5-minute breaks in open air during the course of a 90-minute session, which seems to be about average for the others in the sauna. I have days when I can't bear to leave, and days when I didn't get my hydration right, or otherwise just don't want the warmth as much.
I do love heat and my spouse doesn't - he usually prefers temperatures about 20 °F cooler than I do, and he's constantly in and out of the 180 °F sauna. I wouldn't worry about how long you can tolerate it - just enjoy it while it's enjoyable, exit and recover while it's not, and see how your body behaves. Don't let those mean Scandis bully you!
In the past year, I'd read the book Doctored: Fraud, Arrogance, and Tragedy in the Quest to Cure Alzheimer’s. It's a compilation of articles by Charles Piller, an investigative journalist for...
In the past year, I'd read the book Doctored: Fraud, Arrogance, and Tragedy in the Quest to Cure Alzheimer’s. It's a compilation of articles by Charles Piller, an investigative journalist for Science magazine. There's a cumulatively damning story about gross research misconduct, outright scams, malpractice, lack of institutional controls, pharmaceutical industry greed, regulatory capture, and wilful blindness in pursuing the amyloid hypothesis to the exclusion of all other possible Alzheimer's mechanisms. There've been lives lost and damaged, billions of dollars and a couple of decades wasted. The foundational papers "proving" that beta-amyloid accumulation causes Alzheimer's are among the clear fakes.
I'm not 100% certain that amyloid buildup is harmless, but it's very likely a symptom and not a cause; removing amyloid does not produce clinically significant improvement in the course of the disease in humans.
Which just made the OP story all the more infuriating. Not just that pharma is greedily trying to expand the customer base unnecessarily, but the industry is doing it with high-risk, potentially fatal treatments that work poorly if at all.
This story makes a compelling case that pharma profits by overdiagnosis, with a current 600,000 early Alzheimer's patients receiving anti-amyloid drugs set to become 47 million "pre-clinical" healthy people who receive dangerous treatments because they test positive for amyloid buildup that is less than 20% likely to cause clinical symptoms.
This article is U.S.-centric, and American systemic incentives for care of elderly people through Medicare are closely aligned with drugmakers' priorities. However, it's my impression that other countries with national health systems are vulnerable to the same manipulative marketing for "preventative" Alzheimer's testing and treatment.
The "amyloid hypothesis" for Alzheimer's and related dementias has been called into question due to research misconduct, narrowly based research, and drug company biases. As the article illustrates, the risk/benefit ratio for the eye-wateringly expensive amyloid-busting drugs is very questionable.
There's growing evidence that herpesviruses, autoimmunity, and nutritional deficiency contribute to the development of symptomatic Alzheimer's dementia.
Disclosure: I have a personal stake in Alzheimer's research and prevention. I have rheumatoid arthritis, which used to carry a 40% increased risk of early dementia. I'm on a TNF-alpha inhibitor, and current research says this means I now have a 20% reduced risk of Alzheimer's compared to the general population. I've gotten my shingles vaccination. I've also started taking 1 mg lithium orotate daily, in part because I'm in a region with naturally low lithium content in water and soils. So yes, I'm biased against the single-cause amyloid hypothesis.
Apparently, the beta amyloid hypothesis is false:
Also, saunas. Apparently, the key to dodging Alzheimer's is to spend more time in a sauna. Or out in the sun in hot weather. It is less convenient than a pill, but also far less expensive.
Us millennial gamers are screwed.
On the other hand, imagine the LAN parties we can have in the group retirement homes...
Assuming we can remember how to connect the ethernet ports with our Alzheimer ridden brains.
But assuming we can, UT2004, Quake 3, Battlefield 1942 and Command & Conquer (Never was big on Starcraft) all the way.
I yearn for UT2k4. It's an absolute shame what Epic has become.
I am so looking forward to this. My parents are very well cared for and comfortable at their nursing home, but the TV is always on when I visit. What a waste! I'm sure I could get a good game of Noita going. I might not be able to do to well in Dwarf Fortress, but I didn't do to well when I used to play it in those happy care-free days of yore. Maybe Nethack will be too much for me to be able to ascend, but it's too much right now, so what's the difference? Maybe I'll finally be able to get an ascended play before... I... ascend for real.
My first time encountering noïta in the wild. I love/hate that game.
It doesn’t sound like that article disproves the hypothesis. It sounds like the patient is unusual.
