アダルト Chapter 2

アダルト The entropy machine

Do you remember entropy? If you did physics at school, you probably will; if not, never mind, because it is a surprisingly simple concept once you get the hang of it. The second law of thermodynamics states that the energy in a system always tends to degenerate from order into chaos. The most obvious example is that heat dissipates. If you leave a hot cup of tea standing for half an hour, most of the heat in it will have been lost. The heat energy in the tea has spread outwards into the area around it - the cup, the table it was standing on, and the air surrounding it.

 

You started with heat energy that was useful because it was all contained in a small object that you could utilize - the cup of tea. When this heat energy became spread more thinly throughout the room, it was of no further use to you. Entropy describes this process of heat loss, but it also describes a general rule that energy of any kind is eventually lost and wasted, spread into the rest of the universe. Mostly, it ends up as heat energy which diffuses outwards - just like that in the cup of tea.

アダルト The green net

On earth, all energy, whether stored in living organisms, in machines, in the weather or the potential energy of water in high places, originates from the sun and gradually gets degraded into heat energy which diffuses outwards to equilibrate with beat around it, and is lost into space. This is entropy. All life is a system for trapping energy, and thereby for defying entropy. Entropy is the supreme antilife force of the universe, the downward slope from the pure energy of sunlight to the empty wastes of outer space. This is the slope on which we live our lives, and down which we struggle not to slide. To this end there is a certain amount of teamwork between the different organisms on our planet.

The biggest and best energy trap in the world is photosynthesis in green plants. The leaves of such plants have an array of structures called 'fight-harvesting antennae'. Each of these consists of around three hundred molecules of chlorophyll, the pigment which gives plants their green colour, surrounding a single 'reaction center'. As we shall later be looking at the importance of the mineral magnesium to human health, it is worth noting here that at the heart of the chlorophyll molecule sits an atom of magnesium, which gives it its shape and therefore its function.

The energy of sunlight is absorbed by the 'antennae' of chlorophyll molecules, and transmitted, rather like a chain of dominoes falling, from molecule to molecule inwards to the reaction center. Here there is a complex system of enzymes which uses the energy supplied to it by the chlorophyll to combine the carbon dioxide and water into carbohydrates. In the process oxygen is released into the atmosphere.

These carbohydrates are the prime source of energy for life on this planet; not just for plants but also for animals and humans. In our bodies a complex biochemical cycle called the Krebs cycle breaks down the molecules of carbohydrate in our food, step by step, into carbon dioxide and water again, extracting the stored energy at each stage and sending it off in biochemical form to be used throughout our bodies. The carbon dioxide is breathed out into the atmosphere, where it can be used again by plants in photosynthesis.

Although photosynthesis wastes a vast majority of the energy available to it, having an estimated efficiency of only 0.2 per cent (it wastes 99.8 per cent of the energy it receives), it is still the major energy trap for all life on our planet. [2]

Similarly, plants take up atoms such as carbon and nitrogen, and 'fix' them into their tissues. We eat the plants and utilizes the proteins and other molecules that contain the carbon and nitrogen. When we excrete and when we die, these elements return to the soil, where they can again be used by plants. We are only one part of a cycle, the wheel of life, which needs to balance in order to keep going round. The destruction of the forests of the world to make paper and provide wood for building disturbs the balance by reducing the amount of oxygen available for us to breathe and increasing the carbon dioxide in the atmosphere.

Over the millennia, plants and animals have developed some ingenious mechanisms for coexistence, with animals depending on photosynthesis in plants for their food sources, and plants depending on animals, from pollinating bees to agricultural man, for the survival of their species. But photosynthesis predates animals by millions of years, so it clearly did not develop for the purpose of feeding them. We of the animal kingdom are, in a sense, parasites on the plant world; we survive by being more adaptable or more sophisticated or clever than plants, and we have developed a variety of other mechanisms for trapping and using the sun's energy.

These include the synthesis of vitamin D in the skin to improve our absorption of minerals; the triggering of certain enzymes that repair our DNA; the activation of oils on our skin by sunlight to make them antiseptic and protective; the production of hormones in the skin, in response to sunlight, that stimulate our immune systems, and a range of other mechanisms that science has yet to explain.

アダルト Buried treasure

Mankind has also invented his own ingenious methods for taking the stored energy of photosynthesis by using the fossil fuels such as oil and coal, but we as a race were alive long before these methods were invented and, God willing, we will be alive long after they are gone.

Looking at the graph of fuel consumption you will see that the fossil fuels are just a passing phase we will be forced to grow out of. And yet they have changed all our lives drastically. As well as making possible modern forms of transport, they mean that we are no longer dependent on the sun for warmth or light, and so we can live in places where previously man could not survive. They also make it possible for us to spend nearly all of our time indoors, out of the sun.

Our bodies have mechanisms for trapping the energy in particular wavelengths of the light reaching earth, and we depend on receiving the full spectrum of this light. This is the light environment for which we are designed. But indoor light, whether through the windows or from electric lights, provides only a narrow portion of this full-spectrum. Take a look at the whole range of solar radiation.

アダルト The light program

優良アダルトビデオ

All of these wavelengths are produced all the time by the colossal nuclear reactor that makes up the sun. If we could hear electro-magnetic waves, they would sound like the 'white noise' that you get between stations on a radio or TV. But most of these wavelengths were filtered out by the earth's atmosphere, and only a narrow waveband arrives at ground level. This waveband stretches from the ultraviolet to the infra-red, with visible light making up the middle part of the spectrum. Solar radiation at ground level can therefore be divided into three components: infra-red, visible and ultraviolet. Each of the three components of sunlight has particular effects on organisms in general, and humans in particular.

Infra-red radiation provides heat, causing atoms and molecules to move around faster, and it also causes parts of molecules to vibrate in relation to one another. Infrared is the major, though not the only, reason why we feel warm in bright sunlight.

