Wednesday, September 27, 2017
The Energy of Life: The Science of What Makes Our Minds and Bodies Work
Book Review: The Energy of Life: The Science of What Makes Our Minds and Bodies Work – by Guy Brown, Ph. D. (The Free Press, 1999)
This book is mainly about Biochemistry. It is sometimes informative, sometimes fascinating, and a good introduction to the field from various perspectives in regards to energy. It covers the definition and nature of energy, energy conversions in the body like food to energy to muscular movement, inter and intra cellular energy mechanisms, chemical energy, the history of energy and vitality concepts, optimization of energy for athletic endurance and weight loss, energy effects of sex and sleep, experiments and theories, and potential practical applications.
Having abundant energy has been correlated with perceived happiness and lack of energy is the most common symptom that patients report to their doctors.
“Our bodies and minds are powered by electricity. Our cells are energized by huge electric fields driving vast currents through exquisitely tiny molecular machines: motors, gates, pumps, switches, and chemical factories that together create cellular life.”
Microbes power our cells in a symbiotic arrangement. However, those same microbes trigger cell death and aging. Though we now know much more about how energy powers body and mind there is still much unknown about how it works and how best to influence such processes. Brown reaches across disciplines to try and connect the dots.
He compares the idea of energy to that of money. As money is the capacity to buy things so is energy the capacity to do things or “the capacity for movement or change in a physical or biological system.” Like money, energy is exchanged. Energy comes in different forms: chemical, mechanical, electrical, heat, etc. The key difference between money and energy is that energy is conserved – the first law of thermodynamics states that the total energy in a system is always conserved. More money can be put in or taken out of circulation – not so with energy.
“Energy quantifies the capacity for movement or change in a situation.”
However, as physicist Richard Feynman noted the concept of energy is abstract. It is not a thing nor a substance yet it can be quantified. However, it may also be the most fundamental property of the universe. In physics everything comes from energy and returns to energy.
While energy is the quantification of movement or change it is ‘force’ that causes the movement or change. Newton developed the idea of the gravitational force based on attraction between objects. The electrical force based on electrical charges results in attraction or repulsion between objects. These two forces “account for virtually all movement and change in our universe.” The other two of the four fundamental forces, the strong and weak nuclear forces can only be observed by breaking the nucleus of an atom and thus their ranges are small. The gravitational force is important for large objects like we humans but decreases in significance as objects get smaller. At the cellular level it is insignificant. That leaves the electric force largely predominant at the molecular and cellular levels. The electrical force is due to polarity, negatively charged electrons and positively charged protons, and rules what happens in our bodies. All contact forces from one thing touching another are due to electron repulsion. Molecules are simply stable arrangements of electrons and protons. Any change in arrangement either requires or releases energy. Life takes molecules from the environment and rearranges their electrons and protons to decrease repulsion. Carbon dioxide, water, and energy are produced in the processes.
The laws of thermodynamics (heat and motion) state that entropy (disorder and randomness) always increases in nature. In nature motion can be fully converted into heat but heat cannot be fully converted into motion.
Life exhibits order and seems to defy the 2nd law of thermodynamics, or rather the spirit of the law, he notes. Energy is still released into the surroundings which increases entropy. The physicist Schrodinger suggested that life feeds on negative entropy, or negentropy. Life tends toward order while most processes in the universe and the universe as a whole move toward disorder. Life creates order by ‘coupling’ with other processes that lead to disorder. The net effect is more disorder, increased entropy. Cells do this coupling by controlling what enters and exits the cell membranes. The multiple coupling processes of the cell require the burning of food which is entropic. The sun is the ultimate power source.