You don't have to take my word for it:
I was speaking to the point in the article, that pharmaceutical treatments, mostly based around amyloid targets, have been dubious. Conversely, I was surprised to learn that the production of heat shock proteins from high temperature exposure is correlated with lowered Alzheimer's incidence.
But where would the profit motive be in generating an Alzheimer's epidemic if the treatment were just several sessions a sauna each week?
I think a lot of people are conflating "there's more to the story than just B amyloid" (certainly true) with "the amyloid hypothesis is debunked!" (probably overstated).
More specifically, that's a theoretical mechanism. What we can actually say is that saunaing (among certain populations, etc etc) is correlated with lower AD incidence, and HSP is a reasonably plausible theory suggesting why. But exercise is also linked to lower AD incidence, and so the benefit of sauna might just be the elevated heart rate and have nothing to do with HSP at all. The evidence supporting the B amyloid hypothesis - even accounting for the questionable stuff - is much, much stronger than the evidence supporting the "it's all HSP!" hypothesis.
I know you were being a bit glib, but if the treatment for AD was just "sauna!" we would've already figured it out, because nobody in all of Finland would have AD. And they do. Ironically, in fact, Finns suffer from AD at disproportionately high rates - the highest mortality rate from AD in the world.
Finland has relatively high rates of alcoholism and depression, which are both Alzheimer's risks. The population is somewhat genetically homogenous as well, which might have concentrated predisposing genetic risk factors. Finally, it's a relatively prosperous nation where many people live to the age range in which Alzheimer's can be a cause of death, and they dont die so frequently of other preventable causes.
Yes, of course. I'm not trying to disprove the HSP hypothesis. My point is that it's more complicated than "the B amyloid hypothesis is false... But we've figured it out how to fix it! It's saunaing!"
Apologies - I wasn't trying to argue with your point about the HSP hypothesis, it was more about generalizing any specific population's risk profile without looking at potential confounders. Public health research review habits...
Oh, it's fine, you're completely right. "It's more complicated than that" was my implied point and you helped make it more explicit.
It's funny you should mention Finland, because Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged Finnish men. They found that, "in this male population, moderate to high frequency of sauna bathing was associated with lowered risks of dementia and Alzheimer's disease."
Finland is also very cold, as I understand it. So, sauna bathing might generate a much stronger signal for decreasing Alzheimer's incidence than it would, say, in someplace very hot and humid, like the Amazon. You would expect the hottest places in the world to have lower rates of Alzheimer's and, sure enough, Scientists have found that Indigenous communities have the lowest rates of dementia in the world, identifying two Indigenous groups in the Bolivian Amazon.
Now, lifestyle changes are, of course, really important. But if regular exposure to high temperatures creates abundant heat shock protein in the spinal fluid that prevents the conditions that lead to Alzheimer's, then it might be one particularly desirable lifestyle change.
I'm not trying to disprove the HSP hypothesis. My point is that you're committing the exact same error that you criticize in the B amyloid theory: oversimplifying, coming up with theoretical causal mechanisms to explain an observational effect, and generalizing from quite limited studies. The HSP theory may well have elements of truth, but if so it needs to be experimentally tested and we need to be able to answer why there's so much Alzheimer's in populations that already sauna heavily, in exactly the same way that the B amyloid theory needs to be able to answer why some people have huge amounts of B amyloid buildup but no Alzheimer's.
I was surprised by how many studies are published on HSP and Alzheimer's, around 100 if Google Scholar is to be believed. They are both case control studies and murine model, even c. elegans, going back at least to the '90s. I just found out about this yesterday.
As for Finland, if you tell me that heat shock protien has a protective effect against Alzheimer's and that one of the coldest countries on earth has a high rate of Alzheimer's, I will believe you. However, if you tell me that, in that country, the people who frequent the sauna the most have a significantly decreased rate of Alzheimer's, I will still believe you. Now, if you go and add that, coincidentally, the people who live in the hottest places on earth happen to have the lowest rates of Alzheimer's, that I will also believe. If you told me that the one guy, who was basically guaranteed to get Alzheimer's, somehow didn't get it, perhaps because he spent 20 years working in the hottest rooms on earth, I will believe you.
However, maybe there is more to the story. Maybe this is just something that, upon further inspection, will turn out to be a mirage in the desert, if you will. The human mind is adept at making sense out of that which is later realized to be false, and many errors have been made in this fashion. But the hypothesis has marvelous explanatory power, no?
