The thing that’s always bothered me about reductionist science is how quickly it becomes so abstracted from the world that it no longer usefully models the world.
Human beings, as living organisms, are complex adaptive systems. We are inextricably embedded in multiple contexts, physical, social, and cultural. You can’t truly understand a human being when you consider them isolated from the air they breathe, the food and water they eat and drink, the extensive web of relationships they live in, from family, friends and colleagues, to the networks of production of goods and services.
We are dynamic, open systems. That is, change is the constant of our nature, and there is a permanent flow of energy, information and substances between ourselves and the world in which we live.
A team of researchers in Montpellier has just published an interesting study beginning to try to examine and understand how chemicals in our environment bring about changes in our bodies.
They examined forty common chemicals which are found in the environment and in human bodies. Each of these chemicals has been tested on its own as part of state regulatory processes. Each one on its own has effects on the body, but not large effects (according to the studies). But of course, in the real world they don’t exist in isolation, so what happens when more than one of them is present at the same time?
As the researchers said, one and one normally make two, but when they studied the effects of the different pairs of these forty chemicals (780 variations of pairs in total) they found that sometimes one and one made fifty, or even a hundred. What they mean by that is that as they work together two chemicals don’t have a simple additive effect. Instead their combined effect can be many, many times greater than simple addition would suggest.
There’s an obvious reason for this. As complex adaptive systems, the cells in a human body are connected in a non-linear way, not a simple, linear one.
This study examines the effects of these particular chemicals on a particular receptor in a cell, (“pregnane X” receptor). They looked at this because chemicals have been shown to affect hormone systems within the human body causing widespread changes in the immune and inflammatory systems by interacting with such receptors, potentially setting off chronic metabolic and physiological disturbances in a person.
There study showed that one particular pairing of chemicals worked together as a kind of double key i.e. neither chemical could fit the receptor site, but when the two types of molecule combined they made the shape of a key which resulted in a much better fit to the receptor. So, singly, they produced little activity in the cell, but together their effect was multiplied 50 to a hundred fold. (The two they highlight are a pesticide and chemical from the contraceptive pill)
This is a small study only looking at the effects of pairs of chemicals in a set of forty, and only looking at the effect on a single receptor site. They point out that there are over 150,000 man made chemicals in our environment.
I’ll say that again.
There are over 150,000 chemicals in our environment.
Not just 40.
How many combinations can there be? How many combination effects might there be? Besides this particular one they have demonstrated. And the receptor site they studied is only one of many such sites in human cells.
A bit scary, huh?
They say they would now like to study the effects of pairs of 1600 prescribed drugs.
Are you a little surprised that we know so little about the real world effects of the presence of combinations of chemicals and medicines in the human body?
Well, thank goodness, we are beginning at least to explore real life complexity and stop pretending that single agents can be sufficiently studies in isolation.
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