Do Religious People Really Sleep Better?

New research explores four hypotheses about the faith—sleep connection.

Posted Jul 23, 2018

Antonio Guillem/Adobe Stock
Source: Antonio Guillem/Adobe Stock

Years of research have shown that religious involvement is associated with many dimensions of good health. Among patients with cancer, for example, religion is associated with fewer physical symptoms and better functioning. Additional research has found significant correlations between religion and better mental health

Do people who are involved in religion also sleep longer and better? A recent study addressed this question by reviewing seven relevant studies. Here's what they found:

  1. People who were religiously involved were more likely to get at least 7 hours of sleep per night. Interestingly this association was found only for those from what were described as "liberal-to-moderate" religions (e.g., Presbyterian) and not among those from "conservative" religions (e.g., Baptist).

  2. People who regularly attend religious services are more likely to report sound sleep quality. This effect was found for those who attended religious services at least once per week; attending less often was not associated with an advantage.

  3. People who believe that God is in control of their life report better sleep quality. A similar effect was found for those who believe that their body is sacred, though only among those who also ascribed control to God. 

  4. Among US military veterans, who are predisposed to poor sleep for multiple reasons, religious involvement is associated with less sleep disturbance. This correlation held after statistically controlling for many variables such as sex, marital status, and traumatic brain injury.

It's important to note that religion was not always associated with better sleep outcomes. For example, one study found that being religiously active was correlated with less sleep time; another found poorer sleep quality and greater use of sleep medications among those who were struggling with religious doubts. But on the whole, religious involvement and better sleep went hand in hand.

So how did the authors of the review account for these connections? They offered four possibilities:

  • Religion relieves psychological distress. Many psychological conditions like depression and PTSD are tied to bad sleep; accordingly, any variable that improves these conditions may lead to better sleep. The authors of this review note that religion is a consistent predictor of lower psychological distress, perhaps through encouraging social connection and fostering coping resources like a sense of hope. Thus existing studies provide some support for this hypothesis. 
  • Religion protects against substance use. Many chemical substances like alcohol and nicotine have a negative overall effect on sleep, and many religions teach against the use of these substances. The study authors cite existing research showing that religiously involved individuals are less likely to use nicotine, alcohol, and other drugs; this correlation could account at least partially for the effects of religion on sleep.
  • Religion reduces exposure to stressful experiences. Chronic and acute sources of stress disrupt sleep, and the authors point out that religious involvement can reduce one's exposure to certain kind of stress. For example, they note that many religions promote a lifestyle that lowers the risk of chronic diseases and the associated stress.
  • Religion protects against chronic physiological stress. The stressors we encounter take a toll on our bodies and stress systems, and over time can lead to degeneration and disease (including problems with sleep). Scientists refer to the amount of chronic stress we experience as "allostatic load," and existing research has shown that religion is linked with lower levels of this measure. For example, religious involvement is associated with lower blood pressure and lower markers of inflammation. The review authors posit multiple explanations for religion's link with lower allostatic load, such as social support and the stress buffering effect of some religious world views (e.g., "My suffering is part of a bigger plan").

It's important to bear in mind that all of the data the authors reviewed were correlational, meaning they were collected at a single point in time in each study. It's well known that we can't infer causation from correlation, which in this case means we can't conclude that being religious causes a person to sleep better.

It could be the case, for example, that socially connected people tend to be religious, and also tend to sleep better; thus what looks like an effect of religion on sleep could actually be the effect of a third variable (sociability) on both religion and sleep.

Similarly, the effect could run in the opposite direction, meaning that sleeping better makes one more likely to be religious. For example, sleeping better could make a person more willing to get up on a weekend morning to attend religious services, whereas the chronically sleep deprived might prefer to sleep in on Saturday and Sunday mornings.

In any case, the study authors conclude that additional research is needed to better understand and account for the connections between religion and sleep, including potential negative effects. Longitudinal designs in which data are collected on the same sample at different time points could begin to address the correlation-vs.-causation issue.

They also suggest more advanced measures of sleep (e.g., objective measures like polysomnography) and more sophisticated measurements of religious involvement. 

References

Hill, T. D., Deangelis, R., & Ellison, C. G. (2018). Religious involvement as a social determinant of sleep: An initial review and conceptual model. Sleep Health, 4, 325-330.