Overview

Coffee is a popular drink made from the roasted beans of Coffea fruits (Coffea arabica, Coffea canephora). It contains caffeine and chlorogenic acid.

The caffeine in coffee works by stimulating the central nervous system (CNS), heart, and muscles. Chlorogenic acid might affect blood vessels and how the body handles blood sugar and metabolism.

People most commonly drink coffee to increase mental alertness. Coffee is also used for diabetes, cancer, heart disease, high blood pressure, dementia, and many other conditions, but there is no good scientific evidence to support most of these uses.

Don't confuse coffee with other caffeine sources, such as green coffee, black tea, and green tea. These are not the same.

How does it work ?

Uses & Effectiveness ?

Likely Effective for

  • Mental alertness. Drinking caffeinated coffee throughout the day seems to increase alertness and thinking skills. Caffeine can also improve alertness after sleep deprivation. Even one cup of caffeinated coffee can reduce fatigue and increase alertness.

Possibly Effective for

  • Diabetes. People who drink more coffee seem to have a lower risk of developing type 2 diabetes. The risk lowers more with each cup that's consumed. People with type 2 diabetes who drink more coffee might also have a slightly lower risk of dying.
  • Heart failure. Drinking caffeinated coffee seems to reduce the long-term risk of heart failure in people who do not have heart disease.
  • Death from any cause. Drinking coffee every day is linked to a slightly lower risk of dying from any cause or from heart disease. It's unclear if drinking coffee is linked with a lower risk of death from cancer.
  • Parkinson disease. Drinking caffeinated coffee seems to reduce the risk of developing Parkinson disease. The risk lowers more with each cup that's consumed in males, but not in females. Coffee doesn't seem to help prevent Parkinson disease in people who smoke cigarettes.
  • Impaired movement of food through the intestines after surgery. Drinking coffee might speed up the first stool and a person's ability to eat solid food after certain gut surgeries.

Possibly Ineffective for

  • Cancer of the esophagus. Drinking coffee doesn't seem to lower the risk of developing cancer of the esophagus.
There is interest in using coffee for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Insufficient Evidence for