As well as providing us with vision and colour, the visible part of the spectrum has a number of biochemical effects. These are all related to the absorption of particular wavelengths of light energy by particular molecules. Thus, for example, chlorophyll in leaves appears green because it uses energy chiefly from the blue and red areas of the spectrum for photosynthesis, but the green light is reflected. Hemoglobin appears red because it absorbs green light, and this provides exactly the right amount of energy to shift a molecule from one structure or state to another. In other words, the light energy is absorbed by the molecule and converted into structural energy. The biochemical effects of the visible spectrum are much better researched in plants and bacteria than in man, but there is some very interesting evidence that particular wavelengths of light have important effects on humans.

Similarly, ultraviolet light is absorbed into changes in the structure of molecules. But ultraviolet has a frequency about twice that of visible light, or three times that of infra-red. The energy of electromagnetic radiations is proportional to the frequency; the higher the frequency the more oscillations or waves can be packed into a given length or time, and the more energy can be transmitted.

Electromagnetic waves hitting an atom can cause one of the electrons orbiting around the atomic nucleus to be pushed into a different orbit. This can only happen if the waves of energy provide precisely the right amount of energy - the difference between the atom's energy level at one orbit and at the other. If the energy provided is insufficient the electron will fall back to its original orbit, and if it is too great it may fly off into obscurity.

When an electron returns to a lower energy state, a lower orbit around an atom, it gives off electromagnetic radiation, the wavelength of which is determined by the amount of energy provided, which in turn depends on the difference in energy between the two orbits. This two-way process is crucial to the whole of life. It has also made possible much of modern biochemistry, because by measuring the wavelengths of radiation that are absorbed or emitted, we can calculate the energy changes that have occurred.

For example, one of the most basic techniques in the biochemistry laboratory is called spectrophotometry (wavelength-light-measuring). This involves selecting a particular wavelength of light, usually in the ultraviolet, and measuring the amount of light of that wavelength that a chemical emits or absorbs. The more of the chemical there is, the more light it sends out or soaks up. This is not a way of getting around nature - it is using the very basis of life as a measuring stick.

Everywhere in the world, around us and within us, living cells are sending and receiving signals in the form of light. But it took the genius of Albert Einstein to realize, and to demonstrate, that light and matter are interchangeable - that E=mc2. Light is not just a pleasant side-effect of summer; the whole world runs on light energy.

 

アダルト Chapter 3

アダルト Skin tones and sun zones

優良アダルト動画

Man's original home address is the Olduvai Gorge, East Africa. To the best of contemporary archaeological knowledge, that is where we emerged as a species. From there, over the past four million years, we have spread out to cover the whole land mass of the planet. We cannot tell what colour of skin the original hominids had, or how much hair, but everybody who is indigenous to East Africa and other tropical countries nowadays has very dark skin. The tribes that have spread north and south have progressively lighter skin the further they live from the equator.

The only obvious value of this difference in terms of survival is that white skin transmits more light than dark skin. In general, the further you are from the equator, the less sunlight there is available. In fact, as the diagram shows, nearly everywhere on or near the equator gets twice as much sunlight as Great Britain, and East Africa gets nearly three times as much.

In this respect, at least, we are adapted to the solar environment in that part of the planet in which we live. But from the beginning of history, and particularly since the atrocities of the slave trade, men have moved or been moved in large numbers from one part of the world to another. Nowadays, many of us are black people living in temperate climates, or white people living in the tropics. There are fair-skinned people of Celtic origin living in Queensland, Australia, one of the hottest and sunniest places on earth, for example, and people from the Indian subcontinent living in Birmingham. The former get skin problems from overdoses of sunlight, although there appears to be more to this story than a simple overdose effect; the latter get rickets due to vitamin D deficiency, even though they live on a diet which prevented rickets when they were in their home countries. For these reasons alone, sunlight must be regarded as a major health factor - but there is more.

アダルト Melanin

無料アダルト動画ですね The chemical which produces darkness of skin and protects us from damage from sunlight is called melanin. The amino-acid tyrosine, which we get from our diet, is converted in our bodies by an enzyme to dopa. Sunlight activates an enzyme in the skin which produces a polymer of dopa (a polymer is a large molecule consisting of a chain of small molecules all the same.) This polymer is melanin. In people who are genetically dark-skinned the activity of this enzyme is high throughout life, so they always have more melanin. The same molecule gives black coloration to hair.

People who are genetically light-skinned, particularly Celts with red hair and freckles, produce little or no melanin. Instead they produce a different polymer, made up of another amino-acid, called cysteine, which imparts a red colour to hair. These people only ever tan to a very slight degree, and are therefore much more vulnerable to sun-burning. This is known as Type One skin. In everybody else sunlight stimulates the tyrosinase enzyme to produce more melanin.

There are two phases to this; within the first hour of exposure to sunlight, there is a rapid production of a small quantity of melanin (this is known as IPD, or immediate pigment darkening). Over the next few days there is a slower production of a larger quantity, known as melanogenesis, which provides the major sun-tanning effect. Sun burning, when the skin becomes red and tender, is a sign of damage to the skin by sunlight, and is not necessary for sun-tanning.

 

Skin types

It is possible to divide the world's people into six different skin types, according to their coloration and response to sunlight. The importance of this is not how much sunlight we need - we all need sunlight and benefit from it - but in just how much we can get away with.

If you are born with Type One skin, it is clearly not a very wise move to live in Ethiopia or the Arizona Desert, but if you have Type Five or Type Six skin then it may be equally bad for you to live in temperate climates, because your high skin melanin content will increase the effect of climate in filtering out ultraviolet light, and may cause you a light deficiency.

It is equally clear that if you have lived for months in a light-poor environment, to switch to spending much of the day undressed in a light-rich environment, as so many of us do on our annual holiday, is bound to be more than a pale skin can quickly adapt to. This much has been said over and over again by journalists in women's magazines and elsewhere; but unfortunately the overall effect has often been to lead us to believe that sunlight is bad for us in any amount and in any form. Such an idea goes counter to common sense, as well as to the cumulative body of scientific knowledge.

