Health benefits and risks of drinking coffee
Worldwide, experts estimate that people consume around 2.25 billion cups of coffee per day.
Researchers have looked at the benefits of drinking coffee for conditions such as diabetes, cardiovascular disease, inflammatory bowel disease, and liver disease. There is evidence to support some, but not all, of these claims.
Coffee contains a number of useful nutrients, including riboflavin (vitamin B-2), niacin (vitamin B-3), magnesium, potassium, and various phenolic compounds, or antioxidants. Some experts suggest that these and other ingredients in coffee can benefit the human body in various ways.
This article looks at the health benefits of drinking coffee, the evidence supporting those benefits, and the risks of drinking coffee.
5 benefits of drinking coffee
The potential health benefits associated with drinking coffee include:
- protection against type 2 diabetes, Parkinson's disease, liver disease, and liver cancer
- the promotion of a healthy heart
In the sections below, we cover these benefits in more detail.
1. Coffee and diabetes
Coffee may help prevent type 2 diabetes and some other conditions.
Coffee may help protect against type 2 diabetes.
In 2014, researchers who gathered data on over 48,000 people found that those who increased their coffee consumption by at least one cup per day over 4 years had an 11% lower risk of type 2 diabetes than those who did not increase their intake.
A meta-analysis from 2017 concluded that people who drank four to six cups of either caffeinated or decaffeinated coffee each day appeared to have a lower risk of metabolic syndrome, including type 2 diabetes.
2. Coffee and Parkinson's disease
Various studies have shown that caffeine, which is present in coffee and many other beverages, may help protect against Parkinson's disease.
One team concluded that men who drink over four cups of coffee per day might have a fivefold lower risk of Parkinson's than those who do not.
In addition, the caffeine in coffee may help control movement in people with Parkinson's, according to one 2012 study.
The findings of a 2017 meta-analysis suggested a link between coffee consumption and a lower risk of Parkinson's disease, even among people who smoke. This team also found that people who drink coffee may be less likely to experience depression and cognitive conditions such as Alzheimer's.
There was not enough evidence to prove that drinking decaffeinated coffee would help prevent Parkinson's disease, however.
3. Coffee and liver cancer
Italian researchers found that coffee consumption lowers the risk of liver cancer by around 40%. Some of the results suggest that people who drink three cups per day might have a 50% lower risk.
Also, a 2019 literature review concluded that "coffee intake probably reduce the risk of liver cancer."
4. Coffee and other liver diseases
People who consume coffee may also have a lower risk of gallstone disease.
In 2014, researchers looked at coffee consumption among people withprimary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). These are autoimmune conditions that affect the bile ducts in the liver.
They found that people with PSC were more likely to have a lower coffee intake than those without the condition. There was no evidence to suggest that coffee intake was different among people with or without PBC.
Also, one 2014 study suggested a link between coffee consumption and a lower risk of dying from nonviral hepatitis-related cirrhosis. The researchers suggested that drinking two or more cups of coffee every day might reduce the risk by 66%.
5. Coffee and heart health
People who drank moderate amounts of coffee each day had an 11% lower risk of heart failure than those who did not.
Some studies, however, found higher levels of blood lipids (fat) and cholesterol in people who consumed more coffee.
Does decaf coffee have benefits or risks? Learn more here.
Coffee is low in calories, but adding sugar and cream will change its nutritional value.
Regular black coffee (without milk or cream) is low in calories. In fact, a typical cup of black coffee only contains around 2 calories. However, adding cream or sugar will increase the calorific value.
Coffee beans also contain polyphenols, a type of antioxidant.
Antioxidants can help rid the body of free radicals, a type of waste product that the body naturally produces as a result of certain processes.
In 2018, some researchers suggested that the antioxidant content of coffee may offer protection from metabolic syndrome.
The author of one article from 2017 note that although scientists can prove that certain compounds are present in coffee beans, it remains unclear what happens to them once they enter the human body.
Drinking too much coffee can also have some adverse effects. In the sections below, we cover some of these risks.
Some studies have found that women who drink a lot of coffee may have a higher risk of bone fractures.
Men with a higher coffee intake, on the other hand, appear to have a slightly lower risk.
The researchers added that coffee consumption may not be safe during pregnancy. In fact, there is some evidence to suggest a link between high coffee consumption and pregnancy loss, a low birth weight, and preterm birth.
There may be a higher risk of endometriosis among women who drink coffee, but there is not enough evidence to confirm such a link.
Gastroesophageal reflux disease
People who drink a lot of coffee may have a slightly higher risk of this condition.
Consuming high amounts of caffeine may increase the risk of anxiety, especially among people with panic disorder or social anxiety disorder. Less commonly, it may trigger mania and psychosis in those who are susceptible.
One study from 2016 concluded that a high intake of caffeine during adolescence can lead to permanent changes in the brain.
The scientists behind the study expressed concern that this could increase the risk of anxiety-related conditions in adulthood.
Presence of toxic ingredients
In 2015, researchers found relatively high levels of mycotoxins in commercial coffee. Mycotoxins are toxic substances that can contaminate coffee as a natural product.
Some people worry that acrymalide, another chemical present in coffee, may be dangerous. Find out more here.
Drinking three to four cups of coffee per day may have health benefits.
One meta-analysis from 2017 concluded that it is "generally safe" for most people to consume three to four cups of coffee per day, and that doing so may actually reduce the risk of certain health conditions.
The study authors warned, however, that smoking may cancel out any benefits of drinking coffee.
Caffeine is an important feature of coffee, but coffee contains many compounds, and there are different ways of drinking it. This makes it difficult to determine exactly how coffee affects a person and which components have which benefits and risks.
A person who wishes to derive health benefits from coffee should avoid exceeding the daily recommended intake and try to monitor the ingredients they add, such as sugar, cream, or flavorings, as these may not be healthful.
Pregnant women and those at risk of bone fractures may wish to avoid coffee.
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