All too often, the foods and drinks we love the most turn out to be bad for our health, but a new study on two of the most popular drinks in the world is surprisingly easy to swallow.
The findings suggest that caffeine consumed regularly in coffee or tea may be good for your heart – especially when multiple cups are consumed a day.
Studying the health data of more than 300,000 participants in the UK Biobank, researchers in China and Sweden have found that drinking caffeine is associated with a lower risk of developing multiple cardiometabolic disorders.
These include conditions such as hypertension, stroke, diabetes, or coronary heart disease. According to some estimates, having two of these disorders at once, as opposed to just one, can more than double the risk of death.
Participants in the study who consumed a moderate amount of caffeine each day – roughly three or more cups of coffee or five or more cups of tea – had more than a 40 percent lower relative risk of developing two or more cardiometabolic diseases over the proceeding years.
"The findings highlight that promoting moderate amounts of coffee or caffeine intake as a dietary habit to healthy people might have far-reaching benefits for the prevention of cardiometabolic multimorbidity," write the researchers, led by epidemiologist Xujia Lu from Soochow University in China.
Plenty of previous studies have found that coffee consumption is associated with improved cardiovascular and neurological health outcomes, and those who have about three and a half cups a day seem to reap the most benefits.
The new findings agree with that dosage.
The study included one group of 172,315 healthy participants, who were free of any cardiometabolic disease at the start of the study, to investigate the association of caffeine on ongoing heart health.
In addition, another group of 188,091 participants was used to investigate the association of coffee or tea on heart health. Participant health was tracked for an average of 11 years.
Compared to non-drinkers, both coffee and tea drinkers had better cardiovascular health outcomes, no matter how many cups they consumed a day. Those who sipped in a moderate amount of caffeine, however, had the least risk of developing multiple morbidities.
A subset of the caffeine drinkers and the coffee and tea drinkers were further studied for blood biomarkers. Blood tests revealed an association between caffeine drinks and signs of lower cholesterol and improved insulin resistance.
In a sensitivity analysis, researchers found that 3 cups of coffee a day was associated with a lower risk of first developing type 2 diabetes and then coronary heart disease. There was also a lower risk of a stroke leading to coronary heart disease.
In addition, five cups of tea a day was associated with a lower risk of type 2 diabetes progressing to coronary heart disease, and also a lower risk of type 2 diabetes leading to stroke.
The findings need to be verified with further research, but they indicate that moderate caffeine intake may have a protective effect for cardiovascular health among many people, no matter age, sex, smoking status, physical activity, or general diet.
The authors hope the metabolites they've identified, which link caffeine to cardiovascular health, will "provide clues" to uncover the biological mechanisms behind caffeine's potentially powerful health effects.
The study was published in The Journal of Clinical Endocrinology & Metabolism.