A new study has revealed the impact coffee and energy drinks could be having on the hearts of adults.
Researchers from the American Heart Association found that caffeine, the most widely used stimulant in the world, is safe in levels of up to 400mg a day for most adults.
The new scientific analysis of several sets of data, published in AHA Journals, suggests “most adults can safely consume up to five 8-ounce cups of regular black caffeinated coffee per day”.
This level of consumption may even be associated with a lower risk of cardiovascular disease, such as stroke and heart failure, in some adults.
Chair of the scientific statement volunteer writing group, Gregory Marcus, said: “Caffeine consumed in coffee is a key part of daily life for millions of people, and in our review of the most recent research, for most adults, intake of up to 400mg of caffeine a day, the equivalent of up to five cups of caffeinated coffee a day without added sugars or fillers, is safe and does not increase cardiovascular risk.”
However, high caffeine intake may pose greater risks, especially when consumed from high-dose sources like energy drinks, which can contain three to four times more caffeine than regular coffee.
He added: “However, high doses of caffeine, such as those found in energy drinks, including energy shots, may have harmful effects on the heart and should be avoided.”
A typical cup of coffee has 9.5 to 20.6mg of caffeine per fluid ounce, compared to 40 to 69mg of caffeine found in some energy drinks.
Inside the body, caffeine from coffee is processed by the liver and reaches its highest concentration within an hour, where it may cause short-term increases in blood pressure, heart rate, and blood sugar, as well as alertness.
Participant-reported health information suggested that consuming one to three cups of caffeinated coffee per day was not associated with a higher risk of atrial fibrillation – an irregular heart rhythm which increases stroke risk – or abnormal heart rhythm.
But very high caffeine doses, like those from energy drinks and energy shots, have been linked to abnormal heart rhythms in people who are normally considered low-risk for cardiovascular disease.
The researchers have called for more trials examining coffee and other caffeinated products, and warned products should not all be treated as interchangeable due to the varying amounts of caffeine in them.
They say despite caffeine benefiting some people, “it’s important to remember that there is no ‘one-size-fits-all’ strategy for safe caffeine consumption,” and people can respond differently based on individual factors like age, genetics, and health conditions.
