Drinking coffee has long been linked to better heart health and increased longevity.
However, recent research suggests that when you drink coffee may be just as important as how much you consume in achieving these benefits.
A study published in the European Heart Journal recently indicates that limiting coffee consumption to the morning could be most beneficial, regardless of factors like the amount consumed, genetics, or added sweeteners.
“This is the first study to examine how the timing of coffee drinking might affect health outcomes,” said Dr. Lu Qi, the study’s lead author and a professor at Tulane University’s Celia Scott Weatherhead School of Public Health. “While we don’t usually offer timing advice in dietary guidelines, this research suggests it could be a factor worth considering moving forward.”
Previous studies have linked moderate coffee intake to a reduced risk of type 2 diabetes, heart disease, and premature death.
However, the impact of variables like genetics, the quantity consumed, or sweeteners remained uncertain.
This new study analyzed health and dietary data from 40,725 adults aged 18 and older in the National Health and Nutrition Examination Survey (1999-2018).
Participants provided information on their daily food and beverage consumption, and a subset of 1,463 adults was included in a separate validation study. Both caffeinated and decaffeinated coffee were considered, and consumption was categorized into three time periods: morning (4 a.m. to 11:59 a.m.), afternoon (12 p.m. to 4:59 p.m.), and evening (5 p.m. to 3:59 a.m.).
The study identified two main drinking patterns: morning-only and all-day coffee drinking. After almost 10 years of follow-up, there were 4,295 deaths from all causes, including 1,268 from heart disease and 934 from cancer.
Those who drank coffee only in the morning had a 16% lower risk of premature death and a 31% lower risk of death from cardiovascular disease compared to non-coffee drinkers. On the other hand, all-day coffee drinkers showed no reduction in risk.
These results remained significant even after adjusting for factors like sleep, age, race, sex, education, physical activity, diet, and health conditions such as diabetes and high blood pressure.
Interestingly, the quantity of coffee consumed in the morning—whether less than one cup or more than three cups—did not affect the outcome, with any morning coffee consumption still linked to a lower risk of mortality.
Vanessa King, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics, noted that the study was observational, meaning it cannot establish a direct cause-and-effect relationship.
However, she highlighted its significance, as heart disease is the leading cause of death in the U.S.
Why Timing Matters
Dr. David Kao, a heart health expert, praised the study as one of the most comprehensive on the topic, particularly due to its use of machine learning to categorize coffee consumption patterns and validate findings with external data sources.
However, Kao pointed out that participants’ dietary recall may not be entirely accurate, and the study did not account for long-term habits.
The researchers also acknowledged that morning coffee drinkers might lead generally healthier lifestyles, potentially exercising more and consuming less processed food.
A possible explanation for the findings is that drinking coffee in the afternoon or evening could interfere with circadian rhythms and melatonin production.
Melatonin, a hormone that regulates sleep, is also involved in blood pressure and oxidative stress, which are linked to heart disease.
Additionally, coffee contains antioxidants that help reduce inflammation, a contributor to cardiovascular problems.
The study suggests that the anti-inflammatory effects of coffee may be stronger in the morning, as blood markers of inflammation tend to be highest at that time.
Adjusting Your Coffee Routine
If you’re thinking about limiting your coffee intake to the morning but struggle with afternoon fatigue, experts recommend evaluating your sleep quality.
Poor sleep, possibly caused by conditions like sleep apnea, could be contributing to your tiredness. Staying hydrated or diluting your coffee with water during the day may also help improve alertness.
For those who don’t currently drink coffee but are considering adding it to their routine, dietitians advise evaluating your overall lifestyle.
A balanced, active lifestyle combined with a sustainable diet is key to reaping the potential benefits of coffee.
Until more research clarifies the best timing for coffee consumption, it’s advisable to follow guidance from your doctor or dietitian regarding caffeine intake.
