Coffee May Be Good For the Heart- A Look at What the Science Says

If you can’t imagine starting the day without your cup o’ joe, you aren’t alone.  On average, American’s drink 3 cups of coffee every day–collectively that’s 400 million cups of coffee-- daily.

Given those kinds of numbers, it’s no wonder that the question of whether or not the coffee habit is beneficial or detrimental to patient health is one that generates a lot of interest- and there’s been plenty of studies devoted to it.

Coffee hasn’t always been considered a healthy drink.  Over the years, researchers have raised questions about whether drinking large amounts of coffee raised the risk of cardiovascular disease, diabetes, or certain types of cancer.  But the studies over the last decade or more have shown that exactly the opposite appears true: drinking 1-3 cups of coffee daily reduces the risks of all those things and more and may even increase lifespan.

Brew it Hot – Not Cold
One of the reasons drinking coffee is thought to be beneficial are the high levels of antioxidants found in the beans. As it turns out the temperature of the water used in the brewing can impact the amount of antioxidant punch packed by your morning Starbucks. During the brewing process antioxidants known as polyphenols – which incidentally are the same sort of beneficial antioxidants found in berries, tea, red wine and chocolate – are released from the ground beans into the water.  And hot water releases more antioxidants than cold.  At least according to a 2018 study published in Nature Scientific Reports.   That study showed that not only does hot-brewed coffee impart more antioxidants, the pH of hot and cold brews is roughly the same.  Cold brew had been previously touted as less acidic and therefore easier on the stomach –something that turns out not to be true.  So even though cold-brew is all the rage, and still has plenty of benefit, hot-brewed coffee is actual healthier. 

Filter It
A number of studies have demonstrated that coffee contains oily compounds known as diterpenes that affect the body’s ability to metabolize and regulate cholesterol. The two main diterpenes in coffee are cafestol and kahweol.  Cafestol is considered the single most potent dietary cholesterol elevating compound.  As shown by this metanalysis from 2001, scientists have long been aware of the fact that coffee is capable of elevating serum cholesterol levels in both mice humans, as well as the fact that the cholesterol raising effects  can be avoided by filtering the brew.  Studies estimate that heavy unfiltered coffee consumption can raise LDL cholesterol levels as much as 8% .  By comparison, filtered coffee has no effect on cholesterol levels at all. 

What’s more, a large population study was just released last week linking coffee consumption to reduced rates of cardiovascular death.  

"Our study provides strong and convincing evidence of a link between coffee brewing methods, heart attacks and longevity," said study author Professor Dag S. Thelle of the University of Gothenburg, Sweden. "Unfiltered coffee contains substances which increase blood cholesterol. Using a filter removes these and makes heart attacks and premature death less likely.”

Read our coverage of the article published in the European Journal of Preventive Cardiologyhere.

But don’t be fooled.  The health benefits of coffee go beyond cardiovascular disease. In 2012 a study in the American Journal of Epidemiology  reported a strong inverse association between caffeinated coffee intake and oral/pharyngeal cancer mortality.

And coffee also seems to have a positive impact on diabetes as well.   A 2019 study, published in Food and Chemical Toxicology, showed that when fat cells of mice were treated with water-based extracts from coffee beans skins, two phenolic compounds--protocatechuic acid and gallic acid--in particular reduced fat-induced inflammation in the cells and improved glucose absorption and insulin sensitivity.  And another in the Journal of Internal Medicine reported specific biomarkers in the blood demonstrating that filtered – but not unfiltered-coffee has a positive effect in terms of reducing the risk of developing type 2 diabetes.  With the use of these biomarkers, the researchers were able to show that people who drank two to three cups of filtered coffee a day had a 60% lower risk of developing type 2 diabetes than people who drank less than one cup of filtered coffee a day. Consumption of unfiltered coffee had no effect on the diabetes risk in the study.

So while whether you’re a busy physician relying on a much-needed caffeine boost to get you through the workday,  because you’re burning the midnight oil on COVID-19 lockdown trying to get some work down when the kids are finally asleep, or you just plain love the stuff, keep up the good work: coffee is actually good for you.  But for the sake of health, brew it hot and it’s probably best to ditch the french press.