Daily Mail Article 24 hours
This article was published in the Daily Mail, Tuesday, August 10, 2004 
under their 'Good Health' section.
 
Published on our web site with the kind permission of the Daily Mail 
- copyright © Daily Mail 2004

24 Hours in the Life of Your Body

At 6am fertility is highest. At 4pm nails grow fastest. At 5pm your grip is strongest... Hour by hour, how the human body renews itself.

You are most likely to go into labour at midnight, die at 4am and have a heart attack at 8am. Depending on our in-built 24-hour body clock, controlled by 20,000 cells at the base of our brain, our body know when to work hardest and when to take a break, when to tolerate pain, and when a disease is most likely to hit. MARIANNE POWER introduces the fascinating world of chronobiology - the study of the ticking human clock.

Time Body function description
00.00
AT MIDNIGHT, while our minds are asleep, our bodies are busy absorbing the fat we have consumed during the day, our hair growing and our cells are beginning their intricate repair processes.

Midnight is the time when pregnant women are most likely to begin experiencing labour pains. At this hour, the body experiences a rush in progesterone - which is the hormone secreted by the ovary during the menstrual cycle and by the placenta during the menstrual cycle and by the placenta during pregnancy to bring on labour. This is thought to be the body's evolutionary way of making sure the mother's partner is with her when her baby is born.

01.00
ANYONE who has suffered from gout will tell you that the worst attacks often come around this time of night. This is because the concentration in joints causes pain - peaks between midnight of the night.
02.00
LEVELS of the hormone vasopressin, which suppresses bladder activity, increase, so you should not need to go to the loo in the middle of the night.
03.00
ASTHMA sufferers are 300 times more likely to have a severe asthma attack now then at any other time. Adrenaline and anti-inflammatory hormones are at their lowest between 3am and 4am, which causes airways to narrow. Spasm-triggering compounds called leukotrienes and also at their highest.

Some doctors recommend taking vitamin C and vitamin B before bedtime to help to support the adrenal glands and reduce the risk of getting an asthma attack during the night.

04.00
YOU are most likely to die at this time in hospital, according to figures from the Harvard Medical School. The reason could be that blood pressure reaches a low during deep sleep. Sudden infant death syndrome is also most likely to occur at this time for the same reason. On a more positive note, more women give birth naturally between 4am and 6am than at any other time.
05.00
GROWTH hormones are secreted through the night to repair tissue and strengthen bones, so at this time the body does not want to be awake. Those working the night shift are at their least alert now because of the high levels of melatonin, which make us want to sleep.

According to Dr Russell Foster, from Imperial College, London, if you're driving a car or operating equipment, your performance would be 'worse than if you were drunk'. It is no coincidence that many of the world's major accidents - such as Chernobyl and Three Mile Island - happened at this time.

06.00
ANYONE wanting to become pregnant should try to conceive now. You are most likely to conceive a few hours after ovulation, which usually starts around midnight. Fortunately, this coincides with the time that our libidos are at their peaks. In the early morning, the male sex hormone testosterone, which is responsible for sex drive in both males and females, surges. Women are most likely to start menstruation at this time.
07.00
YOUR joints and body feel stiff in the morning because anti-inflammatory hormones are at their lowest level and your muscle temperature is low after a night of sleep. This is why sufferers of rheumatoid arthritis usually feel more pain in the early morning.

It is also the time you are most likely to get migraine because of fluctuations of the 'feel good' hormone serotonin. The trigger for an attack is a lack of this chemical, which occurs naturally in the brain. It is this chemical imbalance that makes the blood vessels constrict in the head, causing the eyes to widen and leading to extreme pain and sensitivity to light.

08.00
AS YOUR body wakes up, blood pressure and temperature start to rise and there is a surge in the stress hormone cortisol. It is at this time that heart attacks, angina and sudden cardiac deaths are most common because the combination of cortisol and the increase in heartbeat puts pressure on the heart.

When you are sleeping, the average human heart beats about 60 times per minute. As soon as you get out of bed, it rises to between 72 and 78 beats. According to American research, acute heart attacks are three times more common in the early morning than in the late evening.

Research has also found that on a Monday morning you are 40 per cent more likely to have a heart attack than at any other time - possibly because of the higher levels of stress hormones in the morning, combined with a weekend excess of food and drink which will increase blood pressure. Your blood clots the most at this time, which also makes your risk of stroke highest at 8am.

