Drinking coffee can add years to your life—but only if you do this, research shows

Is drinking coffee good for your health? The answer appears to be yes. Quite a lot of research shows that coffee drinkers stay mentally sharper and may live longer than those who don’t. That’s welcome news to many entrepreneurs and business leaders who depend on coffee to stay alert and productive.

More recent research adds a twist to the welcome news that coffee is good for you. To get coffee’s life-extending benefits, make sure to drink it in the morning. Don’t keep on guzzling the stuff all day long.

That’s the finding of a massive study from Tulane University in New Orleans. Researchers examined data from the National Health and Nutrition Examination Survey (NHANES), which had 40,725 U.S. adult participants and ran from 1999 to 2018.

They wanted to know whether the timing of coffee consumption affected its health benefits. So they divided the cohort into three groups. Thirty-six percent were “morning-type” coffee drinkers. They did most of their coffee drinking between 4 a.m. and noon, and “barely” drank any coffee after that. Fourteen percent were “all-day-type” coffee drinkers who drank coffee throughout the day. And 48 percent were defined as “non-coffee drinkers.”

The researchers did statistical analysis to determine the mortality rates for each of these groups after about 10 years.

Morning coffee drinkers live longer

Because the NHANES study collected very detailed information on its subjects, the Tulane research team was able to adjust for a wide range of other lifestyle and health factors that could affect longevity. These included everything from body-mass index, to healthy or unhealthy eating habits, to cholesterol levels, and even whether people had trouble sleeping. After accounting for all of these other factors, the researchers consistently found that the morning coffee drinkers had lower mortality than those who drank coffee all day, or not at all.

Taking a closer look, they found that morning coffee drinking particularly seemed to lower the risk from cardiovascular disease. Cardiovascular disease was the leading cause of death for study participants, and is the leading cause of death for Americans overall.

Why should time of day matter so much to getting the benefits of coffee consumption? The researchers found two possible explanations. “First, consuming coffee in the afternoon or evening may disrupt circadian rhythms,” they wrote. An earlier study had found that heavy coffee drinking in the afternoon or evening interferes with melatonin production at nighttime. “Some evidence suggests that low levels of melatonin are associated with higher oxidative stress levels, blood pressure levels, and [cardiovascular disease] risk.”

Research has repeatedly shown that not getting enough high-quality sleep is bad for both your health and cognitive function, and even for your leadership abilities. So it seems highly plausible that if drinking coffee later in the day affects the quality or quantity of your sleep, those ill effects could outweigh any benefits you get from coffee drinking.

Coffee is anti-inflammatory

The second possible explanation is that coffee’s benefits mostly come from its anti-inflammatory properties. Again, this would make sense because many of the worst human ailments, including cardiovascular disease and cancer, are associated with inflammation. The researchers note that inflammation within the body seems to have its own circadian rhythm. It’s highest in the morning and lowest around 5 p.m. According to this theory, morning coffee drinking brings the most benefits because it attacks inflammation when it’s at its worst.

Whatever the explanation, the takeaway is clear. If you love coffee, then great! Drink all you want. But if you want to enjoy coffee’s health benefits, drink it from when you wake up until noon. After that, consider switching to water, sparkling water, or tea.

—Minda Zetlin

This article originally appeared on Fast Company‘s sister publication, Inc. 

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