The most dangerous theories always seem to have marvelous explanatory power on the surface, but often fall apart at closer examination. For example, it would be easy to assume that the Bolivian rainforest is hot because that would seem to fit our theory so nicely. But I might suggest you Google the average temperatures in the Bolivian rainforest. Not even close to the hottest place on earth and in fact it's kind of chilly through winter. Texas is much hotter. Southern Spain is much hotter. Southern Italy. Most of Pakistan. All of the middle east. Etc etc. All of these places are much hotter and yet have vastly more Alzheimer's than the tribes in Bolivia.
Same thing with the guy who worked in the engine room. Sure, it seems to fit, but what if his engine room history is completely unrelated and it just sounds good? What if he's got some sort of genetic mutation that's the actual cause of his resistance? It's the same potentially with the saunaing Finns, and basically everything else.
To make things even more complicated, the hottest places on Earth tend to have the highest relative food scarcity per person. Caloric restriction is known to contribute to longevity and cognitive health...
Dubious how?
https://jamanetwork.com/journals/jama/fullarticle/2807533
Sounds pretty legit, and
Donanemab, another anti-Alzheimer's drug with risk and uncertain benefit
It is clear that there isn't consensus here:
Efficacy, safety, and ARIA risk of anti–β-amyloid antibodies in early Alzheimer’s disease: a systematic review, meta-analysis, and meta-regression
Most evidence I've seen points to the beta amyloid hypothesis being likely true despite the research misconduct, just more complicated.
There were some articles I think last year about a new drug being tested that supposedly isolated the mechanism of why some people with lots of beta amyloid plaques are still doing fine, with great success in animals so far. That would be an incredible breakthrough, but the proposed explanation is in tune of "beta amyloid buildup is definitely a problem, but we can activate some protective mechanisms that seem to negate it".
The reason why drugs targeting beta amyloid plaque buildup do not work very well may easily just be because the ones used so far don't cross the blood-brain barrier well, and so the patient needs to take high doses to get an effect, which increases side effects. Next generations of drugs that try to solve this difficult problem are being worked on and could solve the issue.
So I've gotten into Nordic saunas, too - it's an easy way to get some of the benefits of cardiovascular exercise without the joint pounding, raises body temperature enough to reduce infectious disease risk, and you've just provided evidence of yet another benefit. Plus a sauna just feels ecstatically good when it's January, -20 °C outside, and the sun has been invisible for months.
I'm not a great example because I can't tolerate the traditional cold water plunge to bounce back into the heat. It's how I found out the hard way that I've got cold-induced urticaria... That being said, I normally take 3 or 4 5-minute breaks in open air during the course of a 90-minute session, which seems to be about average for the others in the sauna. I have days when I can't bear to leave, and days when I didn't get my hydration right, or otherwise just don't want the warmth as much.
I do love heat and my spouse doesn't - he usually prefers temperatures about 20 °F cooler than I do, and he's constantly in and out of the 180 °F sauna. I wouldn't worry about how long you can tolerate it - just enjoy it while it's enjoyable, exit and recover while it's not, and see how your body behaves. Don't let those mean Scandis bully you!
In the past year, I'd read the book Doctored: Fraud, Arrogance, and Tragedy in the Quest to Cure Alzheimer’s. It's a compilation of articles by Charles Piller, an investigative journalist for Science magazine. There's a cumulatively damning story about gross research misconduct, outright scams, malpractice, lack of institutional controls, pharmaceutical industry greed, regulatory capture, and wilful blindness in pursuing the amyloid hypothesis to the exclusion of all other possible Alzheimer's mechanisms. There've been lives lost and damaged, billions of dollars and a couple of decades wasted. The foundational papers "proving" that beta-amyloid accumulation causes Alzheimer's are among the clear fakes.
I'm not 100% certain that amyloid buildup is harmless, but it's very likely a symptom and not a cause; removing amyloid does not produce clinically significant improvement in the course of the disease in humans.
Which just made the OP story all the more infuriating. Not just that pharma is greedily trying to expand the customer base unnecessarily, but the industry is doing it with high-risk, potentially fatal treatments that work poorly if at all.
Charles pillar wrote this article as well. Maybe you knew that - couldn't quite tell from your comment.