As mentioned earlier, caffeine passes on to all parts of the body where there is presence of water. This means that the chemical compound travels to almost all parts of the body and possibly influences majority of the functions carried out by our body. In effect, ingestion of caffeine results in severe (acute, but short-term) consequences on the cardiovascular system, including the heart and the blood vessels, on the respiratory system (breathing), digestive system, on energy expenditure as well as on urination. This aspect of caffeine has also enabled caffeine to contribute to the remedial actions of ailments and diseases. Nevertheless, this feature of caffeine also makes it possible for the chemical substance to demonstrate its poisonous consequences all over the body. In extreme cases, ingestion of caffeine can also prove to be fatal.
The two primary aspects of cardiovascular function include maintaining the blood pressure as it passes through the arteries as well as sustaining a normal heart beat (the rate at which the heart pumps blood). Of these, blood pressure is of greater worry as high blood pressure or hypertension is a sign of stress on the heart and the blood vessel and is caused by some type of stumbling block somewhere in the circulatory system. Hence, any thing that results in high blood pressure or helps to deteriorate the condition may prove to be precarious.
The blood pressure of an individual is basically dependent on two things at any given period of time. While the first aspect is the flow of blood from the heart, the second entails any kind of opposition of the circulatory system to the blood flow. To some extent the amount of blood flowing out of the heart depends on the heart beat or the pace of the heart pumping blood. In situations when the resistance to the flow of blood as well as the volume of blood pumped by the heart and flowing through the circulatory system at every heart beat is unvarying, the blood pressure and the rate of heart beat increase and decrease concurrently.
Consumption of substances containing caffeine generally enhances the heart rate, but the variation is usually little and not very important from the point of statistics. However, during a number of researchers scientists observed that the heart rate dropped following the administration of caffeine. Some other researches on the subject have demonstrated that when an individual is administered caffeine, the heart rate drops slightly in the beginning and then rises.
In some studies, it was found that administration of caffeine enhanced the rate of breathing by intensifying the feeling of the section of the brain that reacts to the concentration of carbon dioxide present in the blood. In fact, caffeine has the aptitude to augment the depth of breathing by making the action of the diaphragm, the main muscle responsible for inhaling and exhaling, stronger. According to the findings of one study, caffeine may be beneficial for persons suffering from lung ailments, especially breathlessness. On the other hand, people who desire to lose surplus weight may be interested in the short-term consequences of using caffeine on the energy expenditure by the body. It has been found that when caffeine is consumed along with any food, it enhances the pace of converting the food into utilizable energy. On the other hand, if caffeine is ingested or administered between meals, it results in the fats to be relocated from the accumulations in the cells to the bloodstream. Hence, the fats are now converted into free fatty acids; it is now possible for most organs of the body to utilize them as energy.
In addition to the above mentioned characteristics of caffeine, this chemical compound also has the ability to boost the intensity of the body's activity. This, in fact, denotes that the energy obtained from foods is spent in exercise instead of storing it up as fat in the cells and, thereby result in unwanted weight gain. Apart from this, caffeine also invigorates the different hubs in the body that control the temperature resulting to increased body temperatures when the chemical compound is administered. In order to maintain this change in body temperature, the body uses energy, which would have been stored as fats otherwise. Hence, even when the body is at rest, considerable amount of food is burnt to release energy.
It may be noted that most non-prescription dietary supplements contain caffeine as a common element. Such non-prescription dietary aids are occasionally also known as appetite suppressants. Nevertheless, so far there is no support or proof to the claim that caffeine works to decrease the hunger for food.
Notwithstanding the noticeable connection between the consequences of caffeine and weight loss and the fact that administration of caffeine to animals on a regular basis has demonstrated remarkable weight loss in them, thus far, it could not be ascertained if using caffeine on a long-term basis actually helps in losing weight in humans. Meanwhile, even if caffeine is found to be useful in losing unwanted weight, one should consider the other side effects of this chemical compound before using caffeine for this purpose. It has been noticed that often the adverse side effects of a drug makes it unwelcome as well as hazardous. Moreover, for a weight loss program to be useful and result in permanent effects, it needs to be accompanied with regular exercises and changes in diet and lifestyle of people desiring weight loss.
