The following is from a friend of mine. He is in the middle of a self-experiment to measure the effect of various forms of Coca-Cola (regular, diet, diet w/o caffeine) on his mood.
TODAY’S EVENT
Today ~20 oz of coca cola (w/ caffeine and w/ sugar) dramatically eliminated (in about a minute) a very real, strong feeling of irritability.
BACKGROUND
I am on day 17/30 of the experiment and I am still blinded to the results of the first 16 days. I do know that none of my previous mood experiences in the past 16 days were like the one today.
I had a significant bought of irritability (6/10) today. This irritability has been brewing last 48 hours but was palpable all morning after I woke up this AM. This irritability was the REAL DEAL that I have been seeking the past few weeks – my family was well aware of my irritability yesterday and this AM. Since this irritability was so palpable, I decided to break my experimental protocol and drink a known real coke. Quite remarkably, within a minute or so of consuming the whole coke (~20 oz – large) my irritability was gone (really gone). [He drank the coke in 2 or 3 minutes. The effect lasted about an hour.] Be clear, this was not some psychological maybe I feel this maybe I don’t, this was real psychiatric, can’t miss it, need some drugs, psychotropic bad/irritable feeling.
The past 16 days of this experiment has made me very familiar with hunger, bad moods, hunger irritability, assessing my feelings around hunger, assessing feelings around soda pop, assessing feelings around a good meal. Therefore, today I was well prepared to focus on the minute to minute dynamics around drinking this coke – the coke abruptly ended hours of feeling irritable (no better word to describe the mood than irritable).
RESULTS
-1) Now that I am half way through the experiment, I think I can break the blind by identifying the three different types of coke. I can taste the clean sweetness of real coke immediately, I can feel caffeine in my body from the diet coke in about 5 minutes.
0) I am currently blinded to the results of the experiment I am doing. However, I do have some anecdotal impressions that presumed diet w/o caffeine causes no mood affect, diet w/ caf does affect mood, coke w/ caffeine and w/ sugar does affect mood. My anecdotal impression is that these effects are mild to modest.
1) Today was the first time I felt psychiatric grade irritability confounded by hunger irritability. Today unblinded Coke abruptly eliminated the bad feelings associated with this irritability.
2) I have been rating my mood with full meals 20-40 minutes after my soda pop drink and my impression is that real satiation does have some positive mood effects.
DISCUSSION
The big target is understanding how 20 oz of sugar and caffeine totally eliminates the strong and persistent feeling of psychiatric grade irritability confounded by hunger irritability. Designing an experiment to go for this issue is challenged by the infrequentness of this psychiatric grade irritability.
Coke eliminating irritability appears to produce happiness by eliminating the presence of bad irritability feelings. In this setting, Coke did not produce any positive feelings, Coke simply eliminated some strong bad feelings. Coke is not producing a good mood, it removed a bad one. (There may have been some “psychological” grade good mood, but this was so tentative and hard to assess that I am happy saying Coke produced no positive affect. The removal of the psychiatric irritable mood was clear and absolute).
In contrast to the absence of irritability caused by coke (and no good mood effects), I think the satiation I have experienced these past 16 days from the big healthy meals following my soda pop does has some positive feelings associated with it. Satiation presumably feels good not just because of elimination of hunger, there seems to be some warm glow from eating a large, well-balanced, fatty, carbo, vegetable, sweet meal.
There appear to be different kinds of irritability. More than six hours without food brings on a form of irritability, but this hunger irritability appears to be different from “mood” irritability. Mood irritability lasts for days while hunger irritability lasts for hours. Hunger irritability produced in the setting of no mood irritability is not that profound. Hunger irritability on top of mood irritability appears to be the REAL DEAL of irritability. It is this REAL DEAL of irritability which today (and typically) creates the setting such that a large caffeine/sugar soft drink eliminates the persistent palpable bad feelings associated with REAL DEAL irritability.
I understand why it would be nice if the subject is blinded. However, I am not sure the subject needs to be blinded. I think one still gets meaningful results even if placebo/nocebo effects are folded into the results.
CONCLUSION
A couple of days of irritability compounded by hunger produces a strong form of irritability which was dramatically relieved by a large glass of caffeine/sugar coke today (unblinded N = 1 in experiment). Strategies for further behavioral characterization of this phenomenon are needed. A physiological hypothesis is needed. A future design for FMRI measurements of this quick irritability response to caffeine/sugar will be fun to design.