He favors the analogy of the machine as applicable to modern cell and molecular biology. No effective gravity and friction in the smallness world of cells and molecules and interactions happening at the rate of a thousand or even a billion times per second make it a different world than the one to which we are accustomed. Two major types of machine are the enzyme and the transporter. The enzymes convert one type of molecule to another by adding or subtracting parts. The transporters carry molecules from one compartment to another across cell membranes by binding or changing shape. There may be 10,000 different types of enzymes and transporters in a cell. The number of copies of each ranges between 10 and a hundred million. Each perform their tasks at about a thousand times per second. Aside from enzymes and transporters there are many other types of molecular machines as well. The structure of cells, the cytoskeleton made of living proteins, is not fixed but continually being built up and dissolved. Other motors, pumps, clocks, switches, assembly factors, and information processors within the cell are often powered by ATP (adenosine tri-phosphate) which itself is produced by an electrically-driven rotating motor. Other functions require complex proteins to coordinate. Making proteins is the body’s most energy-expensive process – about 20% of our resting energy is devoted to protein synthesis. Even more is consumed during growth. Proteins are responsible for muscle contraction and the synthesis, transport, regulation, and breakdown of molecules. They are also the antibodies, hormones, receptors, and structural components of a cell. DNA merely provides the information, plans for actions. Sequencing the human genome is complex but figuring out the functions of over 100,000 different types of proteins that those genes provide codes for is much more complex. We are indeed complex machines. Brown says we know the functions of about 1% of them. (presumably about 1000). It took Max Perutz 23 years (1937-1960) to determine the structure and function of the protein hemoglobin. Brown also notes that currently much of biology is concerned with determining protein structure and function.
The patterned process of enzymes converting molecules into different forms is known as a metabolic pathway. There are many such pathways in cells. There are three types: 1) those that transfer bits of molecules or mass (metabolic pathways), 2) those that transfer energy, and 3) those that transfer information. Metabolic pathways were mapped in the first half of the 20th century, energy pathways later, and information pathways from 1960 to current, most still unmapped.
Brown ponders whether humans are machines:
“Today evolutionary biologists would say that evolution by natural selection provides the designer, and survival and reproduction of the genes provide the purpose. There remains the question of free will and subjectivity.”
Is free will an illusion as many philosophers and neuroscientists assert? Will machines become more human-like? Will we integrate more and more with machines?
Bodies are powered by electrical energy. Within cells, most electric currents are carried by protons and salt moving within cells that are 70% water. Electrical energy, or electricity, is simply the flow of charge. Within body cells protons, electrons, phosphate ions, and sodium ions are the carriers of electricity. The food we eat and the air we breathe powers us.
“Within our cells, electrons are ripped off the food and fed to the oxygen, the electrons pass down an electron transport chain, consisting of a little wire of copper and iron atoms located within proteins in a membrane. Electrons are fed into the wire at high energy, and electrons are pulled out of the other end of the wire to oxygen at low energy. Thus, an electric current flows along the wire and can be used to do work as the wire passes through various protein machines within the membrane.”
Brown likens the process to a waterwheel that might run milling stones. It is a harnessing of available resources. It is such chemical ordering through ionic polarity that animates us.
The opposing views of German biochemists Heinrich Wieland (1877-1957) and Otto Warburg (1883-1970) were fused to develop the model of the electron transport chain. Oxygen from breathed air aids food digestion, through processes called ‘cellular respiration.’ The electron transport chain utilizes cytochromes, “molecular machines that take electrons from dehydrogenases and pass them on to the oxidase.” The electron transport chain results in a continuous supply of cellular electricity.
In the 1960’s it was discovered that this electron electricity is used to generate proton electricity. The flowing electrons power ‘proton pumps’ that pump protons out of the mitochondria. Mitochondria within a cell are said to power cells. This happens through slight voltage differences being maintained by accumulated charges inside and outside cell membranes. Since the polarity and thus the flow is maintained by pumped protons it is called proton electricity. In turn proton electricity is used to generate phosphate electricity, or ATP (adenosine triphosphate). Brown likens ATP to a chemical compressed air gun. Three charged phosphate ions that repulse one another are forced together creating potential for a repulsive burst when the force holding them together is removed. One of the three phosphates, the terminal one, is shot off, with the result that ATP becomes ADP (adenosine diphosphate) and the gun is ‘reloaded’ through extra energy supplied by ATP. Food-oxygen-electron transport-proton pumping-ATP-sodium pumping seems to be the sequence of cellular energizing with ATP/phosphate electricity being the accessible form utilized by molecular machines and the final form, sodium pumping (sodium electricity) being what powers our bodies and minds. After ATP was discovered in the 1930’s by biochemists Otto Warburg and Otto Meyerhof, it was briefly sold in a bottle as an ‘energy booster’ but it did not work in such a way. It only carries phosphate.
