Caffeine, a stimulant found in beverages such as coffee, tea and cola, is the most widely used mind-affecting drug in the world. The principal caffeine source is coffee, and contains about 100 to 150 milligrams of caffeine per cup. Tea contains about 45 to 100 milligrams, while Cola contains about 45 milligrams per cup. People like to drink these beverages because they yearn to remain alert since it directly affects the neurons in our brain, making us feel more energetic and more awake. According to Hales (2007), most medication that contains caffeine is one third to one-half the strength of a cup of coffee (p.305). Numerous researches have been done to either assure the public that the consumption of coffee has no or minimal side effects, or to convince them that coffee is harmful to their health and therefore must not be consumed. Interestingly, many people still avoid coffee despite several reassuring researches that have been done, citing worry of its health effects.The mechanism of action of caffeine is that it can be absorbed so fast in humans that within 45 minutes of consumption, 99% will have been absorbed in the intestinal tract. Interestingly, there is a complete absorption of caffeine in animals. Research reveals that it is the hydrophobic properties of caffeine that allows it to pass through all biological membranes. As a consequence, there is no blood- brain or fetal animal barrier to caffeine pharmacology. It is notable that the metabolism of caffeine occurs in the liver and diethyl- and monomethyxanthines, dim ethyl and monomethyl uric acids, trimethyl and dimethallantoin, and uracil are the resultant products. Caffeine works by effectively blocking adenosine effects on A2A and A1 receptors.Arguably, when taken in moderation, that is, a few cups a day, coffee is actually a safe drink that can have some health benefits. Caffeine is known to stimulate the central nervous system, lowers fatigue in the body leading to a clearer flow of thoughts; leads to a sustained intellectual effort and a more better association of ideas and appreciation of sensory stimuli in man. Other attendant benefits involved include lowered risk of type 2 diabetes, and reduced likelihood of gallstones, colon cancer and Parkinson's disease. Caffeine is said to relieve drowsiness and helps especially in the performance of repetitive tasks. Leveraged work output has been observed among people that take coffee. To a greater degree, caffeine boosts performance in athletes who do prolonged and exhaustive exercises. In addition, though to a lesser degree, it enhances short-term high intensity performances. Bandelow et al. (2008), reports that caffeine is considered to be an ergogenic, with beneficial effect on both physical and mental performance and minimal side effects. A research involving men between ages 18 and 35 years, participated in cycling three times a week and in addition, testing their cognitive abilities with increased caffeine intake confirmed that caffeine, in a performance bar can, to a significant degree boost performance and promotes complex cognitive ability during and after exercise. The results further point out that these effects may be strongly evident for sports performances that demand a high focus and concentration (p.1841).To further reinforce the advantage that caffeine has during exercises, it was pointed out that caffeine inhibits adenosine receptors, increases sympathetic activity and can direct intracellular actions. In addition, caffeine has been proposed to promote exercise capacity by enhancing the oxidation of fats and hindering the oxidation of carbohydrates through feedback mechanism in the muscle. The resultant effect of this is the reduced dependence on the glycogen that is stored in the muscles.The conclusion from a research carried out by Spyridopoulos et al. (2008) reveals that caffeine has also been found to promote the formation of the endothelium in part through an AMPK-dependent mechanism (p.1967). From this research it is evident that caffeine has a critically beneficial role in endothelial repair. Caffeine affects this by enhancing the migration of endothelial cell, evidenced by the mouse model, in which the use of caffeine led to the reendothelization of a denuded carotid artery. This research demonstrates that when caffeine is in physiologically relevant concentrations, it promotes the migration of human endothelial progenitor as well as mature endothelial cells. This means that conditions that lead to the injury of endothelial cells can be treated using caffeine.
One of the most frequently asked question is if coffee can be overdosed. Concerns have been raised about the adverse consequences of caffeine overdose. Overdose can lead to caffeine toxicity which is defined by specific symptoms that emerge as a direct result of caffeine consumption. According to Hales (2007), it is true that caffeine can be overdosed, the characteristics of which are restlessness, nervousness, excitement, insomnia, digestive complaints, rapid heart race, flushed face, periods of inexhaustibility and physical restlessness (p.305). Several cases of caffeine intoxication have been reported in the media and have always been linked to heavy consumption of energy drinks, which contain high concentrations of caffeine (p.305).Despite the fact that some studies have linked increased risk of heart attack to high caffeine intake, research has found that such risks occur only to individuals whose bodies metabolize caffeine slowly. Addiction and caffeine dependence are also possible consequence of intensive and prolonged use of caffeine. According to Reissig, Strain and Griffiths (2010), the symptoms of dependence are: inability to quit using the substance; continued use despite being affected; uncontrolled use of the substance, withdrawal and tolerance (p.5). Caffeine withdrawal can be severely intense with cases of significant distress and impairment in daily functioning due to withdrawal being reported. Interestingly, dependence on caffeine has also been linked to dependence on other substances. More specifically, the smoking of cigarette has been associated with the increased consumption of caffeine. The conclusion that can be drawn from this study is that caffeine can act as a gateway to other forms of drug dependence. Experts have offered that cautionary measures should be taken not to mix caffeine with alcohol. Caffeinated energy drinks have also been found to have side effects on health of both youth and children. It is also cautioned that caffeine should not be taken before intense exercises since it increases the risk of dehydration (Reissig, Strain and Griffiths, p.304). Apparently, there has been an exponential growth in the consumption of energy drinks in the last two decades due to the absence of a regulatory oversight body, and have acted as gateways to other forms of drug dependence. According to Reissig, Strain and Griffiths (2009), the Food and Drugs Administration (FDA) recommends that over the counter caffeine containing products for medication purposes must indicate that the product has much caffeine than a cup of coffee since too much caffeine may cause nervousness, irritability and sleeplessness (p.2).
