Latte, cold brew, dalgona, flat white, espresso — there are seemingly infinite formulations of coffee. Bean juice is a beverage we can't get enough of: In America, 83 percent of adults regularly down coffee, contributing to a 30 billion dollar industry.
People love a cup of joe, but one question persists: How does drinking coffee actually affect our health?
In a recent, comprehensive analysis that stacked brewing methods head to head, researchers analyzed the health effects of an essential part of drinking coffee — how you make it.
One method came out on top: After following the health outcomes and coffee drinking habits of over half a million people in Norway for 20 years, the team found that moderately drinking filtered coffee resulted in the lowest risk of cardiovascular mortality.
Based on these findings, it seems that drinking filtered coffee (or drip coffee) is the healthiest way to consume the beverage. The scientists report that it appears to help people stave off disease and early death — and it may even boost longevity. Oddly enough, drinking filtered coffee could be healthier than skipping coffee altogether (whether or not coffee is "good for you" is a on-going debate).
"Our study provides strong and convincing evidence of a link between coffee brewing methods, heart attacks, and longevity," Dag Thelle, co-author of the new study and a researcher at the University of Gothenburg, Sweden, says.
This study was published Wednesday in the European Journal of Preventive Cardiology.
In contrast, unfiltered coffee is the most dangerous brewing approach, according to this analysis. Unfiltered coffee methods involve letting coffee grounds sit for a prolonged period of time in hot water. It (perhaps, unfortunately) is a category of coffee that includes some of the most delicious brews: espressos, cappuccinos, Turkish coffee, and coffee made with a French press.
This is because unfiltered coffee contains substances that spike "bad" LDL cholesterol, including diterpenes, kahweol, and cafestol. A single cup of unfiltered coffee contains about 30 times the concentration of the lipid-raising substances compared to filtered coffee, the study reports.
"Unfiltered coffee contains substances which increase blood cholesterol," Thelle explains. "Using a filter removes these and makes heart attacks and premature death less likely."
To see which method reigned supreme, the researchers rounded up a representative sample of the Norwegian population: 508,747 healthy men and women, aged between 20 to 79.
These participants were tracked from 1985 to 2003. The researcher's surveyed the group's coffee habits, including what type and how much coffee they drank regularly. They also documented other lifestyle factors like smoking, weight, physical activity, education, blood pressure, and cholesterol, that influence heart health.
Fifty-nine percent of participants preferred filtered coffee while 20 percent preferred unfiltered brew. Nine percent drank both and 12 percent did not drink coffee.
By 2003, when the study concluded, a total of 46,341 participants had died. Of those, 12,621 deaths were due to cardiovascular disease. Of the cardiovascular deaths, 6,202 were caused by a heart attack.
When the researchers analyzed the participants' coffee habits, they observed some striking patterns.
Overall, coffee drinking was not a dangerous habit. In fact, drinking filtered coffee was associated with a 15 percent reduced risk of death from any cause compared to people who didn't drink coffee at all. While this study can't prove the coffee drinking helped the participant's health, the authors theorize that these positive effects may stem from the fact that coffee is rich in antioxidants, including polyphenols.
The lowest mortality was among people who drank one to four cups of filtered coffee per day.
In turn, drinking filtered coffee was observed to be less risky than unfiltered coffee, when it came to the likelihood of death due to cardiovascular disease and death from heart attacks.
Interestingly, unfiltered coffee did not raise the risk of death compared to abstaining from coffee — except in men aged 60 and above, where unfiltered brew was linked with elevated cardiovascular mortality. This jibes with previous research, which linked a high intake of unfiltered coffee to a mild increase in cholesterol.
More research, on populations outside Norway and on older populations, is needed to clarify the study's findings. At the end of the day, die-hard French press lovers might not give up their habit. But swapping in a cup of drip coffee every once in a while could be wise, Thelle argues.
"For people who know they have high cholesterol levels and want to do something about it, stay away from unfiltered brew," Thelle says. "For everyone else, drink your coffee with a clear conscience and go for filtered."
Aim: The aim of this study was to investigate whether the coffee brewing method is associated with any death and cardiovascular mortality, beyond the contribution from major cardiovascular risk factors.
Methods and results: Altogether, 508,747 men and women aged 20–79 participating in Norwegian cardiovascular surveys were followed for an average of 20 years with respect to cause-specific death. The number of deaths was 46,341 for any cause, 12,621 for cardiovascular disease (CVD), 6202 for ischemic heart disease (IHD), and 2894 for stroke. The multivariate adjusted hazard ratios (HRs) for any death for men with no coffee consumption as reference were 0.85 (082–0.90) for filtered brew, 0.84 (0.79–0.89) for both brews, and 0.96 (0.91–1.01) for unfiltered brew. For women, the corresponding figures were 0.85 (0.81–0.90), 0.79 (0.73–0.85), and 0.91 (0.86–0.96) for filtered, both brews, and unfiltered brew, respectively. For CVD, the figures were 0.88 (0.81–0.96), 0.93 (0.83–1.04), and 0.97 (0.89–1.07) in men, and 0.80 (0.71–0.89), 0.72 (0.61–0.85), and 0.83 (0.74–0.93) in women. Stratification by age raised the HRs for ages !60 years. The HR for CVD between unfiltered brew and no coffee was 1.19 (1.00–1.41) for men and 0.98 (0.82–1.15) for women in this age group. The HRs for CVD and IHD were raised when omitting total cholesterol from the model, and most pronounced in those drinking !9 of unfiltered coffee, per day where they were raised by 9% for IHD mortality. Conclusion: Unfiltered brew was associated with higher mortality than filtered brew, and filtered brew was associated with lower mortality than no coffee consumption.
Conclusion: Unfiltered brew was associated with higher mortality than filtered brew, and filtered brew was associated with lower mortality than no coffee consumption.
LONGEVITY HACKS is a regular series from Inverse on the science-backed strategies to live better, healthier, and longer without medicine.
HOW THIS AFFECTS LONGEVITY — This study shows how moderately drinking filtered coffee can lead to less risk of heart disease and mortality compared to unfiltered methods of brewing like French press, cappuccinos, or Turkish and Greek styles of coffee.
WHY IT’S A HACK — The data on the health merits of coffee are mixed but this comprehensive analysis reveals a moderate filtered coffee habit doesn't jeopardize health. In fact, it might help you stave off disease and live longer.
SCIENCE IN ACTION — For the millions of people who already drink coffee regularly, putting these findings in practice shouldn't be hard. This study doesn't mean you have to toss out your French press, but instead, use it for the occasional treat. If you have high cholesterol levels, stay away from unfiltered brews, the researchers say.
HACK SCORE OUT OF 10 — 😋😋😋😋😋😋😋 (7/10 on the yum scale)