From fighting memory decline to warding off some cancers, drinking coffee continues to emerge as a way to improve your health. Now, a new study says that the time of day during which you drink your daily brew is key to boosting some of its effects.
For the new research, which has just been published in the European Heart Journal, a team led by Ju Qi from Tulane University, looked at data from over 40,000 adults who participated in the US National Health and Nutrition Examination Survey between 1999 and 2018. Participants in that project were asked to track their daily nutritional intake, including how much coffee they drank and when they drank it.
"Research so far suggests that drinking coffee doesn't raise the risk of cardiovascular disease, and it seems to lower the risk of some chronic diseases, such as type 2 diabetes," said Qi. "Given the effects that caffeine has on our bodies, we wanted to see if the time of day when you drink coffee has any impact on heart health."
To do so, he and his team split the participants into groups based on the timing of their coffee consumption. About 36% of them consumed their daily coffee in the morning, sometime before midday. Another 16% had their coffee intake spread throughout the whole day. And 48% of the people studied were not coffee drinkers.
Then, the researchers standardized and screened the study members for a variety of factors and looked at their mortality rates and causes of death. They found that, compared to people who didn't drink coffee at all, morning coffee drinkers were 16% less likely to die from all-cause mortality and a 31% lower rate of death from cardiovascular disease than non-coffee drinkers or those who drank coffee throughout the day.
"This is the first study testing coffee drinking timing patterns and health outcomes," said Qi. "Our findings indicate that it's not just whether you drink coffee or how much you drink, but the time of day when you drink coffee that's important. We don't typically give advice about timing in our dietary guidance, but perhaps we should be thinking about this in the future."
Qi's team also found that the morning coffee drinkers received the health benefits whether they only drank moderately, considered to be two to three cups a day, or were heavier drinkers who had more than three cups. The most important factor was wrapping up coffee consumption before midday.
The researchers point out that their study only shows a link between morning coffee drinking and reduced mortality from heart disease, not the reason why this exists, but they do say it might have something to do with coffee's effect on our hormones and internal body clocks.
"This study doesn't tell us why drinking coffee in the morning reduces the risk of death from cardiovascular disease," concluded Qi. "A possible explanation is that consuming coffee in the afternoon or evening may disrupt circadian rhythms and levels of hormones such as melatonin. This, in turn, leads to changes in cardiovascular risk factors such as inflammation and blood pressure. Further studies are needed to validate our findings in other populations, and we need clinical trials to test the potential impact of changing the time of day when people drink coffee."
If you do decide to shift your coffee consumption to the morning hours, you might also want to heed another study from 2020 that showed it's best to drink your java after you've eaten some food to avoid its impact on the body's glucose response. And tossing in a bit of milk might also be a smart way to further boost the beverage's health-augmenting effects, as a 2023 study showed that doing so might enhance its anti-inflammatory properties.
Source: European Society of Cardiology
