Below are some excerpts from a paper which can be accessed in full here. Keep in mind that much of the information in this paper deals with physics and complex chemistry. I am not trained in either discipline and I know that most of the people on this forum are not either. So I will include only the pieces of information that are comprehensible for the average reader.
“A quantum theory for the irreplaceable role of docosahexaenoic acid in neural cell signalling throughout evolution”
Six hundred million years ago, the fossil record displays the sudden appearance of intracellular detail and the 32 phyla. The ‘‘Cambrian Explosion’’ marks the onset of dominant aerobic life. Fossil intracellular structures are so similar to extant organisms that they were likely made with similar membrane lipids and proteins, which together provided for organisation and specialisation. While amino acids could be synthesised over 4 billion years ago, only oxidative metabolism allows for the synthesis of highly unsaturated fatty acids, thus producing novel lipid molecular species for specialised cell membranes. Docosahexaenoic acid (DHA) provided the core for the development of the photoreceptor, and conversion of photons into electricity stimulated the evolution of the nervous system and brain. Since then, DHA has been conserved as the principle acyl component of photoreceptor synaptic and neuronal signalling membranes in the cephalopods, fish, amphibian, reptiles, birds, mammals and humans. This extreme conservation in electrical signalling membranes despite great genomic change suggests it was DHA dictating to DNA rather than the generally accepted other way around. We offer a theoretical explanation based on the quantum mechanical properties of DHA for such extreme conservation. The unique molecular structure of DHA allows for quantum transfer and communication of p-electrons, which explains the precise depolarisation of retinal membranes and the cohesive, organised neural signalling which characterises higher intelligence.
DHA abundance controls brain size and function
Comparative evidence on brain composition gave us the first clue to consider both proteins and lipids in six dimensions, and that lipids may specify proteins just as proteins specify lipids. In some animals DHA is present either in the diet or as a product of the strongly rate limited synthesis from plant-derived a –linolenic acid (C18:3n-3). If the velocity of body growth is small then adequate synthesis of DHA for brain growth can occur, resulting in a brain/bodyweight ratio of 4/2% (e.g. small rodents). As the velocity of body growth or protein acquisition increases, the rate limitation of DHA synthesis dominates and relative brain size diminishes. In the largest land-based mammals the ratio shrinks to 0.1% (rhinoceros, Cape buffalo) despite abundant a –linolenic acid in the tissues. An abundant source of preformed DHA, as in the diets of marine mammals, can obviate low biosynthetic capabilities. Such evidence suggests that nutrition, especially with regard to DHA, was a determinant of brain size. For example, the dolphin has a 1.8 kg brain, compared with a land based zebra of a similar bodyweight with only 360 g brain. The rate limitation for DHA with its tortuous synthetic route to its synthesis requiring its import, metabolism and export from the peroxisomes, explains how very small mammals like squirrels with a high metabolic rate and a reasonably efficient biosynthesis achieve a maximally high brain to bodyweight ratio of 2.4%. Incorporation of (isotopically labelled) preformed DHA into the developing rat pup brain was found to be more than an order of magnitude greater than incorporation of DHA synthesised from a-linolenic acid. Humans are much less capable; we can only count on about 1% conversion of a-linolenic acid to DHA. Yet across all mammal species, brain size decreases logarithmically with increase in bodyweight with two exceptions — the dolphin and the human. Clearly we were doing something different during our evolution.
Lipids play a key role in signalling and DHA is involved in the expression of several hundred genes in the brain. The genomic evidence means that an abundant dietary source of preformed DHA, as provided in littoral habitats, would actually stimulate the evolution of the brain, and a lack of DHA would be restrictive. What we were doing differently is that we were a very small group of individuals who consistently ate marine and lacustrine food sources. The superabundance of DHA (and Zn, Cu, I, Se, protein etc.), with its irreplaceable role in neural cell signalling, allowed the synaptic evolution of self-awareness and symbolic thinking and behaviour. Thus began our cultural evolution, very much faster and pervasive than biological evolution : most cultural evolution is dependent on teaching and adaptation rather than pure innovation and hard genetic changes. Yet we remain essentially the same beings, dependent on DHA for 600 million years and unable to move towards a new and improved species without the raw material. Quite apart from any technical arguments, the late Philip Tobias summarised the argument succinctly: ‘‘wherever humans were evolving, they had to have water to drink’’! In other words we did not evolve (especially with our highly dependent infants and children) on the arid savannah.
The curious facet of DHA dominance in evolution is that it's DPA precursor differs by only two protons and would have been more readily available. The difference in fluidity between DHA and DPA is very small; certainly not enough to explain 600 million years of conservation of DHA in photoreception and neural signalling systems. Alternatively, Bloom and colleagues suggested that DHA might have unique electromagnetic properties which have little to do with membrane fluidity. Gawrisch and colleagues have also attempted to explain the DPA/DHA paradox. Using solid-state NMR measurements and molecular simulations they provide an image of DHA as a uniquely flexible molecule with rapid transitions between large numbers of conformers on the time scale from picoseconds to hundreds of nanoseconds. The low barriers to torsional rotation about C–C bonds that link the cis-locked double bonds with the methylene carbons between them are responsible for this unusual flexibility. Both the amplitude and frequency of motion increase towards the terminal methyl group of DHA. Like us, these authors understand that classical biophysics does not have a ready explanation for the irreplaceable DHA.