  • Hardening of the arteries (atherosclerosis). The buildup of calcium-containing plaque in the arteries is an early sign of possible atherosclerosis. Drinking coffee doesn't seem to be linked with a lower buildup of calcium-containing plaque in the arteries.
  • Irregular heartbeat (atrial fibrillation). Drinking more coffee doesn't seem to be linked to a lower risk of atrial fibrillation.
  • Bladder cancer. Drinking coffee doesn't seem to change the risk of bladder cancer.
  • Brain cancer. Some early evidence suggests that Asian people who drink more coffee have a lower risk of developing brain cancer. This does not seem to be true for non-Asian people.
  • Breast cancer. People who drink more coffee don't seem to have a lower chance of developing breast cancer.
  • Heart disease. It is unclear if drinking coffee lowers the chance of developing heart disease. But it might lower the risk for heart failure and the likelihood of death from heart disease.
  • Long-term kidney disease (chronic kidney disease or CKD). People who drink coffee seem to have a slightly lower chance of developing CKD. People with CKD who drink coffee might have a slightly lower risk for kidney failure or death due to kidney failure.
  • Memory and thinking skills (cognitive function). There is developing evidence that drinking more coffee over a lifetime might improve thinking skills among women older than 80 years of age. Coffee also might improve the thinking speed and certain types of memory in healthy adults.
  • Colon cancer, rectal cancer. There is some evidence that Japanese people who drink more coffee have a lower chance of developing colon or rectal cancer. But research conducted in North America and Europe has not found a link between drinking coffee and the risk of colon and rectal cancer. Drinking more coffee seems to slightly reduce the risk of death in people who have colon or rectal cancer.
  • Diseases, such as Alzheimer disease, that interfere with thinking (dementia). People who drink more coffee don't seem to have a lower chance of dementia.
  • Depression. People who drink more coffee might have a lower chance of depression.
  • Cancer of the lining of the uterus (endometrial cancer). The effect of coffee on the risk of endometrial cancer is unclear. Some research suggests that women who drink more coffee have a lower risk of developing endometrial cancer. But other research has not found a link between drinking coffee and the risk of endometrial cancer.
  • Gallbladder disease. People who drink beverages such as coffee that provide at least 400 mg of caffeine per day seem to have a lower risk of developing gallstones. The greater the intake of caffeine, the lower the risk.
  • Stomach cancer. People who drink more coffee don't seem to have a lower risk of stomach cancer.
  • Gout. There is some evidence that both caffeinated and decaffeinated coffee seem to help to prevent gout. But caffeinated coffee seems to work better.
  • Hearing loss. Males who drink at least one cup of coffee daily seem to have a slightly lower chance of hearing loss. But drinking coffee doesn't seem to have this effect in females.
  • High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Some research suggests that drinking caffeinated coffee seems to reduce levels of total cholesterol, LDL or "bad cholesterol", and blood fats called triglycerides by a small amount. But other research suggests that drinking coffee increases triglyceride and cholesterol levels.
  • High blood pressure. People who drink coffee long-term might have a lower risk for high blood pressure. But smoking might eliminate this benefit. Drinking 1-3 cups daily seems to be most beneficial.
  • Low blood pressure. Drinking caffeinated beverages like coffee seems to increase blood pressure in elderly people who experience dizziness after meals due to low blood pressure.
  • Kidney failure. People with long-term kidney disease who drink coffee seem to have a slightly lower chance of kidney failure or death due to kidney failure.
  • Liver cancer. People who drink more coffee might have a lower risk of liver cancer.
  • Liver disease. People who drink more coffee might have a lower risk of liver disease.
  • Lung cancer. Some research suggests that drinking caffeinated coffee may help to prevent lung cancer, but other research disagrees. It's too early to draw firm conclusions. Meanwhile, some research suggests that drinking decaffeinated coffee may help to prevent lung cancer.
  • The most serious type of skin cancer (melanoma). When factors such as age and sun exposure are taken into account, drinking coffee doesn't seem to be linked with a lower chance of developing skin cancer.
  • Build up of fat in the liver in people who drink little or no alcohol (nonalcoholic fatty liver disease or NAFLD). It's unclear if drinking coffee reduces the risk of NAFLD.
  • Nonmelanoma skin cancer. Some research shows that drinking many cups of coffee per day might reduce the risk of a specific form of skin cancer called basal cell carcinoma. But drinking decaffeinated coffee does not seem to have any effect on skin cancer risk.
  • Obesity. The effect of coffee on weight loss in people who are overweight or obese is unclear. Results from research are conflicting. Some research suggests that taking coffee chemicals, called mannooligosaccharides, for 12 weeks might help with weight loss in men, but not women. Drinking a dark roast coffee seems to help reduce food intake and help with weight loss, whereas a light roast coffee does not. Other research suggests that drinking coffee with or without caffeine does not help with weight loss.
  • Mouth cancer. People who drink more coffee don't seem to have a lower risk of mouth cancer.
  • Ovarian cancer. Drinking coffee doesn't seem to change a person's risk for ovarian cancer.
  • Swelling (inflammation) of the pancreas (pancreatitis). Some early research suggests that drinking 3 or more cups of coffee reduces the pancreatitis risk.
  • A type of throat cancer (pharyngeal cancer). People who drink more coffee might have a lower chance of developing pharyngeal cancer.
  • Prostate cancer. In general, people who drink more coffee seem to have a slightly lower risk of developing prostate cancer that has not spread outside the prostate.
  • Thyroid cancer. Drinking more coffee seems to be linked with a lower risk of thyroid cancer.
  • Attention deficit-hyperactivity disorder (ADHD).
  • Constipation.
  • Other conditions.
More evidence is needed to rate the effectiveness of coffee for these uses.

Side Effects

When taken by mouth: Coffee is commonly consumed as a beverage. Drinking coffee in moderate amounts (about 4 cups daily) is likely safe for most people.

Drinking more than 4 cups of coffee daily is possibly unsafe. Drinking large amounts might cause side effects due to the caffeine content. These side effects can range from mild to serious and include headache and irregular heartbeat.

When given as an enema (rectally): Coffee is possibly unsafe. Coffee enemas have been linked to cases of severe side effects, including death.

Special Precautions and Warnings

Pregnancy: Drinking moderate amounts of coffee during pregnancy is possibly safe. Do not drink more than 3 cups of coffee daily. This provides about 300 mg of caffeine. Consuming more than this during pregnancy is possibly unsafe and has been linked to an increased risk of miscarriage, increased risk of sudden infant death syndrome (SIDS), and other negative effects, including symptoms of caffeine withdrawal in newborns and a lower birth weight.

Breast-feeding: Drinking 1-2 cups of coffee daily while breast-feeding is possibly safe. But drinking larger amounts is possibly unsafe. The caffeine in coffee is passed into breastmilk. It might cause irritability and increased bowel movements in nursing infants.

Children: Caffeinated coffee is possibly safe in children when consumed in the normal amounts found in food and beverages.

Anxiety disorders: The caffeine in coffee might make anxiety worse.

Bipolar disorder: The caffeine in coffee might make symptoms of mania worse.

Bleeding disorders: The caffeine in coffee might slow blood clotting and make bleeding disorders worse.

Heart disease: Drinking coffee on a daily basis doesn't seem to increase the risk for serious complications from heart disease. But people who smoke and have heart disease might have an increased risk of dying from heart disease if they consume coffee daily.

