[HN Gopher] Study Suggests Fructose Could Drive Alzheimer's Disease
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       Study Suggests Fructose Could Drive Alzheimer's Disease
        
       Author : elorant
       Score  : 176 points
       Date   : 2023-02-16 16:15 UTC (6 hours ago)
        
 (HTM) web link (news.cuanschutz.edu)
 (TXT) w3m dump (news.cuanschutz.edu)
        
       | m3kw9 wrote:
       | Maybe treating AD as a singular disease is confusing researchers
       | into thinking there is a single factor causing this. It's a
       | spectrum disease, damn do we have to remind them this?
        
         | ProjectArcturis wrote:
         | This is an area of active research and it's misleading to claim
         | that there is any kind of consensus that AD is a spectrum
         | disease. If anything, the recent success of anti-amyloid drugs
         | has pushed the consensus the other way.
        
       | narrator wrote:
       | High fructose corn syrup is also contaminated with mercury[1]. It
       | comes from contamination of the caustic soda used to process the
       | corn.
       | 
       | [1] https://www.webmd.com/food-recipes/news/20090127/mercury-
       | in-...
        
         | jxramos wrote:
         | I've long been curious about understanding the processes
         | involved in creating our processed food and just what sort of
         | chemicals and treatments the raw material pass through to get
         | to what we know and identify on the grocery shelves.
        
           | unglaublich wrote:
           | A classic is: How It's Made - Hot Dogs
           | https://www.youtube.com/watch?v=2NzUm7UEEIY
        
       | giantg2 wrote:
       | Just another theory. I swear this domain is mostly people
       | throwing shit at the wall to see what sticks.
       | 
       | I wouldn't be surprised if diet is one of many factors involved.
       | But I really don't see much value by most of the studies at this
       | point. Maybe we'll get to see who's right in a decade or two.
        
         | tomrod wrote:
         | This is why the scientific method exists, thankfully!
        
         | yieldcrv wrote:
         | So many ailments rely on multiple states occurring at the same
         | time, and yet our way of studying seemingly has no way to
         | factor this in.
         | 
         | Kind of sad. But we got a lot of lower hanging fruit plucked by
         | figuring out cures and preventative measures for single state
         | ailments.
        
           | WalterBright wrote:
           | I expect Alzheimers is caused by a combination of factors.
           | That is why trying to correlate one factor with it has been
           | fruitless.
        
             | canadiantim wrote:
             | Maybe fruitless is a good thing in this case
        
           | polalavik wrote:
           | I've been saying this for a while - science is great at
           | breaking things down to the atomic level and figuring out
           | what does what, individually. But science sometimes is not so
           | good at the systematic, or synergistic view of multiple
           | variables. We keep trying to break things down to one
           | variable that cures all when it's probably a mixture of a lot
           | of things + different for people with different genetic.
        
             | eggnet wrote:
             | Some problems are harder to solve than others. It usually
             | stems from a long testing period. Try X, wait. Try Y, wait.
             | If the wait period is decades, you have a problem.
             | 
             | Broadly, statistics and large sample sets are used to
             | combat that.
             | 
             | Human understanding, or lack thereof, for a given problem
             | also contributes to suboptimal theories.
             | 
             | Ultimately, hard problems are hard.
        
             | yieldcrv wrote:
             | I wonder if its as fundamental as needing a different
             | "scientific method".
        
               | airstrike wrote:
               | Blockchain, DeSci, science3.0
        
             | whatshisface wrote:
             | You can't get to the systematic view of multiple variables
             | until you know the individual variables.
        
       | sys32768 wrote:
       | My mom got Alzheimer's at age 58. She was trim, ate organic,
       | exercised daily, never smoked or drank, and had a happy social
       | life.
       | 
       | She was always a super light sleeper though, and had her own room
       | because dad would wake her up at night. I wonder whether her
       | brain's lymphatic system was working.
       | 
       | Only other thing that stuck in my mind is not long before her
       | symptoms, she had like six metal fillings removed and replaced
       | with porcelain all at the same time.
       | 
       | Her aunt got it early too and was a health nut juicer for years
       | who lived a healthy lifestyle.
        
         | sdwr wrote:
         | Scary stuff! Thanks for the story.
        
