In a new study, researchers found a daytime nap taken once or twice a week may lower the risk of having a heart attack or a stroke.
But no such association emerged for either greater frequency or duration of naps.
The impact of napping on heart health has been hotly contested.
Many studies have failed to consider the napping frequency, or focused purely on cardiovascular disease deaths, or compared regular nappers with those not opting for a mini siesta.
In the new study, the team looked at the link between napping frequency and average nap duration and the risk of heart attack, stroke, or heart failure among 3462 people from Lausanne, Switzerland.
Each participant was aged between 35 and 75 when recruited between 2003 and 2006 to the CoLaus study.
Their health was then subsequently monitored for an average of 5 years.
The team found frequent nappers (3-7 naps a week) tended to be older, male, smokers, weigh more, and to sleep for longer at night than those who said they didn’t nap during the day.
And they reported more daytime sleepiness and more severe obstructive sleep apnea—a condition in which the walls of the throat relax and narrow during sleep, interrupting normal breathing.
The researchers found occasional napping, once to twice weekly, was linked to an almost halving in attack/stroke/heart failure risk (48%) compared with those who didn’t nap at all.
And it didn’t change after factoring in excessive daytime sleepiness, depression, and regularly sleeping for at least 6 hours a night. Only older age (65+) and severe sleep apnea affected it.
No associations with cardiovascular disease ‘events’ were found for nap length (from 5 minutes to 1 hour plus).
In addition, greater frequency of napping was not linked to a different heart disease risk.
The finding contributes to the ongoing debate on the health implications of napping and suggests that it might not only be the duration, but also the frequency that matters.
The study is published in the journal Heart.
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