Creatine can also carry phosphate and is involved in muscle activity. Creatine in supplement form can provide marginal help for athletes and bodybuilders but can be harmful in high doses. Meyerhof also co-discovered the Edman-Meyerhof pathway, now known as glycolysis, which refers to the chemical aspects of muscle function where the pathway is from glucose to lactic acid through fermentation. ATP energy generation was found to be partly electrical and partly chemical. ATP powers many processes but chiefly muscle contraction, protein synthesis, and sodium pumping. Sodium pumping relies on charges that create larger electrical fields and power things like molecular transport, maintenance of cell size, and generation of electrical impulses in muscle, heart, and nerves. In summary the four forms of cellular electricity are electron, proton, phosphate, and sodium. He notes that there is still much unknown about the proton pumping aspect of the electron transport chain such as exactly how the cytochrome oxidase works.
The mitochondria that power us are microbes that entered us through the so-called mitochondrial Eve, a common ancestor female. Now we can’t live without them. They are also implicated in aging and in triggering cell death. He refers to mitochondria as a ‘maternal dragon’ that transforms our food into fire. These “bugs” make our body heat. By cell volume we are 1/10 mitochondria. One big problem for us is that mitochondria leak. Electrons leak out forming what are known as ‘free radicals.’ Accumulated free radicals are implicated in aging and diseases such as cancer. Superoxides, hydrogen peroxide (an intermediate form), and hydroxyls are the main free radicals. So-called antioxidants can quench free radicals although experiments do not show conclusively that antioxidant supplements improve health. Proton electricity also leaks out of mitochondria. Brown and a colleague actually discovered and quantified this proton leakage. It may be the consequence of a large electrical field over a thin membrane and so just inevitable or wastage of the extra protons may be involved in processes yet to be discovered. So-called white fat is stored but brown fat, which is brown because it contains mitochondria, both burns and stores energy. Heat is released. Brown fat is thus a controlled form of heat for the body and also burns off excess fat. Humans have little brown fat overall but newborns have a lot. If we had more it would be easier for us to keep warm. Small mammals like rats rely on brown fat for heat regulation. The proton leak might one day be utilized for heat, for obesity control, or to make humans more efficient, he suggests. Pre-mammals and birds evolved endothermy and warm-bloodedness around 100 million years ago. The risk was that more food was required but the rewards were faster bodily processes, better temperature regulation, better temperature adaptability, and possibly to purposely leak energy out to spread heat around. The leakage seems to be an evolved form of “idling” in order to increase readiness.
Mitochondria evolved from very ancient bacteria, after being swallowed by a bigger creature and developing a symbiosis. Life has been here for about 3.5 billion years. It took off about 2 billion years ago when photosynthesis evolved but eventually the massive increase in atmospheric oxygen began to threaten life. By 1 billion years ago oxygen reached the levels of today. Existing bacteria evolved ways to fend off the toxicity of oxygen. Enzymatic consumption of oxygen evolved in order to decrease and regulate the amount of oxygen in cells. This may have eventually evolved into respiration. Respiration is the reversal of photosynthesis. Instead of excess energy being released as light or heat it was harnessed to do work in the cell. Thus oxygen was transformed from problem to opportunity, from toxic to tonic. About 1-1.5 billion years ago these respiring bacteria cells were consumed by larger cells and became mitochondria as the symbiosis developed. Mitochondria carry their own DNA. All mitochondrial DNA is transferred from mother to offspring. Sperm has mostly nuclear DNA with very little mitochondrial DNA, which is provided by the egg. Mitochondrial DNA mutates and evolves at around 10 times the rate as nuclear DNA. The mutations accumulate as we age. Mitochondrial leakage and creation of free radicals is the basis of the mitochondrial theory of aging. Mitochondrial DNA have aided in tracing human lineages and relatedness in terms of most recent common ancestors. Cell death is of two types: “controlled suicide or chaotic explosion,” apoptosis or necrosis. Necrosis is generally more damaging as nearby cells are also disrupted. Apoptosis utilizes dying cell material and destroyed cells are those no longer needed so it can be considered a healthy process if it does not get out of control. Too much apoptosis and degenerative diseases ensue, too little and cancer cells may spread once developed. Apoptosis often preempts necrosis by suiciding a cell to minimize damage from a stressor before necrosis ensues. Some think that the bacteria mitochondria evolved from already produced a toxin involved in programmed cell death. Mitochondria, the maternal dragons, are both friend and foe.
