Benefits
[edit] Reduced risk of Alzheimer's disease
Several studies comparing moderate coffee drinkers (about 2 cups a day) with light coffee drinkers (less than one cup a day) found that those who drank more coffee were significantly less likely to develop Alzheimer's disease later in life. [2][3]
[edit] Reduced risk of gallstone disease
Drinking caffeinated coffee has been correlated with a lower incidence of gallstones and gallbladder disease in both men[4] and women[5] in two studies performed by the Harvard School of Public Health. A lessened risk was not seen in those who drank decaffeinated coffee.
[edit] Reduced risk of Parkinson's disease
A study comparing heavy coffee drinkers (3.5 cups a day) with non-drinkers found that the coffee drinkers were significantly less likely to contract Parkinson's Disease later in life. [6]. Likewise, a second study found an inverse relationship between the amount of coffee regularly drunk and the likelihood of developing Parkinson's Disease. [7]
[edit] Cognitive performance
Many people drink coffee for its ability to increase short term recall and increase IQ[8].
Likewise, in tests of simple reaction time, choice reaction time, incidental verbal memory, and visuospatial reasoning, participants who regularly drank coffee were found to perform better on all tests, with a positive relationship between test scores and the amount of coffee regularly drunk. Elderly participants were found to have the largest effect associated with regular coffee drinking. [9] Another study found that women over the age of 80 performed significantly better on cognitive tests if they had regularly drunk coffee over their lifetimes. [10]
[edit] Analgesic enhancement
Coffee contains caffeine, which increases the effectiveness of pain killers, especially migraine and headache medications. For this reason some aspirin producers also include a small dose of caffeine in the pill.
[edit] Antidiabetic
Coffee intake may reduce one's risk of diabetes mellitus type 2 by up to half. While this was originally noticed in patients who consumed high amounts (7 cups a day), the relationship was later shown to be linear.[11]
[edit] Antineoplastic
Coffee can also reduce the incidence of cirrhosis of the liver[12] and has been linked to a reduced risk of hepatocellular carcinoma, a primary liver cancer.[13]
[edit] Cardioprotective
Coffee reduces the incidence of heart disease, though whether this is simply because it rids the blood of excess lipids or because of its stimulant effect is unknown.[citation needed]
[edit] Laxative/diuretic
Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation; it is also a diuretic. However, coffee can also cause loose bowel movements.
Practitioners in alternative medicine often recommend coffee enemas for "cleansing of the colon" due to its stimulus of peristalsis, although mainstream medicine has not proved any benefits of the practice.
[edit] Antioxidant
Coffee contains the anticancer compound methylpyridinium. This compound is not present in significant amounts in other food materials. Methylpyridinium is not present in raw coffee beans but is formed during the roasting process from trigonelline, which is common in raw coffee beans. It is present in both caffeinated and decaffeinated coffee, and even in instant coffee.[14]
[edit] Prevention of dental caries
The tannins in coffee may reduce the cariogenic potential of foods. In vitro experiments have shown that these polyphenolic compounds may interfere with glucosyltransferase activity of mutans streptococci, which may reduce plaque formation. In rat experiments, tea polyphenols reduced caries. [15]
[edit] Gout
Coffee consumption decreased risk of gout in men over age 40. In a large study of over 45,000 men over a 12-year period, the risk for developing gout in men over 40 was inversely proportional with the amount of coffee consumed.[16]
[edit] Risks
Many notable effects of coffee are related to its caffeine content. Amongst other known negative health associations it is not clear whether these are due to the caffeine or other unidentified compounds (suggesting that these may be modified by switching to decaffeinated coffee).
[edit] Anxiety and sleep changes
Many coffee drinkers are familiar with "coffee jitters", a nervous condition that occurs when one has had too much caffeine. It can also cause anxiety and irritability, in some with excessive coffee consumption, and some as a withdrawal symptom. Coffee can also cause insomnia in some, while paradoxically it helps a few sleep more soundly.
[edit] Constipation
Due to its diuretic effect, coffee use can lead to dehydration in some individuals, and as a result, contribute to constipation. [17]
[edit] Cosmetic
Like tea, coffee causes staining of the teeth.[18]
[edit] Blood pressure
A recent study by Harvard Med that set out to prove that the caffeine in coffee would put people at risk for high blood pressure ended up rejecting the theory. 155,000 nurses were followed for 12 years and the results showed that large amounts of coffee did not induce a "risky rise in blood pressure"[19]. As a note, this study did not include men.