Mythbreakers: Is coffee bad for your heart?

More than 95 million people in the UK regularly consume coffee and these consumers are increasingly curious about the health effects of their preferred beverage. Some of the more common questions are linked to coffee’s effect on the heart. British Heart Foundation statistics show there are around 7.6 million people living with cardiovascular disease in the UK.

Public health awareness days, such as the recent World Heart Day, help promote messages on healthy living and the role of diet; so it’s no surprise that many want to know whether coffee will help them look after their heart – and if so, how?

Coffee and the heart

Research into coffee consumption and cardiovascular disease (CVD) has suggested that a moderate intake of coffee (around three to five cups per day) may reduce CVD mortality risk. This consumption is defined as moderate based on the European Food Safety Authority’s (EFSA) review of caffeine safety.

Some research has also suggested that a particular set of compounds in coffee may be behind this beneficial effect on the heart. Polyphenols are plant-based compounds present in a variety of foods including fruit, vegetables, whole grains, tea, coffee, cocoa and wine. Research suggests that there is an association between the consumption of polyphenols and a reduction in CVD prevalence.

Those with a higher intake of flavonoids (a type of polyphenol) had a 47 percent lower incidence of cardiovascular events compared to those with the lowest intake, after adjusting for potential confounders. It is suggested that polyphenols in coffee could exert antioxidant and anti-inflammatory effects, including having pivotal roles on lipid and glucose metabolism, potentially contributing to the reduced risk of CVD.

Understanding the headlines on coffee and health

It can be hard to understand the scientific consensus on a particular food or beverage when the research is presented outside the context of a wider body of research. Myths about coffee persist outside the scientific community.

For example, headlines sometimes suggest that coffee is associated with heart attack, high blood pressure and stroke. Taken collectively, scientific research suggests the opposite. Studies indicate that coffee has a protective effect on the cardiovascular system, with the association resembling a U-shaped curve. Regular coffee consumption may also be associated with a reduced risk of stroke; particularly in women, and research to date suggests that regular intake of coffee does not increase the risk of high blood pressure, and in some cases, may have a protective effect.

Coffee before exercise might even improve performance

More health benefits

The EFSA concluded that consuming 3mg/kg body weight of caffeine one hour prior to exercise can actually support exercise performance by increasing endurance capacity and performance. To support the EFSA’s conclusion, this review suggests that consuming a low to moderate amount of caffeine (0.5-4mg/kg) improves alertness, vigilance, attention and reaction time. What’s more, effects on physical performance (time to exhaustion, time trial, muscle strength and endurance) are also evident at amounts of 3mg/kg.

As discovered through 21 research studies, caffeine may also aid muscle endurance and muscle strength for people engaged in regular exercise. One example is in cycling, where the science suggests that endurance cyclists in particular may find coffee a valuable addition to their diet or regime. If coffee can help give people a little extra motivation to go for that run or that cycle, so much the better; ultimately, lifestyle factors such as lack of exercise can contribute to greater risk of heart disease.

In summary

Health is an individual matter and researchers work on the basis of commonality in findings. People with specific health conditions can always discuss their diet – including coffee and caffeine intake – with their healthcare provider. Overall, however, moderate coffee consumption as part of a healthy, balanced diet remains one of many ways in which small changes to our diets can have a beneficial effect on our bodies.

As a lifestyle-focused physician my advice is that one should never consume coffee solely for health reasons, or with a purpose to prevent or treat diseases. But if you like coffee, then the majority of research reassures us that this beverage will do no harm – and it might even make our heart a bit healthier.