Coffee is one of the world’s most popular drinks. Millions of people start their day with a cup of coffee because it helps them feel more awake and alert.
Over the years, research has shown that coffee may have both health benefits and health risks. Some studies suggest it may lower the risk of diseases such as type 2 diabetes and certain liver diseases, while others have shown that some types of coffee can raise cholesterol. A
new study from Norway now suggests that the way coffee is brewed, and whether the drinker is a man or a woman, may make an important difference.
The study was published in the journal Open Heart and included more than 21,000 adults aged 40 years and older. The researchers wanted to better understand how different brewing methods affect cholesterol levels.
They were especially interested in espresso because it has become much more popular in recent years, but its long-term health effects are still being studied.
The scientists used information from the Tromsø Study, one of the world’s longest-running health studies. The project began in 1974 and follows people living in the Norwegian city of Tromsø. For this research, the team analyzed data collected during the 2015–2016 survey.
A total of 11,074 women and 10,009 men took part. Their average age was 56 years. Participants answered questions about how many cups of coffee they drank each day and which type they usually drank.
The researchers also collected blood samples to measure cholesterol. They considered other factors that could influence health, including diet, physical activity, education, smoking, and whether participants had type 2 diabetes.
The researchers compared several brewing methods. These included filtered coffee, espresso made using coffee machines, pods or mocha pots, French press coffee, also called plunger or cafetière coffee, and instant coffee.
The results showed that the brewing method mattered. Among people who drank three to five cups of espresso each day, cholesterol levels were higher than in people who did not drink espresso. The increase was larger in men than in women. Women’s cholesterol levels were about 0.09 mmol/L higher, while men’s levels were about 0.16 mmol/L higher.
French press coffee also increased cholesterol. Women who drank six or more cups each day had cholesterol levels about 0.30 mmol/L higher, while men had an increase of about 0.23 mmol/L.
Filtered coffee had a much smaller effect. Women who drank six or more cups of filtered coffee each day had a small increase in cholesterol, but the researchers did not find the same effect in men. Instant coffee caused only a slight increase in cholesterol in both men and women, and the increase did not become larger as people drank more cups.
The researchers believe these differences are linked to natural substances in coffee called diterpenes. Two of these compounds, cafestol and kahweol, are known to raise cholesterol levels.
Paper coffee filters remove most of these compounds before the coffee reaches the cup. Espresso and French press coffee do not use paper filters in the same way, so they usually contain more of these substances.
The study also found an interesting difference between men and women. Espresso showed the biggest difference between the sexes, with men appearing to be more affected. The scientists do not yet know why. Future research may investigate whether hormones, genetics, or differences in metabolism help explain this finding.
At the same time, the researchers pointed out that coffee is much more than just caffeine and diterpenes. Coffee contains more than one thousand natural plant compounds.
Some of these substances may reduce inflammation, protect the liver, and lower the risk of diseases such as cancer and type 2 diabetes. This means coffee can have both helpful and harmful effects at the same time.
The study also had some limitations. Participants reported their own coffee-drinking habits, which may not always be completely accurate. The researchers also did not measure the exact size of each cup. In addition, espresso prepared using different machines or coffee pods may contain different amounts of cafestol and kahweol.
Even with these limitations, the large number of participants makes the findings valuable. The results suggest that people who are concerned about their cholesterol, especially those who drink several cups every day, may benefit from choosing filtered coffee more often.
A simple paper filter removes most of the cholesterol-raising compounds while still allowing people to enjoy their daily coffee.
The researchers are not suggesting that people should stop drinking coffee altogether. Instead, the study shows that small changes in how coffee is prepared may help improve heart health. A
s scientists continue learning more about coffee and its many natural compounds, people will be better able to enjoy this popular drink while making choices that support their long-term health.
If you care about health, please read studies about the benefits of low-dose lithium supplements, and what we know about egg intake and heart disease.
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