Diabetes: The caffeine in coffee might affect blood sugar. Use coffee with caution if you have diabetes.

Diarrhea: The caffeine in coffee, especially when taken in large amounts, can worsen diarrhea.

Seizures: Coffee contains caffeine. People with epilepsy should avoid using caffeine in high doses. Low doses of caffeine should be used cautiously.

Glaucoma: Drinking caffeinated coffee increases pressure inside the eye. The increase starts within 30 minutes and lasts for at least 90 minutes. If you have glaucoma, drink coffee with caution.

High blood pressure: Drinking caffeinated coffee might increase blood pressure in people with high blood pressure. But this doesn't seem to occur in people who drink caffeinated products regularly.

Irritable bowel syndrome (IBS): Coffee contains caffeine. The caffeine in coffee, especially when taken in large amounts, may worsen diarrhea and other symptoms of IBS.

Loss of bladder control: Coffee contains caffeine. Caffeine can make bladder control worse by increasing frequency of urination and the urge to urinate.

Smoking: People who smoke and drink coffee might have an increased risk of dying from heart disease or cancer.

Thinning bones (osteoporosis): Drinking caffeinated coffee can increase the amount of calcium that is flushed out in the urine. This might weaken bones. If you have osteoporosis, don't drink more than 3 cups of coffee daily. If you are generally healthy and get enough calcium from your food or supplements, drinking about 4 cups of coffee daily doesn't seem to increase the risk of getting osteoporosis.

Interactions ?

    Major Interaction

    Do not take this combination

  • Ephedrine interacts with COFFEE

    Stimulant drugs speed up the nervous system. Caffeine, which is found in coffee, and ephedrine are both stimulant drugs. Drinking coffee and taking ephedrine might cause too much stimulation and sometimes serious side effects and heart problems. Do not take caffeine-containing products and ephedrine at the same time.

    Moderate Interaction

    Be cautious with this combination

  • Adenosine (Adenocard) interacts with COFFEE

    The caffeine in coffee might block the effects of adenosine, which is used to do a test called a cardiac stress test. Stop consuming coffee or other caffeine-containing products at least 24 hours before a cardiac stress test.

  • Alendronate (Fosamax) interacts with COFFEE

    Coffee can decrease how much alendronate the body absorbs. Taking coffee and alendronate at the same time can decrease the effects of alendronate. Don't drink coffee within two hours of taking alendronate.

  • Antibiotics (Quinolone antibiotics) interacts with COFFEE

    Coffee contains caffeine. The body breaks down caffeine to get rid of it. Some antibiotics might decrease how quickly the body breaks down caffeine. Taking these antibiotics along with coffee might increase the risk of side effects including jitteriness, headache, increased heart rate, and other side effects.

  • Birth control pills (Contraceptive drugs) interacts with COFFEE

    Coffee contains caffeine. The body breaks down caffeine to get rid of it. Birth control pills can decrease how quickly the body breaks down caffeine. This might increase the risk for side effects from caffeine, such as jitteriness, headache, and fast heartbeat.

  • Cimetidine (Tagamet) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Cimetidine can decrease how quickly the body breaks down caffeine. Taking cimetidine along with coffee might increase the chance of caffeine side effects including jitteriness, headache, and fast heartbeat.

  • Clozapine (Clozaril) interacts with COFFEE

    The body breaks down clozapine to get rid of it. The caffeine in coffee might decrease how fast the body breaks down clozapine. Taking coffee along with clozapine can increase the effects and side effects of clozapine.

  • Dipyridamole (Persantine) interacts with COFFEE

    The caffeine in coffee might block the effects of dipyridamole. Dipyridamole is often used by doctors to do a test on the heart called a cardiac stress test. Stop drinking coffee or other caffeine-containing products at least 24 hours before a cardiac stress test.

  • Disulfiram (Antabuse) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Disulfiram can decrease how quickly the body gets rid of caffeine. Taking coffee along with disulfiram might increase the risk of caffeine side effects, including jitteriness, irritability, and fast heartbeat.

  • Estrogens interacts with COFFEE

    The body breaks down caffeine to get rid of it. Estrogens can decrease how quickly the body breaks down caffeine. Taking estrogen along with coffee can increase the risk of side effects such as jitteriness, headache, and fast heartbeat.

  • Fluvoxamine (Luvox) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Fluvoxamine can decrease how quickly the body breaks down caffeine. Taking caffeine along with fluvoxamine might increase the risk of caffeine side effects.

  • Levothyroxine (Synthroid, others) interacts with COFFEE

    Drinking coffee might reduce the amount of levothyroxine that is absorbed when taken by mouth. This can decrease how well levothyroxine works. Avoid drinking coffee for at least an hour after taking levothyroxine.

