Many people start their day with a nice cup of coffee, and though it has its benefits, it also comes with some disadvantages.
A new study published in the New England Journal of Medicine found that the daily consumption of at least one cup of joe positively affects movement but negatively impacts sleep. It may also raise the risk of a certain type of heart palpitation.
Researchers looked at 100 healthy adults from the San Francisco area who were at an average age of 39. Participants wore Fitbits to track steps and sleep. They were also provided with continuous blood glucose monitors and electrocardiogram devices to track heart rhythms, CNN reported.
Participants were told at random to drink as much coffee as they wished for two days, avoid it for two days and then repeat for a two-week period.
“The big picture finding is that there isn’t just one single health-related consequence of consuming coffee, but that the reality is more complicated than that,” lead author Dr. Gregory Marcus, cardiologist and professor of medicine at the University of California in San Francisco, told CNN.
On days that they consumed coffee, their step count hit an average of 1,058 more steps than on days without coffee.
However, on the coffee days, participants also got 36 minutes less sleep.
People who drink coffee tend to have more motivation to exercise and might perform better once they do, but Marcus warned that people “shouldn’t extrapolate that to taking energy drinks or high-dose caffeine as a way to enhance workouts.”
The study noted that the reason people who drink more coffee get less sleep might be due to a genetic factor.
Researchers gathered DNA samples and discovered that those who got less slumber after drinking coffee had certain genetic variants that were linked to slower caffeine metabolism.
The study suggested that coffee could also affect the heart, with one cup per day resulting in about a 50% higher risk of premature ventricular contractions (PVCs) — extra heartbeats that disrupt the regular heart rhythm and can feel like a flutter of skipped beat, according to Mayo Clinic.
But the researchers found no evidence of a direct relationship between drinking coffee and premature atrial contractions, which are “very common, early heartbeats that we all experience arising from the top chambers of the heart,” according to Marcus.
“This provides some compelling evidence that experimenting with (going) off coffee might be worthwhile in those individuals who experience bothersome palpitations related to PVCs,” he said.
Marcus added, “There’s also evidence that in some people, more PVCs can lead to a weakening of the heart or heart failure. So it may be that if someone is especially concerned about risks of heart failure — such as they have a family history of it or there’s some other indication that their physician tells them (makes) them at risk — they may want to steer clear of coffee.”
While an individualized approach to coffee consumption is best for figuring out personal health effects, Marcus concluded that there’s no immediate cause for concern.
“Individuals can be reassured that there’s certainly no imminently dangerous effects of drinking coffee,” Marcus said.
