[HN Gopher] Energy-based model explains how chronic stress trans...
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       Energy-based model explains how chronic stress transforms into
       disease over time
        
       Author : andrewstetsenko
       Score  : 129 points
       Date   : 2024-10-20 14:32 UTC (8 hours ago)
        
 (HTM) web link (www.sciencedirect.com)
 (TXT) w3m dump (www.sciencedirect.com)
        
       | bloated5048 wrote:
       | Does it mean exercising regularly does the same?
        
         | mattmaroon wrote:
         | Exercise seems to stimulate the mechanisms it's claiming stress
         | depresses, so probably no.
        
           | bloated5048 wrote:
           | But exercise does use lots of energy. Probably more than
           | stress.
        
             | alexey-salmin wrote:
             | I had a somewhat similar question about exercise vs
             | physically demanding work, since the former helps to have a
             | healthy heart and the latter seems to do the opposite.
             | Explanations I've found were tied to the average daily
             | heart rate. Exercises are intense but it's only a few hours
             | per week, and over time they tend to lower the average
             | heart rate. Physical work is typically less straining but
             | it takes a big portion of the week and as the result
             | increases the average heart rate.
             | 
             | I guess the problem of exercise (intense but short) vs
             | chronic stress (moderate but 24x7) could have a similar
             | explanation.
        
               | mattmaroon wrote:
               | I would be willing to bet that there are just confounding
               | factors. People who do physical work differ from people
               | who do not in so many ways that it would be impossible to
               | do any sort of controlled study.
        
             | mattmaroon wrote:
             | I don't think the claim is that it just uses energy, it's
             | that it uses energy to the detriment of other processes.
             | 
             | The body is extraordinarily complex, so I don't think you
             | can extrapolate that to anything else that uses energy.
             | 
             | Any garden variety gym rat will tell you that when you
             | worked out you eat a lot more. And that may be the same for
             | stress, but perhaps what your body does with the energy
             | when you exercise is different.
        
               | anon84873628 wrote:
               | Exercise modulates hunger (generally, cardio increases
               | perceived hunger while resistance training actually
               | blunts it for a time). But people putting in work at the
               | gym are already in a health conscious mindset and will
               | apply that to their food choices, even if they aren't on
               | an explicit diet plan. If you just left a gallon of sweat
               | on the treadmill you're probably not gonna buy a pizza or
               | McDonald's burger in the way home. It just feels like an
               | obvious step backwards in the moment.
               | 
               | Meanwhile, being in a stressed state that reduces
               | executive function is going to lead people to the quick,
               | easy, hyper palatable, high energy density, unhealthy
               | food options available.
        
             | fnordpiglet wrote:
             | The body tends to use the same amount of energy regardless
             | of what you do in a day. You can certainly over exercise
             | which causes undue stress on the body. However other than
             | an adaptive period at the start of regular exercise your
             | body adapts to the increased caloric use from exercise by
             | down regulating other processes to conserve energy.
             | Typically an excess of calories is used by production of
             | lipid fluid in adipose tissue and over expression of global
             | inflammation. Once you begin exercising regularly the body
             | generally stops using stored lipids for extra energy to
             | compensate for the exercise and instead down regulates
             | inefficient and generally harmful processes like random
             | global inflammation.
             | 
             | As mentioned the Goldilocks zones are where you're not
             | forcing the body beyond what it can safely allocate to
             | exercise in a day without causing stress in other
             | processes. Generally though that Goldilocks zone is
             | significantly greater than most people do in exercise in a
             | week, but would typically fall in the zone of "moderate"
             | exercise from a clinical point of view. This is effectively
             | 3-6 times the expenditure of energy from rest for 150
             | minutes per week spread over a week for at least 10 minutes
             | of moderately strenuous exercise at 70% heart rate per
             | session. Most people in their 40's or 50's would typically
             | find this fairly grueling, but that's because of that
             | homeostatic adaptation - the body resists changing its
             | homeostasis and induces all sorts of negative experiences
             | during the adaptation phase. Once you've adapted the
             | opposite feelings present for the same reason - you begin
             | to crave a routine of exercise because you body resists the
             | adaptation to a more sedentary life.
             | 
             | N.b., This is why while exercise definitely helps lose
             | weight, it's primarily by managing inflammation and mood.
             | This is why the only significant way you can lose weight
             | over time is to reduce caloric intake materially under your
             | homeostatic energy consumption.
        
