Photo by cottonbro studio
The world of health, wellness and performance can be rife with scare tactics. These may be well intentioned, perhaps because whilst the truth is usually a shade of grey, moving people to it will often require an extreme (black or white) message. Similarly, given the power of fear as a motivator, it’s unsurprising it is leveraged in storytelling to create action. This is by no means a condolence of this behaviour, nor is it a significant criticism, consider it a acknowledgment of the reality we live in. However, as folks inhabiting the real world, we have to make real efforts to understand principles (which are few) so that the details (which are many) can be successfully navigated.
It is with this intention I bring you the body as a robust, adaptable, organism.
Toxins, Poisons and Allostatic Load
Many readers would have heard things like: the body only understands stress, not its source. Or maybe come across the concept of the stress bucket (hat tip to James Clear, who’s newsletter I’ve read religiously for over a decade).
These all speak to something similar the concept of allostatic load. “Allostatic load” is effectively a name for the total stress on your body as an organism. This can includes psychological, environmental, emotional, physiological or any other form of stress. The term is somewhat rare outside of the psychiatric and functional medicine realms specifically but many would have a rough appreciation and understanding of the concept, even without a specific term for it or having heard the term “allostatic load”.
The concept is important because it speaks to two things:
1) The body breaks (or doesn’t) under the total load on it, not any one load
2) The body can tolerate a lot of stress or load and is quite resilient to it
The Straw that Broke the Camel’s Back
We humans are fundamentally meaning making machines and we use story, or narrative, to codify and share lessons. We learn best through story, it’s why parables exist. Whilst helpful, this certainly creates a situation where we can end up misattributing risk and causality. As a result behaviour can at times end up overly cautious or conservative, via this misattributed risk.
For example; I ended up developing a stress reaction in my one shin during medical school. The elephant in the room was probably running load, I’d exceeded my capacity given load tolerance. Simple answer; be more conservative with your loading. The complex truth, however, was that there were likely components of stress, non-running load (I was walking a lot in barefoot shoes - see more on this here), diet (on reflection I was probably a little low in both carbohydrates and protein intake - bulletproof coffee anyone?) and social isolation (I was in a rural town) playing a role in the allostatic load. As a result, sure, I ran too much for my load tolerance but the running was probably the straw that broke the camel’s back.
(See that; the power of story, it’s real huh)
The result of the situation is me being overly conservative with one part of my allostatic load (running) via misattributing causation to a degree. This is a little bit over-simplistic but it’s a helpful for the intended purpose. This would have been very helpful when things could kill us, for instance salmonella in raw chicken, but not serve us as well in the more subacute and chronic domains of health (or performance for that matter).
Charles Darwin’s Lesson to us all
I’ve previously written that Charles Darwin’s theory of evolution has been bastardised and taken out of context often (I could be part of the problem here). It is a little more complex than ‘survival of the fittest’ but my read on the take away from it is that the organisms best able to adapt to their environment are the ones that thrive in it, and share their genetic material more widely (think weeds in the garden).
The reason I bring this up is that it speaks to the very heart of this article; your body is an adaptable organism. It can tolerate many stressors and will adapt to dealing with them, heat is one for example. Another may be the stress of those bicep curls you insist on doing (apparently it was over a thousand Ron? - sorry, bad movie reference but the millennials will giggle) your muscle grows to be better able to tolerate this load and you’re much less sore now.
Now some will argue, why haven’t we adapted to pathogens like bacteria then? Well, some have. Ever heard of a Balinese person getting ‘Bali belly’? Not really, because they’ve adapted (at least to a degree) to that exposure. This is a bit of a strawman argument, but the prevailing point is we are more adaptable than many think, though there are certainly some things where the adaptation could be less than optimal. There are also situation we haven’t adapted that well to.
Redundancy in Physiology
Following on from, or as an extension and example of our adaptability is the redundancy that is built into our biology. This redundancy is part of why we have a tolerance for various toxins, because we have ways and means of compensating (and of course not all of these compensations are great, but neither are they all a catastrophe).