It is simply a matter of dosage. just as our body requires carbohydrate to produce energy in order to function properly, but will suffer overdose effects if fed too much, so we require sunlight to stay healthy, but can suffer from an overdose if we are careless or stupid. Unfortunately, in our Western society, overdoses of carbohydrates are more common than under doses; but a deficiency of sunlight is the general rule, and an overdose is hard to come by without traveling hundreds of miles to much hotter countries.

 

Skin	Occurrence	Appearance	Sensitivity to sun
1	Celtic	White skin, freckles, blue eyes red or blond hair	Burn very easily, do not tan
2	Northern Races	White skin, with/without freckles, blue or hazel eyes, red or blond hair	Burn easily, tan slowly and slightly
3	Most white people	Fair skin, blond or brunette	Brown moderately, tan slowly and moderately
4	Mediterranean, Chinese, Japanese, Red Indian	Olive or light brown skin, dark hair, dark eyes	Burn easily, tan easily
5	Indians, Arabs, Malaysians, Mexicans	Brown skin, hair and eyes brown or black	Burn rarely, tan well and deeply
6	Negroes, Aborigines	Skin brown to black, hair and eyes black	Never burn, remain dark-skinned

Light deficiency

The problem is made much worse by electricity. Lighting and heating run on electric power enable us to stay indoors for as long as we wish. In prehistoric times, whether we lived in East Africa or West Sussex, we had to spend much of the daylight hours out of doors. Many societies in the Third World still do, and for the same reasons. Firstly, in a non-technological agricultural society everybody's muscle power is needed for the work of raising food. Secondly, the lack of adequate indoor lighting means that most things that involve vision have to be done out of doors - or at least by an open window.

Nowadays we spend around ninety per cent of our time indoors - in offices, schools and homes - where the light level is usually around one hundredth of that of midday sunlight. Because our eyes adapt well and rapidly, better than any automatic camera, we are unaware of the difference after the first few seconds.

The illustration uses a logarithmic scale, so that the brightness of bright noonday sunlight is about one thousand times that of twilight. The official guidelines for indoor illumination set the required brightness level at somewhere between two hundred and one thousand lux. [2] This is around twilight level. Midday sunlight, even through cloud, should be more than ten times brighter than this. Indeed, it is daylight sunshine intensities that are required by our bodies for a number of functions, including the suppression of melatonin from the pineal gland, which is discussed in the next chapter. This requires a minimum intensity of 2500 lux, compared to the probably maximum of 1000 lux in indoor office environments. [3] Certain body functions, such as the regulation of human sleep-wake cycles and other biorhythms, require exposure to intensities of 4000 lux or more.

 

Kept in the dark

When scientists attached light detectors to the wrists and head of volunteers for stretches of a day or more, they found that their subjects were only infrequently exposed to anything over 1000 lux. They appeared to spend most of their time at an average intensity of around 100 lux. Yet this study was conducted in San Diego, which is one of the sunniest places in the continental USA. [4]

According to the evidence now to hand, we clearly need considerably more sunlight than we receive. We need both a greater intensity of light, and for a longer period. To give an example, light of the intensity that is normally experienced in offices and other indoor environments is only half as effective in shifting human biorhythms backwards or forwards as a weak electrical AC field (of 10 hertz, and 2.5 V/m). This electrical field cannot be perceived consciously. [5]

When the light intensity rises above 2500 or 3000 lux, on the other hand, there is a major difference. It becomes possible to produce distinct effects on human metabolism and diurnal rhythms. Shift workers and transatlantic travelers should pay attention; bright light for three hours per day can retrain your wake/sleep cycle in forty eight hours. [6] Doing it with alarm clocks and coffee can take up to eight days.

The light frequency most effective at suppressing melatonin and therefore at altering biorhythms is between 450 and 550 nanometers. [7] This is blue and green light. The effect spills over into the ultraviolet, but there is virtually no effect from the higher - yellow and red - frequencies. The level of light that is required for melatonin suppression is roughly that of a cloudy day. it does not require blinding summer sunlight, but the light available under dark storm clouds is likely to be insufficient, as is indoor lighting.

 

Good medicine

For all the other benefits of sunlight which appear to be mediated through the skin rather than through the blood, the system of scaling works on the basis of the MED. This is the minimal erythemal dose: the amount of sunlight required just to produce reddening of the skin. Naturally this varies with skin type, extremely dark-skinned people requiring about four times as much. For a pale-skinned, Type One person sunbathing in England in high summer during the middle of the day, the MED might be as low as ten minutes' exposure. But outside the hours of 10 a.m. to 2 p.m., and outside the summer months of June, July and August, it may be impossible for even a Celtic skin to achieve the MED. [1]

In any case, it is not advisable to do so. The MED is only useful as a reference point. Several Russian studies have shown that the ideal starting level for regular therapeutic solar exposure is around half of the MED (0-3 to 0.6 MED). [9] As the skin becomes accustomed to the exposure, this can be built up to as much as 1.5 times the original MED.

Using sunlight as therapy is clearly far easier in hotter countries and those with more predictable weather than Great Britain. In order to avoid light deficiency, most UK residents will need either to travel abroad regularly, or to use artificial lights. The concept of full-spectrum lighting, developed by John Ott, is an attempt to provide a reasonable replication of the frequency pattern of sunlight. There are a number of technical problems involved. For example, nearly all plastic and glass diffusers used to house fluorescent lighting will absorb effectively all of the UV. There is no point, therefore, in putting full-spectrum lights inside them. Some modern light housings, however, have metallic-coasted grid diffusers, with no glass or plastic obstructing the light path.