               | cyberpunk wrote:
               | How did you come by this information and do you have any
               | sources / further reading on this?
        
               | anon84873628 wrote:
               | This is basically exercise physiology 101.
               | 
               | I'm not saying that to be snarky. Just as an FYI that it
               | can be kinda hard to even describe how one came across
               | this knowledge. Like asking someone how they know LC
               | circuits act as a resonator.
               | 
               | And I guess exercise science is even less popular than
               | physics. You can find the latter on Wikipedia, and a bit
               | of the former too:
               | 
               | https://en.m.wikipedia.org/wiki/Exercise_physiology
               | 
               | There is a lot of great YouTube content about exercise
               | physiology too, if you can cut through the "bro science"
               | ecosystem.
        
               | shagie wrote:
               | Kurzgesagt - In a Nutshell : We Need to Rethink Exercise
               | (Updated Version) -
               | https://www.youtube.com/watch?v=vSSkDos2hzo
               | 
               | Their videos have a section where they link the sources.
               | In this case https://sites.google.com/view/sources-
               | workoutparadox
        
             | anon84873628 wrote:
             | I wouldn't be so sure. The brain is responsible for about
             | 20% of resting metabolic rate, which translates to 300-350
             | calories per day for the average person.
             | 
             | 300 calories is about the same as 30 minutes of zone 3
             | cardio (70-80% max heart rate, i.e. pretty high perceived
             | exertion).
             | 
             | Most people in an exercise routine would only do that a
             | couple times per week.
             | 
             | An "overactive" brain, day in day out, could add up to more
             | than most people deliberately exercise.
        
         | sbdhzjd wrote:
         | My understanding is yes.
         | 
         |  _However_ moderate exercise (and stress!) stimulates the body
         | to activate trash /repair/rebuild mechanisms which improve
         | health overall.
         | 
         | EDIT:
         | 
         | For example, aerobic exercise stimulates capillary growth
         | lowering pressure required for blood flow. Periodic, moderate
         | fasting triggers the elimination of accumulated fats which
         | might have toxins built up in them (or have oxidized) Healthy,
         | emotional stress teaches us to deal with inevitable tragedies.
        
       | mattmaroon wrote:
       | So the upshot is that your body is using its energy to deal with
       | stress rather than other problems?
        
       | imjonse wrote:
       | It is about a biological/physiological model based on energy
       | consumption when stressed, not the machine learning energy-based
       | models championed by Yann LeCunn.
        
       | omani wrote:
       | doesn't matter what model you use to explain it.
       | 
       | cortisol.
       | 
       | too much of it or too regularly opens the door to many diseases.
        
         | manmal wrote:
         | Are there any proxy markers we can use to model cortisol, right
         | now? Like HRV or simply continuous heart rate monitoring?
        
       | mojosam wrote:
       | it sounds like the authors are suggesting that additional energy
       | usage caused by stress can, in isolation from other causes, be a
       | mechanism for disease. But that doesn't make much sense:
       | - our metabolisms are adaptable, so why wouldn't this increase in
       | energy use simply be offset by an increase in energy production?
       | It can't be that people who are stressed in general aren't
       | getting enough energy, because that would correlate stress with
       | weight loss, but I would argue that there are plenty of
       | overweight people with stress.            - if the argument is
       | that an increased metabolism by itself is the culprit, then why
       | wouldn't people with higher metabolisms in general -- like anyone
       | who exercises regularly, but certainly athletes -- not also
       | experience more disease? If your answer is "that's different for
       | some reason", then that means that increased energy usage and
       | metabolism is not by itself the cause, which suggests it may not
       | be the cause at all.
       | 
       | Furthermore, even granting the supposition that stress requires
       | increased energy usage, their abstract doesn't make much sense:
       | - "Living organisms have a limited capacity to consume energy."
       | Okay, so that means that no matter how stressed we get, there's a
       | cap to the energy we can use. But how is that relevant, since it
       | also applies to exercise or other energy utilization by the body?
       | Why does a limited capacity to consume energy only apply to
       | stress?            - "Overconsumption of energy by [stress
       | handling] brain-body processes leads to ... excess energy
       | expenditure above the organism's optimum". Thats basically a
       | tautology, but more importantly, it doesn't tell us that energy
       | consumption above "optimal" -- which seems extremely vague -- is
       | a bad thing.            - "In turn, [excess energy consumption
       | above the optimal] accelerates physiological decline in cells,
       | laboratory animals, and humans, and may drive biological aging".
       | So that "may" is a pretty good reason to dismiss this, since
       | again why wouldn't this lead to increased disease among athletes
       | or anyone with higher metabolism?            - "Mechanistically,
       | the energetic restriction of growth, maintenance and repair
       | processes leads to the progressive wear-and-tear of molecular and
       | organ systems" Maybe, but why are they energetically restricted
       | if metabolism has increased to provide more energy? And again,
       | why don't we then see increased disease and aging in anyone who
       | exercises regularly, since that exercise not only uses energy
       | that restricts growth, maintenance and repair, but exercise
       | causes more need for repair.
       | 
       | I think the core problem is that it's all going to boil down to
       | how you define "optimum", which the authors conveniently don't.
       | The authors are going to be left with defining "optimum" as
       | meaning "that energy usage which does not cause disease". But
       | that's no different than simply claiming "stress causes disease",
       | so this model describes nothing, since it tells us nothing about
       | how to identify non-optimum energy usage or how non-optimum
       | energy usage causes disease.
        