This can be quite complex, but to use a simple example from the macronutrient standpoint let’s use energy supply to the brain (you know, the thing that keeps you alive and so is super important). In times of a mixed diet, dietary carbohydrates provide a supply of glucose to the brain. The glucose in our blood is quite a short term supply though, only being around 4g or a teaspoon (side note, I am unsure you’re allowed to write about blood glucose and not use this factoid, it’s actually the name of a paper), the body stores the rest of the glucose as glycogen in muscle and liver - the latter of which can be used to supply the brain over the coming hours. As glycogen stores dwindle for whatever reason; restricting carbohydrates, high usage rates, fasting etc, our body can produce new glucose (in a process called gluconeogenesis - this literally means making new glucose) from amino acids (the building blocks for proteins) amongst other things. As and when we continue to restrict intake of carbohydrates and/or need them at a higher rate than we can synthesise our body can (and does) start to break down fats slightly differently, producing ketone bodies as a fuel that can be used in general but specifically for the brain.
*For the physiology folks out there, yes I’ve skimmed over some nuance but it’s good enough for the purposes intended
The above example speaks to some of the redundant pathways we have in our metabolism. These mean we can cope with various perturbations in physiology, some of which may be as a result of a form of toxin from the environment for instance. To be extremely clear here, I am not for one minute suggesting something like significant arsenic exposure could be overcome through a redundancy in our metabolism but I am suggesting that many exposures that are less than ideal may be able to be overcome or tolerated in part.
A quick word here, which feels necessary, “the dose makes the poison” is a phrase you will here a lot in physiology and toxicology. It’s a extremely useful concept to remember when evaluating claims of toxicity or similar. And yes; in excess both oxygen and water can and will kill us.
The Body as a Solution Creator
In much the same way that the body can handle a certain amount of toxins, or allostatic load, via it’s detoxification systems or similar it can handle some less than perfect movement patterns (what ever these are).
The body is a complex system (I touched on this in this article a while back) but thankfully, it is a self-organising system. That is to say, given a movement or metabolic problem to overcome, it will generally find the optimal solution (for the given constraints of the problem). Now that’s not to say it would have magically ‘chosen’ the fosbury flop for your first ever high jump, but that’s to say when jumping it will optimise for height without needing to actively think about how far you bend your knees. This isn’t to say there’s no value in technique or biomechanics, but it is to say many things will self organise in a way that is close enough to optimal. It also has the ability to compensate and overcome challenges, for instance your gait will probably change if running with a heavy backpack. Moreover the self-selected change will likely be close to the most physiologically efficient way to run with the backpack.
An example that I used to see clinically a lot was a limb length discrepancy, the ‘rule’ I was taught in university was that up to 1cm of difference was not worth treating as the body could compensate and that treatment of any difference should probably only be half of the difference. Ultimately this was a case by case basis but the rule served as helpful for sure. What many students (myself included) started to find a challenge, was understanding aspects the limb length discrepancy given the body’s compensatory mechanisms, ie are the legs actually different in length or does it just look that way? Perhaps there’s a rotation at the pelvis, or a scoliosis (a lateral curvature) of the spine (see below picture) etc etc.
This picture, aside from illustrating Usain’s scoliosis (probably in the direction opposite to what may have helped running on the track for the record), speaks to the body’s ability to compensate. It’s not to say this issue didn’t cause problems, it certainly means certain structures are under more stress and perhaps at bigger risk of injury, but it is to say that the body can compensate and handle a lot via self organising.
On a related note, there’s lots of biomechanical discussion in the running technique world about technique and improving it. As a biomechanics fan, I’d love for this to be impactful, but the research truly does not bare this out much beyond the basics of not over-striding for instance. There’s even researching showing that experienced coaches can’t pick more or less efficient runners and that changing technique reduces efficiency (increasing oxygen cost of running). Again, there may be reasons to do so (injury comes to mind at times) but we are organic life forms, not machines and as such there is a biological underpinnings, not just mechanical ones which drive things like running technique.
Despite all I have said, about the body’s ability to compensate, cope and generally be resilient, I’ve recently been changing my mind about how impactful a few specific ‘toxins’ are. Specifically, I think these are under appreciated and under discussed.
Some Lesser Discussed Toxins that have Caught my Eye
Hopefully the gist of this article imparts the fact that I am generally one who doesn’t catastrophize or over-pathologise things. That said, the more I am learning about two ‘toxins’ or ‘pollutants’, the more I am convinced they’re playing a bigger role in some of our current ailments that we appreciate. Particularly as hard-to-detect, low level, constant exposures which may very much impact our ability to cope with other stressors.
Noise, Light and Air pollution
Concerns around light pollution largely stem from the biological basis that sleep and circadian rhythm disruption are intimately linked to metabolic disease and sequelae thereof such as cardiovascular disease and cancers as is illustrated below. These probably don’t surprise many readers given the discourse around the impacts of late night screen time on health which has been all pervasive of recent times.
From Cao et al
Noise pollution, however, will likely surprise readers. The World Health Organisation (WHO) estimates ≥1.6 million healthy life-years are lost annually from traffic-related noise in Western Europe.
A quick health statistics explainer:
Healthy life years lost is a way of understanding cumulative burden across a society.
Healthy life years are disease free years (think healthspan) as opposed to years of life lost where individuals may not be healthy (think lifespan). The way this statistic is calculated is looking at onset of disease as a result of exposure, subtracting this age from healthy life expectancy at birth. This number is then tallied from individuals to create the sum. So in the statistic above, 1.6 million health life years lost is equivalent to 1.6 million people having the onset of their first disease a year earlier than expected.
These healthy years are lost to a number of issues, including mental health problems, cognitive impairments, and adverse birth outcomes, sleep disorders, and increased annoyance (this is an actual thing, reported in the scientific literature - glad it’s not just me). In addition to this there is a growing body of literature indicating that traffic noise is also associated with cardiovascular disease, through multiple pathways. Of course noise pollution, much like light pollution, has the ability to negatively impact sleep and as a result, wreak metabolic havoc on the system as explained above. (This may seem a little dramatic but I can’t overstate the importance of sleep, it’s probably the sole area of agreement amongst all professionals, across health and performance).
Interestingly, noise pollution can be an issue in hospitals (specifically intensive care units) which would surprise nobody who’s spent significant time there, a place where light pollution can be a huge issue too. These could easily have been parts of my article on improving the health of healthcare.
To sum up; noise pollution is the the second major contributor to the burden of disease (this statistic is effectively is a mixture of prevalence and severity) in Europe, only after air pollution.
When it comes to air pollution most folks would implicitly understand the issue but would likely imagine cities in places like China when thinking about it. Unfortunately it is a little more pervasive than just the most densely crowded cities where this is a problem, for example, Chamonix (the mecca of trailrunning and a renowned ski town next to Mont Blanc) has huge pollution issues, particularly in the winter - perhaps less surprising when considering wood burned in fires and the shape of the valley.
Reduction of air pollution can have significant health benefits:
“Within a few weeks, respiratory and irritation symptoms, such as shortness of breath, cough, phlegm, and sore throat, disappear; school absenteeism, clinic visits, hospitalizations, premature births, cardiovascular illness and death, and all-cause mortality decrease significantly.”
Yes, you read that quote correctly, ‘all cause mortality’ aka death from any cause.
Solutions
The good news is these pollutants or toxins, can be combatted and as usual, my suggested solutions are with view to being actionable with minimal effort (unlike suggesting the 18% of you readers who live in NYC move upstate).
From a noise pollution standpoint, I’ve found noise cancelling headphones to be a great help in general (if you’re working check out some binaural beats for focus, it’s unreal). When it comes to sleep, I use ear plugs for the same. Light pollution is a matter of some discipline when it comes to phones, TVs and computers in addition to some blackout curtains (well worth the investment, I promise). There are certainly advanced lighting solutions too, with circadian lighting, low blue light bulbs etc but I think the bulk of the value (aka the big rocks) is in the things I mentioned first (but I am open to being wrong here).
Air pollution is the most difficult to combat, especially if living in a city. Of course we can talk about individually reducing our creation of pollution and this isn’t without merit, but this article is more about the consequences of the total pollution and toxins. Air purifiers for homes exist and may be helpful but ultimately if the issue is bad enough for the individual (I am thinking about folks with asthma who seem to feel this most acutely) or your concern for long term implications is high enough, it may warrant a move or splitting of time if you have this luxury.
