• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Caffeine is a naturally occurring xanthine.

Extracts from this document...

Introduction

Caffeine Caffeine has played a central role in many cultures. Coffee was first discovered over 1000 years ago, and approximately 75% of Americans drink coffee on a regular basis. Despite the thousand years that have passed, there is still controversy surrounding the biological effects of coffee and it's primary active ingredient, caffeine. Caffeine is the most widely used stimulant drug in the world, usually ingested in the form of coffee, tea, soft-drinks, and chocolate. (Honig) Caffeine is derived from a bean or from tea leaves and can be found in the seeds or fruits of more then 60 species worldwide.(American Academy) Caffeine has numerous effects and it is disputed whether caffeine is overall beneficial or harmful. Caffeine is a naturally occurring xanthine (precursor to uric acid often found in urine) used as a central nervous system (CNS) and respiratory stimulant, or as a mild diuretic. Other xanthine derivatives include the bronchodilator theophylline and theobromine, a compound found in cocoa and chocolate. Caffeine is a mild, but direct stimulant at all levels of the CNS that quickens the heart and cardiovascular system as well. ...read more.

Middle

Therefore, the signal to stop producing adenosine that would have been sent by the adenosine becomes blocked, which results in a surplus of adenosine and explains the stimulatory effects of caffeine. Decades of research and centuries of human consumption suggest the relative safety of caffeine. According to the National Library of Medicine, more than 19, 000 scientific studies to date have been conducted on caffeine, and the US Food and Drug Administration still considers caffeine to be "Generally Recognized as Safe." A study at the University of California showed that the average daily consumption of 200 mg as safe.(Ascherio) The study also concluded that the the lethal dose of caffeine is 192 mg/kg, meaning for the average american would need to drink more than 150 cups of coffee to reach lethal overdose!(Bobrow) Caffeine enhances performance on observational and simple tasks that require sustained response. These effects are in tired or bored subjects, although there is evidence that benefits may still occur when the person is unimpaired. (Smith) Caffeine also boosts the numbing effect of aspirin, and recent scientific research carried out at the Mayo clinic, Harvard School of Public Health, US Veterans Administration and other medical centers show that caffeine is not only safe but also beneficial. ...read more.

Conclusion

(Cherniske) Professor Jack James of the University of Ireland conducted studies that showed that long-term caffeine consumption contributes to adrenal insufficiency, and adversely affecting over 150 hormones . Meaning stress , blood pressure, blood sugar, mineral levels, immune activity, inflammation, cell growth and repair are all negatively affected. Other studies showed caffeine contributed to problems like: Gastritis, acid reflux, ulcers, irritable bowel syndrome, hypoglycemia, vitamin loss, PMS, fibrocystic breasts, premenopausal symptoms, decreased fertility, birth defects, asthma, fibromyalgia, chronic fatigue, autoimmune disease and rheumatoid arthritis.(James) Many studies have suggested a relationship between chronic caffeine use and a number of diseases. However, the cause-and-effect evidence is difficult to prove because of lifestyle variables among the subjects in the studies (eg. smoking, alcohol consumption, exercise), differences in genetic inheritance, form of caffeine intake (coffee, tea, sodas), and the presence of other biologically active substances in the beverage. (Brice) The consumption of caffeine does have side effects, some negative and some positive, but it is clear that when taken in moderation caffeine is never adverse to ones health. However, caffeine consumers should be aware of withdrawal and keep themselves up to date on the latest caffeine research. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Humans as Organisms essays

  1. Marked by a teacher

    Is the MMR vaccination safe?

    5 star(s)

    MMR vaccination Convulsions 1 in 200 1 in 1000 Meningitis or encephalitis 1 in 200 to 1 in 5000 1 in a million Conditions affecting blood clotting 1 in 3000 (rubella) 1 in 6000 (measles) 1 in 22,300 SSPE (complication of measles which causes brain damage and death)

  2. Peer reviewed

    Abortion case study

    3 star(s)

    This means that the fertilised egg cannot be fixed. The baby is disposed through the vagina in little blood clots. As well as the abortion pill destroying the foetus, it also has side effects on the mother. The mother will undergo heavy bleeding for up to one week. She may have heavy cramping due to the contractions caused by the second pill.

  1. Stem Cell Research

    replicate and culture, and then inject them into a different area that requires them. Because the inoculated stem cells are actually taken from the patient, the chances of rejection are much lower. This is because they contain the same genome as the patient and they would also contain no foreign

  2. The Biological and Psychological Impact of Smoking Cigarettes

    Aneurysms may eventually cause the affected artery to burst or clot, resulting in death or severe illness. Smokers are up to eight times more likely to die from a ruptured aneurysm of the abdominal aorta than non-smokers(6). More than 90% of people who suffer from an aortic aneurysm have smoked

  1. is the mmr vaccination safe?

    without us actually becoming infected with the disease.' This would make our immune system produce antibodies against that microbe as if the body had been infected by it even though the inactive microbes cannot cause harm. This is called 'active immunity'.

  2. An investigation into how alcohol and caffeine affect the heart.

    The dilutions used in the experiment are recorded in the table below. Firstly, 10ml of 1% alcohol solution was taken and placed in a test tube. A single daphnia was taken and placed in the test tube with the 1% alcohol solution and left to acclimatise for five minutes.

  1. INVESTIGTING THE EFFECT OF CAFFEINE CONCENTRATION ON

    A stopclock will be much more accurate to use than wrist-watch as it can be ensured that the clock is stopped at the right time. Also if it is stopped late the extra seconds or milli seconds can also be recorded.

  2. Are Vaccines safe?

    ?In the 1950?s there were 50 million cases worldwide? [2] but as a result of a global ?campaign to wipe out smallpox? [2] by the WHO in 1967, the disease has now been totally eradicated and the last recorded case was recorded in Somalia during 1977 This proves that it

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work