         | h4l wrote:
         | Humans have a massive capacity to vary energy use. Highly
         | trained endurance athletes like professional road cyclists and
         | triathletes can average 3x or more the typical daily energy
         | expenditure of a non-athlete on a long term basis. The idea
         | that psychological stress can overwhelm the body's ability to
         | produce energy does not seem credible to me.
        
           | anon84873628 wrote:
           | Those people have trained very deliberately over years to
           | reach that level of performance, on top of an innate genetic
           | disposition.
           | 
           | Undoubtedly, in absolute terms they have a higher capacity to
           | withstand the negative physical effects of psychosocial
           | stress as described in the paper, precisely because of these
           | physiological adaptations.
           | 
           | If regular people trained themselves to deal with stress then
           | they would have a higher capacity too.
           | 
           | The paper is referring to the maximum capacity of a
           | particular organism at a particular moment in time. It
           | doesn't assert that the capacity is uniform across a species
           | or doesn't change over time.
        
         | anon84873628 wrote:
         | >Okay, so that means that no matter how stressed we get,
         | there's a cap to the energy we can use. But how is that
         | relevant, since it also applies to exercise or other energy
         | utilization by the body? Why does a limited capacity to consume
         | energy only apply to stress?
         | 
         | It doesn't. That limited capacity to consume energy applies to
         | exercise, brain activity, thermogenesis, digestion, and every
         | other biological process as well. It is a fundamental aspect of
         | cellular biology and a major focus in the field of exercise
         | physiology.
         | 
         | Fitness training is the very slow and deliberate process of
         | pushing these limits tiny percentages higher.
         | 
         | I suggest you build some practical and theoretical knowledge of
         | the field before dismissing the paper.
        
       | hammock wrote:
       | This paper reminds me of the "insight" / factoid that all mammals
       | are basically born with the same rough number of heartbeats, and
       | then they die. Smaller animals like mice have shorter lifespans
       | and faster heartbeats. Larger ones like whales and elephants have
       | slower heartbeats and longer lives.
       | 
       | The humorous (and obviously false, though apparently not if this
       | paper is out there) corollary is that any exercise and non-
       | sedentary lifestyle means you lose years of your life
        
         | kelipso wrote:
         | I think the theory is that exercise has many other benefits
         | that make up for the increased energy usage.
        
         | mrtesthah wrote:
         | Naked mole rats live over 30 years, because they have
         | additional copies of a gene known to protect against DNA
         | damage.
        
         | fnordpiglet wrote:
         | This is the battery "theory," and is obviously untrue from all
         | evidence collected. Exercise and specifically improvement of
         | VO2max, which is the bodies ability to pump and process a
         | volume of blood and oxygen in a period of time, are some of the
         | strongest predictors of life and health span. A lack of
         | exercise also transpires to significantly increase global
         | inflammation in the body - in fact regular exercise forces the
         | body to adapt to a new homeostatic use of calories away from
         | random inflammation to conserve daily caloric expenditure
         | towards that exercise. There's no evidence to support the
         | battery "theory," despite certain anti science politicians
         | popularizing it.
        