Using such lighting, aimed directly at the face from a short distance, it would be possible for some Type One individuals to develop an crythema after a day's exposure. Since this would be uncomfortably hot and likely also to produce a headache, no matter what form of lighting was used, few people would want to adopt it as a policy. Under normal indoor lighting levels, skin reddening only occurs as a result of other exposures, such as the ionization from computer screens.

Therefore, we keep ourselves for most of our lives in perpetual twilight. All our images of freedom - and many of those used by advertisers to portray health - involve being out of doors and in the country. Locking people up in dungeons and prisons has always been a major form of punishment. Depriving man of the light is nearly as bad as depriving him of his life. Yet nowadays we live, without realizing it, in self-imposed dungeons. Man is born to the light, and is everywhere in the dark.

 

Chapter 4

If you lived in Tibet you'd need three eyes

The health consequences of sunlight, and of light deprivation, have been appreciated intuitively since the dawn of man, but modern science is now making it possible to understand some of the mechanisms involved. One of the most important, and most obvious, is the effect of light on our cycle of waking and sleeping. This is chiefly mediated through a molecule called melatonin, which is produced by the pineal gland.

The pineal has often been referred to by mystical teachers, particularly from the East, as the third eye. The implication is that it perceives something above the awareness of our normal brain power. We now know the major 'cosmic' factor it responds to is light. Melatonin production only occurs in the pineal, in darkness, at night; and it sends us to sleep.

 

Circadian rhythms

Until the arrival of the electric light there was a natural rhythm to our lives. In the daytime, sunlight made it possible for us to go out, to work and to travel. It was a time for expending our energy in the natural purpose of life. At night we retired indoors to the warmth of our cave or house, did very little and slept. This is the first and most basic biorhythm, and one that we share with all mammals.

Nowadays we still have the same bodies and the same biorhythm- but we ask of them that they be active at strange times of the day and night. Many nurses, factory workers and others have to work permanent nights, and many more of us have to work shifts. Ask anybody who works this kind of schedule what their body tells them; do they feel that it is good for them? We have abolished night, yet we have deprived ourselves of the sun.

Now that it is possible to get anywhere in the world in about twenty four hours by jet, many of us regularly cross time zones and suffer jet lag as a consequence. Although a significant component of jet lag is dehydration caused by the high altitudes, and indeed there may be other symptoms from the atrocious food that many airlines serve, it is clear that the major component is a disturbance of the day/night biorhythm. A flight from New York to London, or vice versa, results in a shift of five time zones. Therefore, what was bedtime becomes either the middle of the night or the middle of the afternoon. We either wake up in the small hours and fall asleep at our desk in the afternoon, or the other way round. In fact, many people find that the adrenalin of travel keeps them going for twenty four to forty eight hours after arrival, but then it hits them with a vengeance. Under normal circumstances it takes at least five days to adjust your biorhythm to the new time zone, and the unaccustomed waves of fatigue or attacks of insomnia may linger for up to a fortnight.

Interestingly, when humans are allowed to adjust their own wake/sleep cycles in an environment which gives no clues at all as to time, they invariable select a cycle that is significantly longer than twenty four hours. Results have varied between twenty five and twenty eight hours.[2] Such speculations aside, this internal rhythm explains why the short changeover on a shift system is always more grueling. When the time zone change requires that we turn our watches forward, this reduction in the length of a day goes counter to our natural tendency to a cycle slightly longer than twenty four hours.

 

The body's light meter

Tryptophan is an amino-acid that occurs naturally in our food. It is known to have a sedating effect. In fact the very high concentrations of tryptophan in meat are thought to explain why lions go to sleep after feeding on a kill, dozing in the sun for anything up to three days before they get hungry again. Tryptophan also makes us feel full. Tryptophan is very good at crossing the blood-brain barrier. This is the filtering of the bloodstream, only allowing certain chemicals across into the cerebrospinal fluid which bathes the brain.

As it crosses into the brain, tryptophan appears to carry a lot of amino-acids with it, effectively nourishing the brain. But its most important results are inside the brain, where it appears to relax and sedate. Yet tryptophan has no direct sedative action itself; it has to be converted to serotonin to achieve this. And scrotonin is converted by the pineal into melatonin. Here at last it seems that we may have found the real natural sedative.

When melatonin was given to volunteers in scientific studies, It had effects very similar to those of a sleeping tablet. That is, it made them more sleepy, reduced their energy levels and reduced their performance on tests of motor function. Their reaction times on straightforward tests became longer, although they did not make any more mistakes.' The memory of the subjects in this test was not impaired at all by melatonin, in contrast to the effect of the benzodiazepine drugs (Valium, Ativan, Librium etc) which are commonly used as hypnotics and relaxants. Nevertheless, some of the melatonin subjects did fall asleep in the middle of the day. Given as a tablet, it seems that melatonin might have some potential as a tranquillizers and sleeping tablet - and some serious advantages over the more commonly used drugs now available.

Other effects of melatonin include increasing the sensitivity of subjects to barbiturates and other hypnotic drugs, enabling them to send the subjects to sleep even more quickly. It reduced the subjects' sensitivity to painful stimuli such as heat, [4] so they took longer to respond. It also appears to lower blood sugar, and to increase the activation (conversion into the active form) of pyridoxine, vitamin B6. [1] This vitamin is known to have a degree of anti-anxiety effect, as well as being important in the regulation of dreaming. According to Carl Pfeiffer, individuals who are deficient in B6 do not recall their dreams. When adequate B6 is administered, they have pleasant dreams, in colour, which they recall the following day. [6]

In other words, melatonin is produced by the pineal at times of darkness not only to stop us from being wakeful and doing things, but to prepare us for sleep as well. Because sleep is important as a time for wound healing and repair of tissues - and of injuries to the mind also, even though they may only be cuts and grazes. Whatever powerful spiritual and psychological functions sleep may have, its most basic mental function is to allow the mind to sort out the confusion of the day, throwing away the dross and filing the useful items. Melatonin potentates all of this.

