The time of day you drink a cup of coffee may reduce the risk of premature death, according to a new study.
The study found that people who drank coffee in the morning had a lower risk of dying from cardiovascular disease and a lower risk of mortality than all-day coffee drinkers – but the research couldn’t prove if coffee was the only cause.
Dr. Lu Qi, principal investigator and director of the Tulane University Obesity Research Center, said that while the study does not show why drinking coffee in the morning reduces risk, one explanation could be that consumption later in the day can disrupt a person’s internal body clock. .
The study was published Wednesday in the European Journal of the Heart.
Dr Qi said more studies are needed to see if their results could also be seen in other populations, adding: “We need clinical trials to test the potential impact of changing the time of day. the day people drink coffee.”
“This study does not tell us why drinking coffee in the morning reduces the risk of death from cardiovascular disease,” he explained.
“One possible explanation is that drinking coffee in the afternoon or evening can disrupt circadian rhythms (our body’s 24-hour cycle of physical, mental and behavioral changes) and levels of hormones such as melatonin .
“This in turn leads to changes in cardiovascular risk factors such as inflammation and blood pressure.”
Researchers at Tulane University in New Orleans examined 40,725 adults who participated in the U.S. National Health and Nutrition Examination Survey between 1999 and 2018.
They were asked about their daily consumption of food and drinks, and whether they drank coffee, how much and when.
“Given the effects of caffeine on our bodies, we wanted to see if the time of day you drink coffee had an impact on heart health,” Dr. Qi explained.
While previous research has shown that moderate coffee consumption can have health benefits, this is the “first study testing coffee drinking habits and health outcomes,” he said. -he added.
According to the study, 36% of participants drank coffee in the morning and 14% drank all day.
Dr. Qi and his team followed the participants for nearly a decade, reviewing their records of information and the causes of their deaths during that time.
During follow-up, after almost 10 years, 4,295 people died, including 1,268 deaths related to cardiovascular disease.
Researchers found that morning coffee drinkers were 16% less likely to die than those who didn’t drink coffee, and 31% less likely to die from heart disease.
They also found no reduction in risk for all-day coffee drinkers compared to non-coffee drinkers.
“Drinking coffee in the morning may be more strongly associated with lower mortality risk than drinking coffee later in the day,” they wrote in the research paper.
The researchers said higher amounts of coffee were “significantly” associated with a lower risk of death, but only among people who drank coffee in the morning, compared to those who drank it all day.
In an accompanying editorial, Professor Thomas F. Luscher of the Royal Brompton and Harefield Hospitals in London, asked: “Why should the time of day matter?”
“In the morning, there is usually a marked increase in sympathetic activity (activity that puts your body’s systems on alert) when we wake up and get out of bed, an effect that fades during the day and rises to its peak lowest during sleep.
Professor Luscher said that – as the researchers suggest – it is “possible” that drinking coffee later in the day disrupts our body’s internal clock at a time when we should be resting.
“Indeed, many daily drinkers suffer from sleep disorders,” he explained, adding that “in this context, it is interesting to note that coffee appears to suppress melatonin, an important sleep mediator in the brain “.
The study also suggests that among coffee drinkers, participants who consumed it in the morning were more likely to consume caffeinated tea and soda, but consumed less coffee – both caffeinated and decaffeinated – compared to those who drank coffee all day.
