Scientific studies have examined the relationship between coffee consumption and an array of medical conditions. Findings are contradictory as to whether coffee has any specific health benefits, and results are similarly conflicting regarding negative effects of coffee consumption.<ref name=Kummer2003>{{cite book | author = Kummer, Corby | year = 2003 | title = The Joy of Coffee | url = http://books.google.com/books?id=qNLrJqgfg7wC | chapter = Caffeine and Decaf | chapterurl = http://books.google.com/books?id=qNLrJqgfg7wC&pg=PA151&sig=zL7_XqPYPeBVq8vs3ukYFuwjn2I | pages = 160-165 | publisher  = Houghton Mifflin Cookbooks | isbn = 0618302409 | accessdate = 2008-02-23}}</ref>

Coffee appears to reduce the risk of [[Alzheimer's disease]], [[Parkinson's disease]], [[heart disease]], [[diabetes mellitus type 2]], [[cirrhosis]] of the [[liver]],<ref>{{cite journal | last = Klatsky | first = Arthur L. | coauthors = Morton, C.; Udaltsova, N.; Friedman, D. | date = 2006 | title = Coffee, Cirrhosis, and Transaminase Enzymes | url = http://archinte.ama-assn.org/cgi/content/full/166/11/1190 | journal = Archives of Internal Medicine | volume = 166 | issue = 11 | pages = 1190–1195 | doi = 10.1001/archinte.166.11.1190 | pmid = 16772246 | accessdate = 2008-02-23}}</ref> and [[gout]]. Some health effects are due to the [[caffeine]] content of coffee, as the benefits are only observed in those who drink caffeinated coffee, while others appear to be due to other components.<ref>{{cite journal | author = Pereira, Mark A. | coauthors = Parker, D.; Folsom, A.R. | year = 2006 | title = Coffee consumption and risk of type 2 diabetes mellitus: an 11-year prospective study of 28 812 postmenopausal women. | url = http://archinte.ama-assn.org/cgi/content/full/166/12/1311 | journal = Archives of Internal Medicine | volume = 166 | issue = 12 | pages = 1311–1316 | pmid = 16801515 | accessdate = 2008-02-23}}</ref> For example, the [[antioxidant]]s in coffee prevent [[Radical (chemistry)|free radicals]] from causing cell damage.<ref>{{
cite web | last = Bakalar | first = Nicholas | date = 2006-08-15 | title = Coffee as a Health Drink? Studies Find Some Benefits | publisher  = New York Times | url = http://www.nytimes.com/2006/08/15/health/nutrition/15coff.html?ex=1313294400&en=d420f19ee1c77365&ei=5088&partner=rssnyt&emc=rss 
| accessdate = 2007-07-28 }}</ref>

Coffee's negative health effects are mostly due to its [[caffeine]] content. Research suggests that drinking caffeinated coffee can cause a temporary increase in the stiffening of arterial walls.<ref>{{cite journal | last = Mahmud | first = A. | coauthors  = Feely, J. | year = 2001 | title = Acute Effect of Caffeine on Arterial Stiffness and Aortic Pressure Waveform | url = http://hyper.ahajournals.org/cgi/content/full/38/2/227 | journal = Hypertension | volume = 38 | issue = 2 | pages = 227–231 | pmid = 11509481 | accessdate = 2008-02-23}}</ref> Excess coffee consumption may lead to a [[magnesium deficiency (medicine)|magnesium deficiency]] or [[hypomagnesaemia]],<ref>{{cite journal | author = Johnson, S. | date = 2001 | title = The multifaceted and widespread pathology of magnesium deficiency | url = http://www.george-eby-research.com/html/wide-mag-deficiency-path.pdf | format = PDF | journal = Medical Hypotheses | volume = 56 |issue = 2 |pages = 163-170 |publisher = Harcourt Publishers Ltd |doi = 10.1054/mehy.2000.1133 | pmid = 11425281 |accessdate = 2008-02-23}}</ref> and may be a risk factor for [[Coronary_heart_disease|coronary heart disease]]. Some studies suggest that it may have a mixed effect on [[short-term memory]], by improving it when the information to be recalled is related to the current [[train of thought]], but making it more difficult to recall unrelated information.<ref>{{cite web | author = BBC News | coauthors = Lesk, Valerie |date = 2004-07-20 | title = A coffee can make you forgetful | url = http://news.bbc.co.uk/2/hi/health/3909085.stm | publisher = BBC News | accessdate = 2008-02-23}}</ref> About 10% of people with a moderate daily intake (235 mg per day) reported increased depression and anxiety when caffeine was withdrawn,<ref>{{cite journal |author = Smith, A. | year = 2002 | title = Effects of caffeine on human behavior | url = http://www.erowid.org//references/refs_view.php?A=ShowDocPartFrame&ID=6685&DocPartID=6196 | journal = Food and Chemical Toxicology | volume = 40 | issue = 9 | pages = 1243-1255 | doi = 10.1016/S0278-6915(02)00096-0 | pmid = 12204388 | accessdate = 2008-02-23}}</ref> and about 15% of the general population report having stopped caffeine use completely, citing concern about health and unpleasant side effects.<ref>{{cite web | author = Johns Hopkins University School of Medicine |year = 2003| title = Use and Common Sources of Caffeine | url = http://www.caffeinedependence.org/caffeine_dependence.html#sources | work = Information about Caffeine Dependence | accessdate = 2008-02-23 }}</ref> Nevertheless, the mainstream view of medical experts is that drinking three 8-ounce (236 ml) cups of coffee per day (considered average or moderate consumption) does not have significant health risks for adults.<ref>{{cite web | author = Haines, Cynthia Dennison | year = 2007 | title = Caffeine in the diet | url = http://www.nlm.nih.gov/medlineplus/ency/article/002445.htm | work = MedlinePlus Medical Encyclopedia | publisher  = The U.S. National Library of Medicine | accessdate = 2008-02-23}}</ref>

== References ==
{{reflist}}

Scientific studies have examined the relationship between coffee consumption and an array of medical conditions. Findings are contradictory as to whether coffee has any specific health benefits, and results are similarly conflicting regarding negative effects of coffee consumption.^[1]

Coffee appears to reduce the risk of Alzheimer's disease, Parkinson's disease, heart disease, diabetes mellitus type 2, cirrhosis of the liver,^[2] and gout. Some health effects are due to the caffeine content of coffee, as the benefits are only observed in those who drink caffeinated coffee, while others appear to be due to other components.^[3] For example, the antioxidants in coffee prevent free radicals from causing cell damage.^[4]

Coffee's negative health effects are mostly due to its caffeine content. Research suggests that drinking caffeinated coffee can cause a temporary increase in the stiffening of arterial walls.^[5] Excess coffee consumption may lead to a magnesium deficiency or hypomagnesaemia,^[6] and may be a risk factor for coronary heart disease. Some studies suggest that it may have a mixed effect on short-term memory, by improving it when the information to be recalled is related to the current train of thought, but making it more difficult to recall unrelated information.^[7] About 10% of people with a moderate daily intake (235 mg per day) reported increased depression and anxiety when caffeine was withdrawn,^[8] and about 15% of the general population report having stopped caffeine use completely, citing concern about health and unpleasant side effects.^[9] Nevertheless, the mainstream view of medical experts is that drinking three 8-ounce (236 ml) cups of coffee per day (considered average or moderate consumption) does not have significant health risks for adults.^[10]