Willed movement involves multiple coordinated muscle contractions which require energy from ATP. Only the erection of the penis does not involve muscle contraction. Utilization of energy to create motion involves hundreds of steps. ‘Metabolic control analysis’ was developed in the 1970’s to quantify the limits of each step. Each step partially “rate limits” the whole so that no one method or substance can be used to perpetually increase energy. Many different processes limit our performance of motion activities. Metabolic control analysis theory explains why simply increasing a substance does not produce energy but rather often simply makes available materials that can aid the process by not running out if that happens to be an issue.
Cells process and transport matter, energy, and information. About half the energy used in a cell is used for information processing. Adrenaline is not energy but an information signal passed between organs via the hormone to signal us to produce more energy. It is thus an information signal that regulates.
“The total energy production of a human or animal over a set period of time is called the metabolic rate and can be measured by the heat production or oxygen consumption of the body. The metabolic rate is fundamental and important characteristic of the organism, because it determines how much energy an organism has to spend on processes like muscle use, growth, and reproduction, as well as how much energy it must acquire as food from the environment each day.”
Our energy production when we are resting is known as resting metabolic rate and when we are not generating heat to combat cold nor digesting food it is called basal metabolic rate – that of a human is 60-100 watts. Metabolic rates differ according to level of activity, body size, and species. There is a theory called rate-of-living theory that says pace of life, or metabolic rate related directly to speed of aging. This is incorrect but there is a relationship. These days cumulative free radical damage which generally increases with metabolic rate is the main theory of aging. Babies and children have higher metabolic rates than adults. The thyroid releases a hormone that regulates metabolic rate. Other hormones, adrenaline and noradrenaline, also influence metabolic rate.
Sugar and fat are the two energy sources and what switches them on or off are the respective hormones: insulin and adrenaline. These energy sources and triggering hormones ebb and flow in our bodies. Carbohydrates, fats, and proteins are the three types of food-energy molecules. Carbs are made from sugars, fats from fatty acids, and proteins from amino acids. Sugar, glucose, and fats energize the body but only glucose energizes the brain. The liver produces glucose. The pancreas regulates glucose blood levels. Improper regulation results in diabetes.
Obesity is not caused by slow but efficient metabolism as was once thought. Fat people tend to eat more simply because their appetite and satiety are different. Brain hormones called neuropeptides influence appetite. The appetite centers in the brain monitor short-term and long-term fuel levels and adjust around a “set point.” The convincing ‘set-point theory of obesity’ suggests that thin and heavy people have different set points that trigger hunger. Fat people simply have their fuel availability thermostat set higher. There is also clearly a genetic component to obesity. Some people like the Pima Indians of New Mexico evolved to store more body fat against famine. Those who stored more fat survived and passed on their genes, their ‘thrifty genes, as they are called. The hormone “leptin” has been found to regulate the set-point mechanism. However, leptin has not been able to be developed for weight loss.
He next explores the limits and mechanisms of athletics including optimization and reduction of fatigue. Exercise can drastically increase metabolic rate, up to 10-20 times the resting rate. Athletic limits are influenced by lung and heart limits. During athletics the body switches to burn more carbohydrates than the fats it burns at rest. Thus athletes fuel with carbs, typically complex carbs. Such ‘carb-loading’ works best for endurance sports. Training increases metabolic rate significantly but it can increase endurance rate drastically. He goes on to explain muscle fatigue and the differences of training for speed, power, or endurance. Interval training, which alternates short bursts of intense exercise with short resting periods, has been found to be effective for strengthening the heart as well as increasing athletic success. Stimulants like amphetamines, cocaine, and caffeine can aid athletic performance in the short-term but the side-effects of the first two can be too much.
Stress can involve the fight-or-flight response and subsequent production of hormones like adrenaline as part of autonomic nervous system response. Digestion ceases during such stress periods. Another hormone, cortisol, aids the process of stress response, which is a process that makes excess bodily energy available and makes us hyper-alert. Cortisol also suppresses inflammation and immune-system response. Another hormone, beta-endorphin, implicated in so-called “runner’s high,” is part of the stress-response system. Stress can be without fear and anxiety (eu-stress) or imbued with it (distress).