 

Regulating the pineal

The only way of synchronizing bodily rhythms to a new time zone is by controlling melatonin levels - either by taking it orally or by adjusting the pineal's rhythm of output. Giving melatonin orally brings on sleep at the desired time; the drawback of this, of course, is that there is no corresponding signal for turning off melatonin production, but it does appear to be effective in shifting our wake/sleep rhythm. [7] It is also possible to influence the melatonin production of the pineal by electromagnetism. Artificial magnetic fields of a similar strength to the natural magnetic field of the earth can inhibit melatonin synthesis.' The effect depends on the intensity and the rhythm of the fields, but this finding ties in with other studies which have shown that such fields can affect the production of steroids by the adrenal, the movement of calcium into and out of cells, and even the synthesis of DNA in chromosomes. It has been suggested that disturbances of the geomagnetic field are related to mental and physical illnesses and death.9 Some researchers have speculated that the changes in geomagnetic fields on a diurnal cycle and on an annual cycle may be important in adjusting melatonin rhythms. This research has a long way to go, however, and does not alter the fact that the strongest effect known on the pineal is produced by bright light entering the eye.

When we are exposed to bright light entering our eyes, our pineal's stop producing melatonin within about half an hour. This can even be done in the middle of the night, when our melatonin production is naturally at its highest. But it works best in the morning, when our bodies are prepared for it. So while melatonin is nature's sleeping draught, our natural wake-up medicine is sunlight. Who needs coffee when the real thing is available for free? Personally I've become hooked on stepping outside first thing in the morning, and may often be seen walking the dog at 6.30 a.m., unshaven and carrying a mug of herb tea.

We know that it's not simply a psychological response, though, because it can still happen in blind people. [10] However, it is abolished with loss of the eyes themselves, This is because the pathway starts with the reception of light by cells in the retina but then travels by a different set of nerves from the optic nerve, which carries visual signals. This pathway leads by a circuitous route to the pineal, where the signal is given to turn off melatonin synthesis. In other words, our bodies give us a nightly dose of internal hypnotics, thereby keeping us in phase with the outside world and ensuring that we get the rest and recovery time provided by sleep. Because of its lack of side effects (no confusion or loss of memory, no addiction) melatonin would have great potential as a more natural sleeping tablet, and no doubt any drug company that could produce it would do a service both to mankind and to its investors. But we can produce our own melatonin without chemical assistance, if we understand how it is produced, and how that production is inhibited.

Although light entering the eye inhibits melatonin production, there are two obvious limiting factors on this. The first is that the most effective light is between about 460 and 560 nanometers in wavelength, which is blue and green light. Red and yellow light has no effect at all, but there is an effect, it seems, in the ultraviolet.

This coincides with the peak intensity of natural sunlight, but unfortunately ordinary incandescent light bulbs produce much less at this wavelength than at the red end of the spectrum. Fluorescent lights produce more blue, which is why they tend to look whiter than incandescent bulbs, but they tend to have a trough of intensity right in the middle of the melatonin suppression range. Neither of them produce any ultraviolet at all. Therefore indoor lighting is bound to be poor at suppressing melatonin.

The second problem is that a minimum brightness of about 2500 lux is required to suppress melatonin, and indoor lighting rarely, if ever, reaches this intensity. So there is little chance of indoor light being useful in controlling melatonin, and thus our wake/sleep rhythm. The importance of this on a worldwide scale is impossible to estimate, but we do know that millions suffer transient sleep disturbances, as well as drowsiness and fatigue during the day. These may be due to physical illness, or simply a response to the stresses of life. Whatever the cause, if we can get a good night's sleep, and stay alert through the day, it is bound to be a help.

Disturbances of the wake/sleep cycle are also a recognized feature of the affective disorders - depression, anxiety and manic-depressive illness. Since 1983 there have been several studies which have shown that a dose of 'bright' light, of a minimum intensity of 1500 lux (which means that is likely to have been borderline in effect), for a period of only one hour, can produce a significant but small improvement in mood as well as in sleep, in all types of depressed patients. [12] The effect was not limited to any one type of depression. The obvious comment on this is that a longer period of brighter light might well be even more beneficial. If you think it might help you, try it; there's nothing to lose.

Bodily depression

The medical model of depression says that it is a distinct illness which calls for specific treatment. One of the major pointers to a diagnosis of depression is a disturbance of sleep pattern. However, any doctor in clinical practice who takes the time to talk to his patients about this will confirm that large numbers of people with all kinds of illnesses complain, among other things, of minor variations in mood, of fatigue and lack of energy, and of disturbances of their sleep cycle. How many of these might feel better if they established their natural daily biorhythm again, using sunlight or bright indoor light which mimics sunlight?

Sad cases

There is a small group of people with depression who have a clear worsening in winter, and this is known as SAD - seasonal affective disorder. The characteristics of this are rather different from ordinary depression. The large majority of patients appear to swing the other way in summer months, to some extent, and their symptoms when they are depressed are rather different. Two thirds of them admit to a carbohydrate craving and to an increase in weight, as well as disturbances of the menstrual cycle. interestingly, the disease usually starts earlier than ordinary depression with an average onset age of twenty two, and seventy per cent of them admit to at least one relative with a major depression or other affective disorder. [13] These people feel better when they are nearer the equator, and they almost invariably improve when treated with bright light, of over 2500 lux. They get worse again when given melatonin capsules; as well as the usual drowsiness and slowing down, they develop much the same depressive symptoms as they experience in the depths of winter.

In the spring

In other words they are more sensitive to variations in the sunlight cycle than the rest of us. This does not mean that they are unique, or that the rest of us are free of such effects. There are at least forty variables that have been shown to have a seasonal difference, ranging from growth rates in children through sensitivity to dental pain to the alertness of train drivers. [14] The variation in growth rate was first described in 1886. The fascinating thing about all the studies on growth is that they show a completely opposite phase for increases in height and increases in weight. Children in a number of temperate climates grow most in height in late spring and early summer, just at the time when their weight gain is at its lowest. There can be as much as a fifty per cent difference between summer and winter in the rate of growth, and up to one hundred per cent range for weight gain.