         | ravedave5 wrote:
         | There are links between plaque found on teeth and the
         | alzheimers plaques. There are some studies that introduction
         | into the bloodstream may cause issues.
         | https://www.nia.nih.gov/news/large-study-links-gum-disease-d...
        
           | el_benhameen wrote:
           | That study was what got me to start routinely flossing after
           | many years of off-and-on attempts. Read it, have flossed
           | basically every day since. I'm aware that they didn't show a
           | causative link and that evidence for flossing itself is
           | limited, but my gums feel better and don't bleed anymore, so
           | I figure it can't be a bad thing either way.
        
         | ProjectArcturis wrote:
         | Have you ever been checked for familial early-onset Alzheimer's
         | genes?
        
           | sys32768 wrote:
           | No, I just assume I'll get it in a few years, although
           | neither of her siblings got it.
           | 
           | I'm less healthy than she was at my age (52). My exit plan
           | doesn't involve long term health care insurance, that's for
           | sure.
           | 
           | Mom's still alive at 75, so that's a long run with this
           | disease. I would say it's been about three years since she
           | has declined to that stage where no mentally well person
           | would want to be alive.
        
           | criddell wrote:
           | Is that the kind of information a 23-and-me test will give
           | you?
        
             | mtlmtlmtlmtl wrote:
             | Not reliably. Best would be to seek consultation with a
             | medical geneticist.
        
             | lhh wrote:
             | 23andme will tell you your APOE genotype, one of the
             | variants of which is a major risk factor for Alzheimer's.
        
         | alfor wrote:
         | Did she spend a lot of time outside?
         | 
         | Lack of infrared exposition is linked to inflammation and
         | Alzheimer.
         | 
         | https://youtu.be/wadKIiGsDTw links to medical papers in the
         | video description.
        
           | sys32768 wrote:
           | Yes, daily long walks with her dog.
        
       | [deleted]
        
       | alfor wrote:
       | Lack of infrared exposition
       | 
       | Each of our mitochondria need infrared to remove oxidative
       | stress.(inflammation)
       | 
       | They use infrared to do that but we now live inside more and more
       | (especially elderly and sick) and thus we are in a constant
       | crisis of chronic inflammation.
       | 
       | I know it sound new age, but the research is there, like Vit-D
       | with the sun must have sounded ridicule at the time, the need for
       | infrared was not apparent when most people worked outside.
       | 
       | https://youtu.be/wadKIiGsDTw (medical papers in the video
       | description)
        
         | unglaublich wrote:
         | You confuse IR with UV light.
        
           | alfor wrote:
           | No UV and vit-d is well know
           | 
           | The need for infrared is just starting to get understood,
           | huge potential to improve the lives of people.
        
       | msie wrote:
       | A theory easy enough to test.
        
         | manmal wrote:
         | Unfortunately not, because fructose is also produced
         | endogenously. As mentioned in other comments here, whole fruit
         | consumption seems to not even be the real issue.
        
       | msie wrote:
       | "The study said more research is needed on the role of fructose
       | and uric acid metabolism in AD." - we need more money.
        
         | themitigating wrote:
         | Yes, because that's how research is done.
        
           | [deleted]
        
           | nemo44x wrote:
           | It many ways it is. If your livelihood is based on your
           | research then it's necessary for you to frame your research
           | as important. Existentially important is even better. This
           | way it outcompetes other studies/research/etc for funding
           | from various sources. Why would anyone support your research
           | if it wasn't urgent and important, etc?
           | 
           | This is how incentives work. It's why, for instance, you have
           | gain of function research occurring in many cases. SARS was
           | really interesting but it turns out it was never going to be
           | a large risk for society. Who is going to continue to fund
           | research into it? So, your incentive is to find a way to
           | convince people that fund things that it could in fact find a
           | way to be a global pandemic and gain of function "research"
           | is a great way to do this. Of course you justify it by saying
           | "it could happen and if it did happen then we'd want to know
           | how to prepare for it so lets find the worst ways it could
           | get to that state before it does itself". Now that you've
           | created something terrifying, it's much easier to get gobs of
           | funding for your research.
           | 
           | This is how it works.
        