The concept of mind energy was at first a product of psychology and begins with Freud who developed ideas of mind energy and sex energy, or what he termed libido. He considered sexual drives or what he called the pleasure principle as motivational. Wilhelm Reich took the idea further with the notion of orgasmic orgone energy. Later yet this idea informed something called ‘bioenergetics.’ All of these ideas involve catharsis through energy release. In more modern times two psychological terms describing mental activity are arousal and tension, or anxiety. Arousal waxes and wanes and is akin to general alertness. The brain has an arousal system known as the reticular activating system (RAS), which arouses us toward attention. The autonomic nervous system is the arousal system of the body. Experiments indicate that mental arousal enhances sexual arousal. People often are more attentive and concentrate better when aroused by anger or a sense of injustice. Measuring one’s brain waves can estimate one’s level of arousal. Experiments also indicate that lack of arousal can lead to sluggishness and inability to concentrate. How much ‘background’ arousal one maintains might be an aspect of one’s personality. We need certain levels of arousal to function and thrive. Chronically high arousal is linked with anxiety so it would seem an optimal level exists and that likely varies among people. Some people overreact to situations, becoming hyper-aroused quickly. This becomes anxiety if the hyperarousal is seen as negative. This threshold is often reached when we see our situations going from controllable to uncontrollable. Behavioral psychologist Hans Eysenck thought that extroverts have a lower base level of arousal than introverts and so seek it more in the form of human interaction. The RAS likely interacts with the ANS when threats are perceived. Behavioral inhibition or exhibition is possibly controlled by baseline arousal. Anxiety likely has a genetic component as well. It also seems likely that anxiety is more than simply hyperarousal. Our level of exhaustion also affects the quality of our arousal and thus our ‘moods.’ Emotion seems to be a factor in mood as well. Exercise typically has a positive effect on mood. Our level of illness also affects level of energy and mood. Nutrition and sleep quality are other likely factors. People also experience daily and seasonal fluctuations in level of energy. The hypothalamus has been proposed as a control center for data analysis and stimulation-response dynamics. It has been called the drive center of the brain.
He gives a short history of the development of neuroscience, particularly the discovery that nerves pass both electrical signals along neuronal pathways and chemical signals across synapses. Chemicals called neurotransmitters carry the signals across the synapses. Glutamate and GABA are the two main neurotransmitters. Glutamate is an excitatory transmitter that leads to more firing and GABA is an inhibitory transmitter that leads to less firing. Too much glutamate is toxic to nerve cells thus its designation as an ‘excitotoxin.’ Other neurotransmitters include noradrenaline, associated with arousal, and serotonin, associated with calm and feelings of well-being. Various drugs act on these receptors. Acetylcholine is a neurotransmitter associated with muscle contraction. Dopamine is associated with reward centers in the brain. He goes through the effects of stimulants and depressants and how we can develop tolerance to them over time. Short-term energy boost benefits are often offset with highly unpleasant effects of chronic use for stimulants. Caffeine is generally an exception but we do develop tolerance. He wonders why we seek stimulation and suggests we may have a drive for arousal.
The human brain is 2% of body weight but consumes 20% of total energy consumed. The author volunteered for some early PET scans and fMRI scans to find correlates of brain activity. Due to its energy requirements the brain is very sensitive to energy supply disruptions. Neuro-degenerative diseases like Alzheimers, Huntingtons, and Parkinsons are in part results of brain energy supply disruptions. The brain’s capacity to produce and consume energy declines with age. There is evidence that vigorous mental activity inhibits various types of age-related degeneration and perhaps aging itself.
He explores sex and sexual energy. Production of testosterone in males and both testosterone and estrogen in females is related to sex drive and generally decreases as we age. The hypothalamus regulates testosterone, estrogen, and progesterone production and has been dubbed the sex organ of the brain. Nitric oxide is implicated in causing penile erections in men and vaginal swelling in women. It has since been found to be key in many biological processes including various contractions that aid urination, breathing, childbirth, and it has an information role in memory and immune function. Nitric oxide is actually produced by cells to control rate of blood flow in blood vessels. Some white blood cells produce it in large amounts to kill off pathogens. Many of the discoveries of the role of nitric oxide came in the 1980’s and 1990’s. More physical activity and exercise has been shown to correlate with more sexual interest and activity. Short-term release of testosterone and longer-term release of endorphins may influence that correlation. Sex is a bit like eating as we hunger for it and tend to be satiated afterwards. However, we can abstain from sex with no ill effects which is not true for food.
