Our ancient ancestors emerged from the sea.
Human fetuses still have “gill-slit” structures, remnants of our watery origins. The fact that we are small, mobile, thinking seas has long intrigued writers and researchers.
As pioneering marine biologist Rachel Carson put it, “This is our inheritance from the day, untold millions of years ago, when a remote ancestor, having progressed from the one-celled to the many-celled stage, first developed a circulatory system in which the fluid was merely the water of the sea.”
And that most human of our organs, our massive brain, is profoundly and absolutely a creature of the sea.
According to the book “Blue Mind,” when we are born, our bodies are around 78 percent water. As we age, that number drops to below 60 percent.
But the brain, throughout our lives, continues to consist of 80 percent water.
It is as if the aging body, unable to hold all of the salty water we brought with us from the sea, works hard to ensure the most important organs – the eyes and brain - remain the most “sea-like,” for a lifetime.
Another way to look at it: the eye/brain complex is an independent sea-creature, hauled around the terrain by drier, tougher machinery that assumed some of the characteristics necessary for life on land.
DHA and You
Beyond water, the most vital nutrients that constitute brain tissue are also from the sea, especially docosahexaenoic acid, better known as DHA. The fact that it is abundant in seafood and in the human brain and eyes suggests eating fish and shellfish were essential to both the creation and growth of the human brain.
Which brings us to Michael Crawford. A Director of the Institute of Brain Chemistry and Human Nutrition, Imperial College, London, U.K., he is almost certainly the world’s leading expert in DHA.
“Docosahexaenoic acid (DHA) provided the core for the development of the photoreceptor,” he wrote in a seminal 2012 paper (if you enjoy original journal articles, this one is probably the most amazing one you will ever read). (Crawford et al., 2012)
The photoreceptor is the nerve-tissue structure that converts photons – tiny packets of light that bounce off all of the objects that make up our world into our eyes – into the electrons that power our brain and perceptions.
This evolutionary change represented a huge upgrade in what photoreceptors could do!
Photoreceptors in plants had been around for millions of years, and they turned photons into carbs and protein – food for the plant.
Now, photoreceptors, essentially made from DHA, could change photons into electrons. Food for the thinking brain, one might say.
If the eye/brain complex could not change photons into electrons, perception and cognition would both be impossible.
In this clip, Crawford, in his London home, explains how vital this is. The clip runs just over two minutes, and I daresay it’s well worth listening to it all.
Take it from Michael Crawford, who, incidentally, remains brilliant and tireless at 90 years old, thanks to eating seafood five times a week.
Keep your DHA topped off. Eat seafood often, especially for dinner, so you have plenty available during sleep for renewing the brain’s architecture.
Give that lovely eye-brain creature you haul around what it needs to be happy and healthy – because that creature is you.
Crawford, M. A., Leigh Broadhurst, C., Guest, M., Nagar, A., Wang, Y., Ghebremeskel, K., & Schmidt, W. F. (2013). A quantum theory for the irreplaceable role of docosahexaenoic acid in neural cell signalling throughout evolution. Prostaglandins, Leukotrienes and Essential Fatty Acids, 88(1), 5-13. doi:10.1016/j.plefa.2012.08.005