Is it true caffeine makes you smarter? Sort of, it seems, at least indirectly. Researchers have studied this question a lot, and two groups of researchers did meta-studies (studies of studies) to determine just exactly what, if any, the conclusions of the scientific literature are.
If the title sounds like we’re hedging our bets, we are.
Whether caffeine makes you smarter is one question. Whether it makes you feel good is another. Test subjects in studies report they’re in a better mood after taking caffeine, they’re more alert and less fatigued.
One of the meta-studies concludes that caffeine makes a person smarter indirectly by improving mood and concentration. Another meta-study reports that caffeine directly makes people smarter.
A 2010 meta-study, by Astrid Nehleg of the Faculty of Medicine of the University of Strasbourg, concluded: “Thus, caffeine apparently cannot be considered a ‘pure’ cognitive enhancer. Its indirect action on arousal, mood and concentration contributes in large part to its cognitive enhancing properties.” (PDF here)
In other words, by itself caffeine does not make people smarter, but its stimulating and invigorating effects make one more alert, which makes it easier to learn.
Another article, in Popular Science, citing meta-studies, in effect contradicts Dr. Nehleg’s study and says caffeine has a direct, beneficial effect on thought processes and improves them. The article states:
Coffee doesn’t just keep you awake, it may literally make you smarter as well.
The active ingredient in coffee is caffeine, which is a stimulant and the most commonly consumed psychoactive substance in the world.
Caffeine’s primary mechanism in the brain is blocking the effects of an inhibitory neurotransmitter called Adenosine.
By blocking the inhibitory effects of Adenosine, caffeine actually increases neuronal firing in the brain and the release of other neurotransmitters like dopamine and norepinephrine.
Many controlled trials have examined the effects of caffeine on the brain, demonstrating that caffeine can improve mood, reaction time, memory, vigilance and general cognitive function.
Popular Science cited this 2008 study in Nutrition Bulletin, another meta-study of many other studies that found some benefit. That meta-study, by Dr. Carrie H.S. Ruxton, dietitian, said many of the studies she surveyed had small sample sizes but added “the body of evidence was considerable for mood and cognitive function. … The issue of whether caffeine merely reverses withdrawal symptoms or confers a real cognitive benefit remains controversial and is hard to resolve, because most people are now exposed to some dietary caffeine .”
Indeed, about 90 percent of the world takes caffeine these days, whether in coffee, tea, mate, cola, cocoa or medications. Researchers say because nearly everyone is on the world’s most-consumed mood-altering substance, they have trouble finding people who don’t consume it to ascertain whether or not caffeine makes them smarter.
While the following fact may have nothing at all to do with caffeine (or intelligence), it’s interesting to note that humans are scoring much better on IQ tests as time passes.
Dr. Ruxton’s study is interesting because she writes about the most beneficial dose of caffeine to enhance cognition, physical endurance, alertness and vigilance and mood and perception of fatigue. She says the optimal dose ranges from 38 to 400 mg per day, which does not produce dehydration. That is about 1 to 8 cups of tea or 0.3 to 4 cups of coffee per day.
Sixteen of the studies in Table 2 were on healthy, rested subjects and, of these, 14 reported benefits relating to caffeine consumption, including improved alertness, short-term recall and reaction time. There were also consistent findings for positive mood and lower perceived fatigue. The caffeine dose varied depending upon the study, with most using a single bolus of caffeine, ranging from 37.5 to 450 mg.
Dr. Ruxton said there is some controversy as to whether the reported beneficial effects of caffeine have more to do with its inherent properties or with withdrawal alleviation. In other words, people report feeling better, more alert, smarter after they have their fix of caffeine, to which they may be mildly addicted.
The World Wide Web has article after article about the beneficial effects of coffee. One posting on Huffington Post has the title 11 Reasons Why You Should Drink Coffee Every Day.It states: “You usually drink coffee when you are sleep-deprived, right? Well, that much-needed jolt not only keeps you awake, it makes you sharper. CNN reports that coffee allows your brain to work in a much more efficient and smarter way.”
Viter Life blog did an entire posting on the many benefits of caffeine titled Evidence piles up that coffee is good for us. That posting stated caffeine’s benefits include:
And it tastes great. The caffeine in coffee is slightly addictive, but it is not a dangerous, life-destroying drug like opiates or meth.
And caffeine can enhance memory and concentration, keep you alert, alleviate fatigue and sleep deprivation, and, according to CaffeineInformer, it reduces the risk of type 2 diabetes. That CaffeineInformer article has a long list of areas where caffeine benefits people’s health with links to the studies. Other areas where it may help is in boosting the production of semen, preventing erectile dysfunction, reducing suicide risk, reducing or preventing ringing in the ears and reducing risk of kidney stones.
So enjoy your caffeine without guilt, whether in coffee, tea, mints or other products. And if it doesn’t make you smarter, at least it will make you feel better and may even improve your health.
As we said in this Viter Energy blog  about the work-life balance, it's a good idea to simulate your commute to work. You don't have to drive in to work, so instead take a walk around the block just before your workday starts and just after it ends. Send yourself a psychological signal.
And if you can avoid it, do not work after your walk around the block. Don't check work email. Don't answer calls from co-workers unless you really need to talk to them (or they are friends you socialize with).
Clinical psychologist Kelcey Stratton of Michigan Health Blog  has some sound advice on finding the right time to work:
If you’re a morning person, try to schedule important work and meetings during the first half of the day. Others may peak with energy in the afternoon. Depending on the type of job you have, try to maximize on these levels as you can.
The first bit of advice is to get up from the computer, turn off your phone, and go get some exercise, do something recreational, prepare a meal, or something other than work, on the same schedule as you did when you worked at the brick-and-mortar office.
If you used to get off at 5 p.m., quit working at home at 5. You might need to check email or prepare a report later that night, but be sure to get away from all electronic communications and computing devices for a while.
Another big tip is to take your coffee breaks and lunch breaks on the same schedule, or at least be sure to take them at some point. Do not skip your favorite part of the day!