Featured Research

from universities, journals, and other organizations

Coffee consumption unrelated to alertness: Stimulating effects may be illusion, study finds

Date:
June 3, 2010
Source:
University of Bristol
Summary:
The stimulatory effects of caffeine may be nothing more than an illusion, according to new research that shows there is no real benefit to be gained from the habitual morning cup of coffee.

New research finds that the stimulatory effects of caffeine may be nothing more than an illusion.
Credit: iStockphoto

The stimulatory effects of caffeine may be nothing more than an illusion, according to new research that shows there is no real benefit to be gained from the habitual morning cup of coffee.

Tests on 379 individuals who abstained from caffeine for 16 hours before being given either caffeine or a placebo and then tested for a range of responses showed little variance in levels of alertness.

The study, published online in the journal of Neuropsychopharmacology, reports that frequent coffee drinkers develop a tolerance to both the anxiety-producing effects and the stimulatory effects of caffeine. While frequent consumers may feel alerted by coffee, evidence suggests that this is actually merely the reversal of the fatiguing effects of acute caffeine withdrawal. And given the increased propensity to anxiety and raised blood pressure induced by caffeine consumption, there is no net benefit to be gained.

Peter Rogers, from the University of Bristol's Department of Experimental Psychology and one of the lead authors of the study, said: "Our study shows that we don't gain an advantage from consuming caffeine -- although we feel alerted by it, this is caffeine just bringing us back to normal. On the other hand, while caffeine can increase anxiety, tolerance means that for most caffeine consumers this effect is negligible."

Approximately half of the participants were non/low caffeine consumers and the other half were medium/high caffeine consumers. All were asked to rate their personal levels of anxiety, alertness and headache before and after being given either the caffeine or the placebo. They were also asked to carry out a series of computer tasks to test for their levels of memory, attentiveness and vigilance.

The medium/high caffeine consumers who received the placebo reported a decrease in alertness and an increase in headache, neither of which were reported by those who received caffeine. However, their post-caffeine levels of alertness were no higher than the non/low consumers who received a placebo, suggesting caffeine only brings coffee drinkers back up to 'normal'.

The authors also found that the genetic predisposition to anxiety did not deter coffee drinking. In fact, people with the gene variant associated with anxiety tended to consume slightly larger amounts of coffee than those without the variant, suggesting that a mild increase in anxiety may be a part of the pleasant buzz caused by caffeine.

This research was funded by a grant from the Biotechnology and Biological Sciences Research Council (BBSRC), UK.


Story Source:

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


Journal Reference:

  1. Peter J Rogers, Christa Hohoff, Susan V Heatherley, Emma L Mullings, Peter J Maxfield, Richard P Evershed, Jόrgen Deckert and David J Nutt. Association of the Anxiogenic and Alerting Effects of Caffeine with ADORA2A and ADORA1 Polymorphisms and Habitual Level of Caffeine Consumption. Neuropsychopharmacology, 2010; DOI: 10.1038/npp.2010.71

Cite This Page:

University of Bristol. "Coffee consumption unrelated to alertness: Stimulating effects may be illusion, study finds." ScienceDaily. ScienceDaily, 3 June 2010. <www.sciencedaily.com/releases/2010/06/100602211940.htm>.
University of Bristol. (2010, June 3). Coffee consumption unrelated to alertness: Stimulating effects may be illusion, study finds. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2010/06/100602211940.htm
University of Bristol. "Coffee consumption unrelated to alertness: Stimulating effects may be illusion, study finds." ScienceDaily. www.sciencedaily.com/releases/2010/06/100602211940.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