Using Age Old Geological Debates To Guide Medicine

Geologist in the 1700s had a raging debate on their hands about the forces that shaped the surface of the earth we live on today. The argument went something like this:

Geologist 1: "Only huge cataclysmic events like earthquakes and volcanic eruptions could have created mountains or cut deep canyons through rock."

Geologist 2: "No you dum dum, consistent process over long stretches of time like rivers eroding solid rock create gradual change that leads to the giant formations we see today."

Geologist 1: "No it's earthquakes and volcanic explosions"

Geologist 2: "No it's erosion, weathering, and deposition"

and on and on and on...

Until they realized, it was both.

A new concept that combines uniformitarianism and catastrophism is called "modified uniformitarianism" evolved from these debates. This theory suggests that while most geological changes occur through slow, gradual processes, occasional large-scale catastrophic events also play a significant role in shaping the Earth's landscape, essentially acknowledging both perspectives within a single framework. 

Sooooooo, why are we talking about this?

I think this same thought process can be applied to how we think about medicine and chronic disease.

Let me give you an example. Heart disease. Like geological features, the accumulation of atherosclerotic plaques that define heart disease are formed inline with the premiss of 'modified uniformitarianism'. 

Heart disease develops in both in 'cataclysmic' events (think a week long cocaine bender, flare of inflammatory vasculitis, toxic smoke inhalation event) AND small constant accumulation (think ApoB consistently in the 120s, low level inflammation with CRP in the 4s, smoking cigs). 

Both major events as well as the day to day events work together to determine how the disease progresses. Indulge in your cocaine benders while keeping your ApoB constantly high and you will rapidly develop heart disease. Reduce both your cocaine benders (for the record zero cocaine benders are best) AND reduce your ApoB and you will swing the pendulum of heart disease back to health.

Let's take another example. Sarcopenia. Most population data you see will show a nice smooth curve indicating the gradual loss of muscle mass over time. However when we look at the individual level, it often is not as simple as this smooth line. Sarcopenia is driven by both a daily small overall net reduction in muscle mass AS WELL AS catastrophic events that lead to a 'catastrophic drop' that is never fully recovered. Experiments done with healthy individual put in a hospital bed for two weeks to mimic the effects of an acute illness drastically reduced their muscle mass.

You can see a graphical model of how this works over a patients lifetime. See how the gradual decline is punctuated by 'catabolic crisis'

Link to paper: English, K. L., & Paddon-Jones, D. (2010). Protecting muscle mass and function in older adults during bed rest. Current Opinion in Clinical Nutrition & Metabolic Care, 13(1), 34-39.

This makes intuitive sense to most people. Take for instance a theoretical but very common patient presentation of Mr. NcNullen. Mr. NcNullen is a 65 year old American male. While diligent about his health compared to other Americans his age, he has had a notable decline in his abilities since his 30s. However if you were to ask him year over year if his health is better, worse, or about the same, each and every year he would tell you it was about the same. Though when you zoom out over the three decade time frame there is clearly a loss of muscle mass. The gradual changes include both a reduction in Mr. NcNullen's drive to lift heavy things, his anabolic resistance making it harder for him to gain muscle mass  while eating the same diet and having the same workout routine as before. He also likely eats less protein in his diet in addition to his sleep is generally lower quality and it takes him more time to get the same recovery.

Now Mr. NcNullen, trying to stay active, hikes along a local trail, steps on a root, and breaks his ankle. Let's give him the brightest outlook imaginable and say that he is able to get surgery 2 weeks out from the injury once the swelling goes down, he is able to put weight on ankle 8 weeks post surgery, and through diligent PT and pure indomitable grit he is able to start walking on it meaningfully and return to hiking 4 months after the initial break. This is all assuming there isn't any complications such as infection, blood clots, a second revision surgery required, or the loss of drive to resume. During these 4 months, Mr. NcNullen has lost a ton of lean muscle, and he will almost certainly not recover to his baseline muscle mass the day before the ankle injury. This is the 'cataclysmic' part of the sarcopenia equation.

Let's zoom back out. I believe that overall functional capacity, obesity, kidney disease, diabetes, and neuro-cognitive decline all follow similar patterns. It is the combination of the gradual day to day AND the huge insults that drive most diseases of aging.

Where does this fit into our health management? Grasping this concept is key because in understanding the decline, we can identify how to delay declines and build reserves. We can both be aware when bad things are happening to our longevity and we can build plans to address it in real time as well as build reserves before the inevitable cataclysmic event visits us.

Fortunately, we can also use this same principle in the other direction. Both small consistent positive changes to health and large interventions can get our health on track. I use this framing of disease to gamify health for myself. It makes interventions I do make much more sense and it makes it much more fun.