  • Lithium interacts with COFFEE

    The caffeine in coffee can increase how quickly the body gets rid of lithium. If you take products that contain caffeine and you take lithium, don't stop drinking coffee suddenly. Instead, slowly reduce intake of coffee. Stopping caffeine too quickly can increase the side effects of lithium.

  • Medications for depression (MAOIs) interacts with COFFEE

    Coffee contains caffeine. There is some concern that caffeine can interact with certain medications, called MAOIs. If caffeine is taken with these medications, it might increase the risk for serious side effects including fast heartbeat and very high blood pressure.

    Some common MAOIs include phenelzine (Nardil), selegiline (Zelapar), and tranylcypromine (Parnate).

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with COFFEE

    Coffee might slow blood clotting. Taking coffee along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

  • Pentobarbital (Nembutal) interacts with COFFEE

    Coffee contains caffeine. The stimulant effects of caffeine can block the sleep-producing effects of pentobarbital.

  • Phenylpropanolamine interacts with COFFEE

    The caffeine in coffee can stimulate the body. Phenylpropanolamine can also stimulate the body. Taking caffeine and phenylpropanolamine together might cause too much stimulation and increase heartbeat, blood pressure, and cause nervousness.

  • Riluzole (Rilutek) interacts with COFFEE

    The body breaks down riluzole to get rid of it. Drinking coffee can decrease how fast the body breaks down riluzole. This can increase the effects and side effects of riluzole.

  • Stimulant drugs interacts with COFFEE

    Stimulants, such as amphetamines and cocaine, speed up the nervous system. By speeding up the nervous system, stimulant medications can increase blood pressure and speed up the heartbeat. Coffee contains caffeine. Caffeine can also speed up the nervous system. Taking coffee along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure.

  • Theophylline interacts with COFFEE

    The caffeine in coffee works similarly to theophylline. Caffeine can also decrease how quickly the body gets rid of theophylline. Drinking coffee and taking theophylline might increase the effects and side effects of theophylline.

  • Verapamil (Calan, others) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Verapamil can decrease how quickly the body gets rid of caffeine. Drinking coffee and taking verapamil can increase the risk of caffeine side effects including jitteriness, and fast heartbeat.

  • Medications for asthma (Beta-adrenergic agonists) interacts with COFFEE

    Coffee contains caffeine. Caffeine can stimulate the heart. Some medications for asthma can also stimulate the heart. Taking caffeine with some medications for asthma might cause too much stimulation and cause heart problems.

  • Nicotine interacts with COFFEE

    Coffee contains caffeine. Taking coffee along with nicotine might cause a fast heartbeat and increase blood pressure.

  • Water pills (Diuretic drugs) interacts with COFFEE

    Coffee contains caffeine. Caffeine, especially in large amounts, can reduce potassium levels in the body. "Water pills" can also decrease potassium levels in the body. Taking large amounts of caffeine along with "water pills" might decrease potassium levels too much.

    Minor Interaction

    Be watchful with this combination

  • Alcohol (Ethanol) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Alcohol can decrease how quickly the body breaks down caffeine. Taking coffee along with alcohol might increase the risk of caffeine side effects including jitteriness, headache, and fast heartbeat.

  • Fluconazole (Diflucan) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Fluconazole might decrease how quickly the body gets rid of caffeine. Taking fluconazole and drinking coffee might increase the risk of caffeine side effects, including jitteriness and fast heartbeat.

  • Medications for depression (Tricyclic antidepressants) interacts with COFFEE

    Coffee contains chemicals called tannins. Tannins can bind to certain medications for depression (tricyclic antidepressants) and decrease how much medicine the body absorbs. To avoid this interaction, avoid coffee one hour before and two hours after taking these medications.

  • Medications for diabetes (Antidiabetes drugs) interacts with COFFEE

    Coffee might increase blood sugar levels. Taking coffee along with diabetes medications might reduce the effects of these medications. Monitor your blood sugar closely.

  • Mexiletine (Mexitil) interacts with COFFEE

    Coffee contains caffeine. The body breaks down caffeine to get rid of it. Mexiletine can decrease how quickly the body breaks down caffeine. Taking mexiletine along with coffee might increase the risk of caffeine side effects.

  • Phenothiazines interacts with COFFEE

    Coffee contains chemicals called tannins. Tannins can bind to phenothiazines and decrease how much medicine the body absorbs. To avoid this interaction, avoid coffee one hour before and two hours after taking these medications.

  • Terbinafine (Lamisil) interacts with COFFEE

    The body breaks down the caffeine in coffee to get rid of it. Terbinafine can decrease how fast the body gets rid of caffeine and increase the risk of caffeine side effects including jitteriness and fast heartbeat.

Dosing

Coffee is commonly consumed by adults as a beverage, typically in amounts of 2 cups daily. This provides about 250 mg of caffeine. Speak with a healthcare provider to find out what dose might be best for a specific condition.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2018.