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Drinking coffee has repeatedly been linked to better heart health and a longer life. But the benefits of drinking coffee might depend on when you drink it, according to new research.
It turns out that limiting coffee consumption to the morning might be better — and that appears to be independent of the amount consumed and other potentially influential factors, according to a study published Tuesday in the European Heart Journal.
“This is the first study testing coffee drinking habits and health outcomes,” said lead author Dr. Lu Qi, HCA Regents Distinguished Chair and Celia Scott Weatherhead School Professor of Public Health and Tropical Medicine at Tulane University in New Orleans, in a press release. release. “We don’t usually give advice on timing in our dietary recommendations, but perhaps we should think about it in the future.”
Most previous research examining participants’ coffee consumption over time found that moderate levels of coffee consumption may be associated with lower risks of type 2 diabetes, cardiovascular disease and premature death, according to the latest study. But scientific evidence on whether factors such as genetics, amount consumed or added sweeteners affect these relationships is inconsistent or sometimes controversial, the authors said.
The authors studied diet and health data on 40,725 adults aged 18 and older from the National Health and Nutrition Examination Survey conducted from 1999 to 2018. In 10 cycles over the years , these participants provided details about their dietary intake from the previous day. The authors also included a subgroup of 1,463 adults, from both the female and male versions of the lifestyle validation study, who had completed at least one 1-week dietary record.
Caffeinated and decaffeinated coffee were included and timing was categorized into three 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 a.m. 59). ).
Researchers have identified two consumption patterns: in the morning and throughout the day. At the end of the median follow-up period of almost 10 years, there were 4,295 deaths from all causes, 1,268 from cardiovascular disease and 934 from cancer.
Compared to people who did not drink coffee, drinking coffee only in the morning was associated with a 16% lower risk of premature death from any cause and a 31% lower risk of dying from cardiovascular disease. Those who tended to drink coffee all day did not show a reduction in risk. These results remained even after the authors accounted for confounding factors such as sleep hours, age, race, ethnicity, gender, family income, education, physical activity, a dietary score and health conditions such as diabetes, hypertension and high cholesterol.
For morning coffee drinkers, the amount of caffeinated or decaffeinated coffee consumed also didn’t matter whether they drank less than one or more than three cups of coffee per day. Doing it in the morning was always better than other regimens in terms of mortality risk.
“The study was observational, meaning it was not an experimental setting, (which) is the gold standard,” said Vanessa King, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition. and dietetics, who did not participate in the study. , by email.
The nature of the study also means that it only establishes an association, not a causal relationship, between morning coffee consumption and the risk of early death. But the findings are “significant given that cardiovascular disease is the leading cause of death in America,” King added.
Dr. David Kao, who was not involved in the research, found the study “fascinating” and one of the best investigations of this topic in years, he said.
“Strengths include using a machine learning-like method to categorize coffee drinking habits and validating the results in (more than one) external data source separate from the main source, significantly reducing the probability of an accidental/false positive result. Kao, the Jacqueline Marie Schauble Leffer Chair in Women’s Heart Health at the University of Colorado Anschutz, said by email.
However, the study has a few other flaws: For one, memories of food intake are prone to inaccuracies or bias, and do not account for long-term habits, the authors said.
Second, even though the authors considered several confounding factors, it’s possible there are others that can’t be completely ruled out, they said.
The team “could not rule out the possibility that morning coffee consumption is a marker of an overall healthy lifestyle,” according to the study. “For example, morning coffee drinkers may be more willing to exercise and eat non-ultra-processed foods.”
Additionally, because genetic information was not available, the authors were unable to examine the possible effects of genetically determined caffeine metabolism rates.
One possible explanation for these findings “is that drinking coffee in the afternoon or evening may disrupt circadian rhythms and levels of hormones such as melatonin,” Qi said. Low levels of melatonin have been linked to higher levels of blood pressure and oxidative stress, as well as a higher risk of cardiovascular disease.
Coffee also contains antioxidants that reduce inflammation in the body by neutralizing free radicals that can increase the risk of cardiovascular disease, King said. Free radicals, unstable molecules from environmental sources such as cigarette smoke or pesticides, can damage cells.
Certain inflammatory markers in the blood have their own clocks, the authors said, and they are typically higher in the morning. Thus, “the anti-inflammatory effect of concentrated coffee consumption in the morning may be more beneficial than that of concentrated coffee consumption in the morning”. … spread over the morning, afternoon and evening. This applies to drinking caffeinated and decaffeinated coffee.
If you want to start limiting your morning coffee intake but are having difficulty, consider whether you’re getting enough quality rest regularly, King said. Seeing a sleep specialist to find out if you have a condition, such as sleep apnea, disrupting your rest could also be helpful, Kao said.
You can also start by diluting your daytime servings and accompanying them with water to hydrate, King said — which can also help you feel more awake.
LEARN MORE: 6 ways to wake up without coffee
Having your thyroid, vitamin D and iron levels tested can help you determine if the exhaustion is stemming from something more serious, said Sue-Ellen Anderson-Haynes, a registered dietitian nutritionist and spokesperson for the Academy of Health. nutrition and dietetics.
If you don’t drink coffee and think you might benefit from adding it to your routine, “look at the big picture first,” said Anderson-Haynes, who was not involved in the study. “Do you lead an overall physically active, balanced, sustainable and healthy diet and lifestyle? »
Until more evidence is provided on when to drink coffee, she added, follow your doctor or dietitian’s recommendations regarding caffeine consumption.