Excretion of hormones in the urine varies by a similar degree. The principal male hormone, testosterone, is known to be produced by the effect of sunlight on the skin, and particularly on the skin of the genitals. [15] It is not surprising, therefore, that its levels rise throughout the spring and summer months, being about one third higher by the end of August than in February. Little wonder, too, that the peak month for conceiving babies is June. in the spring, a young man's fancy evidently does turn to thoughts of love - and by summer he's done something about it.

The levels of 17-ketosterolds, the adrenal steroids, which are produced in response to stress, on the other hand, fall steadily to a trough in August. The further north of the equator, the more marked is the trend. Clearly, at these latitudes our bodies find winter something of a strain.

The big sleep

Death from all causes peaks in January. This is hardly news, and does not have to be attributed to a direct effect of sunlight. Some of the reasons are obvious. Respiratory infections, for instance, are more common in winter, as any GP will confirm, This is probably connected with the poorer supply of fresh vegetables leading to lower levels of vitamins, causing us to have weaker immune systems. Also, ultraviolet light kills bugs, and there is less of it about in winter, and we tend to stay indoors more, avoiding what little there is. The risk of hypothermia is obviously greater in winter, too. These and many other seasonal effects should be considered as indirect effects of sunlight.

Aerial display

As well as melatonin, the pineal produces a range of neurotransmitter molecules, such as 5-hydroxytryptamine, noradrenaline, vasotocin and GABA.[16] It also regulates the production of certain of the endorphins - the morphine-like chemicals produced within the brain. All these chemicals have powerful effects on the way our minds and bodies function. The production rate of at least some of them is known to be influenced by dark/light cycles. So the signals from sunlight hitting the retina feed directly into some of our most crucial psychological regulatory mechanisms. There is a lot of work still to be done on finding out just how much, and in what ways, the whole brain is influenced by sunlight.

In addition to darkness and electromagnetic fields, the pineal is also open to influence from bodily hormones. In contrast to the rest of the brain, the pineal is outside the system of the cerebral ventricles, and therefore ticks a blood-brain barrier. As already explained this is a biochemical term for the filtering effect of the ventricular system of the brain, which screens out naturally occurring chemicals, as well as a number of drugs. It is very hard to get penicillin across the blood-brain barrier, for instance, and in the field of antihistamines the race has been on for some time now to produce new models which do not pass into the brain and can therefore stop you sneezing without sending you to sleep.

As a result of its unusual position, the pineal is able to respond to relatively large molecules, such as hormones. It may also be vulnerable to viruses and to toxins from micro-organisms arriving via the bloodstream.17 Situated at the center of the brain, in the mid-line, it may be exposed to minute quantities of light passing through the skull. This could make a little sense when we realize that there are some similarities between cells in the pineal and photoreceptor cells in the retina. More and more, the pineal comes to look like an antenna, put out from the brain for the purpose of receiving a variety of environmental signals.

New found gland

As well as producing effects directly through melatonin, it has been shown that the pineal has an influence on the whole of the endocrine system of the body. In essence melatonin suppresses production by the pituitary gland of the hormones which stimulate- late our other endocrine glands. This reduces the activity of the thyroid, the adrenal cortex and medulla, and the sexual organs. As well as being lower at night, our output of all these hormones it at its lowest in winter. If we weren't actually designed to hibernate in winter, we were certainly meant to take it easy! People who live in the far north of countries such as Finland and Norway, where the winter nights are almost endless, often adapt by sleeping for very long periods in winter, but hardly at all in summer. Thus they make far fewer demands on their bodies in winter. But we have abolished night; under electric lights we can live at the same pace all year round. This sounds great, but it seems there's a price to pay.

There is also a secondary effect of the pineal, through the adrenal cortex and the thyroid, on the thymus gland, which is essential for the development and maintenance of immunity. The thymus is where all the T-cells - about which we suddenly know so much - come from. Without a functioning thymus a child would not reach adulthood, succumbing early on to infections against which he or she has no resistance. Yet this too is regulated through the pineal, and nutritionally-oriented physicians are now coming to regard sunlight as a useful component of therapy designed to stimulate a weak immune system.

Melatonin also suppresses the production of insulin by the pancreas, and therefore causes a rise in blood sugar. In contrast, calcium and vitamin D appears to stimulate the production of insulin. In full health, blood sugar is carefully regulated by the body and prevented from going either too high or too low. But low blood sugar, or hypoglycemia, is becoming recognized as a common complaint which can trigger mood swings, migraine and even epilepsy. Here, too, sunlight plays an important part, producing regulating effects which help to keep the blood sugar stable.

In other words, there is no area of our mental and bodily functioning that the sun does not influence. Our bodies were designed to receive and use it in a wide range of ways. We were not designed to hide from it in houses, offices, factories and schools. Sunshine, reaching us through our eyes and our skin, exercises a subtle control over us from birth to death, and from head to tail.

 

Chapter 5

Vitamin D - the Bone Maker

If your mother ever gave you cod-liver oil capsules then you have been treated with vitamin D. In 1918 a scientist called Mellanby reported that he could cure rickets in puppies by giving them cod-liver oil. Four years later it was proved that there was a component of cod-liver oil which produced calcification and strengthening of the bones, and that this component was not vitamin A. The new ingredient was labeled vitamin D. A whole generation of parents over the next few decades was very aware of the necessity to ensure adequate vitamin D intake for their growing children. Hence the unpleasant little brown capsules that so many of us were forced to swallow.

In this case, mother was right. The shift away from the land and into cities, where sunlight tends to be blocked out by buildings and pollution, has meant that our vitamin D levels are lower than they have been in the past, and particularly so in winter. The result of this, coupled with poor diet in children, was rickets.

