I agree the survey group is too small. A few years ago I did a blind tating to see how many people could taste the differance between regular coffee and decaf. The test group was only 20 people, but 75% could taste the difference, caffein effect not withstanding. Why could these people not? As a side not even decaf contains caffein, so how accurate was this study really?

Um no...... experiments are not survey research. With proper controls, these researchers had more than enough participants in each cell to establish their finding as statistically significant. If you want to debate external validity, that's not related to sample size. You might want to brush up on your research methods courses before making false statements. And, I would guess the blind review panel for the journal (all researchers themselves) would have rejected the study if the sample size was too low. Research methods 101 -- You FAIL.

Perhaps there were proper controls, but without seeing the numbers you can't rule there were stat sig results. What was the study design? It appears to be single blind, which can cause bias, and that it was not randomized. It also appears that there was only one study center, another problem. Certain genetic variations exist between Europeans, North Americans, Asians, and people of African descent. The CYP450 system (study anatomy and pharmacogenomics) can be quite different based on your race, and therefore the effects that a specific drug (yes caffeine is a drug) has on a person based on race alone can vary enormously. Even multimillion $ studies performed in one region come under fire for being in one location, regardless of diverse population. Many drugs have to be tested in tens of thousands of people worldwide to account for these variations. What about the results of each study arm; are the investigators telling us there was NO difference among the four groups? What was the p-value of each (a study can't claim statistical significance without a p-value of less-than or equal-to .05)? What was the CI?
Lastly, concomitant medications, medical history, and tolerance for caffeine were not discussed. The fact that 11 men and 11 women were assigned to each group doesn't even come close to covering all of the factors involved in dose-dependent response/placebo effect.
What I have said may appear to be an over-analysis, but the facts are that claims about drugs in the human body cannot be made by an article or study like this. If they published the actual study so I could see the details, then I might not have to be so critical of its validity. Published in Appetite magazine? LMAO sounds like a lack of funding for a proper study to me.
"Researcher, too": you might want to take the next few courses past 101 before you judge. You sound like a first-semester burnout freshman.

There are many factors that influence how people metabolize and react to caffeine. For instance, tobacco users metabolize it twice as quickly. Pharmacology's points make a good case for all the scenarios you need to cover before you draw an absolute conclusion. However, the study was still interesting and I think does at least continue to show that the placebo effect is alive and well. I'd like them to re-run this study in the AM hours only and pick coffee drinkers who drink coffee first thing in the morning. :)

I would question the selection of the groups because a subgoup of the subjects could be regular coffee-drinkers (see caffeine addiction) and another part of the group is not. They could react differently. Also they need to control other conditions that could influence the results such as smoking habits, stimulant medications (ADHD treatment), illicit drug use, herbal supplements just to name some of them. This study is not too convincing and I also have doubts about the sample size calculations.

Excellent idea! It made me realize a few more points, one being "how much sleep did they get the night before? Was it OK to drink alcohol until 4am?" They were students afer all :)

Second, and perhaps most important, why didn't the students take the psycomotor tests BEFORE AND after the coffee intake, rather than just after? You need a baseline reading to compare improvement, or lack of, in brain power before and after coffee for each group.

But yes, interesting article and I would like a real study on the subject.

Also, were they on any other kind of medication. Caffeine interacts differently with different medications.

Were any of these people tested for ADD? Caffeine is a chemical that affects persons with ADD. Caffeine slows down a person with ADD and helps them focus. A pot of caffeine actually helps me sleep. It is the only medicine we have ever used on my oldest granddaughter. We always tank her up for CRCT tests. When we took her off tea for lunch in the 2nd grade, the teacher asked us to put her back on the caffeine. She saw how much better Ariana performed. P.S. Many medications have a totally opposite affect on someone with ADD. Because of a heart condition I can not drink caffeine anymore and I have lots of trouble sleeping. Caffeine also causes food cravings which I don't have anymore.

OK, doesn't matter the caffeine concentration, the effect is the same. So why bother drinking decaff if you think it is the high octane? You will still stay up at night. Seems the author isn't a slave to logic.

Another point that I think Thomas was trying to make was that decaffinated coffee still has caffeine. Also caffeine is not the only stimulant that is in coffee and decaffination typically does not remove as large of a percentage of these other stimulants as it does caffeine. What they should really do is give them caffeine tablets and true caffeine-free placebos to have a true "caffeine test".

Caffeine headache, anyone! If I had been in the study and been given decaf, I would have developed a terrific headache and known I had been given decaf. Al makes an excellent point about running the study on people who need coffee first thing in the morning. I usually drink two cups of coffee, within the first two hours of waking and cannot taste the difference between decaf and regular coffee. I started a new job and suffered from these terrific headaches, fatigue, and sensitivity to light for a week before a co-worker, I confided in, pointed out that the coffee pot I was going to was decaf and that was maybe why I was having such headaches. She had suffered from the same headaches when she started the job. I suggested a sign or something to make it clear which of the coffee pots contained decaf.