           | alexey-salmin wrote:
           | > This is the battery "theory," and is obviously untrue from
           | all evidence collected. Exercise and specifically improvement
           | of VO2max, which is the bodies ability to pump and process a
           | volume of blood and oxygen in a period of time, are some of
           | the strongest predictors of life and health span.
           | 
           | Exercise and specifically improvement of VO2max also decrease
           | your average heart rate, so it's quite aligned with the
           | battery theory.
        
           | TrainedMonkey wrote:
           | OG study that found a roughly same number of heartbeats was
           | only concerned with averages -
           | https://pubmed.ncbi.nlm.nih.gov/9316546/ . Interestingly
           | humans are outliers with 2-3x the expected number of
           | heartbeats. The way the data was presented always gave me a
           | strong "everything looks linear when plotted on a log scale
           | with big marker" vibe... however it could be totally possible
           | that there is some correlation there.
           | 
           | Maybe evolutionary, there is optimal amount of time for
           | organisms to survive relative to their size. Organism size,
           | in turn, correlates with heart size and heart size correlates
           | with how fast it beats. Probably totally missing the mark,
           | but if it was true, it would be interesting to look into why
           | there are outliers.
           | 
           | Anywho, I find it humorous to think about a battery theory
           | car analogy - "every car has a preset number of miles and
           | maintenance would decrease usable lifespan of the car because
           | you need to drive to the mechanic".
        
         | mcoliver wrote:
         | Haven't done the math but maybe they aren't so disconnected. If
         | I can trade off an elevated heart rate of 170 for an hour every
         | day or two in exchange for dropping my resting heartbeat from
         | 70 to 50, I should end up with more years to use those finite
         | heartbeats. As with most things in life it's about balance.
         | Extremes and absolutes in most everything tend to result in
         | poor outcomes. You don't want to be sitting 24/7 or running
         | 24/7.
        
         | hammock wrote:
         | Do the people downvoting my comment think I believe in this
         | theory, or is there another reason?
         | 
         | "Factoid" means untrue by definition. I thought it an
         | interesting novelty
        
           | chiefalchemist wrote:
           | Down voting on HN on HN seems to be a sign of "this idea
           | breaks the model I have in my head, and my biases tell me I
           | can't be mistaken."
        
       | jgneff wrote:
       | I think this study is related to two books I read this summer:
       | _Burn_ , by Herman Pontzer, presents his "constrained energy
       | expenditure hypothesis," and _Exercised_ , by Daniel E.
       | Lieberman, discusses his "costly repair hypothesis."
       | 
       | Together, they try to explain why exercise can force your body to
       | stop using its energy to destroy itself (inflammation, autoimmune
       | diseases) and instead use its energy to restore itself (releasing
       | antioxidants, repairing damage).
        
         | nobrains wrote:
         | When I search (amazon, google, and other searches) for one
         | these books, the other also shows up as a very close result.
         | And vice versa as well.
        
         | azeirah wrote:
         | Kurtzgesagt had a video about this very recently too. About
         | calory expenditure.
        
           | discordance wrote:
           | This one: https://youtu.be/vSSkDos2hzo
        
       | photochemsyn wrote:
       | Link to full paper:
       | 
       | https://www.picardlab.org/uploads/7/7/8/4/77845210/2022_bobb...
       | 
       | Lots of interesting stuff about mitochondrial allostatic load.
       | It's essentially a Goldilocks problem - the car that's never
       | driven breaks down quickly when you take it out for a drive, but
       | if you're constantly pushing the accelerator and slamming the
       | brakes, the car's lifetime is cut in half. The paper seems to
       | focus on social and psychological factors that unnecessarily
       | increase stress:
       | 
       | > "From this energetic perspective, the evolution of likes and
       | dislikes, feelings and emotions, and approach/withdrawal
       | behaviors arose to minimize the energetic cost of life."
       | 
       | Case example: Someone just asked me about my holiday season plans
       | and my blood pressure probably went through the roof... I think
       | I'm going to send them this paper.
        
         | krackers wrote:
         | Diseases like chronic fatigue syndrome are thought to be the
         | result of mitochondrial dysfunction, right? Maybe that also
         | fits in here.
        
