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Research · Food and drink

Coffee

In cohorts of millions of adults, 3 to 4 cups a day was linked to about 15% lower death from any cause than no coffee, and more coffee to less heart disease, type 2 diabetes and cirrhosis. Genetic studies mostly do not support cause. Unfiltered coffee raised LDL cholesterol in trials. Pregnancy links include low birth weight and pregnancy loss.

Add to Bio HackChecked 2026-11-13
Status
A food, not a regulated health product. For most adults, the FDA has cited 400 mg of caffeine a day, about two to three 12-ounce cups of coffee, as an amount not generally associated with negative effects [1].
Also called
caffeinated coffee, decaf, decaffeinated coffee, espresso, filtered coffee, drip coffee, instant coffee, French press, cafetière coffee, boiled coffee, Turkish coffee, cold brew
Studied for
longer life, heart health, type 2 diabetes prevention, liver health, energy, focus, alertness, mood, depression, blood pressure, weight loss

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help7

Reported risks6

What it was studied for, and what was found

Shown to help7

Strong

Death from any cause

Linked to about 15% lower death from any cause at 3 to 4 cups a day than no coffee, in pooled cohorts, including decaffeinated coffee.

Compared with people drinking no coffee [2][3]

The numbers and sources
Effect
An umbrella review of 201 meta-analyses found the largest relative risk reduction at 3 to 4 cups a day against none, for all-cause mortality (RR 0.83, 95% CI 0.79 to 0.88) [2]. A dose-response meta-analysis of 21 cohorts found the largest reduction at 4 cups a day, 16% (95% CI 13 to 18%) [4]. An update of 40 studies found the lowest risk at 3.5 cups a day (RR 0.85, 95% CI 0.82 to 0.89), with no further fall at higher intakes. The link held by age, weight, smoking, alcohol and caffeine content of the coffee, and was weaker in the US than in Europe and Asia [3].
Population
201 meta-analyses of observational studies and 17 of trials [2]. 997,464 participants and 121,915 deaths in 21 prospective studies [4]. 3,852,651 participants and 450,256 deaths in 40 studies [3].
Sources
[2], [4], [3], [5]
Caveats
Observational. Coffee drinkers differ from non-drinkers in smoking and other habits, and people who fall ill may stop drinking coffee, which can make coffee look protective (reverse causation). The umbrella review authors call for randomized trials to test cause [2]. A review of at least 15 Mendelian randomization studies found most gave no consistent support for coffee causing the health outcomes studied, while noting low statistical power [5].
Strong

Heart disease and stroke

Linked to about 15% lower cardiovascular disease at 3 to 5 cups a day than no coffee, in pooled cohorts. Heavy drinking was not linked to higher risk.

Compared with people drinking no coffee [2]; the lowest intake group, median 0 cups a day [6]

The numbers and sources
Effect
At 3 to 4 cups a day against none, cardiovascular disease was lower (RR 0.85, 95% CI 0.80 to 0.90) and so was cardiovascular death (RR 0.81, 95% CI 0.72 to 0.90) [2]. Across 36 cohorts, cardiovascular disease risk was 0.89 (95% CI 0.84 to 0.94) at a median 1.5 cups a day, 0.85 (95% CI 0.80 to 0.90) at 3.5 cups and 0.95 (95% CI 0.87 to 1.03) at 5 cups, against the lowest intake. Links were nonlinear for both coronary heart disease and stroke [6]. Cardiovascular death was lowest at 3 cups a day, 21% (95% CI 16 to 26%) lower [4], and at 2.5 cups a day in a later update (RR 0.83, 95% CI 0.80 to 0.87) [3].
Population
1,279,804 participants and 36,352 cardiovascular cases in 36 cohorts [6]. Cohorts pooled in [2], [4] and [3].
Sources
[2], [6], [4], [3]
Caveats
Observational, with the same confounding and reverse causation limits as above. Genetic studies mostly did not support a causal effect [5].
Moderate

Type 2 diabetes

Linked to lower type 2 diabetes, 33% lower at 6 cups a day than no coffee, with decaf too. A genetic study did not support cause.

