Caffeine affects blood pressure Term Paper Example | Topics and Well Written Essays - 750 words

Caffeine affects blood pressure - Term Paper Example It is categorized as a psychoactive drug, but its consumption is legal. The substance has several pharmacological actions peripherally and also centrally. It is an antagonist of adenosine, a neuromodulator, blocking the actions of adenosine which are inhibitory (Hartley et al, 2001). Thus, caffeine has a stimulatory effect on the central nervous system. Typical doses of caffeine in day to day consumption are less than 500mg, while the toxic doses are more than 10 grams (James, 2004). Consumption of caffeine can have both negative and positive side effects and is predominantly individual and dose based. Positive effects include protection against Parkinson's disease. Negative side effects include disruption of sleep, elevated blood pressure and elevated heart rate. Caffeine effects on blood pressure are a much controversial topic and several studies have been conducted to ascertain its role in elevating blood pressure and contribution to cardiovascular disease. This effect merits impo rtance, because caffeine is consumed by many people worldwide and this includes populations who have hypertension. In this essay, the effects of caffeine on blood pressure will be discussed. Discussion Caffeine is an adenosine antagonist. Adenosine is a neuromodulator and inhibition of adenosine causes increased activity of various other hormones like adrenaline, dopamine, cortisol and endorphins. At higher doses, caffeine can also cause inhibition of GABA neurotransmission leading to insomnia, anxiety and increased respiratory rate and heart rate. It crosses the blood-brain barrier and placental barrier readily because it is water soluble. In the brain, it acts as a non-selective adenosine antagonist because of its structural similarity to adenosine (Dunwiddie and Masino, 2001). Some studies have shown that administration of caffeine in doses comparable to those consumed everyday can lead to acute elevation in blood pressure by 5-15 mmHg of systolic pressures and 5-10mmHg of diasto lic pressures (James, 2004).. The effects pertaining to elevated blood pressures can last several hours in both sexes and in individuals of all age groups. Another important finding in these studies is the fact that the effect is additive to that caused by other factors like smoking and stress. Effect of caffeine on blood pressure varies from individual to individual and elevations in blood pressure may be an individual susceptibility. Individuals who already have hypertension or borderline hypertension may be even more susceptible. Caffeine can also have synergistic action on blood pressure in times of psychological stress exaggerating the increase in blood pressure. Thus, indirectly caffeine can contribute to cardiovascular disease (James, 2004). One interesting aspect is that the effects on blood pressure are inversely proportional to the number of portions consumed on a particular day. For instance, the initial portion of caffeine produces the greatest hemodynamic effect when co mpared to later portions (James, 2004). According to a study by James (2004), there is extensive evidence over the fact that consumption of caffeine in dietary doses increases blood pressure. However, it is unclear whether this has an impact on cardiovascular disease because habitual use of caffeine leads to tolerance and epidemiologic findings regarding the impact of caffeine on cardiovascular disease is confusing. . Several experimental and epidemiologic studies have proven the impact of dietary caffeine on blood

Watch film and then write the critical views of the film Essay

Watch film and then write the critical views of the film - Essay Example The Future of Food tends to explain in a systematic and organized manner as to how the much praised Green Revolution had a debilitating influence on the small farmers and how it benefitted the large corporations. The objective of the Green Revolution was to facilitate a massive increase in the overall production of crops in the poor or developing nations by promoting an extensive use of high yielding varieties of crops, chemical pesticides and artificial fertilizers (Belasco 116). The basic objective of Green Revolution was to make way for a larger production of food crops that could help the poor nations deal with the long pending issues like hunger and mal-nutrition. However, it is sad to say that though Green Revolution did help the developing nations to some extent, yet the economics of Green Revolution was primarily hijacked by the big multinational pesticide and fertilizer producers. The high yield varieties of crops were so modified that they worked only when treated with spec ific fertilizers and pesticides (Belasco 116). Thereby, this approach towards Green Revolution eventually ended up filling the coffers of large multinational corporations dealing in pesticides and fertilizers. However, it will be true to say that The Future of Food was very constrained about how Green Revolution did benefit large number of hungry and mal-nourished people around the world. The other ironic revelation extended by The Future of Food is that going by the fact that the economics of Green Revolution was skewed in favor of powerful multinational corporations and rich farmers, it negatively impacted the small framers the world over and diluted their role in the larger food economics (Belasco 116). Though, industrial farming aimed to produce massive quantities of crops, on a large scale by resorting to the usage of modern technology and by influencing the economics and politics of food at an international level, yet, actually speaking