Just how many cups of coffee is it safe to drink a day?
Our favorite over-the-counter medication has its limits.
- A study of hundreds of thousands of people finds the upper safe limit for coffee consumption.
- Too much coffee puts drinkers at an increased cardiovascular risk.
- Say no to that seventh cup.
The UK Biobank is a gift that keeps on giving. It's a massive database of medical data belonging to some 500,000 volunteers, tracking their health as they make their way through life. We've written about it before when it made possible new research on staying up late and longevity. This time, a study from the University of Southern Australia published in The American Journal of Clinical Nutrition uses the data to assess how many cups of coffee you can safely drink each day without increasing your cardiovascular risk. It's the world's leading killer. The study is a response of sorts to another recent, eyebrow-raising study that suggested up to 25 cups of joe a day as the limit — the new research finds it's really more like six cups. Not to mention that two dozen cups could also lead to other undesirable effects such as higher blood pressure, headaches, nausea, and stomach problems.
What the second look saw
Image source: Daria Shevtsova/Unsplash
Co-author of the study, Elina Hyppönen of the Australian Center for Precision Health, says, "Coffee is the most commonly consumed stimulant in the world — it wakes us up, boosts our energy and helps us focus — but people are always asking 'How much caffeine is too much?'" Hyppönen and her co-author Ang Zhou analyzed the Biobank data for over 347,077 people, aged 37-73, including their genetic profile, medical history, diet, exercise activity, and, of course, their coffee consumption. They found that those who drank more than six cups daily had a 22% higher risk of heart disease or stroke.
"Most people would agree that if you drink a lot of coffee, you might feel jittery, irritable or perhaps even nauseous — that's because caffeine helps your body work faster and harder, but it is also likely to suggest that you may have reached your limit for the time being." This corresponds to a temporary rise in blood pressure coffee brings on. However, this increase stuck with those who imbibed 7 cups or more, putting them at the higher cardiovascular risk.
Nothing exceeds like excessGiphy
"An estimated three billion cups of coffee are enjoyed every day around the world," notes Hyppönen. And that's not a bad thing, especially for those of us who need to stay alert at work (spoiler alert — all of us). Still, she says, "As with many things, it's all about moderation; overindulge and your health will pay for it." For any of our little daily vices, "Knowing the limits of what's good for you and what's not is imperative."
Step inside the unlikely friendship of a former ACLU president and an ultra-conservative Supreme Court Justice.
- Former president of the ACLU Nadine Strossen and Supreme Court Justice Antonin Scalia were unlikely friends. They debated each other at events all over the world, and because of that developed a deep and rewarding friendship – despite their immense differences.
- Scalia, a famous conservative, was invited to circles that were not his "home territory", such as the ACLU, to debate his views. Here, Strossen expresses her gratitude and respect for his commitment to the exchange of ideas.
- "It's really sad that people seem to think that if you disagree with somebody on some issues you can't be mutually respectful, you can't enjoy each other's company, you can't learn from each other and grow in yourself," says Strossen.
- The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Learn how to redesign your job for maximum reward.
- Broaching the question "What is my purpose?" is daunting – it's a grandiose idea, but research can make it a little more approachable if work is where you find your meaning. It turns out you can redesign your job to have maximum purpose.
- There are 3 ways people find meaning at work, what Aaron Hurst calls the three elevations of impact. About a third of the population finds meaning at an individual level, from seeing the direct impact of their work on other people. Another third of people find their purpose at an organizational level. And the last third of people find meaning at a social level.
- "What's interesting about these three elevations of impact is they enable us to find meaning in any job if we approach it the right way. And it shows how accessible purpose can be when we take responsibility for it in our work," says Hurst.
Erik Verlinde has been compared to Einstein for completely rethinking the nature of gravity.
- The Dutch physicist Erik Verlinde's hypothesis describes gravity as an "emergent" force not fundamental.
- The scientist thinks his ideas describe the universe better than existing models, without resorting to "dark matter".
- While some question his previous papers, Verlinde is reworking his ideas as a full-fledged theory.
TuSimple, an autonomous trucking company, has also engaged in test programs with the United States Postal Service and Amazon.
PAUL RATJE / Contributor
- This week, UPS announced that it's working with autonomous trucking startup TuSimple on a pilot project to deliver cargo in Arizona using self-driving trucks.
- UPS has also acquired a minority stake in TuSimple.
- TuSimple hopes its trucks will be fully autonomous — without a human driver — by late 2020, though regulatory questions remain.