Compared with people drinking no coffee or rarely [7]

The numbers and sources
Effect
Against no or rare coffee, the relative risk of type 2 diabetes was 0.92 (95% CI 0.90 to 0.94) at 1 cup a day, 0.79 (95% CI 0.75 to 0.83) at 3 cups and 0.67 (95% CI 0.61 to 0.74) at 6 cups. Each extra daily cup was linked to a relative risk of 0.91 (95% CI 0.89 to 0.94) for caffeinated coffee and 0.94 (95% CI 0.91 to 0.98) for decaffeinated coffee [7]. In a Mendelian randomization study, genetic variants linked to 29% higher coffee intake were not convincingly linked to type 2 diabetes, obesity or glucose, though high intake was linked to lower diabetes risk in the same people observationally [8].
Population
1,109,272 participants and 45,335 cases in 28 prospective studies followed 10 months to 20 years [7]. 93,179 Danish adults, plus up to 78,021 in a genetic consortium [8].
Sources
[7], [8]
Caveats
Observational cohorts. The genetic study points away from a causal effect, though genetic tools for coffee intake have low power [5].
Moderate

Cirrhosis and liver cancer

Linked to 44% lower cirrhosis and 35% lower liver cancer for each extra 2 cups a day, in pooled studies rated very low in quality.

Compared with 2 fewer cups a day, in a dose-response model [9][10]

The numbers and sources
Effect
For each extra 2 cups a day, the relative risk of cirrhosis was 0.56 (95% CI 0.44 to 0.68), of alcoholic cirrhosis 0.62 (95% CI 0.51 to 0.73) and of death from cirrhosis 0.55 (95% CI 0.35 to 0.74) [9]. For hepatocellular carcinoma it was 0.65 (95% CI 0.59 to 0.72), 0.71 in cohorts and 0.53 in case-control studies. Caffeinated coffee gave 0.73 (95% CI 0.63 to 0.85) and decaffeinated 0.86 (95% CI 0.74 to 1.00). The link held with or without heavy drinking, obesity, diabetes, smoking or hepatitis B and C [10].
Population
432,133 participants and 1,990 cirrhosis cases in 9 studies [9]. 2,272,642 participants in 18 cohorts and 1,825 cases in 8 case-control studies [10].
Sources
[9], [10], [2]
Caveats
Heterogeneity was high for cirrhosis (I² 83.3%). The liver cancer review rated its evidence very low under GRADE, citing no randomized trials, possible publication bias and no accepted definition of a cup [10]. The decaffeinated estimate rests on 3 cohorts.
Moderate

Depression

Linked to 24% lower risk of depression at the highest coffee intake than the lowest, and 8% lower per daily cup, in observational studies.

Compared with the lowest consumption level [11]

The numbers and sources
Effect
Against the lowest level of consumption, the pooled relative risk of depression was 0.757 (95% CI 0.624 to 0.917) for coffee and 0.721 (95% CI 0.522 to 0.997) for caffeine. Each extra cup a day was linked to 8% lower risk (RR 0.92, 95% CI 0.87 to 0.97) [11].
Population
330,677 participants in 7 studies of coffee, and 38,223 in 8 studies of caffeine [11].
Sources
[11]
Caveats
The review pooled case-control, cohort and cross-sectional studies. People with low mood may drink less coffee, which runs the link backward.
Limited

Focus and alertness

One trial found caffeinated coffee helped people take in new information and offset fatigue against decaffeinated coffee, with no change in working memory or mood.

