Deep sleep is vital to our wellbeing

Aug 9 2006

WHEN we sleep, hormones are released, breathing and heart rates, blood pressure and body temperature drop, and our memory is consolidated.

Studies suggest a lack of routine, too little or too much sleep can harm mental and physical health.

Q. Why is a good night's sleep important?

A. Our inbuilt body clock responds to sunlight and our 24-hour social pattern, controlling production by the liver of key enzymes to deal with the meals we eat and toxic by-products.

A Cambridge study shows daily rhythm changes caused by shift work, jet lag, certain sleep disorders and old age, can affect our metabolism including how blood, fats and sugars are regulated, and may even increase the risk of developing certain cancers.

Q. What happens without enough sleep?

A. Lack of sleep is associated with a twofold increase in obesity levels in adults and children as young as five, and is thought to be caused.

Time for bed: The right amount of sleep could help prevent heart problems and diabetes.

by hormonal changes. It can also make the onset of diabetes more likely.

Even healthy individuals experienced increased blood pressure with less than five hours' sleep a night.

Sleep quality is also important. Some people suffer from sleep apnoea - when they stop breathing for at least 10 seconds during sleep, partially awakening them but not enough to remember next morning.

It is more common in the overweight or obese, and sufferers often tend to snore.

They are likely to have an increased risk of coronary heart disease,hypertension, congestive heart failure, heart rhythm disorders, enhanced furring of the arteries and increased levels of C-reactive protein, a risk factor for heart disease.

Q. Is getting too much sleep also bad?

A. Research has shown sleeping more than nine hours nightly, and working shifts may double the risk of Parkinson's disease and triple the risk of diabetes, a risk factor for heart disease.

Getting the right amount of sleep is important for general health and mental alertness but can also help ward off high blood pressure and reduce the risk of heart, stroke and kidney disease.

Rest times are also essential to enable the heart to pump more easily.

Q. How much sleep should I have?

A. Whether you powernap, have a lunchtime siesta, a quick 40 winks after work or prefer uninterrupted nights, the key is to establish a routine favouring deep sleep.

You'll know how well you've slept by how fresh and rested you feel when you wake.

Tips for getting the good night's sleep we need include avoiding late night TV, large meals and high carbohydrate snacks, caffeine and alcohol before bed, and exercising regularly.

The general consensus is around six to eight hours' sleep nightly is best.

* For more information and advice about healthy living, call Heart Research on 0113 297 6206 or e-mail lifestyle@heartresearch.org.uk