Ashes to Ashes

Human bodies contain about 60% water.  Sometimes, it’s noticeable, especially in the brain region, which contains about 75% water.  Politicians may hold more water, possibly even hot air, but scientists have yet to confirm this.

What remains when we take away the water? The rest, as they say, is dust and ashes.

Close on 20% of total body weight (about half the body’s dry mass), is carbon.

That’s one half ashes.

The other half is shared by more than 60 elements – more than half the periodic table. Right there, inside of you.

Elements cannot be produced by biological (organic) processes.  They have to be extracted from the surroundings, before being built into the body.  Most of these elements can be classed as minerals – solid, inorganic substances found in the soil.

That’s one half dust.

In other words, our bodies are basically three parts water, one part ash and one part dust.

The more we study the body, the more surprises we find.

The minerals in our bodies are found throughout the soil in varying amounts.  Typically, we identify 7 major and 9 minor (trace) elements.  The rest?  The amount we need of the rest is too low to measure easily, so they mostly get ignored. We still hardly know anything about their importance. You pick up a bit here, collect a bit there.  It takes time – and some luck. And you need a gut that can detect as little as one atom of certain elements.  Imagine that sort of sensitivity – packed into the tiny surface of a tiny cell deep inside your gut wall.

All these minerals were once deep inside giant stars exploding a long time ago. The dust found its way across aeons of time and oodles of space to a planet near you.  Lucky you.

You know, you’re actually pretty amazing. But you knew that, right?

Where do our bodies find all these minerals in a way that is not random?

Plants to the rescue!

Firstly, plants concentrate minerals in their various parts – roots, stems, leaves, flowers, seeds.  However, each plant has a different mineral profile, just as each plant part has a different mineral profile.  Also, soil conditions determine the mineral make-up of the plant.  In other words, to get your full complement of minerals, you need to eat a wide range of plants from a wide range of soils.  You gotta move around.

Plants also have an important negative function. Like in any public space, there are certain “unwanted elements” in nature.  Some of that wandering stardust is not good for life.  Plants detect these in the soil and refuse to absorb them, or absorb them in low amounts only.  Thus, by eating plants instead of soil, we get our minerals “pre-filtered”, free of charge, courtesy of the sun.

This is not a 100% perfect correlation. Plants and people have different life processes and purposes, after all. But it beats the alternative. Eating soil is even worse than eating broccoli (or Brussel sprouts or kale, come to think of it).  Again, as long as the types of plants and regions of plant harvesting vary, we will (on average) get a full and healthy spectrum of essential minerals.

The absorption of minerals into the body is another matter.  Many of the heavier minerals require a special “basket” to be transported into the body.  Think of this as a cup made from molecules. It holds one mineral atom in the centre, carrying them across cell membranes into the body.  Plants, ever hungry for minerals, have lots of these cups inside them. One example would be the group of chemicals we call polyphenols.

So, plants not only help us find the necessary elements, and avoid the unnecessary ones, they also help us to absorb them.  But here’s a teeny problem:  All that fantastic plant goodness is stuck inside a cell. And not just any prison cell, this is a Fort Knox of a cell.

Plant cells are surrounded by something called the “cell wall”.  Cell walls are support structures designed to fiercely defend the cell contents. After all, plants have no legs to flee “predators”, so they need other ways to play “hard to get”.  Collectively, we call these cell walls “fibre” or “cellulose”.  Tough stuff.

Our bodies cannot digest the cell walls very well.  A little bit, yes, but not enough for us to survive very long.

Microbes to the rescue!

There’s a whole constellation of microbes dedicated to “eating” cellulose.  What is more, they make by-products that are important to our immune system.  And they liberate the minerals we need for all processes of life.

Ain’t that sweet of them?

Now, if you’ve been eating a diet low in fibre for a long time, these microbes probably got hungry, then died off.  Even if you switch to a fibre-rich diet, you still need to get the microbe colonies from somewhere to get the goodness out of the plants.  After two generations of eating refined foods, most of the Western world has lost its colonies of fibre-eating microbes. Just changing your diet to be “rich in fibre” won’t solve the basic problem.  You’d need to find a friendly herbivore and let some of it rub off on you.  Or get it in a bottle.

But that’s a topic for another day.

Ponder those microbes,

Doc Frank


Further reading

Wikipedia on “Dietary elements”

WebMD on “Minerals”