True or False
Caffeine is a central nervous system and metabolic stimulant with a number of positive benefits to the human body.
True – It is used both recreationally and medically to reduce physical fatigue and restore mental alertness when unusual weakness or drowsiness occurs. Caffeine stimulates the central nervous system first at the higher levels, resulting in increased alertness and wakefulness, faster and clearer flow of thought, increased focus, and better general body coordination, and later at the spinal cord level at higher doses. Once inside the body, it has a complex chemistry, and acts through several mechanisms.
Caffeine is completely absorbed by the stomach and small intestine within 45 minutes of ingestion. The effects of caffeine last up to three or four hours.
True - After ingestion it is distributed throughout all tissues of the body and is eliminated or removed by the liver. The half-life of caffeine—the time required for the body to eliminate one-half of the total amount of caffeine consumed at a given time—varies widely among individuals according to such factors as age, liver function, pregnancy, some concurrent medications, and the level of enzymes in the liver needed for caffeine metabolism. In healthy adults, caffeine's half-life is approximately 3–4 hours. In women taking oral contraceptives this is increased to 5–10 hours, and in pregnant women the half-life is roughly 9–11 hours. Caffeine can accumulate in individuals with severe liver disease when its half-life can increase to 96 hours. In infants and young children, the half-life may be longer than in adults; half-life in a newborn baby may be as long as 30 hours. Other factors such as smoking can shorten caffeine's half-life.
Caffeine is hazardous to many animals.
True - While relatively safe for humans, caffeine is considerably more toxic to some other animals such as dogs, horses and parrots due to a much poorer ability to metabolize this compound. Caffeine has a much more significant effect on spiders, for example, than most other drugs do.
Caffeine increases our capacity for mental and physical labor.
True – Caffeine is an ergogenic: increasing the capacity for mental or physical labor. A study conducted in 1979 showed a 7% increase in distance cycled over a period of two hours in subjects who consumed caffeine compared to control tests. Other studies attained much more dramatic results; one particular study of trained runners showed a 44% increase in "race-pace" endurance, as well as a 51% increase in cycling endurance, after a dosage of 9 milligrams of caffeine per kilogram of body weight. The extensive boost shown in the runners is not an isolated case; additional studies have reported similar effects. Another study found 5.5 milligrams of caffeine per kilogram of body mass resulted in subjects cycling 29% longer during high intensity circuits.
Caffeine consumption is tied to serotonin levels in the brain. In the central nervous system, serotonin plays an important role as a neurotransmitter in the modulation of anger, aggression, body temperature, mood, sleep, sexuality, appetite, and metabolism.
True - A reduction in serotonin levels when caffeine use is stopped can cause anxiety, irritability, inability to concentrate and diminished motivation to initiate or to complete daily tasks; in extreme cases it may cause mild depression. Together, these effects have come to be known as a "crash".
Withdrawal symptoms—possibly including headache, irritability, an inability to concentrate, and stomach aches—may appear within 12 to 24 hours after discontinuation of caffeine intake.
True - Withdrawal may peak at roughly 48 hours, and usually last from one to five days, representing the time required for the number of adenosine receptors in the brain to revert to "normal" levels, uninfluenced by caffeine consumption.
Caffeine dependency can result in a number of unpleasant physical and mental conditions.
True - In large amounts, and especially over extended periods of time, caffeine can lead to a condition known as caffeinism. Caffeinism usually combines caffeine dependency with a wide range of unpleasant physical and mental conditions including nervousness, irritability, anxiety, tremulousness, muscle twitching (hyperreflexia), insomnia, headaches, respiratory alkalosis and heart palpitations. Furthermore, because caffeine increases the production of stomach acid, high usage over time can lead to peptic ulcers, erosive esophagitis, and gastroesophageal reflux disease.
There are four caffeine-induced psychiatric disorders recognized by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition: caffeine intoxication, caffeine-induced anxiety disorder, caffeine-induced sleep disorder, and caffeine-related disorder not otherwise specified (NOS).
Excessive consumption and long term use of caffeine cause sleep disorders.
True - Two infrequently diagnosed caffeine-induced disorders that are recognized by the American Psychiatric Association (APA) are caffeine-induced sleep disorder and caffeine-induced anxiety disorder, which can result from long-term excessive caffeine intake. In the case of caffeine-induced sleep disorder, an individual regularly ingests high doses of caffeine sufficient to induce a significant disturbance in his or her sleep, sufficiently severe to warrant clinical attention. A study in the British Journal of Addiction concluded that caffeinism, although infrequently diagnosed, may afflict as many as one person in ten of the population.
