Scientists identify how caffeine reduces bad cholesterol

Your morning vice might not be that guilty a pleasure after all: coffee seems to have a range of health benefits, but exactly how it affects the body to produce these results remains unknown. A new study has identified specific proteins that caffeine works on, which help the liver remove bad cholesterol from the bloodstream and protect against cardiovascular disease.

Several large-scale, long-term studies have revealed that coffee is good for you in various ways. One study tracked the coffee habits of more than half a million people across Europe for 16 years, and found that those who consumed the most had significantly lower mortality rates than those who abstained. Other research has linked coffee to reductions in prostate cancer, Parkinson’s, Alzheimer’s, and heart disease.

Observations are one thing, but scientists hadn’t identified many mechanisms for how compounds in coffee, particularly caffeine, might bestow these benefits. So for the new study, researchers at McMaster University investigated what might be behind caffeine’s apparent knack for preventing cardiovascular disease.

The team found that regular caffeine consumption was linked to lower levels of a protein called PCSK9 in the bloodstream. Lower levels of this protein boosts the liver’s ability to break down LDL cholesterol, the “bad” type that can block arteries and lead to cardiovascular disease. Not only did caffeine and derivatives of it work directly on PCSK9, but the researchers found that it also blocked the activation of another protein called SREBP2. This in turn also reduces levels of PCSK9 in the blood.

“These findings now provide the underlying mechanism by which caffeine and its derivatives can mitigate the levels of blood PCSK9 and thereby reduce the risk of cardiovascular disease,” said Richard Austin, senior author of the study. “Given that SREBP2 is implicated in a host of cardiometabolic diseases, such as diabetes and fatty liver disease, mitigating its function has far reaching implications.”

Of course, it’s not as simple as guzzling coffee to stave off heart disease. Mixing it with cream or sugar (or a donut on the side) may cancel out any positive health effects – and that’s especially true if your caffeine delivery method of choice is soft drinks or energy drinks. Too much caffeine can also be a bad thing, and scientists aren't yet settled on how much is too much. All up, if improving your heart health is the goal, there are probably far more direct methods you could take.

But still, the new work adds to a growing body of research that suggests your caffeine habit may be marginally beneficial – or at least, not actively harmful.

The researchers have created new caffeine derivatives that lower PCSK9 levels in the blood, and hope to develop them into a new type of treatment to lower cholesterol.

The research was published in the journal Nature Communications.

Source: McMaster University

Update (Feb. 17, 2022): This article originally said PCSK9 boosted the liver's ability to break down LDL cholesterol, when it is lower levels of this protein that boosts the liver's ability to do this. We apologize for the error, which has now been corrected, and thank the readers who brought it to our attention.