Compared with decaffeinated coffee [12]; people drinking no coffee [13]

The numbers and sources
Effect
In 144 volunteers, caffeinated coffee had no effect on initial mood or working memory, improved encoding of new information and counteracted fatigue that built up over the test session, against decaffeinated coffee. It raised blood pressure and pulse [12]. In adults 60 or older, those drinking 266.4 to 495 g of coffee a day had lower odds of a low processing speed score (OR 0.56, 95% CI 0.35 to 0.89) than non-drinkers. Decaffeinated coffee was not linked to any cognitive score [13].
Population
144 volunteers, 72 men and 72 women, mean age 21, on one morning [12]. 2,513 US adults aged 60 or older, surveyed once [13].
Sources
[12], [13]
Caveats
One small single-morning trial, and a survey measured at one time point that cannot show cause. Trials of caffeine on attention are on the caffeine page.
Limited

Atrial fibrillation

One trial found less atrial fibrillation recurrence with about a cup a day than with abstaining from coffee, 47% against 64%, after cardioversion.

Compared with abstaining from coffee and caffeine [16]; people drinking one cup a day fewer [17]

The numbers and sources
Effect
In 200 coffee drinkers with persistent atrial fibrillation after electrical cardioversion, recurrence over 6 months was 47% with caffeinated coffee and 64% with abstinence (HR 0.61, 95% CI 0.42 to 0.89). Adverse events did not differ [16]. In 386,258 UK adults, each extra daily cup was linked to 3% lower risk of any arrhythmia (HR 0.97, 95% CI 0.96 to 0.98), and genetic analyses found no link between caffeine metabolism and arrhythmia [17].
Population
200 adults, mean age 69, 71% men, in an open-label randomized trial at 5 hospitals [16]. 386,258 UK Biobank participants followed a mean 4.5 years [17].
Sources
[16], [17]
Caveats
One open-label trial in people who already drank coffee and already had atrial fibrillation [16]. The cohort is observational.

Mixed results1

Moderate

Cancer

Mixed results: high intake was linked to 18% lower cancer incidence, while links to cancer death were small or absent in pooled cohorts.

Compared with the lowest intake group [2]; people drinking no coffee [3]

The numbers and sources
Effect
High against low consumption was linked to 18% lower incident cancer (RR 0.82, 95% CI 0.74 to 0.89), with lower risk of several specific cancers [2]. One dose-response meta-analysis found no link between coffee and cancer death [4]. A later one found cancer death lowest at 2 cups a day (RR 0.96, 95% CI 0.94 to 0.99) [3].
Population
Meta-analyses of observational studies [2]. 21 prospective studies [4]. 40 studies [3].
Sources
[2], [4], [3]
Caveats
Observational. Smoking is tied to both coffee drinking and cancer, and the umbrella review found harmful links largely disappeared with adequate adjustment for smoking [2].

Not shown to help1

Moderate

Blood pressure

Not shown to change blood pressure in pooled trials. Cohorts linked coffee to no change or slightly lower risk of high blood pressure.

Compared with less or no coffee [14]; people drinking no coffee [15]

The numbers and sources
Effect
Pooled randomized trials found no significant change in systolic (-0.55 mmHg, 95% CI -2.46 to 1.36) or diastolic pressure (-0.45 mmHg, 95% CI -1.52 to 0.61). Pooled cohorts found no link with developing hypertension (RR 1.03, 95% CI 0.98 to 1.08) [14]. A later dose-response analysis of cohorts found 2% lower hypertension risk per daily cup (RR 0.98, 95% CI 0.98 to 0.99), and 0.92 at 6 cups a day [15].
Population
10 randomized trials of at least 1 week and 5 cohorts [14]. 243,869 people and 58,094 hypertension cases in 10 cohort studies [15].
Sources
[14], [15], [12]
Caveats
The trial evidence was rated low in quality [14]. Caffeinated coffee raised blood pressure within the hour in a single-morning trial [12], and caffeine on its own raises it slightly (see the caffeine page).

Amounts studied

Cohorts grouped people by cups a day, from none up to 6 or more [7], and most reviews modeled risk per extra cup or per 2 extra cups [9]. No accepted definition of a cup exists across studies [10]. The atrial fibrillation trial asked for at least 1 cup a day, and the coffee group drank a median 7 cups a week [16]. The cholesterol and liver enzyme trial used 5 to 6 strong cups, 0.9 liters a day, for 24 weeks [18]. Trials of coffee and lipids lasted 45 days on average [19].