Energy and sleep is the next topic. Our levels of alertness tend to fluctuate in patterns through the day and then we succumb to sleep. Noradrenaline, serotonin, and the hypothalamus are implicated in our sleep-wake cycles and the hypothalamus has a biological clock which is diurnal and fluctuates between 23 and 27 hours for a full cycle. Non-dreaming sleep (about 75% while REM sleep is about 25%) is a state of decreased temperature and low energy with slowed biological functioning. Chronic sleep deprivation may now affect a significant chunk of the population. Lack of sleep reduces sexual arousal and daily energy cycles indicate that daytime or early evening sex is the most energetic.
The question of how to become more energetic is explored. Mental and physical illness, stress, poor nutrition, and lack of sleep all tend to decrease our energy level. Short-term solutions are things like brisk exercise, cool showers, and laughter but long-term solutions to what is termed chronic fatigue require motivation. Both the motivation to succeed (ambition, pride, avarice) and the motivation to avoid failure (anxiety, guilt, worry) can work. Various forms of socializing also energize us.
The appendix of this book is a 50-something page essay called – The Story of Living Energy. Here he gives an interesting history of the development of ideas about energy in its biological sense. Beginning with Ancient Egyptian concepts of bodily constituents and the ideas of the pre-Socratic philosophers he notes the idea of “breath-energy.” The Greeks called this thymos and most cultures have concepts of vitality as substance or perhaps more accurate as ‘substance-energy.’ Chinese chi and Indian prana refer to breath-energy that circulates throughout the body and relate to health and states of consciousness. Both models postulate different types of chi/prana and ways of harnessing them. Some cultures postulate an anger-energy. Ancient peoples considered vitality carried in the blood. The vital energy, or life-force, was/is thought to be what animates us. In Ayurveda and other systems including Ancient Greece vitality is associated with the internal heat of the body and ‘digestive fire.’ Food was acknowledged as containing the life-force and transferring it to the consumer. Disease according to Ayurveda, ancient Greek medicine/Hippocrates, and Traditional Chinese Medicine is often caused by blockages of the free flow of vitality or imbalances in the primal substances which are related to the four elements. Aristotle considered pneuma (vitality) to be the carrier of the vital heat which was kept going by food. Pneuma was a motive force, an animating force. Rome’s physician Galen and the Stoics also shaped the idea of pneuma. The Stoics saw it as ‘a nonmaterial quality or form imposed on matter,’ something like a force-field. As others have noted, concepts of vitality, souls, and spirit became in the context of science, waves and forces. The concept of pneuma says Brown is the closest we get to a modern concept of energy, at least from the classical world.
Descartes’ mechanistic ideas were somewhat reinforced and negated at the same time as microscopes revealed the inner world of microbes. Now we could theoretically see the vitalities but they were strange. Were they vitalities or just smaller constituents of matter. The latter was revealed to be the case. Ideas of vitalism continued to evolve and change through the development of scientific thought. Improvements in the understanding of chemistry and the development of the idea of electricity revolutionized the concepts of energy. Still, notions of a vital force at some atomic, subatomic, or some other unseen level remained and continue to remain among some. The discovery of enzymes led to disputes about vitality. Enzymes are considered to be the ‘alchemists of the cell’ transforming molecules into different molecules by addition or subtraction.
The modern concept of energy was born in the mid-nineteenth century. The invention of the steam engine was key. Now we can see relationships between heat, motion, and work. Electricity soon factored in. It was later found that energy was not a type of matter but more a motion or arrangement of matter. Some argued that the concept of energy arose from ideas of monetary accounting and indeed today economics and energy are so related that money is sometimes considered a proxy for energy as value is ultimately created by energy, the capacity to do work. Ideas of the conservation of energy also began in the mid-nineteenth century and were pointed out as incompatible with then current theories of vitality. Energy was coming to be considered more fundamental to the universe than matter or force. German physiologist Hermann von Helmholtz noted in his version of the conservation of energy that ‘there was a single, indestructible and infinitely transformable energy basic to all nature.’ Energy was on the way to replacing God and indeed some Hindu teachers say that ‘God is Energy.’ The new concept of energy was in a way the new Promethean fire.