Several researches have confirmed that consumption of coffee enhances the release of acids in the stomach. However, it is believed that this action is caused by other elements present in coffee and the effect is not owing to caffeine. While it is true that caffeine invigorates the secretion of acids in the stomach, it is also true that this chemical compound diminishes the peristaltic (the wavelike muscular contractions of the alimentary canal) activities of the stomach. This action of the stomach is critical keeping in view the fact that it helps to empty the stomach by passing on its contents to the small intestine. Interestingly enough, while caffeine inhibits the movement of substances through the small intestine, it paces up the movement of materials through the large intestine.
Apart from these actions of caffeine on the digestive system, it has been established that tea and coffee, both containing substantial amounts of this chemical compound, actually lowers the absorption of particular nourishments, especially the essential mineral iron, by the body. While it is yet to be ascertain which precise chemicals actually slow down the absorption of iron by the body, it is believed that caffeine, the tannins and other elements present in tea are most possibly responsible for this. Ingestion of caffeine has another major disadvantage. It is well known that caffeine augments urination by approximately 30 per cent for around three hours from ingesting the chemical compound, but many people are unaware of is the fact that considerable amounts of valuable minerals, such as calcium, magnesium and sodium, are eliminated from the body along with increased urination caused by caffeine. Although the body's mechanism builds up some kind of tolerance against such excretion of important minerals with urine, in many cases this could lead to a dearth of these essential minerals in the body.
The pharmaceutical companies often incorporate caffeine as an ingredient in the prescription as well as non-prescription drugs for treatment of headache and in analgesics (pain killers). However, the amount of caffeine contained in these medications is very insignificant compared to the amount of the chemical compound present in an usual cup of coffee. It is interesting to note that today people are unaware why exactly caffeine was initially incorporated in analgesic medications, such as acetaminophen and aspirin. Many people are of the view that caffeine was included in these drugs with a view to neutralize the potential depressant upshots of these medications. According to another theory, caffeine could also have been included as an ingredient in these drugs since it is particularly useful as an antidote for headaches due to the withdrawal effects of caffeine.
Another medical use of caffeine is aiding fertility, especially among men. According to several researches, one of the main reasons of sterility is that sperms are often not sufficiently mobile to reach the egg in the uterus and be able to fertilize it. A number of studies conducted on mammals other than humans have shown that when caffeine is added to the semen, it enhances the mobility of the sperm and thereby boosts fertility. In fact, some studies conducted on humans have also demonstrated that caffeine aids in the mobility of the sperm, and, according to one research, the chemical compound also augments fertility. Some studies conducted on women have shown that if caffeine is artificially added to semen before insemination by their sterile or infertile partners, their prospects of becoming pregnant increase a manifold. Nevertheless, the problem in achieving this effect is that it requires very high concentration of caffeine, around 1,500 mg/ liter, which is three times more than the concentration of caffeine present in an usual cup of coffee that contains 436 mg/ liter of caffeine. In fact, the potential adverse effects of using such high concentration of caffeine are yet to be ascertained.
At times accidental deaths owing to overdose of caffeine ingestion have been reported. Most of these deaths have been caused due to inadvertent administration of excessive caffeine either by injection or by tablet. Some times incidents of suicide owing to the use of tablets containing caffeine have also been reported. In fact, the minimum dosage of caffeine that has led to death in an adult is known to be 3,200 mg of the drug that was mistakenly administered by a nurse intravenously thinking that the syringe contained some other drug. Actually, caffeine related deaths have been reported among children too. Such unfortunate children were mostly victims of overdose of caffeine when they took pills containing caffeine for weight control, wake-up or some other purposes.
The severe lethal dosage of caffeine when the drug is taken orally is said to be a minimum of 5,000 mg of the drug, which is equal to 40 strong cups of coffee drunk within a very short span. Hence, the fear of death owing to an excessive bout of drinking coffee is very doubtful. In addition, when caffeine is taken in excessive dosages, it results in vomiting and this, in turn, would prevent a person from drinking more coffee or tea that may actually result in untimely death.
While the precise reason of death owing to caffeine toxicities is yet to be ascertained, it has been often found that usually the poisonous consequences of any drug are associated with the effects of the drug when administered in lesser measures. Patients who were administered caffeine dosage of 1,000 mg experienced an extensive range of side effects. Some of the side effects experienced by such patients are as follows:
If the side effects owing to the administration of excessive dosages of caffeine are allowed to persist for long, they may even result in death. Several physicians have observed that poisoning by caffeine is akin to the condition that may take place when people suffering from diabetes don't take insulin or when the insulin administered to them is unsuccessful in controlling the intensity of fat and glucose in their bloodstream. In fact, these are among the most common causes of death among people suffering from diabetes.