Newsletter #74: How Modern Work is Draining Our Attention Spans, and What to Do About It 💻
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Here is where we share our work, plus the various studies and media that caught our attention this week. 🤓
This Week’s Research Highlights
🏃 Even a short term reduction in physical activity can have measurable health effects.
Researchers recruited 28 habitually active individuals with an average BMI within the healthy range. They assessed cardiorespiratory fitness (VO2peak) body composition (DXA), and cardiovascular function (flow-mediated dilation) at baseline and at the end of the intervention. Study participants reduced their daily step count by an average of 10,000 steps per day and increased their waking sedentary time by an average of 103 minutes per day. After 14 days of reduced activity, flow-mediated dilation had decreased by 1.8%. In parallel, total body fat, waist circumference, liver fat, insulin sensitivity, and cardiorespiratory fitness were all adversely affected. Happily, all measurements returned to baseline levels once participants returned to their habitually high physical activity routine.
🤤 Manipulating fat intake may alter fat taste perception.
Researchers recruited 13 pairs of twins, and randomly assigned each pair to either a low-fat (<20% from fat) diet or a high-fat (>35% energy fat) diet. After eight weeks, the group that consumed the low-fat diet showed a 38% increase in expression of a fatty acid taste receptor gene (FFAR4). Increased expression of FFAR4 was also associated with greater perception of fatty acid taste. Maintaining a diet relatively low in fat may enhance sensitivity to fatty foods, and help control passive overconsumption.
🧠 Excessive exercise doesn’t just exhaust the body. It can make your brain tired too.
Researchers recruited 37 competitive male endurance athletes, and assigned them to either continue their normal training, or increase their training load by 40% per session over a three-week period. Researchers assessed subjective experience of fatigue using questionnaires every two days, and conducted behavioral testing and fMRI scanning experiments. Participants in the training overload group felt more fatigued, and acted more impulsively in tests evaluating how they’d make economic choices (favoring immediate smaller rewards over larger rewards later in the future). Their brains also showed diminished activation in a region of the brain involved with executive functions.
⌛ Time spent being sedentary is associated with impaired metabolic health - even if you’re physically active.
Researchers recruited 98 habitually active subjects and assessed how their physical activity patterns and cardiorespiratory fitness affected accumulation of fat in the liver — a hallmark of metabolic syndrome. Sedentary time was associated with liver fat, independent of time spent performing moderate and vigorous physical activity. Specifically, each additional hour of daily sedentary time was associated with a 1.15% higher liver fat content.
🏫 Later school times result in more sleep and better academic performance in high schoolers.
A school district in the Seattle area delayed school start times by nearly an hour. Assessments performed before and after the change revealed that there was an increase in daily median sleep duration of 34 minutes. Additionally, there was a 4.5% increase in median grades, and an improvement in attendance.
New humanOS Content
In this episode of humanOS Radio, Dan speaks with Gloria Mark, who is a professor in the department of informatics at UC Irvine. She studies multi-tasking behavior in information workers, and technology use in disrupted environments. Her work examines how interaction with information technology affects attention, mood, and stress.
Much of this research has investigated what we commonly refer to as “multi-tasking.” You already know this: when you are rapidly switching between two different activities, typically your performance on both tasks markedly declines.
This area of research has also examined the impact of interrupted work, which often manifests itself in the form of digital notifications, like from email, text, or phone apps. For most of us, this is a normal aspect of our daily life. But you might not appreciate the insidious impact that this has on you.
For instance, in one study in which she and her colleagues continuously tracked employees at a tech company, they found that office workers who are interrupted take about 25 minutes to return to whatever task they were working on. And impaired productivity may not be the only price we pay. Gloria's research has revealed that these kinds of disruptions also ramp up physiological stress levels, as well as increase subjective feelings of stress and frustration.
So what can we do about this? Fortunately, Gloria has come up with some plausible ideas for how individuals and organizations can reduce the cognitive costs associated with digital distractions. To learn more, check out the interview!
Podcasts We Loved This Week
- Joan Vernikos: The Effects of Gravity on Humans in Space and on Earth. Via STEM-Talk.
- Amy Bender: Why sleep is vital to your sports and fitness regime. Via Sleep Junkies.
- David Sinclair: How cellular reprogramming could slow our aging clock (and the latest research on NAD). Via The Drive with Peter Attia.
Products We Are Enjoying
Terrasoul Superfoods cacao nibs.
Compounds in dark chocolate, as you probably know, are quite good for you. We’ve written before about how cocoa flavanols can improve exercise performance, and how dark chocolate boosts cognition. Good stuff. So why this brand in particular? Not any kind of financial incentives (I wish). The reason has to do with a fundamental characteristic of cacao. The leaves and beans are naturally prone to accumulating heavy metals from the soil, particularly cadmium. This process probably isn’t fully preventable, but it can be monitored. That’s what I like about Terrasoul - they third-party lab test for heavy metals in their products. My favorite way to use them right now is to throw them in my Vitamix with some frozen bananas, dark leafy greens, cashew milk, and fresh mint, for a creamy mint chocolate smoothie.
