It is widely believed that almost no calories are used during sleep. That is incorrect: while the body rests during sleep and energy consumption is not high, it is a long way from zero. A convenient way to measure energy use is known as the “metabolic equivalent” (ME). This is defined as the rate of energy used by a person sitting and awake, the “resting metabolic rate”. A person riding a bicycle may be using five MEs; a runner, nine or more. A sleeping person uses about 0.9 MEs, so we burn calories when we are asleep about 90% as fast as while sitting on the couch watching television.
Energy conservation is important in sleep, but it’s expenditure is still required. It has been proposed that sleep is a physiological adaptation to conserve energy but little research has examined this proposed function. In one study, the effects of sleep, sleep deprivation and recovery sleep on the whole-body, total daily energy expenditure was examined in seven healthy participants aged 22+/-5 years. The findings provided support for the hypothesis that sleep conserves energy and that sleep deprivation increases total daily energy expenditure. I read somewhere that an enthusiastic young astronomer decided that sleep was unnecessary and used his telescope for 13 nights without sleeping during the day. He became extremely ill, thus showing the importance of sleep in survival. The recognition that sleep is one of the foundations of athletic performance is vital.
Research in the general population has highlighted the importance of sleep on neurophysiology, cognitive function and mood. In a post on Hormones Matter, we reported several young people who had a post Gardasil vaccination crippling condition that turned out to be due to thiamine deficiency. All of them had been exceptional athletes and students before the vaccination. We concluded that the brain energy requirement for exceptional people put them at greater risk of succumbing to stress if their capacity for MEs was limited, either for genetic or nutritional reasons. We assumed that their thiamine deficiency before vaccination was marginal and either asymptomatic or producing trivial symptoms ascribed to other “medically more acceptable” causes. The stress of the vaccination required an energy dependent adaptive response that precipitated fully symptomatic thiamine deficiency. You might say that they were “weighed in the balance and found wanting” as the proverb says.
The Stages of Sleep
Sleep is a complicated process. The first sensation is known as “sleep latency” and registers the time taken from eye closure to falling asleep. The sleep cycle is then divided into five stages, each cycle lasting approximately 90-120 minutes. Stage one is known as light sleep. In stage 2 the brain is resting the parts used when awake. Stages 3 and 4 are deeply restorative. Stage V is known as rapid eye movement (REM) sleep and may be the most important part. Movement of the eyes behind closed lids is observed. The autonomic nervous system is activated for unknown reasons. It is in this stage when we dream and most sleep disorders occur.
The word circadian means “about 24 hours”. The circadian clock is a complex, highly specialized network in the brain that regulates its day/night metabolism and is a key for metabolic health. It is modulated by behavioral patterns, physical activity, food intake, sleep loss and sleep disorders. Disruption of this clock is associated with a variety of mental and physical illnesses and an increasing prevalence of obesity, thus illustrating that it is dependent on energy balance (production/consumption). Reduced sleep quality and duration lead to decreased glucose tolerance and insulin sensitivity, thus increasing the risk of developing type 2 diabetes. In other words there is a close link between circadian rhythm and available energy . I have seen patients who were unable to take the night shift at work because they were unable to adapt. The increase in obesity has been paralleled by a decline in sleep duration but the potential mechanisms linking energy balance and the sleep/wake cycle are not well understood. An experiment was reported in 12 healthy normal weight men. Caloric restriction significantly increased the duration of deep (stage 4) sleep, an effect that was entirely reversed upon free feeding.
This condition is fairly common in the United States and is probably generally fairly well-known by most people. The patient stops breathing during sleep and may repeatedly awaken with a start. The disease was discovered because a woman reported that her husband kept waking up with a start because “he was affected by an evil spirit”. Fortunately, the physician took her seriously and it led to the studies that determined its cause. Many patients with, or at risk of, cardiovascular disease have sleep disordered breathing (SDB). These can be either obstructive because of intermittent collapse of the upper airway, or central because of episodic loss of respiratory drive. SDB is associated with sleep disturbance, hypoxemia, hemodynamic changes and sympathetic activation. Brainstem dysfunction combined with heart disease is the hallmark of the thiamine deficiency disease, beriberi.
What that means is that there are two types of sleep apnea. In the obstructive type, the tongue falls back into the pharynx and blocks the airway. In the one where there is loss of respiratory drive, the centers in the brain stem are compromised. It is these centers that completely take over the control of breathing when we are unconscious as in sleep. If their supervisory mechanisms fail, breathing ceases. Carbon dioxide concentration increases and stimulates the brain controls that restart breathing. Occasionally these mechanisms are so sick that breathing does not restart. Hence a form of nocturnal sudden death follows. When we are awake we can override these centers and control our breathing voluntarily. Obesity and obstructive sleep apnea have a reciprocal relationship depending on the regulation of energy balance. When I was in practice I treated several patients with sleep apnea using large doses of thiamine. Because of this I hypothesized that the association of dysautonomia with so many different diagnoses is because of loss of oxidative efficiency and subsequent disorganization of controls that are mediated through the limbic system and brainstem. I came to the conclusion that energy deficiency in the brain was the core issue.
