Drinking coffee doesn't make you more alert, caffeine study reveals

[bananas]

http://www.guardian.co.uk/science/2010/jun/02/drinking-coffee-alert-caffeine

Drinking coffee doesn't make you more alert, caffeine study reveals

• Data shows coffee addicts only stave off caffeine withdrawal
• Stick with coffee or keep off it altogether, concludes study

* Jacob Aron
* guardian.co.uk, Wednesday 2 June 2010 14.55 BST

The millions of people who depend on a shot of coffee to kickstart their day are no more alert than those who are not regular coffee drinkers, say researchers.

A cup of coffee, suggests a study, only counteracts the effects of caffeine withdrawal that has built up overnight.

<snip>

How genetic differences may influence response was also examined. Blood samples were taken from 379 volunteers who were asked to avoid caffeine for 16 hours.

<snip>

Caffeine did not increase the alertness of any group above the levels of non-users who were given the placebo. But caffeine fiends who were given a placebo after abstaining from coffee for 16 hours felt less alert and experienced worse headaches than those who received their usual dose. Four people had to drop out of the study owing to the severity of their headaches.

Infrequent users had more headaches after taking the caffeine pills, but did not feel any more alert than normal.

Among people who usually consumed little or no caffeine, a dose boosted their anxiety levels. Those participants who had a variant of a gene called ADORA2A, which has been linked to panic attacks, became particularly anxious after a dose of caffeine.

Medium-to-high level caffeine users, however, did not become any more anxious after caffeine, implying that regular consumption helps build up a resistance to its anxiety-inducing effect.

People in this group who were genetically predisposed to anxiety drank more coffee than the rest, suggesting mild feelings of tension might even contribute to their enjoyment of the caffeine buzz.

The research is significant because previous studies into the effects of caffeine have involved far fewer participants.

"It's an interesting piece of evidence, and a very ambitious study," said Lorenzo Stafford, a psychologist at the University of Portsmouth. "Getting the DNA samples of so many participants is a huge effort."

The study was published today in the journal Neuropsychopharmacology.

[obxhead]

1. It works for me, but I only drink coffee 15 days or so a year

as well, usually if I'm on a long road trip. For me 2 or 3 cups and I resemble a ping pong ball in a room full of paddles.

[hyphenate]

2. Caffeine wreaks havoc with heart patients

Because it can speed up the heartbeat quite a bit. I think if I have a cup of coffee about once a month, I'm not too worried about it. During the summer, though, I'm likely to have a bit more in the form of an iced coffee. I especially like the Dunkin Donut version called a Coffee Coolata. I'm mainly a tea drinker, anyhow.

[relayerbob]

3. Not really ...

http://www.newsmaxhealth.com/health_stories/coffee_helps_heart_patien/2010/05/10/315133.html

[hyphenate]

4. Thanks for the post

But I am not likely to believe anything from Newsmax. They aren't one of the most reliable sources of information. Around DU, they're put with Faux, Drudge, Freeperland, and a few choice right-winged propaganda sites. Even though it's belated, welcome to DU!

[pokerfan]

11. Newsmax is pretty worthless

but how about New Scientist?

http://www.newscientist.com/article/dn14151-guzzling-coffee-may-cut-heart-disease.html

Edit to add Harvard Med...

http://www.health.harvard.edu/press_releases/coffee_health_risk

[Captain Hilts]

9. You have to drink a ton of coffee for that to happen. nt

[hlthe2b]

5. I think there is a lot of confounding in this study...

That people habituate to the effects of caffeine is widely known and might well explain their findings if these are long term consumers. But, more recently, studies have shown that titrating caffeine in smaller doses throughout the day is more effective than bolus intake. In other words sipping a cup throughout the morning is more effective than drinking a cup first thing in the morning. And it is known that when habituation occurs, backing off levels of caffeine for a period of time can overcome this seeming loss of effectiveness.

I also believe that there are some dietary studies showing food-caffeine interaction effects and that (at one extreme) high glycemic index foods plus caffeine accentuates the jitters, while (at the other extreme) high fat may seem to delete the effectiveness of the caffeine, probably from reduced absorption.

[Captain Hilts]

6. I sometimes have a cup before going to bed and falling asleep. nt

[intheflow]

7. I can't drink caffeine after 2pm

because it messes with my already bad insomnia. But often in the morning, on my days off, I'll drink a cup of coffee and go back to sleep for a few hours. Funny how that works.

[Captain Hilts]

8. It really varies from person to person. nt

[4_TN_TITANS]

10. I'll have a hard time selling this to the wife...

I spent a week accidentally making the morning coffee out of some decaf that was in the fridge. I didn't really notice much, but the wife had a miserable week. I got quite a tongue-lashing when she realized why she hadn't been able to 'get going' all week long.

[Thor_MN]

12. Do you still have to make the coffee?

Making coffee with decaf could be the equivalent of washing her wool sweater in hot water...