             | themitigating wrote:
             | Most people's livelihood hood is based on their job.
             | 
             | Money as a motivation is in no way sufficient to make an
             | accusation of corruption. So much so I didn't even read
             | your argument
        
               | nemo44x wrote:
               | I'm not saying things are corrupt. Just how they are
               | because of how incentives are structured. For instance,
               | who would fund a climatologist that says climate change
               | probably won't be too bad based on his models? You'd be
               | far better off trying to find the model that predicts
               | disaster. That will turn heads and open wallets.
        
         | el_benhameen wrote:
         | This seems overly cynical. You're taught as a freshman science
         | student that a research paper should describe its own
         | deficiencies and point to next steps. It's a pretty basic part
         | of writing about research.
        
       | scavenger5 wrote:
       | This is a junk study. Here is the link:
       | https://www.sciencedirect.com/science/article/pii/S000291652...
       | 
       | If you look at the evidence hierarchy, this study is at the
       | lowest form of evidence (it's a narrative review -i.e expert
       | opinion), they didn't even run a study.
       | 
       | The ultimate study would multiple randomized controlled trials
       | showing sugar/fructose when controlled for calories, causes
       | increased Alheimer's disease. Since we haven't seen that, we
       | should not draw conclusions.
       | 
       | As the saying goes 'correlation does not imply causation'. We
       | don't even have correlation yet, the headline is an overreach.
        
         | JPLeRouzic wrote:
         | hummm, many Alzheimer patients are insulin resistant...
         | 
         | https://pubmed.ncbi.nlm.nih.gov/34576151/
        
         | profstasiak wrote:
         | how do you expect we will ever get a randomized control trial
         | controlling for fructose in diet?
         | 
         | Your right, but RCT would take how long? 50 years? How can you
         | make people not eat fructose or limit that for 50 years?
         | 
         | Wouldnt call the article junk sciensce. We also need hypothesis
         | builing articles. I think they are proposing a specific
         | mechanism of action about how fructose might cause Alzheimers.
         | 
         | I believe there are other clues also pointing in this
         | direction, which I wont bore you with.
         | 
         | Just want to note, that I think everyone would prefer high
         | powered RCTs, but I dont believe they are feasible to fund and
         | run
        
           | TaupeRanger wrote:
           | We won't. That's why nutrition epidemiology studies are so
           | bad and mostly useless. It's ok to simply say "let's not do
           | this study which we know won't add anything to our knowledge
           | of how nutrition affects health outcomes in real people". See
           | David Chapman for an entertaining review:
           | https://metarationality.com/nutrition
        
         | AnIdiotOnTheNet wrote:
         | I predict HN will look on this favorably anyway, because my
         | experience is that a rather large number of them are
         | practitioners of ketogenic or other high-fat low-carb diets and
         | 'fructose bad' may as well be part of their religion.
        
         | azubinski wrote:
         | Well, at least something is in order :)
        
         | exfatloss wrote:
         | I would say this comment is a bit unfavorable. The study
         | details some metabolic pathways that were recently discovered
         | and are activated by fructose intake. They then explore a
         | hypothesis as to why this could lead to certain outcomes like
         | Alzheimer's.
         | 
         | Not exactly a "junk study." It's step 1 in a chain of studies
         | that could validate this hypothesis.
        
           | [deleted]
        
         | [deleted]
        
         | ProjectArcturis wrote:
         | A review article is not necessarily junk science. This sort of
         | paper is the first step in allowing us to conduct the more
         | interventional studies you recommend.
        
           | crazygringo wrote:
           | True, it's the headline that's junk. It calls it a "study"
           | which implies running an experiment and observing the
           | results.
           | 
           | A review article is a review article. It isn't a study.
        
         | XFrequentist wrote:
         | Agree that it's a poor headline and that the
         | fructose/Alzheimer's hypothesis is quite speculative, but I
         | don't think calling it a "junk study" or gesturing at evidence
         | hierarchies is particularly helpful.
         | 
         | Theory (almost) always precedes evidence, and coming up with a
         | novel, biologically-plausible explanation for a common ailment
         | is absolutely a valid, useful scientific contribution.
         | 
         | Your general point, that drawing firm conclusions would be
         | radically premature, is spot on. I just stiffen up a bit when I
         | encounter "RCT or GTFO" type arguments; where in the world do
         | you think the ideas for which RCT to run come from?
        
           | colincooke wrote:
           | While I agree that these theory based papers are useful, and
           | are often the precursor to experiments, I believe the general
           | understanding of "study has found X" in pop culture is that
           | there is "hard evidence" of the finding being tauted.
           | Theories are risky to place too much credence in without
           | being steeped in the field yourself (is this a theory that
           | most people in the field agree with, or is the one suggesting
           | it an outlier?).
           | 
           | As usual science communication is never done as well as we
           | could all hope, but I personally like this "hierarchy of
           | evidence" approach in understanding if something is ready to
           | be consumed by the general public, rather than requiring
           | further discussion with the scientific community.
        
             | jstummbillig wrote:
             | Agreed. At this point I am also not willing to just let
             | science off the hook and blame it all on the press: If our
             | smartest people can not find ways to differentiate between
             | ideating and good results in a way that a sensationalist
             | press can't simply ignore, then just maybe they are not
             | trying all that hard.
        
             | dv_dt wrote:
             | I wish sci comms practice would have a standard set of
             | terms for stages of development/belief. Here the headline
             | should be something like "theory proposed that ..."
        
               | birdman3131 wrote:
               | We have that term already. Hypothesis.
        
           | mtlmtlmtlmtl wrote:
           | There's nothing wrong with research like this per se. I think
           | the way it's publicised is the main issue. Broadly I think
           | there are two types of papers: those who are only relevant to
           | other researchers, and those who are interesting to the
           | public as a whole. This is very much in the former category.
        
           | a4isms wrote:
           | _Theory (almost) always precedes evidence, and coming up with
           | a novel, biologically-plausible explanation for a common
           | ailment is absolutely a valid, useful scientific
           | contribution._
           | 
           | This is the case in physics and astronomy. People make
           | predictions that are not only untested, but we have to invent
           | equipment to test them.
           | 
           |  _One of the great early accomplishments in science was when
           | astronomers, observing our Sun, noted an unknown yellow
           | spectral line signature. In 1868, Norman Lockyer predicted
           | that it must be created by a hitherto unknown element, which
           | he named "Helium" after the Greek Titan of the Sun, Helios._
           | 
           |  _In 1895, two Swedish chemists detected helium in ore
           | samples here on Earth, and in the great tradition of the
           | scientific method, we had a theory, a prediction, and a
           | confirmation of the theory by test._
           | 
           | http://braythwayt.com/2017/12/29/crown.html
        
         | hilbert42 wrote:
         | _" This is a junk study"_
         | 
         | I hope you're damn-well right. I love fruit and eat lots of it!
        
         | MarkMarine wrote:
         | Comments like this are why I love hacker news. Thank you for
         | saving me the minutes I would spend trying to wade through this
         | stuff myself.
        
           | rising-sky wrote:
           | You probably still want to at least look at the research
           | yourself, trusting other "off-hand" comments is, uh,
           | ironically, akin to the moral from the "off-hand" parent
           | comment in this case
        
           | themitigating wrote:
           | Let's hope the poster isn't lying or wrong
        
             | labster wrote:
             | We can always have Bing read the study for us and ask what
             | it thinks.
        
               | Shared404 wrote:
               | It thinks that we're bad users :(
        
               | labster wrote:
               | But it's such a good Bing :)
        
           | throwaway4aday wrote:
           | Trusting a random commenter to dismiss the contents of an
           | article for you seems almost as bad as only reading the
           | headline. In both cases you're putting full faith in someone
           | else to summarize the article in a way that serves their
           | interests more than yours.
        
             | InCityDreams wrote:
             | Sometimes it's just the way they do it, that counts.
        
           | exfatloss wrote:
           | I skimmed the abstract and would say the comment isn't quite
           | fair to the study. I'm glad I spent the time checking it out
           | myself.
        
           | canadiantim wrote:
           | I personally find the parent comment to be way too
           | dismissive. Throwing the baby out with the bathwater.
        
