Description
coffee, beverage brewed from the roasted and ground seeds of the tropical evergreen coffee plants of African origin. Coffee is one of the three most popular beverages in the world (alongside water and tea) and one of the most profitable international commodities. Though coffee is the basis for an endless array of beverages, including espresso, cappuccinos, mochas, and lattes, its popularity is mainly attributed to its invigorating effect, which is produced by caffeine, an alkaloid present in coffee.
Two species of coffee plants, Coffea arabica and C. canephora, supply almost all of the world’s consumption. Arabica is considered a milder and more flavourful and aromatic brew than Robusta, the main variety of C. canephora. The flatter and more elongated Arabica bean is more widespread than Robusta but more delicate and vulnerable to pests, requiring a cool subtropical climate; Arabica must grow at higher elevations (2,000–6,500 feet [600–2,000 metres]), it needs a lot of moisture, and it has fairly specific shade requirements. Latin America, eastern Africa, Asia, and Arabia are leading producers of Arabica coffee. The rounder, more convex Robusta bean, as its name suggests, is hardier and can grow at lower altitudes (from sea level to 2,000 feet). Robusta coffee is cheaper to produce, has twice the caffeine content of Arabica, and is typically the bean of choice for inexpensive commercial coffee brands. Western and Central Africa, Southeast Asia, and Brazil are major producers of Robusta coffee.
Some potential health benefits associated with Trusted Source drinking coffee include protection against type 2 diabetes, Parkinson’s disease, liver disease, and liver cancer. Coffee consumption may also support cardiovascular health.
The sections below cover these benefits in more detail.
Coffee and diabetes
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 2017 meta-analysis Trusted Source 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.
Coffee and Parkinson’s disease
Various studies have suggested 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 disease than those who do not.
The findings of the 2017 meta-analysis Trusted Source 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 disease.
However, there was not enough evidence to prove that drinking decaffeinated coffee helps prevent Parkinson’s disease.
Coffee and chronic liver disease or cancer
In 2019, a literature review Trusted Source concluded that coffee intake is likely to reduce the risk of liver cancer.
Earlier, in 2015, a cohort study of a multiethnic population in the United States suggested that depending on the dose, consuming two to three cups of coffee daily reduced the participants’ risk of developing hepatocellular carcinoma and chronic liver disease (CLD) by 38% and 46%Trusted Source, respectively.
The meta-analysis from 2017 Trusted Source also concluded that consuming any type of coffee appears to reduce the risk of liver cancer, nonalcoholic fatty liver disease, and cirrhosis. These findings are now bolstered by a 2021 study Trusted Source suggesting that consuming all types of coffee may offer some protection against CLD.
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 with primary 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 Trusted Source 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, another 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%Trusted Source.
Coffee and heart health
The 2017 meta-analysis Trusted Source found that caffeine consumption may have at least a small benefit for cardiovascular health, including blood pressure.
In a 2018 study, researchers found that drinking three to five cups of coffee per day may reduce the risk of cardiovascular disease by 15%. Drinking one to five cups daily also seemed to be associated with lower overall mortality resulting from any cause.
For those people who have already experienced a heart attack, drinking coffee does not appear to increase their risk of experiencing another or dying as a result.
The 2017 meta-analysis, however, also found that there may be higher levels of blood lipids (fat) and cholesterol in people who consume more coffee. These substances may predispose a person to heart problems.
Does decaffeinated coffee have benefits or risks?
Coffee and obesity
There is some evidence suggesting that consuming coffee may help people lose weight. One 2018 paper Trusted Source indicated that the more coffee the participants drank, the higher their mean reduction in weight, body mass index (BMI), and fat mass.
A 2019 study Trusted Source suggested that drinking coffee may have a modest association with weight loss, with a greater association in men than in women. However, these results have not been replicated, so they may not be definitive.
Although coffee may provide some benefits in reducing obesity, it is not a substitute for eating a balanced diet and exercising often.
Drinking a lot of coffee can also have some adverse effects Trusted Source. These may include the following.
Bone fractures
Some studies have suggested 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.
Complications during pregnancy
Coffee consumption may also not be safe during pregnancy. In fact, there is some evidence to suggest a link between high coffee consumption and pregnancy loss, low birth weight, and preterm birth.
Endometriosis
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.
Anxiety
Consuming high amounts of caffeine may increase the risk Trusted Source of anxiety, especially among people with panic disorder or social anxiety disorder. Less commonly, caffeine may trigger mania and psychosis in those who are susceptible.
Mental health conditions
One study from 2016 Trusted Source concluded that a high intake of caffeine during adolescence could 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.
Exposure to toxic ingredients
In 2015, a group of 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 acrylamide, which is another chemical present in coffee, may be dangerous.
