Summary

Human Body

by Team 01639.

Many scientific studies on coffee and health produce contradicting results. This section attempts to give you a different, comprehensive summary on the matter. The effects of coffee on the human body are classified into 4 types:

• “Coffee DOES” means that all scientific papers published agree with this statement
• “Coffee MAY” means that the majority of scientific papers published agree with this statement
• “Coffee MAY NOT” means that the majority of scientific papers published disagree with this statement
• “Coffee DOES NOT” means that all scientific papers published disagree with this statement.

Please click on one of the links below to view the effects of coffee on...:

• The circulatory system
• The digestive system
• The excretory system
• The muscular system
• The nervous system
• The reproductive system and pregnancy
• The respiratory system
• The skeletal system

Effects of coffee on the circulatory system:

• Coffee DOES: increase blood pressure in normal people who do not consume caffeine regularly, but this increase is insignificant which the body can tolerate; increase LDL cholesterol level for those who drink boiled coffee.
• Coffee MAY: increase the level homocystine in the blood (homocystine is suspected as a risk factor of cardiovascular diseases); increase blood pressure in borderline hypertension subjects for a longer period of time, but only in large doses.
• Coffee DOES NOT cause cardiac arrhythmias

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Effects of coffee on the digestive system:

• Coffee DOES: protect against liver cirrhosis.
• Coffee MAY: reduce the chance of colorectal cancer, reduce the risk of gallstone disease, promote gastro-oesophageal reflux disease, increase the risk of pancreatic cancer.

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Effects of coffee on the excretory system:

• Coffee DOES: lower the risk of developing kidney stones if consumed regularly
• Coffee MAY: reduce glucose tolerance, trigger type 1 diabetes ( and decrease insulin sensitivity in healthy people (so it may be a risk factor for type 2 diabetes); has diuretic effect, increases detrusor instability.
• Coffee MAY NOT: cause bladder and urinary tract cancer.
• Coffee DOES NOT: cause renal cancer.

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Effects of coffee on the muscular system:

• Coffee DOES NOT: cause female breast cancer
• Coffee MAY: reduce the risk of male breast cancer

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Effects of coffee on the nervous system:

• Coffee DOES: increase alertness, increase mental performance, and increase anxiety (only with large dosages: 300mg of caffeine or more).
• Coffee MAY: reduce the risk of developing Alzheimer’s disease, and reduce the risk of developing Parkinson’s disease
• Coffee does NOT cause addiction.

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Effects of coffee on the reproductive system and pregnancy:

• Coffee MAY NOT: cause ovarian cancer, delayed conception, miscarriage, reduced birth weight, sudden infant death syndrome (SIDS.)
• Coffee DOES NOT: cause foetal abnormalities, affect breast feeding.

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Effects of coffee on the respiratory system:

• Coffee DOES: reduce the risk of getting asthma and helps in managing asthma

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Effects of coffee on the skeletal system:

• Coffee DOES: reduce calcium absorption in calcium deficient women, leading to a loss in calcium (about 4 – 6mg per cup of coffee consumed).
• Coffee MAY NOT: reduce bone health (which leads to osteoporosis)

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Related articles:

• Research brews debate about whether caffeine is addictive
  http://www.psych.org/pnews/99-05-07/caffeine.html
• Caffeine and habituation
  http://www.cosic.org/caffeine-and-behaviour/
  habituation-withdrawl-tolerance-reinforcement-and-dependence

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