A morning cup of coffee may do more than just perk you up, according to new research.
Moderate amounts of caffeine intake — defined as about three cups of coffee or tea a day — were associated with a lower risk of developing cardiometabolic multimorbidity, said the study’s lead author, Dr. Chaofu Ke, associate professor of epidemiology and biostatistics at Soochow University in Suzhou, China.
Cardiometabolic multimorbidity, or CM, is the coexistence of at least two cardiometabolic diseases such as coronary heart disease, stroke and type 2 diabetes.
“Coffee and caffeine consumption may play an important protective role in almost all phases of CM development,” Ke said.
Researchers analyzed data from about 180,000 people in the UK Biobank, a large biomedical database and research resource that follows people long-term. Those involved did not have cardiometabolic diseases at the outset.
The information included the participants’ self-reported caffeine consumption through coffee or black or greentea and the cardiometabolic diseases they developed through their primary care data, hospital records and death certificates, according to the study published Tuesday in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.
Moderate caffeine consumers had a reduced risk of new onset cardiometabolic multimorbidity. The risk was reduced by 48.1% if they had three cups a day, or 40.7% if they had 200 to 300 milligrams of caffeine daily, compared with people who didn’t drink or drank less than one cup, Ke said.
The study had a large sample size and used multiple biomarkers to support the findings, making it a strong look at how caffeine affects heart health, said Dr. Gregory Marcus, associate chief of cardiology for research and professor of medicine at the University of California, San Francisco. He was not involved in the research.
“These observations add to the growing body of evidence that caffeine, and commonly consumed natural substances that contain caffeine such as tea and coffee, may enhance cardiovascular health,” Marcus said in an email.
What researchers don’t know
The methodology is strong and the results line up with existing data about caffeine and heart health, but there are still questions about the extent of the connection between caffeine and heart health, Marcus said.
“It is important to emphasize that, while these data suggest a relationship between caffeine, tea, and coffee and a reduced risk of a combination of cardiovascular diseases, we need to be careful before we infer true causal effects,” Marcus said.
Because the study is observational, it can only show a connection between caffeine and heart health, he said. Other factors may actually be the cause of the improved heart health, he added.
“It remains possible that the apparent protective effects do not truly exist at all and that the positive associations are all explained by some as yet unknown or unmeasured true determining factor,” Marcus added.
“For example, perhaps those more likely to consume these substances also tend to have a healthier diet or to be more physically active.”
The study also didn’t take into consideration the impact of caffeine from carbonated beverages or energy drinks, meaning that researchers can’t say whether those substances would also have a positive effect, Ke said.
Should you start drinking coffee?
Plenty of literature shows a benefit from caffeine consumption.
Several studies have suggested a lower risk of diabetes, Marcus said. And contrary to popular wisdom, drinking caffeine in coffee is associated with experiencing a lower risk of abnormal heart rhythms, he added, pointing to his and others’ research.
But much of that research is observational, and one study showed a mixed result, with more caffeine linked to additional daily step counts but less sleep, Marcus said.
Although the new study should provide comfort to those who already have a coffee or tea habit, it isn’t necessarily a sign to start a regular caffeine routine, Marcus said.
“It is also important to mention that more is not necessarily better,” he said.
“Even if caffeine, coffee, and tea in the amounts described in this study … are indeed healthy, there is also strong evidence that high-dose caffeine, particularly when included in artificial concoctions like energy drinks, may actually cause harmful and even dangerous heart rhythm problems.”
Clarification: A previous version of this story listed high blood pressure as a cardiometabolic disease. It has been removed from the list of such diseases to reflect the scope of the study.
Correction: A previous version of this story misstated the sample size of data collected from the UK Biobank and how many cups of coffee reduced risk.
