Molecule of caffeine: structure and description
Vitello Michael-Pasquariello Devis
Caffeine is a bitter, white crystalline xanthine alkaloyd
Xanthine (3,7-dihydro-purine-2,6-dione), is a purine base found in most human body tissues and fluids and in other organisms.
A number of stimulants are derived from xanthine, including caffeine and theobromine.
Xanthine is a product on the pathway of purine degradation.
It is created from guanine by guanine deaminase.
It is created from hypoxanthine by xanthine oxidoreductase.
It is also created from xanthosine by purine nucleoside phosphorylase(PNP).
Xanthine is subsequently converted to uric acid by the action of the xanthine oxidase enzyme.
(http://en.wikipedia.org/wiki/Caffeine)
Caffeine acts as a stimulant drug.
Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants. It is most commonly consumed by humans in infusions extracted from the seed of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut. Other sources include yerba maté, guarana berries, guayusa, and the yaupon holly.
Caffeine work increased cAMP with a double pathways:
blocking inibitor of enzyme adenylate cyclase
inhibiting phosphodiesterase
The first transforms ATP into cAMP and the second one transforms cAMP into AMP.
It is, also, believed to work blocking the neurotransmitter adenosine's receptors, increasing excitability in the brain. Caffeine influences other neurotrasmitters too, including norepinephrine, dopamine, and acetylcholine.
(http://en.wikipedia.org/wiki/Caffeine)
Effects of Caffeine on Mood
Caffeine increases alertness, and many people find that caffeine improves their mood through improving their sense of being switched on, and having a sense of task accomplishment. However, like other stimulants, it also increases anxiety.
The effects of caffeine on mood are related to how the person expects the caffeine to make them feel, and to the context of the caffeine consumption, also known as set and setting.
So caffeine can provide a lift to your mood, but this is most noticable when your energy is already low. For many people, this is when you haven't had caffeine for a while, so some experts believe that the positive effects are actually simply a warding off of caffeine withdrawal. This is only partially true -- research shows that the positive effects of caffeine on mood occur in people who are not withdrawing as well as those who are. But for those who experience an increase in anxiety, the effects of caffeine on mood are unpleasant.
Effects on Mental Performance
Caffeine has been shown to improve performance on a range of different tasks, including vigilance, response times, information processing, and some -- but not all -- proofreading tasks.
But don't assume that it is worthwhile using caffeine as a shortcut to improving your performance. When comparisons are made between people whose daily intake of caffeine is low (up to 100 mg caffeine per day) and those who regularly consume a lot of caffeine (more than 300mg caffeine per day), we find that the improvements are quite small, and don't get better with more caffeine. While people who use a lot of caffeine every day do show improved performance with more caffeine, it may be that they are simply counteracting the effects of caffeine addiction -- so by taking more caffeine, they are getting closer to what their performance would be if they weren't addicted to caffeine in the first place.
Not sure whether your caffeine intake is high or low? Read about the amount of caffeine in food and drinks.
And while there have been several studies showing that caffeine improves vigilance and reaction times, others exploring the subtleties of how this works have found that at least some of the time, this is an expectancy effect. Expectansy effects are a significant aspect of the effects that drugs have on people's perceptions and behaviors. People's expectancies of how caffeine will affect their performance -- in particular, if they think it will impair their performance -- seems to underlie some of the improvements in performance. In other words, if people think consuming caffeine will make their performance worse, they try harder and compensate for the expected effects of caffeine.
Is Caffeine a Good Way of Improving Mental Performance?
Overall, it probably isn't worth trying to enhance your performance by using more caffeine. The short-term benefit you may get from caffeine will be offset by increased anxiety while you are under the influence of caffeine, and when the effects wear off, withdrawal symptoms may worsen the very mental processes you are hoping to improve.
A better strategy for low users of caffeine, who drink the equivalent of one or two cups of coffee a day, would be choosing when to consume them, and timing your caffeine intake so that you are getting the stimulant effects, and not the withdrawal effects, before a task that requires your full attention. And remember, your performance could also be negatively impacted by caffeine.
If you use a lot of caffeine -- drinking the equivalent of more than three cups of tea or coffee per day -- it may be negatively affecting your health, so lowering your intake is worth considering.
Caffeine and headaches
When it comes to headaches, caffeine can be either a positive or negative force. For some chronic caffeine users, stopping the use of it can lead to withdrawal syndrome, in which headache and fatigue are prominent. However, some studies have shown that for people about to enter surgery, stopping the use of caffeine for an extended period, and then restoring its use on the day of surgery led to fewer headaches after surgery. On the flip side, habitual caffeine use can lead to the development of headaches like migraines and chronic daily headache if used enough, and for those cases, reduced caffeine intake is recommended. Judging by this, caffeine usage, as well as a reduction in usage, can both be effective in their own way.
(http://sgptr.com/caffeine-intake)
Caffeine and non-pharmacological pain treatsment
Acupuncture is a traditional Chinese medicine that uses needles to manipulate tissue with the intention of relieving pain, and the process leads to increased levels of a number of chemicals including adenosine.
Since caffeine blocks adenosine receptors, which was explained earlier, caffeine use could also inhibit the pain-relieving effects of acupuncture. No studies have yet examined this possible connection, but some have shown caffeine to inhibit the effectiveness of transcutaneous electrical nerve stimulation (TENS), an analgesic treatment that uses electrodes to deliver stimulation designed to relive pain. This could mean stopping caffeine use could create better pain relief from acupuncture and other treatments, but the matter needs to be investigated in greater detail.
