WHY A NAP IS BAD FOR YOU
40 winks during day raises risk of heart attack
AN afternoon nap increases your chances of having a heart attack or stroke, say scientists.
Dozing off during the day has been found to raise people’s blood pressure by almost a fifth. Left untreated, that increases the risk of heart attack, heart failure, kidney disease, stroke and dementia.
The revelation of a “significant association” between napping and high blood pressure comes after scientists reviewed nine studies involving more than 112,000 patients. For generations, 40 winks in an armchair after lunch was thought
to be a fail-safe way of recharging body and mind.
But the new findings could overturn that theory and act as a warning to the 16 million Britons already suffering with high blood pressure, also called hypertension.
The condition is known as a “silent killer” because there are no obvious symptoms.
Scientists at the Mayo Clinic in Rochester, Minnesota, found napping for between 30 and 60 minutes increased the risk of hypertension by between 13 and 19 per cent. The risk is highest in those aged 40 to 50.
Fatigue
Sleep expert Dr Wisit Cheungpasitporn, who led the research, said: “Previous studies have shown benefits of napping, including reduction of fatigue and improvement of alertness, mood, work performance and safety.
“On the other hand, we found potential deleterious effects of midday naps on hypertension.
“It is possible that previously reported associations between napping and cardiovascular diseases are via napping-induced hypertension, a major underlying cause of cardiovascular disease.” Analysis of night workers who took naps during their shifts did not show the same link. One study found employees who dozed off at night had a 21 per cent reduced risk of heart attacks.
Experts say the highest risk is within the first hour after waking. At this time there is a rapid rise in blood pressure as the heart races and blood vessels are constricted. It is estimated that more than five million people in the UK are unaware they have high blood pressure – defined as a reading of 140/90 or more.
The condition affects one in three adults, with those over 65 most at risk.
Adrian Williams, Professor of Sleep Medicine at King’s College, London, said: “Daytime napping suggests possible nocturnal sleep disruption, most commonly obstructive sleep apnea, which is known to cause hypertension. Shift workers napping at night do so because they are sleep deprived, because it is very difficult to get adequate sleep in the daytime.”
The findings were presented to the American Society of Hypertension in New York.
Dr Mike Knapton, of the British Heart Foundation, said: “This study appears to contradict previous research by suggesting an afternoon nap may increase your risk of having high blood pressure.
Beneficial
“There are many factors that can affect blood pressure, including not doing enough physical activity, being overweight or obese, having too much salt in your diet or regularly drinking too much alcohol. Having high blood pressure increases risk of heart attack or stroke and we recommend everyone over 40 should get their blood pressure measured.”
A Sleep Council spokesman said: “A nap can be very beneficial for a bad night’s sleep but napping should not be a long-term solution to sleep deprivation.”
NEW research shows that having a midday nap leads to an increased risk of hypertension. Everybody enjoys the occasional snooze, who would ever have thought it could be bad for you?