I recently had a letter from the parents of a then five-year-old child who came under my care 35 years ago. She has a genetically determined disorder that affects energy balance and I had treated her by dietary restriction and providing non-caloric nutrients. They informed me that she was doing very well. The condition is known as Prader Willi syndrome, a terminology that indicates that nothing was known about its cause when it was initially described. Today, 10 studies have provided evidence that total energy, resting energy, sleep energy and activity energy expenditure are all lower in individuals with this syndrome. Dietary discipline and nutritional supplementation had paid off.
An Explanatory Analogy
You may think that comparing the human body with an automobile is manifestly absurd, but the principles that I will use in the analogy are simple.
First of all, both use fuel: gasoline is the fuel for a car, but it must be calibrated to the design of the engine, giving rise to the gasoline choices at the pump. Although different forms of human food may be compared to gasoline choices, the primary fuel for our cells is glucose and this is particularly true for the brain. Glucose, a carbohydrate, can be synthesized in the body from other components in the diet and different diets are sometimes used therapeutically. Unlike the car, the human body must derive its “spark plug” from the food and is the basic reason why organic, naturally occurring, food is a necessity. The food industry cannot imitate or replace it.
The engine in a car burns gasoline to create energy. It requires spark plugs to ignite the gasoline and waste gases are eliminated through an exhaust pipe.
Every cell in the human body has an “engine”. Without going into details this is known as the Krebs cycle (named after its discoverer). Its objective is to produce energy and glucose has to be “ignited” (oxidized). The oxidation process, while releasing energy, gives rise to carbon dioxide (the “ash”) that is eliminated in the breath. Energy is stored in an eletrochemical form known as adenosine triphosphate (ATP).The nearest parallel would be a battery. It releases an electrical form of energy that is then used for function. Whether we like to recognize it or not, we are electrochemical machines and the only way that we can preserve or retrieve health is by furnishing the complex of ingredients that enable food to be converted into energy.
To continue the analogy, when you put your car in the garage and turn off the ignition the car is technically “dead”. Obviously, we are unable to do that with the human body, but let us make a simple comparison. Supposing for some reason it was desirable to keep the car “alive” when it was in the garage. The engine would continue to run and it would be consuming fuel. Because the body requires energy to remain alive, the “engines” have to continue running, even when we are asleep. This does make sense for the consumption of energy when we are asleep———it keeps us alive !
The energy developed from burning gasoline has to be transmitted to the wheels in order to produce the normal function of the car, which is the ability to move. The transmission is a series of levers that are interconnected.
The same is true in the human body, but it is biochemical in nature. A series of energy consuming enzymes use the protein, fat and carbohydrate to build the diversity of tissues that make up the body. Throughout life, cells are destroyed and replaced, so this is a continuous process of energy consumption and repair. Every physical movement, every thought and emotion, consumes energy. Like the transmission in the car, the energy produced by the citric acid cycle engine is consumed in every movement of the body, every thought occurring in the brain and every emotion.
The body of a car is just a container on wheels designed to carry around human beings. Its sole function is to move and until we have driverless cars a human being must be the driver.
In comparison, the body of a human being is merely a chassis that carries the brain around. It might be said that the brain can be compared with the car driver and every function of the body is under the command of the brain. Another analogy that I have used is an orchestra where the brain is the conductor and the organs are banks of instruments in which the cells come under the command of the conductor.
Putting It All Together
The 2019 Nobel prize has just been awarded to three scientists who have discovered how our body cells respond to low concentrations of oxygen (hypoxia). The reaction of medical scientists is very positive since this discovery will certainly be applied to the treatment of many diseases. Apparently scientists are already trying to find drugs that will influence this effect. For example, it has long been known that hypoxia will introduce inflammation. My forecast is that the use of nutrients will often correct the genetics by epigenetic mechanisms and this is already under way.
I found the Nobel prize extremely interesting because of a little-known phenomenon that was described by the early investigators of the vitamin B1 deficiency disease, beriberi. They had found in this disease that the arterial concentration of oxygen was low while the venous concentration was relatively high. Arterial blood carries oxygen from the lung to all the tissues of the body. It has to be unloaded into the cells that then use it to produce energy. The venous blood then returns to the lung to be loaded again with oxygen. A relatively low arterial oxygen reflects an inadequate loading at the lung tissues, while a relatively high venous oxygen indicates poor utilization by the cells to which it is delivered. This means that thiamine (vitamin B1) is an essential catalyst in the delivery of oxygen to the tissues. Its deficiency induces gene expression similar to that observed in hypoxia and has been referred to as a cause of pseudo-hypoxia (false hypoxia).
The heading of this article is that sleep requires energy, but I am making the case that being alive and well simply means that oxygen is being consumed efficiently, as long as the “blueprint” of DNA is healthy. It strongly suggests that hypoxia and/or pseudo -hypoxia are the underlying causes of disease and may explain why thiamine and its derivative are such important therapeutic agents.
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