3 discoveries that change our understanding of coffee and the heart

According to RCO News Agency, Coffee is one of the most widely consumed psychoactive substances on the planet, but despite drinking more than two billion cups a day, its effects on heart health are surprisingly complex and often misunderstood.

A psychoactive compound is a chemical compound that alters brain function and causes changes in perception, mood, self-awareness, or behavior. These substances can be used for medical or therapeutic purposes to intentionally improve performance or alter consciousness, or for research.

Coffee has been blamed for increased heart rate, anxiety, and poor sleep, while being praised for helping to improve focus, mood, and reduce the risk of chronic disease.

In 2025, a handful of new studies help us cut through the noise about coffee consumption’s connection to heart, chronic disease and mortality. Randomized trials, imaging tools, and biochemical analysis also helped us gain a clearer understanding of coffee’s potency.

One study challenged long-held assumptions about caffeine and irregular heartbeats, while another showed how something as simple as a paper filter can alter the effects of cholesterol and reduce the risk of cardiovascular disease. Also, a third study showed a correlation between protection against chronic diseases and the amount of time you drink coffee per day.

While caffeine consumption increases with the start of the holidays in many countries, it is worth revisiting these three coffee studies.

First global findings on coffee and irregular heartbeat

Researchers from the University of Adelaide (Adelaide) and the University of California San Francisco (UCSF) conducted a randomized clinical trial of 200 adults from Australia, the United States and Canada with atrial fibrillation (AF) to test the effect of coffee on irregular heartbeats. Over 6 months, 100 of the participants consumed at least one cup of coffee or one shot of espresso per day, while the other half avoided all types of caffeine.

At the end of the trial, those who continued to drink caffeinated coffee experienced a 47 percent recurrence rate of atrial fibrillation, compared to 64 percent in the caffeine-abstaining group, meaning about a 39 percent lower risk of recurrence for coffee drinkers. Besides, there was no significant difference in side effects between groups.

This is the first randomized clinical evidence that moderate coffee consumption can prevent the recurrence of atrial fibrillation (AF); A result that contradicts decades of conventional advice to avoid caffeine for people with irregular heartbeats.

Professor Christopher X. The results were surprising, said Christopher X. Wong, first author of the paper from the University of Adelaide and Royal Adelaide Hospital. Contrary to popular belief, we found that coffee drinkers experienced a significant reduction in atrial fibrillation compared to those who avoided coffee and caffeine.

He added: This is surprising, because it is contrary to the common assumption of doctors and patients that coffee worsens heart rhythm disorders such as atrial fibrillation. Doctors have always advised patients with atrial fibrillation to minimize their coffee consumption, but this trial suggests that coffee is not only safe in this case, but possibly protective.

This research was published in the journal of the American Medical Association.

Coffee brewing, diterpenes, cholesterol and heart health

Researchers at Uppsala University investigated how coffee brewing methods can affect the levels of natural compounds called diterpenes, which can increase levels of low-density lipoprotein, also known as LDL or “bad cholesterol,” and affect cardiovascular health. What they found was remarkable.

David Iggman, the responsible author of this study and a researcher at Uppsala University’s Nutrition and Clinical Metabolism Unit, said: We wanted to get a picture of the content of cholesterol-raising substances in coffee from these types of devices, considering the amount of coffee consumed in workplaces in Sweden. We studied 14 coffee machines and found that the levels of these substances in the coffee of these machines were much higher than in regular drip filter coffee makers.

Out of 14 devices, 11 were coffee brewing devices and 3 were liquid models. Also, samples of home coffee brews were taken for comparison, which included drip, brew, French press and boiled methods. Then, each sample was analyzed by “liquid chromatography-tandem mass spectrometry” (LC-MS) and the levels of cafestol and kahweol were measured.

Among their intriguing findings, the researchers discovered that coffee from brewers had higher diterpene concentrations than paper-filtered coffee, but less than brewed coffee. For the liquid model devices, there was one sample with unusually high concentrations of kefstol and alcohol, but when this was removed, the brewing method was equivalent to the paper-filtered variety.

“We deduce from this that the filtering process is very important for the presence of these cholesterol-raising substances in coffee,” Eggman said. Obviously, not all coffee machines are able to filter them, but the problem varies between different types of coffee machines, and the concentrations also showed a lot of variation over time.

The researchers also estimated that replacing three cups of brewed coffee with paper-filtered coffee (five days per week) reduced LDL cholesterol by 0.58 mmol/L.

Eggman added: “For people who drink a lot of coffee every day, it’s clear that coffee filtered with drip paper or other filter coffees is preferable.”

This study was published in Nutrition, Metabolism & Cardiovascular Diseases journal.

Reducing the risk of chronic diseases with the correct timing of coffee consumption

Tulane University researchers analyzed data from more than 40,000 adults who tracked their daily nutrient intake, including how much and when they drank coffee, and noticed a pattern.

Ju Qi from Tulane University said: Research so far shows that drinking coffee does not increase the risk of cardiovascular disease and seems to reduce the risk of some chronic diseases such as type 2 diabetes.

He added: Considering the effects of caffeine on our body, we wanted to see if the time of drinking coffee during the day has an effect on heart health.

Participants were divided into groups based on the time of coffee consumption. About 36% drank their coffee in the morning, while another 16% spread their consumption throughout the day and 48% of the study subjects were non-coffee drinkers.

After adjusting for variables, the researchers found that compared to people who didn’t drink coffee at all, people who drank coffee in the morning were 16 percent less likely to die from all-cause mortality and 31 percent less likely to die from cardiovascular disease than people who didn’t drink coffee or drank coffee during the day.

“This is the first study to test coffee drinking timing patterns and health outcomes,” added Joe Shi. Our findings show that it’s not just how much or how much coffee you drink that matters, but also when you drink it during the day. We don’t usually make recommendations on timing in our dietary guidelines, but maybe we should think about that in the future.

This study was published in the European Heart Journal.

end of message