It has been known for centuries that the leaves of some plants regularly open during the daytime and close at night. It was always assumed that this phenomenon was a response to sunlight. But over two 250 years ago, in 1729, a French astronomer called Jean-Jacques de Mairan, conducted a very simple experiment which showed that this assumption was wrong. He discovered that this phenomenon occurs even if a plant is kept in the dark. The only possible explanation was that the plant opens and closes in response to some sort of 24 hour internal clock. That was the first experiment in chronobiology.
Since then chronobiology (the study of temporal patterns related to biological phenomena) has become an acknowledged science. It is now known that just about every living organism - from a nucleated single cell to a human being - follows a 24 hour or circadian rhythm. So, for example, your pulse rate and blood pressure are highest first thing in the morning (with the result that the incidence of heart attack and stroke is highest at that time of day). In the evening your pulse rate and blood pressure will naturally fall. Your body temperature rises during the day and falls at night. Your blood platelets - which help with blood clotting - are stickier in the morning than at any other time of day. You are, therefore, likely to have less trouble with bleeding if you nick yourself in the morning than if you nick yourself in the evening. Your tolerance for alcohol peaks at five o'clock in the afternoon. And finally, most babies are born - and most people die - between the hours of midnight and dawn.
Our bodies respond in a cyclical way because we have evolved on earth - and the amount of light and heat and the level of electromagnetic and gravitational forces on our planet all vary in a rhythmic way.
The important thing - still widely ignored by doctors and many alternative health care professionals - is that the abnormalities associated with disease also vary in a cyclical and circadian way.
Whether you are suffering from cancer, heart disease, arthritis or asthma your disease will change during the day and, consequently, whatever you do to tackle the disease should also be arranged according to a circadian rhythm. For example, during the day and the night your body's ability to absorb drugs will vary. When given at the right time of day a drug will have a powerful and positive effect on an illness. But when given at the wrong time of day a drug may prove toxic.
Next, consider allergy reactions.
Allergy reactions develop when the body's natural defenses against foreign organisms over-react. If you are exposed to a pollen, or a type of food to which you are allergic, your body will send white blood cells to the site at which the foreign organisms have been spotted. The white cells will then proceed to eat up the foreign organisms. Some of the white cells release a substance called histamine which increases local blood flow and triggers the release of more white cells. The symptoms produced by this reaction include pain, itchiness, burning, redness and swelling. Your body's ability to deal with outside threats in this way is influenced by the amount of glucocorticoid (a steroid hormone) in your blood stream. When the amount of glucocorticoid is at its highest your body's ability to deal with an outside organism will be at its lowest.
Now, under your body's circadian rhythm the amount of glucocorticoid in your blood is at its highest level in the morning - at around 5.00 a.m. or 6.00 a.m. Inevitably, therefore, your body's ability to deal with an external threat is lowest at this time of day.
But in the evening when your body's levels of glucocorticoid fall your body's ability to deal with a threat rises.
This means that you are least likely to develop an allergy reaction early in the morning. But, at that same time of day, you are also, because of the same effect, most susceptible to infection.
On the other hand you are most likely to develop an allergy reaction - and least susceptible to infection - in the evening.
(The fact that the body's levels of steroids are naturally highest early in the morning mean that a patient who has to take a steroid drug - which carries with it a risk of serious side effects - will probably suffer fewer side effects if he or she takes the drug very early in the day when the body is best prepared for it.)
Next, consider arthritis - a common inflammatory disease which also runs on a biological clock.
In rheumatoid arthritis the joints are attacked by a malfunctioning immune system. The joints of a rheumatoid arthritis sufferer are usually stiffest and most swollen early in the morning. They become easier during the day. In other types of arthritis - such as osteoarthritis - the stiffness and pain get worse during the day.
It is clear from this knowledge that the time when medication is given for these two different types of disease is vital. A drug given for rheumatoid arthritis should be timed to act in the morning, whereas a drug given for osteoarthritis should be timed to be working most efficiently later in the day.
Asthma is one of the commonest diseases in the world. It is getting commoner. (Although as I have explained in my book How To Stop Your Doctor Killing You I believe that many of the diagnoses of asthma - and other disorders - currently being made are false.) Because of the circadian rhythms associated with a number of normal physiological processes (such as airway size and breathing patterns) the majority of asthma attacks take place between 2.00 a.m. and 6.00 a.m. in the morning. The airways are naturally open widest during the day and there is a reduction in airflow after midnight.
Heart disease is linked to body rhythms (heart attacks are twice as common in the morning as they are during the rest of the day - making high stress breakfast meetings a risky venture).
The activity of cancer cells is also linked to body rhythms. Drugs prescribed to attack cancer usually operate by killing cells when they are most vulnerable - during the process of division. Anti-cancer drugs target cancer cells because cancer cells grow and divide far faster than other human body cells. However, other rapidly dividing cells (particularly cells inside the intestine and cells in the bone marrow) are likely to be killed unnecessarily by anti-cancer drugs. However, if an anti-cancer drug is given at the right time of day the problems associated with such a drug can be minimised and the effectiveness of the drug can be maximised. One trial showed that women with ovarian cancer who were given their drugs at the right time of day were four times as likely to survive for five years as other women - whose drug taking was not regulated in this way. Other researchers have found a similar difference when treating patients with colon cancer.
It isn't just drug therapy which is influenced by time. There is evidence which suggests that far more pre-menopausal women survive breast surgery if they have an operation which is done during the second half of their menstrual cycle than if they have an operation in the first two weeks of their cycle. This difference can probably be explained by the change in hormone levels which occurs during a menstrual cycle. If researchers put more effort into studies of this sort, and wasted less time and money on pointless research such as animal experimentation, far more lives would be saved. The link between surgery, breast cancer, survival rates and the menstrual cycle was first observed in 1836 (yes, 1836 - over 175 years ago) so I really don't understand why more research hasn't been done to find out the precise link between hormone levels and cancer. If I were a woman having breast surgery for cancer I would want to have the operation done in the second half of my menstrual cycle (though I probably wouldn’t be given the choice).
Any patient who needs drug therapy should ask their doctor to check if there is any evidence to show whether the treatment works best at a particular time of day. My guess is that most doctors will have never heard of chronobiology. But getting the timing right could make a life or death difference so it is well worth while being persistent.
This really is an area where more research is needed - and needed fast. It seems to me to be quite absurd that we have failed to pay much attention at all to this absolutely vital branch of medical science. Many deaths and a good deal of illness could be avoided by the expenditure of a relatively small amount of effort in this area. I don't have any doubt that timing is vital - for patients as well as for comedians. But, amazingly, it is a phenomenon that doctors still ignore - either simply because it's inconvenient and they're too lazy to bother with it, or because it isn't something that has yet been introduced into the official, established way of doing things.
Taken from Why and how doctors kill more people than Cancer by Vernon Coleman (available as a paperback).