 

Rickets

Rickets is returning to our inner cities, particularly in the children of immigrants, who develop it even when they eat a diet which prevented rickets when they were in their home countries. Children with rickets develop deformities of the bone that are with them for life. The long bones soften due to lack of calcium, and the child's weight causes the legs to bow outwards. The teeth are poor and fall out easily, and there is also a marked muscle weakness associated with the disease. If a girl develops rickets in childhood, she is likely to have a deformed pelvis when she grows up; that will make childbirth difficult, and may threaten the life of both mother and child.

At the turn of the century, it was estimated that as many as ninety per cent of children in some of the crowded cities of northern Europe and the northern United States had rickets.[2] This is despite the fact that the value of sunlight and fresh air in treating rickets had been remarked on in 1822. It took an investigative committee of the British Medical Association in 1889 to state clearly that there was a relationship between urban industrialized environments and rickets. And it was not until 1919 that it was shown that ultraviolet light could cure rickets. Over the next few years it became clear that sunlight healed or prevented rickets, and that exposing the food had this effect as well as exposing the patient; in both cases vitamin D is produced.[4] As a result, vitamin D is now added to milk and other foods in very large quantities in the United States, with the result that there have been problems with vitamin D overdose. In Britain and northern Europe, however, the supplementation of food is not required by law and is much less common, and vitamin D levels in human beings are much lower.

 

Vitamin or hormone?

Although we still call it a vitamin, it is now clear that the active form of vitamin D is in fact a hormone, with great similarities to the other steroid hormones - the corticosteroids produced by the adrenal gland, which control the ability to respond to stress, together with such basic functions as fluid balance and blood pressure; and the androgens, estrogens and other sex hormones produced by the ovaries and testes which control our sexual characteristics. All of these hormones, including vitamin D, are formed in the body from the same precursor molecule, and they all fit the definition of a hormone: a chemical that is produced in one part of the body and transported to another part, where it has its effect.

The necessary added ingredient to the reaction which enables vitamin D to be formed is ultraviolet light, and for this reason the only organ in the body that can manufacture vitamin D is the skin. The more sunlight that reaches the skin, the more vitamin D we produce. The vitamin then has to go through two further chemical conversions before it becomes the active form. The first of these happens in the liver, and the second in the kidney. Both of these reactions are affected by hormonal and other biochemical factors, with the result that there are a series of regulatory mechanisms that control the level of vitamin D in the body. This is important as it guarantees that an overdose of vitamin D from sunlight is impossible.

 

Calcium absorption

Although the biochemistry is complex, the major function of vitamin D is simple. It helps the body to make efficient use of calcium. There are three major target organs where this effect operates. Firstly, the percentage of calcium in the diet that is taken up into the bloodstream is increased by vitamin D. Since the range of dietary intake for calcium is quite large, from about 200-1200 mg daily, our bodies need to be able to adapt over a comparable range.[6] In fact, the percentage of calcium that we absorb when we are eating a lot of it may be as little as twenty five per cent, but on a low-calcium diet this can go up to sixty per cent - more than double - so the range of adaptation is considerable.[7] This happens under the influence of vitamin D. For example, a Norwegian study of healthy middle-aged prisoners showed that their absorption and retention of calcium was considerably better in summer than in winter.[8] The best month was August, and the worst months were February and March.

Unfortunately, there are several dietary and environmental factors which can interfere with calcium absorption. In common with other minerals, calcium needs to be freed from the matrix of food and made available for absorption into the bloodstream by the initial stages of digestion. These include the effects of saliva and of chewing your food, but the most important factor, and one which seems to go wrong quite often, is hydrochloric acid secretion in the stomach. Without adequate HCl production, protein, in particular, will not be broken down into smaller molecules, and the subsequent pancreatic and intestinal phases of digestion will be wasted.[9]

In old age, up to half of us can expect to be deficient in hydrochloric acid production. In younger age groups, probably more than half of food-allergy sufferers have low HCI output, and it is known that children with asthma are very commonly deficient.[11] Diets high in animal protein, which contains high proportions of the sulphur-bearing amino-acids, appear to impair HCl output, as do alcohol, cannabis, and the more recent and widely prescribed drugs for stomach and duodenal ulcers. These drugs, including those trade-named Tagamet and Zantac, actually work by suppressing stomach acid production. This serves their purpose of relieving symptoms, but it also interferes with digestion for these obvious reasons.

There are some factors in food which can also interfere with calcium availability. Junk-food diets in particular tend to have a high level of phosphorus, and although it is an essential mineral, too much phosphorus can interfere with calcium absorption and produce a deficiency.[12] Despite the universal belief that without milk it is impossible to get enough calcium, dairy products also contain a high level of phosphorus - high enough to interfere with calcium uptake, Too much fat, and even too much protein, can have the same effect.

Unfortunately, bran or wholegrain wheat, particularly when unleavened or unbaked, contain some chemicals called phytates which bind calcium and make it unavailable to the body. This can cause a deficiency, and the classical error to make is to add bran to a junk-food diet in order to increase its fiber, but thereby adding two anti-calcium factors together to produce a worse deficiency.[13]

Magnesium is the sister element to calcium and is necessary for using calcium properly. A low magnesium intake interferes with calcium conservation in the body and can cause a deficiency.[14] Vitamin D also increases the uptake of magnesium from the diet, providing yet another means of enhancing calcium control.

In other words, Vitamin D appears to influence every known mechanism by which calcium can be absorbed from the intestine. It is essential if our bodies are to make maximum use of what available calcium there is in our food.[1] Yet many of us are deficient in Vitamin D already.

