The Rhythm and the Blues

The spinning of the earth round its central axis structures our lives. It is this spinning which gives us our days and our nights and which provides us with a pattern for living. We sleep and work, rest and play, eat and drink according to the daily rhythm which results from the earth’s movement.

Nevertheless, important as this daily rhythm is, there are known to be many other physiological, psychological and biomedical rhythms which also have an effect on the way we live. Of these, the best known is the one which ensures that a woman’s hormone levels will rise and fall in such a way that she will alternately ovulate and menstruate, allowing each fresh egg to have its day, then seeing that it is discarded before fresh pastures are prepared in the womb. Surprisingly, we know little or nothing about the twenty-eight day clock inside each woman which is capable of operating relatively smoothly for some twenty or thirty years.

There are other body rhythms about which we know no more. There is, for example, an internal clock which controls body temperature from day to day. The fact that this clock seems to match the clock which regulates the menstrual cycle means that women can judge the best time to conceive by taking their temperature each day. Yet we know little or nothing about the clock mechanism involved.

Nor do we know why more people die at 4.00 a.m. than at any other time of day. Or why suicide is more common in the spring and the autumn when duodenal ulcers are also especially likely to perforate. Or why the best time to learn anything is just before you go to sleep. Or why the best time for making important decisions is round the middle of the day. Or why most of us are most alert during the early evening.

What we do know is that there seems to be a relationship between body rhythms and health. There is evidence, for example, that there is a link between depression and some sort of body rhythm. In an article published in the British Medical Journal in 1976, Nikitopoulou and Crammer showed that there is a change in the daily temperature rhythm in patients suffering from a particular type of depression. Other researchers have found the same thing. But as yet no one seems to know whether these patients are depressed because their body clocks are disordered or whether their body clocks are disordered because they are depressed. However, there is one clue which suggests that it is when the body rhythm goes wrong that depression strikes. It seems that a drug called lithium can be used to help some depressed patients. And when it works, lithium seems to slow the body rhythm down to normal. There may, therefore, be a link between lithium, a body clock and the mental state of an individual. There is another clue too. Back in 1938 G.M. Griffiths and J.T. Fox published a paper in which they reviewed 110 male epileptics who lived in an English city called Lichfield. The men had a total of 39,920 fits during the period in which they were under observation. By making a careful note of the time of day when these fits occurred, Griffiths and Fox discovered that many of the epileptics had their fits at a regular time of day. It may well be, therefore, that epilepsy can sometimes be a result of a disordered body clock.

We know also that there are several different clocks which govern what takes place when we are asleep. These produce massive changes in hormone levels, a fall in the body temperature and a change in the rate of body hair growth. Electroencephalographic recordings taken in special sleep laboratories have even shown that there are two different types of sleep which alternate throughout the night. Rapid Eye Movement sleep is characterised by the fact that the muscles of the head and neck become floppy, the eyes jerk and the tone of the muscles round the rest of the body varies a good deal. Men often develop erections during REM sleep and dreams are frequently very active. Non Rapid Eye Movement sleep, on the other hand, is characterised by the absence of eye movements, a lowering of the pulse rate and blood pressure and a generalised lowering of muscle tone.

We understand little enough about these changes.

We know no more about many others.

Why, for example, should the amount of iron in the blood be greater in the morning than in the evening? Why should the amount of serum zinc in the blood fall in the morning? Why should the frequency of sexual intercourse be considerably greater during the months of April to June than during the latter part of the year? And how do we explain the fact that a study done in the Netherlands showed that people born in the winter months had a greater chance of eventually developing carcinoma of the bronchus than those born during the summer?

There are, of course, many individuals who strongly believe that these rhythms govern all aspects of human life. For some years now some people have believed that their health and fortune is ordained not by the position of the stars but by three different body cycles. In a book called The Periods of Human Life, published in 1904, Hermann Swoboda, Professor of Psychology at Vienna University, announced that our physical vitality and strength is governed by a 23-day cycle and that our emotional strength and stability is governed by a 28-day cycle. A few years later, Professor Alfred Teltscher of Innsbruck declared that there is a third, 33-day cycle, which governs intellectual activity.

All three of these cycles are said to begin on the individual’s birthday and to follow a wave pattern after that, with the waves repeating themselves after 23,28 and 33 days. The theory is that the peaks and troughs of the cycle are the most critical times and that on these days an individual is particularly likely to be at his best or his worst.

By a careful study of the way the three waves relate to one another it is said to be possible to select the most suitable time of the month for particular types of action. It is alleged, for example, that if the date of a surgical operation is picked with care then the patient’s recovery will be speedy and smooth. One published survey decided that over 30 per cent of all deaths from surgical misadventure could be prevented by avoiding dates when the patients’ biorhythms were unfavourable.

The information we have is tantalising. Some body clocks seem to be controlled by hormones released by the pituitary gland or the hypothalamus. Others seem to be controlled without the use of any circulating hormones. There seem to be some clocks which can be controlled voluntarily, for there are individuals who claim that they can make themselves wake up simply by switching on an internal alarm clock.

However many separate clocks there are, however they may be controlled and whatever their role may be, there is no denying the fact each one of us has inside us a complex series of timing mechanisms which have a powerful effect on the way we tick.