DHA and quantum mechanics
The van der Waals equation hints that DHA will have both stereochemical and electromagnetic properties. Quantum mechanics can predict the existence of energy levels inside lattices, whereby any electron in that level can be effectively spread across the whole structure, thus becoming a quasi-particle or a wave. Albert Szent Gyorgyi postulated that common energy levels could exist in protein structures, as they contained ‘‘a great number of atoms, closely packed with great regularity’’. He considered the communication of energy between molecules in biological systems could be achieved through coherence of electrons raised to a higher energy state. The formation of a triplet state of the p-electrons around double bonds in aromatic amino acids was the basis for this mechanism. Since Szent-Gyorgyi, the electron transfer of the energy production system in mitochondria has become well known. Bendall considered the conformal dynamics of proteins to be reliant on the long range transfer of electrons. The method of transport is quantum mechanical tunnelling, a feature of proteins demonstrated by Hopfield. Hackermuller et al. obtained evidence that tetraphenylporphyrin exhibits wave like behaviour, indicating quantum coherence in nature. Hammeroff and Penrose proposed a model based on quantum mechanics that can explain consciousness and is testable. In the ‘‘Orchestrated Objective Reduction’’ model of consciousness, quantum coherence exists in the microtubules found in neurons. It is hypothesised that microtubules are capable of quantum computing, and quantum computations are translated to classical outputs—hence consciousness. Hammeroff then proposed the connections between neurons were linked to consciousness. Gap junctions are small enough for quantum objects to cross by quantum tunnelling, allowing cohesion across regions of the brain and creating consciousness. The brain can contain numerous proteins but is absolutely dysfunctional without DHA and AA. We hypothesise that the p-electrons in DHA could behave in similar quantum manner, explaining the unique and irreplaceable role of DHA in neuronal signalling. We must also consider that beyond consciousness, cohesion across regions of the brain drove the evolution of symbolic thinking and behaviour, which is the hallmark of humanity.
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Incoming light hits the back end of the photoreceptors and has to squeeze through the slits between the cell structures. This may split the light into a wave form interference pattern as in Young’s double slit experiment. Acting as a wave, the incoming photon has a far better chance of activating the very specific location of the retinal cis-double bond than as a discreet particle which could easily miss such a small target. A photon wave form also raises the question as to whether or not the incoming wave could activate retinal and DHA simultaneously. Visible light ranges from about 380 to 740 nm; the distance between the retinal and the DHA phosphoglycerides is within this range. Although it is unlikely that there is sufficient energy for a photon to energise both retinal and DHA electrons simultaneously, more than one photon is usually involved in what we see. This situation raises the possibility of cohesion between the retinoid and DHA p-electron activation. In this theory, the energy released in the signalling would be absolutely and precisely quantised by tunnelling, giving us the clear vision, high acuity necessary for reading, fine motor skills, and three-dimensional vision; together with smooth mental processing of our external environment upon which we depend. A similar process might take place in the synapse where the DHA is also densely packed. There DHA might act as a quantum gate controlling the signal in a fashion reminiscent of semi-conduction (Anyone interested should read the work of Robert. O. Becker on bodily DC electric current generation and semi-conduction within bodily cells. Specifically “Cross Currents” or “The Body Electric”).
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Conclusion
As far as our knowledge goes, DHA has been the dominant fatty acid in the membrane phosphoglycerides of the photoreceptors, neurones and synapses for all 600 million years of animal evolution. Even today, the composition of the photoreceptor and brain varies little between species despite large scale species variation in the lipid composition of the diet, liver and muscle. This consistency is despite the fact that its DPA precursor, which differs by only two protons, is more readily available, requires significantly less energy to synthesise, and is more resistant to peroxidation. Moreover, the difference in membrane liquidity by substituting DPA is minimal. By contrast over 600 million years animal genomes underwent countless mutations with enormous variation in protein composition and structures. We suggest that DHA is one Darwin’s ‘‘Conditions of Existence’’ which made DHA the master of DNA since the beginning of animal evolution. Proteins are selected to function with the constancy of DHA: it was the ‘‘selfish DHA’’ not DNA that ruled the evolution of vision and the brain. We propose protein–lipid interactions operate in a multi-dimensional fashion similar to what has been described for proteins. This relationship has to be a two way system. During cell differentiation, the specialist proteins that arrive will seek a lipid match and vice versa. If the matching lipids are not present the system may fail. A practical point is that random mutation and selection for survival have little predictive power. However, has powerful predictive power because it predicts human biological evolution slows or reverts if DHA is not superabundant.
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The extraordinary conservation and irreplaceable nature of DHA in neuronal signalling and its high concentration in the photoreceptor can be explained if it functions as an electron tunnelling device providing quantised signals. Quantum mechanical treatment explains the absolute precision of the membrane depolarisation in phototransduction. This precision is essential to visual acuity and synaptic signalling. Quantum mechanics also explains the photoreceptor oriented counter-intuitively away from incoming light.
We have established that energy minimised structures, molecular polarisation and moment of inertia allow for the theoretical possibility of DHA operating in the realm of supra-molecular chemistry with electron quantum coherence but we clearly acknowledge that further investigation is required.