Caffeine may prevent Parkinson’s Disease.
True - Several large studies have shown that caffeine intake is associated with a reduced risk of developing Parkinson's disease (PD) in men, but studies in women have been inconclusive. The mechanism by which caffeine affects PD remains a mystery. In animal models, researchers have shown that caffeine can prevent the loss of dopamine-producing nerve cells seen in Parkinson's Disease, but researchers still do not know how this occurs.
Caffeine may be a ‘nootropic’ or smart drug.
True - An array of studies found that caffeine could have nootropic effects, inducing certain changes in memory and learning. However, it is still not definitely clear whether the effect is negative or positive.
Researchers have found that long-term consumption of low dose caffeine slowed hippocampus-dependent learning and impaired long-term memory. Caffeine consumption for 4 weeks also significantly reduced hippocampal neurogenesis compared to controls during the experiment. The conclusion was that long-term consumption of caffeine could inhibit hippocampus-dependent learning and memory partially through inhibition of hippocampal neurogenesis.
Another study showed that subjects—after receiving 100 milligrams of caffeine—had increased activity in brain regions located in the frontal lobe, where a part of the working memory network is located, and the anterior cingulum, a part of the brain that controls attention. The caffeinated subjects also performed better on the memory tasks. However, a different study showed that caffeine could impair short term memory and increase the likelihood of the 'tip of the tongue' phenomenon. The study allowed the researchers to suggest that caffeine could aid short-term memory when the information to be recalled is related to the current train of thought, but also to hypothesize that caffeine hinders short-term memory when the train of thought is unrelated. In essence, focused thought coupled with caffeine consumption increases mental performance.
Used in significant amounts over time caffeine dependency results in unpleasant side effects and two 12 oz. Starbucks consumed within several hours could send you over the edge.
True - An acute overdose of caffeine, usually in excess of about 300 milligrams, dependent on body weight and level of caffeine tolerance, can result in a state of central nervous system over-stimulation called caffeine intoxication, colloquially "caffeine jitters". The symptoms of caffeine intoxication are not unlike overdoses of other stimulants. It may include restlessness, nervousness, excitement, insomnia, flushing of the face, increased urination, gastrointestinal disturbance, muscle twitching, a rambling flow of thought and speech, irritability, irregular or rapid heart beat, and psychomotor agitation. In cases of much larger overdoses mania, depression, lapses in judgment, disorientation, loss of social inhibition, delusions, hallucinations, psychosis, rhabdomyolysis, and death may occur.
Caffeine coupled with analgesics such as aspirin contribute to tinnitus or ringing in the ears.
True - I went to an ENT specialist this past week and he recommended cessation of caffeine consumption. In the three weeks I have stopped consuming caffeine the ringing is still present, seems to be unchanged. I do have hearing loss associated with with the tinitis in the high frequency range.
My dose has been generally two, but sometimes three in a morning. We have bottles of Excedrin in every vehicle, suit case, brief case, and I carry them in my shirt pocket like breath mints. Never leave home with out them. For comparison here are caffeine amounts in chocolate, meds, tea, sodas and coffee:
Excedrin tablet 1 tablet 65 mg,
Chocolate, Dark (Hershey's Special Dark) 1 bar (43 g; 1.5 oz) 31 mg.
Soft drink, Coca-Cola Classic 355 mL (12 U.S. fl oz) 34 mg.
Tea, leaf or bag 177 mL (6 U.S. fl oz) 50 mg.
Coffee, drip 207 mL (7 U.S. fl oz) 115–175 mg.
Soft drink, Jolt Cola 694 mL (23.5 U.S. fl oz) 150 mg.
Coffee, Starbucks (Tall 12 U.S. fl oz) 240 mg.
Wired X344 473 mL (16 U.S. fl oz) 344 mg.
Because of the ‘rebound’ headaches I have been suffering from over the years I have gone ‘cold turkey’ with respect to all caffeine consumption, namely Excedrin and Cokes, and generally all analgesics. Chocolate still remains in my diet due to its salutary effects and simply how much I enjoy it. The headaches occur daily and some days they are worse than others causing me to take a couple Ibuprofens on Sunday. Headaches seem to run in the family and I have been, no doubt, an over medicator of Excedrin. Time will tell if the headaches decrease in the long term and any lowering of blood pressure. Haven’t checked it since I stopped consumption.