Many of these problems are remedied or not an issue in areas with more green space of course.. Biophilia anyone?
Voltaire’s well known (at least in medicine) quote comes to mind to summarise this piece well: “The art of medicine consists in amusing the patient, while nature cures the disease”. I’d suggest, perhaps evolving things a little towards something more like “the role of a practitioner is to create the environment in which the body can heal itself”. All of which is to say, the body can and will tolerate a great deal, it is robust and adaptable, don’t be fooled into believing the opposite.
References:
Guidi J, Lucente M, Sonino N, Fava GA. Allostatic Load and Its Impact on Health: A Systematic Review. Psychother Psychosom. 2021;90(1):11-27. doi: 10.1159/000510696. Epub 2020 Aug 14. PMID: 32799204.
Cao M, Xu T, Yin D. Understanding light pollution: Recent advances on its health threats and regulations. J Environ Sci (China). 2023 May;127:589-602. doi: 10.1016/j.jes.2022.06.020. Epub 2022 Jun 18. PMID: 36522088.
Falchi F, Cinzano P, Elvidge CD, Keith DM, Haim A. Limiting the impact of light pollution on human health, environment and stellar visibility. J Environ Manage. 2011 Oct;92(10):2714-22. doi: 10.1016/j.jenvman.2011.06.029. Epub 2011 Jul 13. PMID: 21745709.
Walker WH II, Bumgarner JR, Walton JC, Liu JA, Meléndez-Fernández OH, Nelson RJ, DeVries AC. Light Pollution and Cancer. International Journal of Molecular Sciences. 2020; 21(24):9360. https://doi.org/10.3390/ijms21249360
Münzel T, Sørensen M, Daiber A. Transportation noise pollution and cardiovascular disease. Nat Rev Cardiol. 2021 Sep;18(9):619-636. doi: 10.1038/s41569-021-00532-5. Epub 2021 Mar 31. PMID: 33790462.
Pal J, Taywade M, Pal R, Sethi D. Noise Pollution in Intensive Care Unit: A Hidden Enemy affecting the Physical and Mental Health of Patients and Caregivers. Noise Health. 2022 Jul-Sep;24(114):130-136. doi: 10.4103/nah.nah_79_21. PMID: 36124521; PMCID: PMC9743307.
Krittanawong C, Qadeer YK, Hayes RB, Wang Z, Virani S, Zeller M, Dadvand P, Lavie CJ. Noise Exposure and Cardiovascular Health. Curr Probl Cardiol. 2023 Dec;48(12):101938. doi: 10.1016/j.cpcardiol.2023.101938. Epub 2023 Jul 7. PMID: 37422031.
Schraufnagel DE, Balmes JR, De Matteis S, Hoffman B, Kim WJ, Perez-Padilla R, Rice M, Sood A, Vanker A, Wuebbles DJ. Health Benefits of Air Pollution Reduction. Ann Am Thorac Soc. 2019 Dec;16(12):1478-1487. doi: 10.1513/AnnalsATS.201907-538CME. PMID: 31774324.
Cochrum RG, Conners RT, Caputo JL, Coons JM, Fuller DK, Frame MC, Morgan DW. Visual classification of running economy by distance running coaches. Eur J Sport Sci. 2021 Aug;21(8):1111-1118. doi: 10.1080/17461391.2020.1824020. Epub 2020 Oct 29. PMID: 32930647.
Schücker L, Parrington L. Thinking about your running movement makes you less efficient: attentional focus effects on running economy and kinematics. J Sports Sci. 2019 Mar;37(6):638-646. doi: 10.1080/02640414.2018.1522697. Epub 2018 Oct 11. PMID: 30307374.
Moore IS. Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy. Sports Med. 2016 Jun;46(6):793-807. doi: 10.1007/s40279-016-0474-4. PMID: 26816209; PMCID: PMC4887549.
Patoz, A., Blokker, T., Pedrani, N. et al. Biomechanical adaptations during exhaustive runs at 90 to 120% of peak aerobic speed. Sci Rep 13, 8236 (2023). https://doi.org/10.1038/s41598-023-35345-8