 

Excretion

The second target organ for vitamin D is the kidney. Its effect there is complementary to that in the intestine, helping us to conserve our calcium stores. Since dietary factors can increase our output substantially, this is equally important. There are three major factors which do this. The first two are sugar and coffee, and both of these probably operate through the increase that they cause in the body's production of insulin. The major physiological effect of insulin is that it lowers blood sugar by pushing sugar into cells. It also pushes it into the urine, and a number of other nutrients, including amino-acids and minerals, are transported into cells or urine at the same time. A high-sugar meal or drink can increase by up to eight times the amount of calcium that we put out in our urine over the next few hours.[16] Thirdly, it appears that a diet which is high in acid residue from foods such as meat, dairy products and refined carbohydrates, as opposed to alkaline, will have a similar effect, possibly by making the urine more acid and therefore more able to dissolve calcium.

The effect of vitamin D in the kidney is simple; it causes a greater proportion of calcium (and of course of magnesium too) to be recycled back into the bloodstream rather than passed out in the urine. So not only do we absorb more of it; we also waste less.

 

Deposition

The third target is bone, where vitamin D increases the turnover of calcium, ensuring that more of it goes into the bones, and stays in. This means that vitamin D is essential for strong and healthy bones, not only in children, but in all age groups. Old people, and elderly women in particular, are especially vulnerable to gradual softening of the bone due to a loss of calcium. One of the commonest problems in this age group is that people fall down and break their wrists or their hips, necessitating surgical repair of the fracture under anesthetic.

Calcium and vitamin D are also essential for growing bones. Without them children's bones grow soft and may bend under the pressure of gravity. This is what happens in rickets. It is not just for the prevention of rickets, though, that a healthy calcium metabolism is important, but also to ensure good posture and strong bones in all children, because bones that they form in childhood will be with them all their adult life.

Teeth are also bones, of a specialized sort, and they too are dependent on calcium intake. A deficiency of sunlight, as well as calcium, can cause poor dental health and cavities in teeth.[19]

Hans Selye became famous for his description of the way that organisms adapt to stress, and without him stress would certainly not be the household word that it is. He conducted a series of experiments showing that a variety of hormones and stress factors mobilizing calcium from bone into the bloodstream could lead to abnormal calcifications. This is a process of deposition of calcium into soft tissues so that they become hard and very like bone. It is an important part of the process of hardening of the arteries, occurring as a result of damage to the lining of the artery.

One of the major factors that can lead to abnormal calcification is an excess of vitamin D, which causes a characteristic pattern of calcified areas round joints and bones. But a deficiency of vitamin D can also lead to a rise in the level of calcium circulating in our bloodstreams. When there is more calcium than normal in the blood, it readily finds a target on which to deposit, and any local irritant or inflammation can therefore lead to abnormal calcification.

 

Vitamin D deficiency

Many factors influence the level of active vitamin D in our blood. The first and most important is the amount of ultraviolet hitting our skin, and therefore the amount of sunlight available and the extent to which we expose ourselves to it.

In the United States, researchers found that the average levels throughout the year for people living in Palm Beach, in sunny Florida, were twice those of people living in Seattle or Boston, a thousand miles to the north. Moreover, for both these cities, the average level in February, when vitamin D was at its lowest, was higher in men who worked outdoors than the level in August in people who worked indoors. In other words, indoor workers spend their whole lives with lower vitamin D levels than outdoor workers.[22] In these circumstances it is meaningless to talk of normalcy, because if everybody is deficient, then the normal level will be deficient.

Put simply, a large proportion of this country is permanently vitamin D-deficient. The major at-risk groups are the elderly, children, pregnant and lactating mothers, and the chronically ill. Although these may not represent the majority of the population, they do amount to just about everybody who goes to see doctors. Apart from them, nobody needs a doctor! If sunlight exposure can improve the health of only a fraction of these, therefore, it can alleviate a great deal of suffering and reduce the cost to the NHS significantly.

For example, a study in Massachusetts found that ten per cent of apparently healthy elderly people were vitamin D-deficient. Of patients admitted to hospital with fractures of the hip (neck of femur), however, more than twice as many were vitamin D-deficient.[24]

The message is clear: go for a walk outside. You will raise your vitamin D levels, and at the same time the pressure of your weight on your long bones will encourage calcium to be deposited into them, making them stronger. Since this is of particular importance to old people, perhaps the most beneficial thing you can do on retirement is buy a dog!

 

A pain in the neck

Some of the known symptoms of vitamin D deficiency are bone and joint pain, and muscle weakness.[26] Since teeth are largely made of calcium, and since calcium absorption depends on vitamin D from sunshine, this is hardly surprising.

Spacemen are fastidiously screened from any ultraviolet radiation reaching them, because of the risk of unpredictably high levels occurring. They also are known to suffer from demineralization of the bone, with muscle weakness and general ill health as a consequence. This may be largely due to the effects of weightlessness, since pressure along the axes of the long bones is necessary to maintain their mineral content. But when a study was carried out by the Royal Navy at their Institute of Naval Medicine in Gosport, they found that keeping young healthy males in a sunlight-free environment on the ground led to their developing serious problems within two months. By this time the vitamin D levels in their blood had gone down by half, and they were starting to lose more calcium than they took in.[27]

Unfortunately, in the true military fashion, they do not appear to have asked the subjects how they felt, so we are not told whether there were any symptoms associated with this. We do know, however, that this is precisely the sort of environment in which many chronically ill people find themselves: indoors, deprived of any ultraviolet light and with very little pressure on their long bones to stimulate mineralization. Small wonder that when they do finally stand up their muscles and bones are weak.

When you think about it, we can add to our list of people likely to be vitamin D-deficient, anybody who has been in an English hospital for more than eight weeks. If you are having bone surgery, in other words, try not to spend too long in hospital beforehand. If you do, your bones will be weaker and take longer to heal, your heart and arteries may be at risk, and your muscles will be flabby and weak. Before the war, both children and adults in hospital were often taken out into the sun during the day, and many hospitals were designed with verandahs and French windows to make this possible. Nowadays hospitals tend to be multi-story, and a little like car parks too, and we have all forgotten the wisdom that was ours for free, concerning the necessity of sunlight for the elderly, children, convalescents - in fact, for every one of us.