In addition the labels should indicate that they are to be used occasionally and not suitable for children under that age of twelve. Directions for use should also be indicated. However, companies, in quest for money have failed to do this, resulting in the increased consumption of caffeine by the oblivious public. In fact, caffeine amounts gained through soft drinks or capsules can be of higher concentration than that in a cup of coffee. The findings from the research conducted by Reissig, Strain and Griffiths (2008) show that the consumption of high caffeine content drinks has increased tremendously in the recent years due to lax in regulatory bodies in the United State (p.2). As a consequence, caffeine overdose and its attendant negative consequences have been frequently reported. Surprisingly, some of the actions of caffeine in the body are inhibitive. Recent studies show that coffee and tea markedly reduce the absorption of iron. It was found that coffee with milk is twice as inhibitive as black coffee. This finding has far reaching consequences on nutrition, taking into consideration the fact that caffeine is popular beverage, and can be highly addictive. It means that people using caffeine regularly must find alternative ways of sourcing iron for them to realize balanced nutrition. Alternatively, total withdrawal of caffeine consumption to ensure iron absorption in the body is equally effective.Studies conducted by Weng, Odouli and Li (2008) with the objective of examining whether the risk of miscarriage is associated with caffeine consumption during pregnancy (p.1). The results showed that an increasing dose of daily caffeine intake during pregnancy was correlated with an increased risk of miscarriage relative to intake with adjusted levels of caffeine. 172 women who represent 16.18% of the total women involved had consumed caffeine in large amounts during pregnancy and then miscarried indicating a strong correlation between caffeine intake and miscarriage. The research further indicated that the extent of association seemed stronger among women without a history of miscarriage more than among women with such a history. Thus in situations where the mother is not aware miscarriages associated with caffeine may occur, and information of such a risk should be disseminated by doctors and public health practitioners.Another documented problem of associated with coffee is peptic ulcers of the stomach and the duodenum. According to Wanyika et al. (2010), caffeine stimulates the brain to pour out large amounts of acid which leads to the burning in the pits of the stomach and causes the peptic ulcers of the stomach and the duodenum (p.354). Research has also found that in pregnant women, caffeine taken crosses over the placenta and joins the fetal circulation. The use of caffeine in large quantities by pregnant women has been associated with low birth weight in babies. In addition, it has been found that excessive use during lactation may result in irritability and wakefulness in babies that are breastfed. Breastfeeding women are therefore advised to consume caffeine containing products in small amounts to avoid these risks. This research also found that caffeine consumption raises the blood sugar level, thus elevating the rate of respiration. Additionally, it is said to cause reduced flow of blood to the brain by constricting the brain blood vessels. It is therefore recommended that people suffering from high blood pressure should avoid the use of caffeine containing beverages because caffeine increases blood pressure. Patients who have coronary heart diseases should also avoid it due to the fact that it disrupts the normal heart rhythm.Sleep problems have also been associated with the consumption of caffeine. It has been found that sleep problems are a cardinal symptom in children and adolescents. Use of caffeine may have effects on youth with depression. An investigation done to examine how caffeine uses relates to sleep and how it affects the youth's natural environment, suggests that both sleep quality and caffeine are altered in pediatric depression. It was found that as much as caffeine may improve treatment, it may exacerbate daily anxiety among youth with depression. Because caffeine affects the central nervous system, cessation of a habitual morning intake may result in nervousness, irritability, drowsiness, poor work performance and headache that can only be cured by taking more caffeine.The findings of this paper are beneficial to the nutrition and disease management in that the paper points out the various advantages and disadvantages of caffeine consumption, thus people can be advised from an informed perspective about what is good or bad for their health. This paper defines the effect of caffeine intake by such people as athletes, pregnant women, children and adolescents, adults and people with heart problems. Due to the diverse ways in which caffeine intake affects these people, nutritionists and disease control agents can advise appropriately. In nutrition, for example, people who take coffee or tea regularly should find alternative ways of getting iron, since caffeine inhibits the uptake of iron. Consequently, society will effect the habits formed as far as caffeine intake is concerned and thus a healthy society is realized. In addition, some of the researches discussed will form a foundation for further research on the benefits and disadvantages of caffeine intake. This paper may also be used by as a reference by nutritionists as a reference on caffeine and also in creating awareness in the community on the advantages and disadvantages of caffeine consumption. In conclusion, caffeine whose primary sources are coffee, tea and cola, is the most widely consumed psychoactive along with the fact that it has many beneficial effects on its consumers. Used in moderation, it is known to have medicinal purposes, making it beneficial to humans. Its pharmacologically active substance in small intake amounts can be mild to the nervous system. Research findings indicate that caffeine use results in decreased fatigue and increased attentiveness, and this constitutes the primary reason why people take coffee. Interestingly as recently discovered, caffeine promotes the repair of a denuded endothelium. They are vital in building endurance among athletes and other strenuous long term exercises.Of importance to note as well is the finding that caffeine does not accumulate in the body over time and it is excreted a few hours after its consumption. Many research findings have shown that caffeine, especially if taken consistently in large amounts has adverse side effects on the unborn, children, adolescents and adults. Notable problems associated with caffeine use are dehydration, underweight births, ulcer aggravation, insomnia, nervousness, addiction, miscarriage and accelerated heart problems such as high blood pressure and constriction of blood vessels. From the various researches done, it is evident that excessive consumption of caffeine has more adverse side effects than the good it promotes. It is therefore advisable that caffeine be taken in moderation, and if possible be used only for medication purposes.