How Coffee Can Impact Your Health

Coffee is a staple of many breakfast routines, thanks to the energy boost it provides. One 8oz cup typically contains 95mg of caffeine. The Dietary Guidelines for Americans defines a moderate amount of coffee as 3 to 5 cups per day (about 400mg caffeine). In addition to caffeine, coffee also contains vitamin B12, magnesium, and polyphenols.1 

Consuming low-to-moderate amounts of caffeine is associated with increased energy, alertness, and concentration, whereas higher amounts can cause negative symptoms, including increased heart rate, anxiety, restlessness, and insomnia.1 The response to caffeine differs from person to person,1 so it is important for coffee drinkers to understand how much coffee they can safely consume.  

Much research has been conducted to study the effects of coffee intake on human health. Below is a brief overview of the various effects of coffee intake on health.

The Impact of coffee on Health

Cancer. There is a plethora of research on the relationship between coffee consumption and cancer. Coffee consumption has been associated with a decreased risk of liver cancer, particularly hepatocellular carcinoma, the most common form of liver cancer.2–4 Greater coffee intake (>2–3 cups/day) is associated with increased protection against liver cancer.3,4 Both caffeinated and decaffeinated coffee are linked to reduced liver cancer risk,3 though the association with decaffeinated coffee is weaker.4 One study that focused on the United States (US) population found that caffeinated coffee consumption was associated with a nonsignificant reduced risk of hepatocellular carcinoma.5

Research has demonstrated a significant inverse association between coffee intake and risk of endometrial cancer in a dose-dependent manner, with greater coffee consumption associated with greater reductions in endometrial cancer risk.5,6 This association might be stronger in individuals with a higher body mass index (BMI)2,6 and postmenopausal individuals.6

Limited evidence indicates that coffee intake might be associated with a decreased risk of breast cancer, particularly among postmenopausal individuals, but some studies have shown no association between coffee and breast cancer.2,4 The relationship between coffee consumption and colorectal cancer is mixed, with some studies suggesting that coffee might decrease colorectal cancer risk, and others indicating that coffee might increase the risk.2–4 The impact of coffee intake on stomach cancer is also unclear, but high daily intake (≥5–6 cups) has been associated with increased risk.3,4 Caffeinated coffee intake has been associated with a decreased risk of developing melanoma and nonmelanoma skin cancers in the US.5

Cardiovascular disease (CVD). Evidence indicates that coffee has a protective effect on cardiovascular health. Multiple studies have shown an association between moderate coffee consumption and decreased risk of CVD.1,5,7 However, the impact of coffee consumption in individuals with hypertension is less clear. One study showed that caffeinated coffee consumption elevated blood pressure for about 1 to 3 hours, but longer-term consumption did not increase blood pressure, nor was the risk of CVD increased.8 According to another study, individuals with severe hypertension experienced an increased risk of CVD-related mortality with an intake of two or more cups of coffee per day, compared to non-coffee drinkers.9

Gastrointestinal health. Research has shown that coffee consumption can reduce the risk of chronic liver disease. Elevated coffee intake has also been linked to a decreased risk of liver fibrosis, even among patients with nonalcoholic fatty liver disease (NAFLD) and those coinfected with human immunodeficiency virus and hepatitis C virus. Coffee does not appear to increase the risk of peptic ulcers.3

Mortality. Moderate-to-high daily coffee intake is linked to decreased risk of all-cause mortality.1,2 However, according to one study, daily consumption of four or more cups of coffee was associated increased risk of all-cause and CVD-related mortality among patients with CVD, whereas decaffeinated coffee intake was associated with a decreased risk of both.10  

Neurodegenerative diseases. Some research has shown a positive relationship between coffee intake and risk of neurodegenerative diseases, including Parkinson’s disease, stroke, and dementia.1,2 However, further research is needed in this area.

Type 2 diabetes. Habitual coffee consumption is associated with a decreased risk of Type 2 diabetes.1,2,5 Disease risk has been shown to decrease with increasing daily coffee consumption.1,5 Both caffeinated and decaffeinated coffee can reduce this risk.1,11,12

Bottom Line

There are many benefits to drinking a moderate amount of coffee, whether it’s caffeinated or decaffeinated. 

  1. Harvard T.H. Chan School of Medicine. Coffee. Reviewed Jul 2020. Accessed 29 Jan 2024.
  2. Safe S, Kothari J, Hailemariam A, et al. Health benefits of coffee consumption for cancer and other diseases and mechanisms of action. Int J Mol Sci. 2023;24(3):2706. 
  3. Nehlig A. Effects of coffee on the gastro-intestinal tract: a narrative review and literature update. Nutrients. 2022;14(2):399. 
  4. Pauwels EKJ, Volterrani D. Coffee consumption and cancer risk: an assessment of the health implications based on recent knowledge. Med Princ Pract. 2021;30(5):401–411. 
  5. Di Maso M, Boffetta P, Negri E, et al. Caffeinated coffee consumption and health outcomes in the US population: a dose-response meta-analysis and estimation of disease cases and deaths avoided. Adv Nutr. 2021;12(4):1160–1176.
  6. Lafranconi A, Micek A, Galvano F, et al. Coffee decreases the risk of endometrial cancer: a dose-response meta-analysis of prospective cohort studies. Nutrients. 2017;9(11):1223. 
  7. Ding M, Bhupathiraju SN, Satija A, et al. Long-term coffee consumption and risk of cardiovascular disease. Circulation. 2014;129(6):643–659.
  8. Mesas AE, Leon-Muñoz LM, Rodriguez-Artalejo F, Lopez-Garcia E. The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. Am J Clin Nutr. 2011;94(4):1113–1126. 
  9. Teramoto M, Yamagishi K, Muraki I, et al. Coffee and green tea consumption and cardiovascular disease mortality among people with and without hypertension. J Am Heart Assoc. 2023;12(2):e026477.
  10. Zheng H, Lin F, Xin N, et al. Association of coffee, tea, and caffeine consumption with all-cause risk and specific mortality for cardiovascular disease patients. Front Nutr. 2022;9:842856. 
  11. Ding M, Bhupathiraju SN, Chen M, et al. Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis. Diabetes Care. 2014;37(2):569–586. 
  12. Kolb H, Martin S, Kempf K. Coffee and lower risk of Type 2 diabetes: arguments for a causal relationship. Nutrients. 2021;13(4):1144.  

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