While there has been a lot of debate about whether or not coffee is good for you, a new study reported in Clinical Nutrition cautions against drinking a lot of unfiltered coffee, like espresso or French-press style brews. The study authors agreed, however, that like in most things, moderation is key.
This research examined data from 362,571 people that have volunteered to participate in the UK Biobank, which tracks genetic and health information. This work focused on people age 37 to 73, and found that people who tend to consume six or more cups of unfiltered coffee a day can raise the levels of fats or lipids in the blood. This increase in blood lipid levels can lead to a greater risk of cardiovascular disease.
The link between blood lipid levels and coffee consumption was also dependent on the amount of intake: the more coffee that was consumed, the greater the risk of cardiovascular disease.
"There's certainly a lot of scientific debate about the pros and cons of coffee, but while it may seem like we're going over old ground, it's essential to fully understand how one of the world's most widely consumed drinks can impact our health," said UniSA researcher, Professor Elina Hyppönen.
"In this study, we looked at genetic and phenotypic associations between coffee intake and plasma lipid profiles - the cholesterols and fats in your blood - finding causal evidence that habitual coffee consumption contributes to an adverse lipid profile which can increase your risk of heart disease. High levels of blood lipids are a known risk factor for heart disease, and interestingly, as coffee beans contain a very potent cholesterol-elevating compound (cafestol), it was valuable to examine them together," explained Hyppönen.
"Cafestol is mainly present in unfiltered brews, such as French press, Turkish and Greek coffees, but it's also in espressos, which is the base for most barista-made coffees, including lattes and cappuccinos. There is no, or very little cafestol in filtered and instant coffee, so with respect to effects on lipids, those are good coffee choices.
"The implications of this study are potentially broad-reaching. In my opinion, it is especially important for people with high cholesterol or who are worried about getting heart disease to carefully choose what type of coffee they drink. Importantly, the coffee-lipid association is dose-dependent - the more you drink unfiltered coffee the more it raises your blood lipids, putting you at greater risk of heart disease."
It's estimated that people drink 3 billion cups of coffee a day, while cardiovascular disease is the world's number one cause of death. We still have to learn more about how coffee impacts health and whether certain people may be more susceptible to the potentially detrimental impacts of coffee than others. Ths study also does not appear to have examined how caffeine might be affecting these findings.
"With coffee being close to the heart for many people, it's always going to be a controversial subject," Hyppönen said. "Our research shows, excess coffee is clearly not good for cardiovascular health, which certainly has implications for those already at risk. Of course, unless we know otherwise, the well-worn adage usually fares well - everything in moderation - when it comes to health, this is generally good advice."