         | craigyk wrote:
         | Thanks for the DD, I spent 30 secs scanning the article before
         | thinking "this sounds like drivel, I'm going to check the
         | comments"
        
       | ProjectArcturis wrote:
       | I've spent about 10 years doing research into brain metabolism
       | and Alzheimer's. This is an interesting paper! It explains a lot
       | of observed phenomena in the novel context of fructose
       | metabolism. I certainly am convinced that fructose has short-term
       | effects on regional brain activity and whole-body metabolism.
       | 
       | However they don't make great links between fructose and known AD
       | pathology. Beta-amyloid buildup is now pretty convincingly a
       | critical step in the progression of AD. They link a few low-
       | quality papers claiming fructose increases amyloid, but the
       | evidence is pretty weak. Similarly, APOE genotypes are well
       | documented AD risk factors. The authors aren't really able to
       | explain APOE's role in the context of fructose.
       | 
       | Fun read (for me, anyway), but not particularly convincing.
       | Hopefully it provokes some more research to try to fill in some
       | of the missing links.
        
       | Baloo wrote:
       | "...other foods can also stimulate fructose production in the
       | body and induce features of metabolic syndrome. These include
       | foods that provide the glucose substrate for the polyol pathway,
       | such as high glycemic carbohydrates, and foods that stimulate
       | aldose reductase, such as *salty foods and alcohol*. Umami foods
       | (especially processed *red meats, organ meats, shellfish, and
       | beer* that is rich in yeast extracts) also engage the purine
       | degradation pathway leading to uric acid.
       | 
       | The second more proximate factor has been the dramatic rise in
       | the intake of added sugars that contain fructose and glucose,
       | such as *table sugar (sucrose) and high-fructose corn syrup
       | (HFCS)*."
       | 
       | And...
       | 
       | "Interestingly, *whole fruits tend not to activate this pathway*
       | owing to a relatively low fructose content in individual fruits
       | and the presence of neutralizing factors (such as fiber, vitamin
       | C, potassium, and flavanols) and because the small intestine
       | metabolizes some fructose before it reaches the liver and brain."
       | 
       | So basically processed meats, table sugar & high-fructose corn
       | syrup are bad for you. I'm shocked /s
        
         | 11235813213455 wrote:
         | honey also
        
           | unglaublich wrote:
           | Yes, most forms of sugars contain 40-60% fructose.
        
         | unglaublich wrote:
         | > So basically processed meats, table sugar & high-fructose
         | corn syrup are bad for you. I'm shocked /s
         | 
         | The interesting part of the research is that the authors
         | identified a common player that might progress the development
         | of chronic diseases: high uric acid levels.
         | 
         | Uric acid has historically been associated with gout. But more
         | recently, there has been growing interest in the role of uric
         | acid on the development of chronic diseases like metabolic
         | disease, cardiovascular disease and Alzheimer.
         | 
         | An interesting (imo) pop-medscience video by Dr. David
         | Perlmutter - Uric Acid: A KEY Cause of Weight Gain, Diabetes,
         | Heart Disease & Dementia
         | https://www.youtube.com/watch?v=QZ6jPCcFNa8
        
           | avastmick wrote:
           | Uric acid may be a complex symptomatic expression rather than
           | a cause.
           | 
           | My own journey may reflect this. I suffered from gout and
           | also other worrisome blood work markers that indicated
           | metabolic syndrome. I am now largely vegan, alcohol free and
           | avoid sugar and processed food. I have not had a gout attack
           | for a long time. Then in a recent blood test my uric acid was
           | through the roof. My (excellent) doctor first wanted to raise
           | the amount of allopurinol I was taking but I suffer from side
           | effects and was reluctant. My doctor did some research and
           | found that uric acid levels are raised during periods of
           | weight loss.
           | 
           | So it's complicated and not well understood.
        
             | unglaublich wrote:
             | With regards to gout, I don't think it's symptomatic:
             | actual uric acid crystals are causing the inflammation that
             | is called gout. The crystals are deposited when the serum
             | level of UA goes above ~400umol/l.
             | 
             | But it's fascinating to hear your story, where you have
             | high UA serum but no gout attack. Were you on 300mg allo or
             | more?
             | 
             | With Alzheimer's and cardiovascular disease, there is much
             | uncertainty, agreed!
        
