This Huge Health Benefit From Coffee Is Hiding In Plain Sight

Good news for coffee drinkers: Your morning cup of joe might help you get more exercise over the course of the day. Although that’s great news — yay, fitness! — it might come with a costly catch.

A new study published in the New England Journal of Medicine found that people take around 1,000 additional steps each day they drink coffee, compared to days when they skip their morning pick-me-up. These findings could be one reason coffee drinkers are less likely to develop chronic diseases such as type 2 diabetes, cancer, liver disease, and depression, and potentially why they experience greater longevity than non-coffee-drinkers.

But, because we just can’t have nice things that make us happy and productive and feel like the world may not be a horrible place, coffee has a downside — it robs you of your zzz’s.

The research team, led by Gregory Marcus, a cardiology professor at UC San Francisco's medical school, collected data from 100 healthy adults for two weeks. Participants were equipped with fitness trackers, continuous glucose monitors, and portable electrocardiogram devices and instructed to drink coffee as usual for two days and then skip coffee for two days. They followed this pattern for two weeks.

Participants were sent daily reminders, and their trips to coffee shops were tracked using geofencing tech. They were also reimbursed for coffee shop visits.

On coffee days, participants drank between one and three coffees per day, but some overachievers consumed as many as six coffee drinks. Participants got around 6.6 hours of sleep on these days, whereas on non-coffee days, they got around 7.2 hours — a difference of around 36 minutes.

Research has shown that poor sleep can affect several aspects of cognitive function, including memory, problem-solving, emotional regulation, and judgment. As we age, sleep deprivation is also linked to the development of both Alzheimer’s disease and dementia in older adults.

The researchers also recorded participants’ heart function using ECG monitors to check for certain types of cardiac arrhythmias that may be caused by coffee consumption. Premature atrial contractions (PACs) originate in the upper chambers of the heart, called the atria, and premature ventricular contractions (PVCs) originate in the lower chambers of the heart, the ventricles. Researchers recorded more PVCs on coffee days than on non-coffee days, but the incidence of PACs remained relatively stable whether coffee was consumed or not.

Both types of irregular contractions are normal and relatively harmless. However, there is evidence that some people who frequently experience PVCs are at higher risk for developing heart failure at some point in their lives.

It’s important to note that the study only included a small group of coffee drinkers and followed them for a short period of time.

“The reality is that coffee is not all good or all bad — it has different effects,” Marcus said. “In general, this study suggests that coffee consumption is almost certainly generally safe. But people should recognize that there are these real and measurable physiological effects that could — depending on the individual and their goals of care — be harmful or helpful.”

It basically boils down to personal preference and comfort. If you have palpitations that bother you or your insomnia is affecting your quality of life, cut back on your coffee. If you need a little extra juice in the morning to get you moving, have a cup. “There’s no one size fits all prescription or recommendation,” Marcus added. “It really depends on the individual.”