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."
To create wiser adults, add empathy to the school curriculum.
- Stories are at the heart of learning, writes Cleary Vaughan-Lee, Executive Director for the Global Oneness Project. They have always challenged us to think beyond ourselves, expanding our experience and revealing deep truths.
- Vaughan-Lee explains 6 ways that storytelling can foster empathy and deliver powerful learning experiences.
- Global Oneness Project is a free library of stories—containing short documentaries, photo essays, and essays—that each contain a companion lesson plan and learning activities for students so they can expand their experience of the world.
BASE particle physicists have discovered a very precise way to examine antimatter.
Thank your lucky stars you’re alive. It’s truly a miracle of nature. This has nothing to do with spirituality or religion and everything to do with science. Life itself may not be the miracle. Although we haven’t found it elsewhere yet, our galaxy alone is so replete with Earth-like planets that, mathematically speaking, one of them must hold life, even if it’s just the microbial variety. Intelligent life may be another matter.
Just before I turned 60, I discovered that sharing my story by drawing could be an effective way to both alleviate my symptoms and combat that stigma.
I've lived much of my life with anxiety and depression, including the negative feelings – shame and self-doubt – that seduced me into believing the stigma around mental illness: that people knew I wasn't good enough; that they would avoid me because I was different or unstable; and that I had to find a way to make them like me.
A joint study by two England universities explores the link between sex and cognitive function with some surprising differences in male and female outcomes in old age.
- A joint study by the universities of Coventry and Oxford in England has linked sexual activity with higher cognitive abilities in older age.
- The results of this study suggest there are significant associations between sexual activity and number sequencing/word recall in men. In women, however, there was a significant association between sexual activity in word recall alone - number sequencing was not impacted.
- The differences in testosterone (the male sex hormone) and oxytocin (a predominantly female hormone) may factor into why the male cognitive level changes much more during sexual activity in older age.
Mathematicians studied 100 billion tweets to help computer algorithms better understand our colloquial digital communication.