Risks

Reported risks5

LimitedVery common

Raised ALT liver enzyme from unfiltered coffee

Small trials found unfiltered coffee raised the liver enzyme ALT. In one, 8 of 22 people drinking 5 to 6 strong cups of French press coffee exceeded the normal limit.

The numbers and sources
How common
Very common: more than 1 in 10 people.
Effect
Against filtered coffee, cafetière coffee raised alanine aminotransferase by up to 80%, and by 45% (9 U/L, 95% CI 3 to 15) after 24 weeks. ALT exceeded the upper limit of normal in 8 of 22 people on cafetière coffee, twice the limit in 3. The abstract gives no count for the filtered coffee group. All rises reversed after stopping [18]. Eating 8 g of fine coffee grounds a day for 3 weeks raised ALT by 18 U/L (95% CI 4 to 32) against controls [21].
Population
46 adults, 22 on cafetière coffee and 24 on filtered coffee [18]. 14 volunteers in a parallel study and 15 in a crossover [21].
Sources
[18], [21]
Caveats
Small trials of high intakes of unfiltered coffee. Cohorts of all coffee types link coffee to lower liver disease (see Outcomes).
StrongHow often is not known

Higher LDL cholesterol from unfiltered coffee

Shown to raise total and LDL cholesterol in trials, mainly with unfiltered brews such as boiled or French press coffee. Filtered coffee raised it very little.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
Across 12 randomized trials averaging 45 days, coffee raised total cholesterol by 8.1 mg/dL (95% CI 4.5 to 11.6), LDL by 5.4 mg/dL (95% CI 1.4 to 9.5) and triglycerides by 12.6 mg/dL, more with unfiltered and caffeinated coffee and in people with high cholesterol [19]. An earlier pooling of 14 trials found a dose-response rise in total and LDL cholesterol with unfiltered coffee and very little with filtered coffee [20]. Five to 6 cups a day of cafetière coffee raised LDL by 0.26 mmol/L (95% CI 0.04 to 0.47) against filtered coffee over 24 weeks. Triglycerides first rose 26% and then returned near baseline [18].
Population
1,017 participants in 12 Western trials [19]. 14 trials [20]. 46 adults aged 19 to 69 [18].
Sources
[19], [20], [18]
Caveats
The trials attribute the rise to cafestol and kahweol, oily compounds present in unfiltered coffee [21]. The lipid trials were all in Western countries [19].
ModerateStudied in pregnancyHow often is not known

Low birth weight, preterm birth and pregnancy loss

Linked to more low birth weight, preterm birth and pregnancy loss at high intake during pregnancy, in pooled observational studies.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
High against low or no coffee during pregnancy was linked to low birth weight (OR 1.31, 95% CI 1.03 to 1.67), preterm birth in the first (OR 1.22, 95% CI 1.00 to 1.49) and second trimester (OR 1.12, 95% CI 1.02 to 1.22), and pregnancy loss (OR 1.46, 95% CI 1.06 to 1.99) [2]. Across 8 studies of coffee, pregnancy loss was more common in drinkers (OR 1.11, 95% CI 1.02 to 1.21), rising 8% per 2 extra cups a day [22].
Population
Meta-analyses of pregnant women [2]. 26 case-control and cohort studies in pregnancy, 8 of them on coffee [22].
Sources
[2], [22]
Caveats
Observational, and the abstracts do not give the intake that counted as high. The umbrella review found these links remained after adjustment for smoking, unlike most other harmful links [2].
LimitedHow often is not known

