In one study, Rogers et all studied how caffeine research is done and found that in order to correct for confounding variables, such as decreased alertness and cognitive performance from caffeine withdrawal, only long term prior withdrawal from caffeine could provide accurate results. Most studies on the cognitive effects of caffeine had been done on subjects who were in acute caffeine withdrawal, resulting in an apparent increase in alertness after consuming coffee or a caffeine pill.
In fact, It has now been shown that people were merely retuned to a more normal state; that is more coffee blunted the affect of caffeine withdrawal, it did not actually increase alertness above baseline levels.
So really caffeine withdrawal decreases alertness and more caffeine can mask the withdrawal.
Think your java is helping you?
Nope. It's hurting you. And once you're hooked it's hard to stop because along with cognitive impairment comes headaches. Caffeine withdrawal is not pleasant for most, and more caffeine makes you feel pleasant again. Well, not really.. a drug is masking its withdrawal symptoms.. you're not actually improving.
So if caffeine is a bust for alertness; is there anything that does work?
You guessed it, diet and exercise. Not enough sleep is fantastic for causing decreased alertness and cognitive performance and feeling "brain fog", so consistently getting a good nights sleep is the best preventative medicine.
Alertness and cognition rise above baseline levels after exercise. A study on school children suggests that a single 20 minute bout of moderate walking is enough to improve academic performance. The effect of acute treadmill walking on cognitive... [Neuroscience. 2009] - PubMed result
This study demonstrated that exercise increases brain volume in areas implicated with in executive processing. Exercise is brain food: the effects of physical ac... [Dev Neurorehabil. 2008] - PubMed result
Association of the Anxiogenic and Alerting Effects... [Neuropsychopharmacology. 2010] - PubMed result
Absence of reinforcing, mood and psychomotor perfo... [Psychopharmacology (Berl). 2003] - PubMed result
Effects of caffeine and caffeine withdrawal on moo... [Psychopharmacology (Berl). 2005] - PubMed result
Effects of caffeine on performance and mood: withd... [Psychopharmacology (Berl). 2005] - PubMed result