       | ralala wrote:
       | I have fructose malabsorption and when I eat or drink too much of
       | it, I get brain fog (slow reaction, dizziness etc.) for one or
       | two days. Would be interesting to see if fructose malabsorption
       | and Alzheimer's correlate.
        
         | saool wrote:
         | If you haven't yet, check out Dr Richard Johnson on the
         | fructose metabolism.
         | 
         | https://peterattiamd.com/rickjohnson2/
         | 
         | https://drhyman.com/blog/2022/05/18/podcast-ep540/
        
       | joenathanone wrote:
       | Diabetes and Alzheimer's, quite the combo if true.
        
         | shagie wrote:
         | The link has been an area of study for a while.
         | 
         | https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-mi...
         | 
         | https://www.alz.org/media/documents/alzheimers-dementia-diab...
         | 
         | https://www.health.harvard.edu/blog/whats-the-relationship-b...
         | 
         | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7246646/
        
         | wtetzner wrote:
         | Some researchers have started calling Alzheimer's "Type 3
         | Diabetes".
        
           | exfatloss wrote:
           | Anecdata, but haven't people with dementia (not just
           | Alzheimer's) been found to have very strong sugar cravings
           | too? I've heard the term "Diabetes of the brain" for it.
        
       | spacephysics wrote:
       | Someone with more domain knowledge, does this study hold water?
       | Even perhaps as a reason to look further into the relationship
       | between diet and Alzheimer's?
        
         | Synaesthesia wrote:
         | I watched an interesting presentation on YouTube about how
         | fructose is digested in the body, its totally different to
         | glucose, and arguably more harmful becuase the liver can only
         | handle so much, there are various metabolic products which also
         | need to be dealt with... So I do believe this may be very
         | plausible.
        
           | chasebank wrote:
           | "This leads to the overeating of high fat, sugary and salty
           | food prompting excess fructose production."
           | 
           | Perhaps I'm reading this wrong but the article suggests that
           | it's not from digested fructose, rather the body is producing
           | fructose. I'm confused.
        
             | Py-o7 wrote:
             | if you read Johnson's work, it's typically both. Direct
             | fructose consumption as well as the polyol pathway being on
             | and your body converting 'extra' glucose into fructose.
             | 
             | excess fructose (in particular in ultra-processed forms)
             | causes metabolic derangement but consuming too much of
             | those other 3 esp from ultra processed foods, also
             | activates the "switch" leading to endogenous fructose
             | production and more derangement.
             | 
             | The role of sedentarism in all this is somewhat under-
             | explored though.
        
             | TeaBrain wrote:
             | Glucose can be converted to fructose in the body via the
             | enzyme glucose-6-phosphate isomerase.
             | 
             | https://en.m.wikipedia.org/wiki/Glucose-6-phosphate_isomera
             | s...
        
             | abosley wrote:
             | Agreed....the part where it states that "Fructose produced
             | in the brain could possibly lead to inflammation..." made
             | me eye-roll...really hard.
        
               | unglaublich wrote:
               | Hwang JJ, Jiang L, Hamza M, Dai F, Belfort-DeAguiar R,
               | Cline G, Rothman DL, Mason G, Sherwin RS. The human brain
               | produces fructose from glucose. JCI Insight. 2017 Feb
               | 23;2(4):e90508. doi: 10.1172/jci.insight.90508. PMID:
               | 28239653; PMCID: PMC5313070.
               | 
               | https://pubmed.ncbi.nlm.nih.gov/28239653/
        
           | lab14 wrote:
           | Would you mind sharing said YouTube presentation?
        
             | VLM wrote:
             | Probably "Sugar The Bitter Truth" by Lustig 2009 which was
             | "controversial" at the time but more than a decade later
             | its pretty much mainstream.
             | 
             | You're always going to have members of the general public
             | and docs who don't keep upon on continuing nutritional
             | education (snark, there isn't any) saying stuff that was
             | out of date decades ago but I'd say the stuff in that video
             | is pretty much mainstream now.
        
       | [deleted]
        
       | snshn wrote:
       | I am convinced that boredom is the main cause of Alzheimer's and
       | many other neurological ailments.
        
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