Body has natural ‘rush-hours’, study finds

By Efrosini Costa

Body has natural ‘rush-hours’, study finds
Scientists have discovered a pair of natural 'rush hours' throughout the body.

The study monitored the function of cells in various tissues throughout the day and found large shifts in activity just before dawn and dusk.

Researchers say the discovery could assist in medication, by timing doses to hit ‘sweet-spots’ in the body clock.

These body’s natural internal clock is known to drive massive changes, altering alertness, mood, physical strength – even the risk of a heart attack – in a daily rhythm.

A team at the University of Pennsylvania investigated the impact of the time of day on DNA function in mice.

They took samples from the kidney, liver, lung, aorta, brainstream, adrenal gland, cerebellum, brown fat, white fat, heart hypothalamus, lung and skeletal muscle.

Almost half of all genes involved in the manufacturing of protein altered their activity throughout the day.

Two major windows of fluctuating activity were observed in particular – dawn and dusk.

“I’m hopeful that we can use this information to design better therapies with existing drugs, and that’s huge because it’s not going to cost any more money,” lead researcher Dr John Hogenesch said of the findings.

“I think there is a real opportunity to improve current medication in a way that will be impactful,” he told reporters.

It is  already well known that some medications work better when take at certain times of the day.

Heart disease, for example is driven by artery-clogging cholesterol, which is mostly made in the liver at night. Hence why taking satins in the evening makes them more effective.

The study’, published in Proceedings of the National Academy of Sciences, said 56 out of the top 100 selling drugs worldwide acted on genes that were known to be effective during these natural ‘rush hours’.

“If 40-50% of genes are going up and down over 24-hours and these are drug targets, then it’s going to be important,” said body clock scientist, Dr Simon Archer, from the University of Surrey.

“Thousands, millions of people potentially, could benefit from taking their medication at a different time of day and raising this kind of awareness is important.”

Body Clock – Find out what goes in your body throughout the day.

0.00-2.59 AM – Body shuts down

Sleep hormone melatonin peaking

Minimum levels of attention and vigilance

Brain washes itself and consolidates memories

3.00- 5.59 AM – Body fast asleep

Minimum core body temperature

Severe asthma attacks more common

Most natural births occur

6.00-8.59 AM – Slowly waking up – heart attack danger zone

Good time to wake up

Heart attacks more likely

Men have their testosterone peak

9.00-11.59 AM – Most alert

Maximum cortisol levels

Maximum alertness

Best short-term memory

12.00-2.59 PM – Biological siesta

Increased gastric activity

Post lunchtime dip in alertness

Surge in road deaths

3.00-5.59 PM – Go exercise!

Best lung & cardiovascular performance

Core body temperature rising to its peak

Good time to exercise

6.00-8.59 PM – Watch what you eat

Poor time to eat a big meal

Liver handles alcohol better

Intuitive thinking is better

9.00-11.59 PM – Ready for sleep

Melatonin production building

Core body temperature dropping

Good time to go to sleep


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