09.00
YOUR digestive system is working at its peak now, so first thing in the morning is the best time to eat a big meal. Metabolism is most active in the morning, which means fats absorbed from foods are less likely to be deposited in the body than in the evening.

If you need to have an injection, now is the time to have it because you are least likely to feel pain. The hormone adrenaline which helps us to endure pain, peaks now.

10.00
THIS is the best time to take an exam or interview because wakefulness peaks mid-morning so concentration, shirt-term memory and logical reasoning are at their best. The body's glucose levels are also high, giving the brain and body good energy levels.
11.00
YOUR immune system is at its most vulnerable now because the helper T lymphocytes of the immune system are at their least active during this time. T lymphocytes are the crucial white blood cells that move around the body fighting infection and disease, including cancer.
12.00
THE risk of stroke due to clot formation and blood vessel blockages is at its highest because blood pressure peaks around midday. Strokes known as cerebral infarctions are 50 per cent more likely to strike between 6am and midday that at any other time. High blood pressure puts extra pressure on blood vessels that are already narrowed by fatty deposits - often caused by cholesterol - and can cause the vessel to rupture and bleed into the brain.
13.00
YOUR urinary production is reaching a high point after a morning of liquid consumption, and your kidneys are working at maximum efficiency to wash out any toxins in the body.
14.00
AS your body works to digest lunch, physical efficiency and energy drops - which is why most of us would like a siesta now. You are more likely to be in a road accident at this time, because the body slows down dramatically and concentration levels can dip.
15.00
RESEARCH shows that toothaches are at their least painful in the late afternoon. It could be that endorphins that protect against pain reach a peak now.

The skin is at its most porous mid-afternoon because your body is warm. With heat pores open, this is the most effective time to rub cream into your skin.

16.00
A GOOD time to have an aerobic workout. The body is at its strongest, most flexible and responsive now because it is warm and adrenaline levels are at a high. Adrenaline is pumping around your body, increasing your heart rate and dilating blood vessels and airways. Most Olympic records have been set at this time.

Hair and nails grow quickest between 4pm and 5pm and lung function can change by up to 50 per cent over the course of a day.

17.00
YOU can give your firmest handshake as tests have shown grip strength is at its peak now. This could be because the little muscles in the figures - the intrinsic hand muscles and finger flexors - are at their strongest after a day of constant use.
18.00
AS THE body begins to tire, muscle tone is lessening and heart rate and blood pressure are gradually reducing. By early evening, your stomach is producing more acid. The more food that is in the stomach, the more acid it produces. The acid build-up can sometimes be pushed up the oesophagus, causing acid reflux. It can also aggravate any existing stomach ulcers.
19.00
AS daylight fades, your body is starting to secrete melatonin to prepare for sleep. As the body relaxes, your sense of smell and taste are at their most acute - making it the ideal time for a delicious meal.
20.00
LIVER enzymes increase now, meaning that they are best able to break down alcohol - so treat yourself to a drink. They decrease again by 10pm.
21.00
YOU are most likely to suffer from pain as your pain threshold is at its lowest. This is because levels of pain-blocking endorphins are falling.
22.00
YOUR immunity is at its optimum level because levels of interlukin 1, one of your body's immune system regulators increases at this time.
23.00
YOUR sensitivity to allergies is at a peak. By 11.30pm, high melatonin levels make us feel ready to sleep. Ten minutes after we fall asleep, the heart rate slows and brain waves reduce. Twenty-five minutes later, we are in a deep sleep.

THE BODY CLOCK AND MEDICINE

PIONEERING researchers around the world believe that medicine should take into account what is happening to the body at specific times of the day. Drugs which have no effect at midday might be very potent 12 hours later. Similarly drugs may have fewer side-effects if taken in the morning rather than at night.

Cronotherapetics is the branch of medicine researching the effect of testing patients at specific times of the day. According to Dr. Michael Smolensky at the Hermann Hospital in Houston, there are about 30 diseases which could be more effectively targeted if the treatment was carefully time. Treating pancreatic cancer, for example, with certain drugs is most effective at 4am, because at this time the enzyme that protects healthy cells is at its highest, so higher doses can be given.


 
 
 

Registered Charity no. 1105985