Does coffee harm or heal? New evidence suggests it might benefit our health

Coffee is rapidly competing with tea as the British go-to hot beverage (1) as cafe culture swept the nation by large chains such as Starbucks appearing in most neighbourhoods, train stations, and even office spaces. 

Coffee has clearly become big business, putting increasing demand on coffee producers around the world to feed our ever-demanding love of it (2).

But how healthy is it? With more of us turning down alcohol (3) and favouring the hot brown stuff (4), are we just reducing one toxic habit and replacing it with another?

New research published in the European Journal of Preventative Cardiology (5) suggests that drinking two to three cups of coffee per day can increase life span and lower the risk of heart disease compared to zero coffee consumption.

This large study suggested that whether your choice of coffee is instant (popular in the UK, not so much in Europe) or ground coffee made fresh from roasted beans, the health advantage is still there.

The paper goes on to suggest that whilst all types of coffee confer a health advantage, there is a clear rank of position. Ground coffee had the strongest association with lower heart disease and overall longevity, then instant, then decaffeinated coffee.

What was interesting about this study is that it found that with ground coffee, it didn’t really matter how much you drank during the day, there was still a health benefit. Both decaffeinated and instant coffee appeared to have a limit associated with them, where the more we drank, the less the beneficial effect was.

The problem with these observational type studies is that they can only suggest an association, not a cause and effect. That is, the results cannot prove that coffee improves health outcomes. That said, this study did allow for other factors such as alcohol and tea consumption which could influence results, as well as smoking habits and whether the study participants had pre-existing diseases that are known to cause heart disease such as high blood pressure or diabetes.

This study also adds strength to previous research that had similar outcomes. In 2014, a systematic review (a type of study that reviews previous studies with a common research proposal) was published in the prestigious journal, Circulation, which pooled the results of 36 studies totally over one million participants. It also found a protective effect of coffee from heart disease (6).

For men, the news gets even better because in 2021, a meta analysis (a scientific method of pooling together the results of several studies) found that coffee consumption can also be protective against prostate cancer (7)- a disease that is sadly becoming more common (8)!

Coffee and blood pressure

It’s long been known that coffee can increase blood pressure for over three hours after consumption. High blood pressure has a strong link to both heart disease and strokes, so if coffee increases blood pressure, does coffee-drinking among people with diagnosed high blood pressure (known medically as hypertension) increase the risk of heart disease?

In 2011 a meta analysis found that coffee did not increase the risk of heart disease in people with diagnosed hypertension or have an adverse effect on blood pressure among habitual drinkers (9). A 2012 meta analysis also found that habitual drinking of coffee did not increase the long term risk of developing high blood pressure either (10).

However, the current medical advice as published by NHS is to limit consumption of caffeinated drinks, which includes coffee, if you’ve been diagnosed with hypertension (11). Therefore, whilst it is safe to drink coffee in moderation, it would not be advised to make it your main source of hydration. 

All in all, coffee is not only perfectly safe to drink, but it’s likely that it has health benefits too – particularly if you prefer your coffee freshly ground! The benefits can also be maximised if you take milk, as milk is a good source of protein, vitamins, calcium and other minerals. However, sugar and flavoured syrups simply add to the overall calorie content and can easily negate the health effects. It’s best to limit flavoured coffees to a now-and-then treat if they’re your regular go-to.

For me, I prefer my coffee straight from the pot as it comes. And occasionally, I’ll have an espresso!

Image by Jill Wellington/Pixabay