Featured Research

from universities, journals, and other organizations

Coffee And Nighttime Jobs Don't Mix, Study Finds

Date:
November 4, 2009
Source:
University of Montreal
Summary:
Night-shift workers should avoid drinking coffee if they wish to improve their sleep, according to recent research. A new study has found the main byproduct of coffee, caffeine, interferes with sleep and this side-effect worsens as people age.

Night-shift workers should avoid drinking coffee if they wish to improve their sleep, according to research published in the journal Sleep Medicine.

A new study led by Julie Carrier, a Université de Montréal psychology professor and a researcher at the affiliated Hôpital du Sacré-Cœur Sleep Disorders Centre, has found the main byproduct of coffee, caffeine, interferes with sleep and this side-effect worsens as people age.

"Caffeine is the most widely used stimulant to counteract sleepiness, yet it has detrimental effects on the sleep of night-shift workers who must slumber during the day, just as their biological clock sends a strong wake-up signal," says Carrier. "The older you get, the more affected your sleep will be by coffee."

Twenty-four men and women participated in the study: one group was aged 20 to 30, while a second group was aged 45 to 60. Everyone spent two sleepless nights in lab rooms before being allowed to sleep. "We all know someone who claims to sleep like a baby after drinking an espresso. Although they may not notice it, their sleep will not be as deep and will likely be more perturbed," says Professor Carrier.

Both participant groups had to take a pill three hours before sleeping; either 200 milligrams of caffeine or a lactose-based placebo. All subjects who consumed caffeine pills had their sleep affected, especially older participants who slept 50 percent less than usual. In both age groups, caffeine decreased sleep efficiency, sleep duration, slow-wave sleep (SWS) and REM sleep.

The combined influence of age and caffeine made the sleep of middle-aged subjects particularly vulnerable to the circadian waking signal. Professor Carrier suggests that lower brain synchronization -- caused by age and caffeine -- produces greater difficulty in overriding circadian waking signals during daytime and that leads to fragmented sleep.

These results have implications for the high proportion of the population using caffeine to cope with night work and jetlag, particularly the middle-aged. Carrier recommends that everyone over 40 reduce their coffee consumption, especially if they work at night. Her study builds on recent findings that reducing coffee consumption is the best way to improve sleep for the middle-aged.

This study was supported by the Canadian Institutes of Health Research, the Fonds de Recherche en Santé du Québec and the Natural Sciences and Engineering Research Council of Canada.


Story Source:

The above story is based on materials provided by University of Montreal. Note: Materials may be edited for content and length.


Journal Reference:

  1. Julie Carrier, Jean Paquet, Marta Fernandez-Bolanos, Laurence Girouard, Joanie Roy, Brahim Selmaoui and Daniel Filipini. Effects of caffeine on daytime recovery sleep: A double challenge to the sleep–wake cycle in aging. Sleep Medicine, 2009; 10 (9): 1016 DOI: 10.1016/j.sleep.2009.01.001

Cite This Page:

University of Montreal. "Coffee And Nighttime Jobs Don't Mix, Study Finds." ScienceDaily. ScienceDaily, 4 November 2009. <www.sciencedaily.com/releases/2009/11/091103112239.htm>.
University of Montreal. (2009, November 4). Coffee And Nighttime Jobs Don't Mix, Study Finds. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2009/11/091103112239.htm
University of Montreal. "Coffee And Nighttime Jobs Don't Mix, Study Finds." ScienceDaily. www.sciencedaily.com/releases/2009/11/091103112239.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) — The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) — Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) — Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) — Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins