Can Napping Reduce Your Risk of Heart Disease?

Heart disease has been the leading cause of death worldwide for over 50 years. It is a metabolic dysfunction that has its roots in poor sleep quality.

Poor sleep quality can lead to higher blood pressure, inflammation, stress, and metabolic changes that can contribute to cardiovascular disease. It's caused by a wide variety of factors and leads to increased levels of cortisol (the stress hormone) and disrupt the body's circadian rhythms, which can affect heart rate, blood pressure, and more and also contribute to atherosclerosis, a condition where plaque builds up in the arteries.

But there is good news.

Sleep research suggests that incorporating naps into your weekly routine can significantly improve heart health and overall metabolic function, potentially adding years to your life.

In this article, we'll investigate the vital connection between napping and heart health.

Insufficient sleep duration is widespread in the population and is linked with weight gain and obesity, inflammation, cardiovascular disease, diabetes, and mortality.

Insomnia is also highly present and represents an important risk factor for cardiovascular disease, especially when accompanied by short sleep duration.

Sleep apnea is a well-characterized risk factor for cardiometabolic disease and cardiovascular mortality. Other issues are relevant as well. For example, sleep disorders in pediatric populations may convey cardiovascular risks. Also, sleep may play an important role in cardiovascular health disparities⁽¹⁾.

The American Heart Association (AHA) recommends that adults get 7–9 hours of sleep each night to help prevent heart disease.

Sleep can help your heart in several ways, including:

• - Lowering blood pressure and heart rate. During sleep, your breathing becomes regular and stable, and your blood pressure and heart rate decline. When you have sleep problems, your blood pressure may stay higher for longer periods of time.
• - Weight management. Getting sufficient sleep can help you manage your weight, which can also help protect your heart.
• - Cholesterol management. Sleep can also help you manage your cholesterol, which can help safeguard your heart.

It is very clear that quality sleep is crucial to cardiovascular health, but how and to what extent does napping play a part in this?

Habitual daytime napping is a common practice worldwide.

Whereas daytime napping has been consistently linked to overall mortality, the effect of napping on cardiovascular disease remains unclear. Evidence indicates that habitual nappers have lower coronary heart disease⁽²⁾.

Nap duration was reported to be important with respect to cardiovascular disease. Although there are some disparities in the literature on nap duration, nighttime sleep duration in combination with napping seems to play a role with respect to cardiovascular disease.
 
Most research only distinguished between nappers and non-nappers or investigated the effect of nap duration on cardiovascular disease but did not take the frequency of napping into account. Further, most studies only focused on cardiovascular disease mortality, and failed to consider the effect of napping on non-fatal cardiovascular disease events.

A recent study investigated the effect of nap frequency and average daily nap duration over a week on fatal and non-fatal cardiovascular disease events in a population-based cohort⁽³⁾.

Major Findings

This is the first population-based cohort study investigating the effect of nap frequency and daily nap duration over a week on fatal and non-fatal cardiovascular disease events. Results demonstrated that subjects napping once or twice weekly had a lower risk of developing a cardiovascular disease event compared with non-nappers.

Subjects who nap once or twice per week have a lower risk of incident cardiovascular disease events, while no association was found for more frequent napping or napping duration. Nap frequency may help explain the discrepant findings regarding the association between napping and cardiovascular disease events.

Another study conducted an analysis based on a sizable cohort with a high frequency of napping and information on potentially confounding variables including reported comorbidity, physical activity, and diet⁽⁴⁾.

Because midday napping is a common practice in Mediterranean culture, researchers studied more than 23,000 Greek adults for an average of six years and found that subjects who indulged in regular snoozes were 37% less likely to die of heart disease than those who pushed through the day without a nap.

After controlling for potential confounders, napping in apparently healthy individuals is inversely associated with coronary mortality, and the association was particularly evident among working men.

Problems from Lack of Sleep

It seems that the main issue from lack of sleep is cardiovascular inflammation.  A loss of only a few hours’ sleep can cause cardiovascular inflammation and it is this inflammation that is thought to eventually lead to cardiovascular problems later in life. Chronic, insufficient sleep can negatively affect immune cells, which may lead to inflammatory disorders and cardiovascular disease.

A recent study was the first to demonstrate that sleep alters the structure of DNA inside the immune stem cells that produce white blood cells—also known as immune cells—and this can have a long-lasting impact on inflammation and contribute to inflammatory diseases⁽⁵⁾.

Immune cells fight infection, but if the number of these cells gets too high, they overreact and cause inflammation. This research was also the first to show that catching up on sleep doesn’t reverse the effects of sleep disruption.

Findings suggest that sleep recovery is not able to fully reverse the effects of poor-quality sleep. This research was able to detect a molecular imprint of insufficient sleep inside immune stem cells, even after weeks of recovery sleep. This molecular imprint can cause the cells to respond in inappropriate ways leading to inflammation and disease. The reduction in overall diversity and aging of the immune stem cell population is an important contributor to inflammatory diseases and cardiovascular disease⁽⁵⁾.

Summary

It is very clear from the research that sleep is crucial to our health.  Sleep impacts optimal functioning of nearly every cell and organ in the body.  

Sleep can have a protective effect against a variety of conditions, including heart disease, cancer, and dementia. Evidence on napping and its positive effect on heart health is also coming to fruition. To enhance health to the greatest extent possible, it is recommended that sleep be a priority.  

It is important to establish sound sleep patterns early in life, which may reduce the severity of other inflammatory conditions such as sepsis. Most adults should get 7-8 hours of uninterrupted sleep each night. Older adults need about 7-9 hours, while children ages 11-17 need about 8-10 hours, and that's where RESTED-AF can help.   

RESTED-AF is a pharmacist formulated, scientifically designed sleep aid to improve the speed at which you fall asleep and the rate at which your body reaches R.E.M to help you achieve high-quality sleep so you receive comprehensive recovery benefits for both your body, and mind.

If you're looking to improve your sleep quality, consider adding RESTED-AF to your nightly routine!

References:
    1.    Grandner MA, Alfonso-Miller P, Fernandez-Mendoza J, et al: Sleep: important considerations for the prevention of cardiovascular disease. Curr Opin Cardiol 31:551-65, 2016
    2.    Naska A, Oikonomou E, Trichopoulou A, et al: Siesta in healthy adults and coronary mortality in the general population. Arch Intern Med 167:296-301, 2007
    3.    Häusler N, Haba-Rubio J, Heinzer R, et al: Association of napping with incident cardiovascular events in a prospective cohort study. Heart 105:1793-1798, 2019
    4.    Naska A, Oikonomou E, Trichopoulou A, et al: Siesta in Healthy Adults and Coronary Mortality in the General Population. Archives of Internal Medicine 167:296-301, 2007
    5.    McAlpine CS, Kiss MG, Zuraikat FM, et al: Sleep exerts lasting effects on hematopoietic stem cell function and diversity. J Exp Med 219, 2022