Coffee lovers around the world who reach for their favorite morning brew probably aren’t thinking about its health benefits or risks. And yet this beverage has been subject to a long history of debate. In 1991 coffee was included in a list of possible carcinogens by the World Health Organization. By 2016 it was exonerated, as research found that the beverage was not associated with an increased risk of cancer; on the contrary, there was a decreased risk of certain cancers among those who drink coffee regularly once smoking history was properly accounted for. Additional accumulating research suggests that when consumed in moderation, coffee can be considered a healthy beverage. Why then in 2018 did one U.S. state pass legislation that coffee must bear a cancer warning label? Read on to explore the complexities of coffee.
Coffee and Health
While past studies hinted that coffee might have a dark side, newer research suggests that it may actually have health benefits.
Why the reversal? It’s hard to look at just one aspect of diet and connect it to a health condition because so many other factors that could play a role. For example, early research on coffee didn’t always take into account that heavy coffee drinkers also tended to use tobacco and be sedentary.
When newer studies adjusted for such factors, they found a possible association between coffee and decreased mortality. Coffee may offer some protection against:
Type 2 diabetes
Liver disease, including liver cancer
Heart attack and stroke
Coffee still has potential risks, mostly due to its high caffeine content. For example, it can temporarily raise blood pressure. Women who are pregnant, trying to become pregnant or breastfeeding need to be cautious about caffeine. High intake of boiled, unfiltered coffee has been associated with mild increase in cholesterol levels.
The bottom line? Your coffee habit is probably fine and may even have some benefits. But if you have side effects from coffee, such as heartburn, nervousness or insomnia, consider cutting back.
Coffee and heart health
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.
Coffee and chronic liver disease or cancer
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 2017Trusted 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.
Nutrition in Coffee
Coffee contains a number of useful nutrients, including riboflavin (vitamin B2), niacin (vitamin B3), 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.
Vitamin B2 (riboflavin): 11% of
Vitamin B5 (pantothenic acid): 6% of
Vitamin B1 (thiamine): 2% of
Vitamin B3 (niacin): 2% of
Folate: 1% of the DV
Manganese: 3% of the DV
Potassium: 3% of the DV
Magnesium: 2% of the DV
Phosphorus: 1% of the DV
Low to moderate doses of caffeine (50–300 mg) may cause increased alertness, energy, and ability to concentrate, while higher doses may have negative effects such as anxiety, restlessness, insomnia, and increased heart rate.  Still, the cumulative research on coffee points in the direction of a health benefit.
Drinking a lot of coffee can also have some adverse effects
Some studies have suggested that women who drink a lot of coffee may have a higher risk of bone fractures.
adverse interactions with particular, medications such as certain psychiatric drugs, thyroid medications, heartburn drugs, and antibiotics
Possible spinal bone loss in women who drink more than 300 milligrams (mg) per day and who do not consume enough calcium
An increase in blood pressure
An increase in the risk of myocardial ischemia, which is a type of heart disease, if a person consumes coffee during exercise
Fertility difficulties trusted Source
Negative effects on a growing fetus, such as low birth weight, if a person consumes a large amount of coffee during pregnancy
Irritability and insomnia in nursing infants, if a person consumes coffee during lactation
If you drink more than 4 cups of coffee a day
Frequent urination or inability to control urination.