In the final analysis, I guess it is worth finishing the current experiment – even though I think I can determine the identity of each drink. Good data from an inadequate experimental design will be helpful in creating a better experimental design.
About the author: John Keltner has a Ph.D. in Physics from UC Berkeley and an M.D. from Harvard. He is a research fellow at the University of Oxford. Given these results, I asked John if he was addicted to caffeine. He told me no, going without caffeine did not make him more irritable.
I’m confused as to why he doesn’t think he is addicted to caffeine. Clearly he is irritable until he has had it.
Does this mean he was just as irritable on a regular basis before he started drinking coke reguarly?
Right. About once/month he is irritable — whether or not he has been drinking coke.
Not easy to confirm this effect: he needs to be in a real bad mood to check this fact.
And even though he might not be addicted this effect might be behavioural. Maybe he just connects such a good feeling with drinking coke / sugar with caffeine?
Interesting start, needs more data
I concur with Pearl that this low-grade “irritability” sounds a lot like the symptoms of withdrawal. I’d find this whole experiment more plausible if the subject consumed a no-caffeine, low-sugar diet for a month and then attempted to gauge his responses to various types of coke (and other caffeinated and/or sugary beverages).
He seems to imply that the change in irritability is from the composition of the cola. That might be true, but it could also be from a learned association between cola and a positive mental state or even a feeling of liberation due to carrying out an unplanned act. No way to really test the latter, but the former could be tested by trying an unfamiliar beverage with similar composition like Mountain Dew or a caffeinated root beer.
I agree, a great deal of light on the mechanism will be shown by learning what else does and doesn’t have this effect.
If John’s irritability were due to withdrawal from caffeine, there should be a strong positive correlation between two things:
1. time since last caffeine
2. irritability
There isn’t. If I understand John correctly, there is almost no correlation. The one-hour relief from irritability that a Coke provides is a small change relative to the whole pattern.
Hello all,
Great to see interest regarding food and mood. Here is a bit of clarification of the background of my current experiment.
My brother and I (and some friends we have met over the years) have noticed that periodically (once a month or so) we both get really grumpy (irritable is best description) for a few days. There may be low grade irritability the other 27 days of the year, but these three days of irritability are unmistakable. His family and mine both know when we get irritable.
Both my brother and myself (and some of our friends) have noticed that being hungry is the worst excacerbant (spel?) of the really irritable 3 day state.
This bad irritability (made a lot worse by hunger) is remarkably fixed by eating a good meal. To a significant degree this irritability can be significantly helped by any caffeine/sugar soda pop drink.
My present experiment attempts to tease apart the affects of caffeine vs sugar upon this hyperirritable state (irritability plus hunger).
To eliminate expectation bias I have blinded myself to coke, diet coke, and diet coke w/o caffeine. I did not use real coca-cola. Instead, I used a cheap co-op version of coke since I felt the caff/sugear and caff/diet and diet w/o caffeine all tasted more similar than the equivalent real coca-cola versions. Based upon a set of 30 random numbers (1, 2, or 3), my wife pours me two pint glasses of the soft drink of the day.
Half way through the experiment, I have concluded that I am not totally blind to which drink is which. I think I can taste sugar and I think I can feel caffeine.
Eventhough I am not completely blind, I believe some amount of being blinded has some benefit compared to not being blinded at all. Furthermore, even if I knew exactly what I was drinking, I think it would be fine to have placebo/nocebo effects as part of the measured effect.
Also, my 17 days of experiment to date indicate that a healthy full meal has a lot more alleviation of hyperirritability than 2 pints of caffeinated/sugar drink.
In the long run, I want to continue to pursue understanding food effects upon mood. Better understanding of these dynamics may shed light on the mechanisms of food and mood. I also believe that food affecting mood has important implications for obesity in depressed populations.
I look forward to your additional insights.
John Keltner
It looks like there`s only one way to fix this…. noseclipping
They can help you out on that at the SLD forum.
I get agitated sometimes, too. After 3 years of finding out what might or might not work, I see that eating something is the only thing that gets rid of the anxiety.