Absolutely agree with Shea. Several times I've been served what was supposed to be caffeinated coffee, only to develop a very specific, raging, caffeine-deprivation headache. That isn't to say that I don't feel more "awake" psychologically regardless of the caffeine level, but my brain sure knows the difference between the real stuff and the fake stuff.

@Teresa:

My grandmother discovered very early that when she let me drink a cup of coffee in the morning I was somewhat less likely to bounce off the walls all day . . . :D

Basically, I like to think and I tend to be energetic which, along with having the full array of what I call the "South American Coffee Achiever" genes, maps to coffee being a stellar beverage for me . . .

At present, I enjoy at least two pots of Massimo Zanetti Master Chef ground coffee made in the ratio of 1/2 cup of ground to 12 ounces of water at the ideal brewing temperature of 200 degrees Fahrenheit using the single drip method . . .

Once I get into the third pot I am ready to go and then continue enjoying cups of coffee throughout the day, but in the evening I switch to Mexican Coca-Cola, Dublin Dr. Pepper, Pepsi Throwback, and Mountain Dew Throwback, all of which have plenty of caffeine and are made with pure cane sugar . . .

Later in the night, I either have a few glasses of soda pop or a pot of coffee before sleeping . . .

@Pharmacology:

Depending on what time the testing was done, it is virtually trivial to determine whether it was bogus, and this only requires knowing two things:

(a) Was it early in the morning?

(b) Was the caffeinated coffee strong?

If it was early in the morning and the caffeinated coffee was as strong as the coffee I drink, then probably 95 percent of the test subjects would be dead . . .

In other words, I think that your observations are spot on, as the British say, and my best guess is that both types of coffee were not very strong . . .

Having a placebo effect for a while is not troublesome, but the fact of the matter is that caffeine is a drug, and it is a strong drug that produces real and tangible metabolic and physiological effects . . .

And I am being very factual about the consequences of drinking strong caffeinated coffee early in the morning for people who do not have the full array of "South American Coffee Achiever" genes, since it can be a deadly experience for such folks . . .

A 2006 study by Dr. Ahmed El-Sohemy at the University of Toronto discovered a link between a gene affecting caffeine metabolism and the effects of coffee on health. Some people metabolize caffeine more slowly than the general population due to variations in a specific cytochrome P450 gene, and there is evidence people with this gene may be at a higher risk of myocardial infarction when consuming large amounts of coffee. For rapid metabolizers, however, coffee seemed to have a preventative effect. Slow and fast metabolizers are comparably common in the general population, and this has been blamed for the wide variation in studies of the health effects of caffeine.

[SOURCE: http://en.wikipedia.org/wiki/Caffeine ]

Without all the data, it is difficult to determine whether the study indicates much of anything, because for example all the caffeine folks might have had a cup of caffeinated coffee or a soda pop with caffeine on the way to the test . . .

How strong was the coffee?

Were these folks who drank only two or three cups of coffee a day?

One of the results mentioned in the article is a bit odd, which specifically is the bit about all the test subjects becoming depressed after a while, which is pretty weird . . .

In addition, while students in all four groups reported feeling more depressed over the course of the testing, those who drank or thought they drank caffeine didn't feel as glum as the others.

The article does not specify how long the mood and brainpower testing lasted, but it does state how long the students had to drink their cups of coffee and to "chill" . . . .

The students drank their coffee in five minutes and then chilled for 55 before taking tests to evaluate mood and brainpower.

If the testing for mood and brainpower lasted an hour, then the entire thing lasted for two hours, and why would anyone become depressed in two hours unless they already were depressed . . .

One might suppose that the mood and brainpower tests themselves were depressing or that the particular type of "chilling" was depressing, but this aspect certainly appears to be odd . . .

The fact of the matter is that if someone who does not drink caffeinated beverages drinks one cup of coffee the way I brew it, they are quite likely to have rapid pulse and heart palpitations within just a few minutes, unless the have the full array of "South American Coffee Achiever" genes, but if that were the case, then they would dedicated coffee drinkers, for sure . . .

For sure! :-o

P. S. There are lot of excellent benefits to drinking caffeinated coffee for some folks, where one of the benefits is that it helps with asthma, since the chemical structure of caffeine is similar to theophylline . . .

BACKGROUND: Caffeine has a variety of pharmacological effects; it is a weak bronchodilator and it also reduces respiratory muscle fatigue. It is chemically related to the drug theophylline which is used to treat asthma. It has been suggested that caffeine may reduce asthma symptoms and interest has been expressed in its potential role as an asthma treatment. A number of studies have explored the effects of caffeine in asthma, this is the first review to systematically examine and summarise the evidence.

AUTHORS' CONCLUSIONS: Caffeine appears to improve airways function modestly, for up to four hours, in people with asthma . People may need to avoid caffeine for at least four hours prior to lung function testing, as caffeine ingestion could cause misinterpretation of the results. Drinking caffeinated coffee before taking exhaled nitric oxide measurements does not appear to affect the results of the test, but more studies are needed to confirm this.