Shorter sleep

One randomized trial found 36 fewer minutes of nightly sleep on days people drank caffeinated coffee than on days they avoided caffeine.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
Nightly sleep was 397 minutes on coffee days and 432 minutes on caffeine-free days (mean difference 36 minutes, 95% CI 25 to 47), measured by wrist accelerometer [23].
Population
100 adults, mean age 39, 51% women, each randomized day by day for 14 days [23].
Sources
[23]
Caveats
One trial. Pooled trials of caffeine and sleep are on the caffeine page.
LimitedHow often is not known

Extra heartbeats from the lower chambers

One randomized trial found 51% more premature ventricular beats on coffee days than caffeine-free days, and no significant rise in atrial beats.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
Premature ventricular contractions averaged 154 a day on coffee days and 102 on caffeine-free days (rate ratio 1.51, 95% CI 1.18 to 1.94). Premature atrial contractions were 58 and 53 (rate ratio 1.09, 95% CI 0.98 to 1.20). Steps rose by 1,058 a day and glucose did not differ [23].
Population
100 adults wearing a continuous ECG for 14 days [23].
Sources
[23]
Caveats
One trial of 14 days. Extra beats were counted, not symptoms or harm.

Mixed results1

LimitedHow often is not known

Fracture

Mixed results: an umbrella review linked coffee to fracture in women but not men, while a meta-analysis found no link with hip fracture.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The umbrella review reported an association between coffee and fracture risk in women and not in men [2]. Pooling 14 studies, hip fracture risk at the highest against the lowest coffee intake was 0.94 (95% CI 0.71 to 1.17) [24].
Population
Meta-analyses of observational studies [2]. 195,992 people and 9,958 hip fractures in 6 cohort and 8 case-control studies [24].
Sources
[2], [24]
Caveats
Observational. The umbrella review abstract gives no effect size for women [2].

Claims tested and not found

  1. That coffee raises blood pressure over time. Pooled randomized trials found no significant change in systolic or diastolic pressure, and pooled cohorts no link with developing hypertension [14].
  2. That coffee brings on atrial fibrillation. In a trial after cardioversion, recurrence was lower with coffee than with abstinence [16]. In a 14-day randomized trial, atrial premature beats did not rise significantly [23], and genetic analyses found no link between caffeine metabolism and arrhythmia [17].
  3. That coffee lowers body weight. Genetic variants linked to higher coffee intake were not convincingly linked to obesity, body mass index or waist size [8].
  4. That coffee raises cancer death. A dose-response meta-analysis of 21 cohorts found no link between coffee and cancer death [4].

