There’s no denying Australians love their coffee with more than one in four saying they cannot get through a day without it. But how much is too much?
A new study has shed light on how much caffeine you can consume before it starts increasing your risk of a heart attack – and it might be less than you think.
“Due to its effect on the autonomic nervous system, regular caffeine consumption could put otherwise healthy individuals at risk of hypertension and other cardiovascular events,” explained the research’s lead author Nency Kagathara at the Department of Internal Medicine at Zydus Medical College and Hospital in Dahod, India.
“Increasing awareness of these risks is vital to improve heart health for all.”
According to Food Standards Australia and New Zealand (FSANZ), adults who aren’t pregnant or breastfeeding can safely consume up to 400mg of caffeine.
That equates to around five single-shot espressos (depending on strength), 10 cups of black tea, 11 cans of Coca Cola, or two and a half 500mL cans of energy drink.
However, the new study suggests even this level consumed daily is enough to raise an individual’s blood pressure, putting them at increased risk of hypertension and heart disease long-term.
To assess how much caffeine people could drink before it started raising their blood pressure and heart rate, the researchers studied 92 young adults aged between 18 and 45.
All were healthy and had blood pressure in the normal range before the study began.
The participants underwent a three-minute step test and then had their blood pressure and heart rate measured at one minute and five minutes after the test.
These results were compared against their daily caffeine intake.
The highest caffeine intakes were observed in city-dwelling women working in business and management roles.
One in five of those studied consumed more than 400mg of caffeine every day, exceeding the recommended daily limit.
But even for those who drank at this recommended maximum level, the authors found significant impact on blood pressure and heart rate over time.
Those who had the highest caffeine intake – around 600mg every day – had significantly elevated heart rates and blood pressure after five minutes of rest following the step test.
High blood pressure, also known as hypertension, is associated with an increased risk of numerous illnesses including coronary artery disease, heart failure, chronic kidney disease, and dementia.
Over time, hypertension weakens your heart and is a leading risk factor for heart disease.