[SOURCE: http://www.ncbi.nlm.nih.gov/pubmed/20091514 ]

This is another interesting bit of information about drinking caffeinated coffee, especially for the ladies . . .

Coffee, that morning elixir, may give us an early jump-start to the day, but numerous studies have shown that it also may be protective against type 2 diabetes. Yet no one has really understood why.

Now, researchers at UCLA have discovered a possible molecular mechanism behind coffee's protective effect. A protein called sex hormone-binding globulin (SHBG) regulates the biological activity of the body's sex hormones, testosterone and estrogen, which have long been thought to play a role in the development of type 2 diabetes. And coffee consumption, it turns out, increases plasma levels of SHBG.

Reporting with colleagues in the current edition of the journal Diabetes, first author Atsushi Goto, a UCLA doctoral student in epidemiology, and Dr. Simin Liu, a professor of epidemiology and medicine with joint appointments at the UCLA School of Public Health and the David Geffen School of Medicine at UCLA, show that women who drink at least four cups of coffee a day are less than half as likely to develop diabetes as non-coffee drinkers.

And it is especially to observe that the protective benefit with respect to developing diabetes only occurs with caffeinated coffee . . .

And there's bad news for decaf lovers. "Consumption of decaffeinated coffee was not significantly associated with SHBG levels, nor diabetes risk," Goto said. "So you probably have to go for the octane!"

[SOURCE: http://www.sciencedaily.com/releases/2011/01/110113102200.htm ]

Whether drinking coffee works for someone is highly dependent on a lot of factors, including genetics, but if you have the right set of genes, coffee can be an excellent drug once you determine the correct amount that works best, for sure . . .

For sure! :)

@Baldenario

Outstanding research! It's nice to have some back up, and I think you were irritated by words like "chill" in the article as much as I was.

Great point about caffeine beaking a weak bronchodialator. I believe it is a methylxanthine, like theophylline, and although the mechanism of action is not fully understood, theophylline is also used in patients with Chronic Obstructive Pulmonary Disease to help them empy air out of their lungs (as in asthma). I think this is why some doctors recommend a strong cup for atheletes before they take his/her morning jog, so the muscles can recive more oxygen through the relaxed lung parenchyma.

Either way there's no need to repeat what you have found, you have been 100x more thorough than the investigators of this article's "study." Thank you for the real science!

I believe it said they did do that, and that all four possiblities were included: thinking you were getting caffeine and not actually getting it; thinking you weren't getting it and not actually getting it; thinking you were getting it and actually getting it, and thinking you weren't getting it and actually getting it.. get it?

Personally, I always get a headache several hours into the day if I don't get a little caffeine in the morning, and other people have told me they feel the same

I think it may have been interesting to have a third group in the mix that was not told which coffee they were given, only that it could be caf or decaf. The study as designed seems to only prove that the placebo effect is stronger than caffeine over a short duration of about an hour. If I miss my morning coffee, I don't usually start feeling odd until the afternoon.

Did any of you not read the study? You all are like most people...think you know more than you really do...I absolutely believe in the placebo effect....Maybe someone close to one of you should try it on you. I bet you guy's would be so wrong!

Another FAIL. The point was to see if being told they were getting caffeine was enough. READ.

There are two types of decaffeinating processes and only one uses the 'chemicals' you mention. The Swiss Water process is the other one. Caffeine is VERY water soluable so it doesn't take much to leach it out.the caffeine

Lately they mostly use supercritical carbon dioxide to remove caffeine which goes on to commit global warming but does not "contaminate" the coffee. They used to use chlorinated solvents or ethyl acetate or even benzene in the old days.

Unless your chosen religion forbids all caffeine intake, "decaf" is considered to contain a negligible amount of the substance. http://coffeefaq.com/site/node/50. This is actually one of the better quality studies shared on MSN.

Decaf is equivalent to NA beer. There is enough in it to "not" have an effect.

Unless they say they measured the amount of caffiene in the decaf, then I dont see how this study has any merit in anyway.

They were 22 each (11 men and 11 women). Four groups of 22 = 88 total. Not that I disagree with your overall assessment, but I wanted to point that out.

It's just like dumb girls getting virgin drinks they THINK are alcoholic, then immediately losing inhibitions and becoming morons. Morons who won't hesitate to have sex with you.

I tend to agree, but I wouldn't want to say I was certain.. these things are always more complicated than we realize.

That's weird. What is in decaf coffee that isn't in caffeinated and would cause an allergic reaction? Some artificial ingredient? Any coffee experts know?

organic solvents are used to remove the caffeine, if there´s traces of the solvent left she could be having an allergic reaction to it.

I used to work at a coffee shop, and I had a daily customer who would get two 8-shot (espresso) mochas: one in the morning, and one after lunch. 16 shots a day, so he was very much like you. He was also one of the most laid back, reserved customers I ever had... I found that very interesting.

I have had similar experiences. While I've only been drinking it for about 5 years, it never keeps me awake, and a lack of it doesn't hinder my daily performance. I wouldn't go so far as to say it has zero effect on me, but I mostly just drink it for the flavor (and to give myself something to do).