Coffee and Health Studies

Here are some results from notable research performed on coffee & health:

Liver Disease

  • Surveyed approx. 240,000 people (2,260 people had been diagnosed with liver disease) and found that the likelihood of developing liver disease for people who drank coffee vs. those who didn’t dropped by 23% with each daily cup. (Hepatology journal reported in 2007 on 10 studies conducted in Europe & Asia on coffee & liver disease)
  • Found regular coffee consumption could reduce risk of developing hepatocellular carcinoma by about 40% and could be as much as 50% for those drinking 3+ cups/day. ("Coffee Reduces Risk for Hepatocellular Carcinoma: An Updated Meta-analysis." Clinical Gastroenterology and Hepatology 11.11 (2013): 1414-1421 – 2013 Italian meta-analysis of 16 studies published in Clinical Gastroenterology and Hepatology on coffee & hepatocellular carcinoma (most common form of liver cancer))

Type II Diabetes

  • A meta analysis on 28 scientific studies combined representing over 1.1 million participants over more than 20 years showed your risk of developing type two diabetes goes down 9% for every cup of coffee you drink. ("Caffeinated and Decaffeinated Coffee Consumption and Risk of Type 2 Diabetes: A Systematic Review and a Dose-Response Meta-analysis." Diabetes Care 37.2 (2014): 569-86)
  • Surveyed 125,000 people over 18 years and found that men who drank 6+ cups/daily reduced their risk of being diagnosed with adult-onset diabetes by 54%, and women drinking the same amount reduced their chances by 30%. (2004 study published in Annals of Internal Medicine from researchers at Harvard School of Public Health and Brigham and Women’s Hospital on coffee & type II diabetes)


  • Followed 1,400 people over 20 years and found that those drinking 3–5 cups per day reduced their risk of being diagnosed with dementia or Alzheimer’s by 65%. (2009 Scandinavian study published in the Journal of Alzheimer’s Disease on coffee and dementia or Alzheimer’s)

Coffee & Heart Disease

  • Followed 40,000+ male health professionals over 18 years and found men drinking 5+ cups/day reduced their risk of dying from heart disease by 44%. (2008 Nurse’s Health Study published in the Annals of Internal Medicine on coffee & heart disease)

Breast Cancer

  • Moderate to high consumption was associated with lower risk for breast cancer events in tamoxifen-treated patients with ERþ tumors (adjusted HR, 0.51; 95% confidence interval, 0.26–0.97). ("Caffeine and Caffeic Acid Inhibit Growth and Modify Estrogen Receptor and Insulin-like Growth Factor I Receptor Levels in Human Breast Cancer." Clinical Cancer Research 21.8 (2015): 1877-887)


  • Surveyed 400,000 people over 14 years and found the overall mortality rate of those drinking 2-6 cups/day was reduced by 10% for men and 15% for women. (2012 National Institutes of Health study published in the New England Journal of Medicine on coffee and mortality rates)


  • Followed 83,000 women over 24 years and found that women who drank 2+ cups/day reduced their risk of stroke by 19% with a greater reduction the more they drank – non-smoking women who drank 4+ cups/day reduced the risk of stroke by 43%. (A Harvard study done with researchers from the Universidad Autonoma de Madrid using data from a Nurse’s Health Study (no date was mentioned for publication) on coffee & strokes in women)

Parkinson's Disease

  • Followed 8,004 participants in the Honolulu Heart Program for 30 years and found that people who did not drink coffee had 5 times more risk of eventually being diagnosed with Parkinson’s than those who consumed 3+ cups/day. (2000 study published in Journal of the American Medical Association on Parkinson’s and coffee)
  • Found that regularly drinking 3+ cups/day reduces the chance of getting Parkinson’s by 25%, and drinking more further reduces the risk. (2010 meta-analysis of 26 studies by the Center for Evidence-Based Medicine at the University of Lisbon on coffee and Parkinson’s (didn’t say how many people in studies collectively or the total amount of time))


  • Followed almost 90,000 women over 30 years and found those drinking 2-3 cups of caffeinated coffee/day had a 22% lower risk of developing gallstones. (Study published in 2002 from the Nurse’s Health Study on coffee and gallstones in women)


  • Followed 50,000 women from the U.S. and Finland who were initially free of depression for as long as 24 years (in some cases but not all), and found that women drinking 4+ cups/day reduced their risk of depression by 20% – drinking decaf or other caffeinated drinks was found to have nearly zero benefit. (NIH-supported study published in 2011 and conducted by the Department of Nutrition at the Harvard School of Public Health on depression and coffee in women)
  • Followed 86,000 nurses over the course of 10 years and found women drinking 4+ cups/day reduced their risk of committing suicide by more than half. (Study published in 1996 by the Journal of the American Medical Association on women and risk of suicide)

Prostate Cancer

  • Closely surveyed 50,000 male health professionals over 20 years and found that those drinking 6+ cups/day reduced their chances of developing advanced prostate cancer by 60% – 3 cups reduced risk by 20% and 4-5 cups reduced risk by 25%. (2009 study funded by National Institutes of Health on drinking coffee & prostate cancer)