Australia-based team conducted the world’s largest study to date analysing the effects of regular coffee consumption on blood lipid levels and risk of heart disease.

A new study reports a positive, dose-dependent, association between coffee intake and levels of lipids in the blood, which can contribute to the development of heart disease.

The research team, led by Prof Elina Hyppönen, from Australian Centre for Precision Health at the University of South Australia, aimed to test how coffee intake can affect levels of blood lipids and heart health. “We have shown earlier that high coffee intake increases heart disease risk, and here, we wanted  to try and explain why that is the case,” Prof Hyppönen said.

To address their questions, the team analysed data from more than 362,000 UK Biobank participants, linking self-reported coffee intake data with plasma lipid profiles and data from Genomic Wide Association Studies. The genetic component of this study, which used a method called “Mendelian randomisation”, added an important layer to the findings: causality. “Our study is new in the use of genetic methodology, which is important, as it allows us to show that coffee intake is a causal risk factor for high cholesterol,” Prof Hyppönen explained.

The study also focused on a special type of coffee brew: unfiltered coffee. These brews contain cafestol, a well-known cholesterol-elevating chemical. Unfiltered coffee brews, like Scandinavian boiled coffees, Frenchpress, Turkish/Greek coffee, and espresso (often the base for Latte, Cappuccino, Macchiato, and Caffe Americano) contain significant amounts of cafestol.

Previous studies have shown that intake of unfiltered coffee results in a higher increase of blood lipid levels, compared to filtered coffee, suggesting a role for cafestol in the accumulation of lipids in the blood.

Cafestol increases cardiovascular disease risk
The study found was a positive dose-dependent association between coffee intake and blood levels of low-density-lipoproteins cholesterol (LDL-C or “bad cholesterol”), apolipoproteins B (ApoB) and total cholesterol. These blood lipids are key markers of cardiovascular disease risk.

“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,” said Prof Hyppönen, in a press release.

“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,” she added.

Should you avoid coffee?
This study provides solid evidence for a causal link between high coffee consumption and increased risks of high cholesterol. People at risk of heart diseases are advised to avoid cafestol-rich coffee varieties. “Our research shows, excess coffee is clearly not good for cardiovascular health, which certainly has implications for those already at risk,” Prof Hyppönen said.  “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,” she added.