Related

Caffeine

Sources

  1. US Food and Drug Administration. Spilling the Beans: How Much Caffeine is Too Much? FDA Consumer Updates. Content current as of 2024-08-28. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
  2. Poole R, Kennedy OJ, Roderick P, et al. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ. 2017. https://doi.org/10.1136/bmj.j5024
  3. Kim Y, Je Y, Giovannucci E. Coffee consumption and all-cause and cause-specific mortality: a meta-analysis by potential modifiers. European Journal of Epidemiology. 2019. https://doi.org/10.1007/s10654-019-00524-3
  4. Crippa A, Discacciati A, Larsson SC, et al. Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis. American Journal of Epidemiology. 2014. https://doi.org/10.1093/aje/kwu194
  5. Cornelis MC, Munafò MR. Mendelian Randomization Studies of Coffee and Caffeine Consumption. Nutrients. 2018. https://doi.org/10.3390/nu10101343
  6. Ding M, Bhupathiraju SN, Satija A, et al. Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies. Circulation. 2014. https://doi.org/10.1161/circulationaha.113.005925
  7. 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. https://doi.org/10.2337/dc13-1203
  8. Nordestgaard AT, Thomsen M, Nordestgaard BG. Coffee intake and risk of obesity, metabolic syndrome and type 2 diabetes: a Mendelian randomization study. International Journal of Epidemiology. 2015. https://doi.org/10.1093/ije/dyv083
  9. Kennedy OJ, Roderick P, Buchanan R, et al. Systematic review with meta-analysis: coffee consumption and the risk of cirrhosis. Alimentary Pharmacology and Therapeutics. 2016. https://doi.org/10.1111/apt.13523
  10. Kennedy OJ, Roderick P, Buchanan R, et al. Coffee, including caffeinated and decaffeinated coffee, and the risk of hepatocellular carcinoma: a systematic review and dose-response meta-analysis. BMJ Open. 2017. https://doi.org/10.1136/bmjopen-2016-013739
  11. Wang L, Shen X, Wu Y, Zhang D. Coffee and caffeine consumption and depression: A meta-analysis of observational studies. Australian and New Zealand Journal of Psychiatry. 2016. https://doi.org/10.1177/0004867415603131
  12. Smith AP, Clark R, Gallagher J. Breakfast cereal and caffeinated coffee: effects on working memory, attention, mood, and cardiovascular function. Physiology and Behavior. 1999. https://doi.org/10.1016/s0031-9384(99)00025-6
  13. Dong X, Li S, Sun J, et al. Association of Coffee, Decaffeinated Coffee and Caffeine Intake from Coffee with Cognitive Performance in Older Adults: National Health and Nutrition Examination Survey (NHANES) 2011-2014. Nutrients. 2020. https://doi.org/10.3390/nu12030840
  14. Steffen M, Kuhle C, Hensrud D, et al. The effect of coffee consumption on blood pressure and the development of hypertension: a systematic review and meta-analysis. Journal of Hypertension. 2012. https://doi.org/10.1097/hjh.0b013e3283588d73
  15. Xie C, Cui L, Zhu J, et al. Coffee consumption and risk of hypertension: a systematic review and dose-response meta-analysis of cohort studies. Journal of Human Hypertension. 2018. https://doi.org/10.1038/s41371-017-0007-0
  16. Wong CX, Cheung CC, Montenegro G, et al. Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation: The DECAF Randomized Clinical Trial. JAMA. 2026. https://doi.org/10.1001/jama.2025.21056
  17. Kim EJ, Hoffmann TJ, Nah G, et al. Coffee Consumption and Incident Tachyarrhythmias: Reported Behavior, Mendelian Randomization, and Their Interactions. JAMA Internal Medicine. 2021. https://doi.org/10.1001/jamainternmed.2021.3616
  18. Urgert R, Meyboom S, Kuilman M, et al. Comparison of effect of cafetière and filtered coffee on serum concentrations of liver aminotransferases and lipids: six month randomised controlled trial. BMJ. 1996. https://doi.org/10.1136/bmj.313.7069.1362
  19. Cai L, Ma D, Zhang Y, et al. The effect of coffee consumption on serum lipids: a meta-analysis of randomized controlled trials. European Journal of Clinical Nutrition. 2012. https://doi.org/10.1038/ejcn.2012.68
  20. Jee SH, He J, Appel LJ, et al. Coffee consumption and serum lipids: a meta-analysis of randomized controlled clinical trials. American Journal of Epidemiology. 2001. https://doi.org/10.1093/aje/153.4.353
  21. Urgert R, Schulz AG, Katan MB. Effects of cafestol and kahweol from coffee grounds on serum lipids and serum liver enzymes in humans. The American Journal of Clinical Nutrition. 1995. https://doi.org/10.1093/ajcn/61.1.149
  22. Li J, Zhao H, Song JM, et al. A meta-analysis of risk of pregnancy loss and caffeine and coffee consumption during pregnancy. International Journal of Gynaecology and Obstetrics. 2015. https://doi.org/10.1016/j.ijgo.2015.03.033
  23. Marcus GM, Rosenthal DG, Nah G, et al. Acute Effects of Coffee Consumption on Health among Ambulatory Adults. The New England Journal of Medicine. 2023. https://doi.org/10.1056/nejmoa2204737
  24. Sheng J, Qu X, Zhang X, et al. Coffee, tea, and the risk of hip fracture: a meta-analysis. Osteoporosis International. 2014. https://doi.org/10.1007/s00198-013-2563-7

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