       | tmshapland wrote:
       | So what do you do about stress? How do you recognize it's
       | happening? I found this part informative:
       | 
       | "Stress reactivity occurs specifically in situations that
       | diminish one's control and where the prospect of being negatively
       | evaluated, rejected, and/or shamed are contextually manipulated
       | (Dickerson et al., 2004)."
       | 
       | I find I get the most stressed when I'm excited about a new
       | challenge -- a new work project, seeing a path to achieving a
       | goal I've been working towards for a while. When I start to feel
       | too excited (or in the framework of this paper, I start to expend
       | too much energy and my heart rate is elevated thinking about all
       | I want to do to overcome the challenge), I can generally reign in
       | the stress by reminding myself that failure happens, my peers
       | will understand it, and I don't have complete control over
       | anything anyway.
        
         | vmasto wrote:
         | Stress most times doesn't reveal itself like that. What you're
         | describing is short term excitement and perhaps anxiety.
         | 
         | Stress is a silent killer. It's basically being mostly unhappy,
         | feeling unfulfilled and trapped. It's a spectrum that can range
         | from simply being unhappy to being deeply depressed.
        
       | diskevich wrote:
       | Stress management isn't just about understanding the problem--
       | it's about actionable solutions.
       | 
       | Exercise, even a brief walk, reduces cortisol and boosts mood-
       | enhancing endorphins.
       | 
       | Meditation and mindfulness, once seen as trendy, are now
       | scientifically proven to rewire the brain for better stress
       | handling.
       | 
       | Nutrition plays a surprising role; omega-3-rich foods like salmon
       | can lower stress hormones.
       | 
       | Quality sleep, especially deep sleep, allows the brain to reset
       | and repair.
       | 
       | Finally, don't underestimate the power of social support. Sharing
       | your struggles with others can significantly lighten your mental
       | load.
        
         | chiefalchemist wrote:
         | Agree, with all in full sans the last one. Of course, if you're
         | struggling, seek support.
         | 
         | We all have bad days or even bad weeks, life happens and often
         | it's best to learn this. The current fad (?) of "I'm going to
         | experess my non-positive feelings as they are all the time"
         | gives too much weight to what are normal passing moments.
         | 
         | I don't want to say being a hypochondriac is normalized (else I
         | might get canceled) but... Words, they create worlds. It's
         | important to be mindful of what we choose to create.
         | 
         | Belief drives behavior, and when allowed to perpetuate the
         | victim mentality can cause unnecessary (semi) permanent damage.
         | It's perfectly normal to experience some pain. Don't make more
         | of it than necessary.
        
       | gregwebs wrote:
       | Lets agree for the sake of argument that if the body does not
       | have enough energy to do what it needs that causes harm. Then why
       | not eat more food to deal with the problem?
       | 
       | I think this model is missing a critical component: the bodies
       | ability to use energy effectively is limited by having the proper
       | nutrients available. The easiest example being a deficiency of B
       | vitamins since they are used for energy metabolism. Many other
       | factors can impair energy metabolism and just eating more will
       | not fix the situation.
       | 
       | Whereas with this model we have statements that seem too over-
       | simplified:
       | 
       | > The organism's energy consumption capacity is biologically
       | limited
       | 
       | This seems overstated- we know that certain athletes can consume
       | 2x or even 3x a resting amount to support physical exertion- the
       | human body seems designed to be able to produce more power for
       | physical exertion when needed by consuming more energy (in
       | addition to making long-term adaptations to make energy usage
       | more efficient).
       | 
       | I also think that readers of this paper may take away an
       | understated understanding of the possible negative effects of
       | energy deficiency. Any physiological problem could be impacted by
       | energy metabolism. For example, even if something is known to be
       | caused by a deficiency in a nutrient that cannot be synthesized
       | by the body, it's still possible that improved energy metabolism
       | might be able to reduce the usage of that nutrient in some
       | pathways to conserve more for where it is needed.
        
         | t0bia_s wrote:
         | - _the human body seems designed to be able to produce more
         | power for physical exertion when needed by consuming more
         | energy (in addition to making long-term adaptations to make
         | energy usage more efficient)._
         | 
         | Most top athletes are retiring around 35. Their bodies are
         | ruined like those who need to physically work hardly every day.
         | They look elder as well.
         | 
         | We are not machines that will do more when given more sources
         | without consequences.
        
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