Newsletter #161

Newsletter #161: The Hidden Benefits of Petting Animals 🐱

Welcome to the month of June 🌞 and to the latest humanOS newsletter!

This week, we learned a major reason why getting enough sleep is important for exercise recovery and muscle building; we got some insight into just how bad working long hours is for people’s health on a population level; and we found out that interacting with dogs and cats could have a surprising impact on stress management and mental performance.

To get the details, scroll down 👇🏼

This Week's Research Highlights

😴 Sleep deprivation may interfere with muscle rebuilding.

Healthy young adults were subjected to one night of normal sleep (control) and one night of total sleep deprivation in a randomized crossover design (meaning that all participants were eventually exposed to both conditions over the course of the study). When the subjects were deprived of sleep, muscle protein synthesis (the process of building muscle mass at the cellular level) was reduced by 18%. When the researchers examined the participants’ bloodwork, they found two major clues as to why this was the case. First, plasma testosterone area under the curve (AUC) decreased on average by 24% in the sleep deprived condition, especially in males - all male subjects showed lower testosterone levels when they lost sleep. Testosterone, obviously, plays a key role in the promotion of muscle protein synthesis. Secondly, cortisol levels were 21% higher during sleep deprivation, compared to control. Cortisol, in contrast to testosterone, actually drives muscle breakdown. This lines up with prior research suggesting that inadequate promotes loss of muscle mass, and suggests that this may be mediated by a catabolic hormonal environment.

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Summary: This study found that sleep deprivation can interfere with muscle rebuilding. The study found that muscle protein synthesis was reduced by 18% when participants were deprived of sleep, and that this was likely due to decreased testosterone levels and increased cortisol levels. The findings suggest that sleep is important for maintaining muscle mass.

👔 Long working hours was found to carry the largest disease burden of any occupational risk factor - and its impact is growing.

The World Health Organization (WHO) and International Labour Organization (ILO) analyzed data on exposure to long working hours (≥55 hours/week) versus standard hours (35–40 hours/week), and estimated the attributable burden of working hours on ischemic heart disease and stroke for 183 countries (yeah, huge study!). The researchers determined that working 55 or more hours per week was associated with an estimated 35% higher risk of a stroke and a 17% higher risk of dying from ischemic heart disease, compared to working 35-40 hours a week. Furthermore, the number of people working long hours has increased over the past twenty years, which in turn has increased this disease burden. Between 2000 and 2016, the number of deaths from heart disease due to working long hours increased by 42%, and from stroke by 19%. The study concluded: “These WHO/ILO Joint Estimates demonstrate that the disease burden attributable to exposure to long working hours is the largest of any occupational risk factor calculated to date, compared with those attributable to other occupational risk factors included in global Comparative Risk Assessments.”

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Summary: The World Health Organization and International Labour Organization have found that long working hours (55 or more hours per week) are associated with a 35% higher risk of stroke and a 17% higher risk of dying from ischemic heart disease compared to working 35-40 hours per week. The number of people working long hours has increased over the past twenty years, which in turn has increased this disease burden. This disease burden is the largest of any occupational risk factor calculated to date.

🐶 Petting animals for just ten minutes lowers physiological stress and boosts cognitive performance.

Two recent studies took a look at how interacting with dogs and cats affects stressed-out university students. In the first, researchers from Washington State University randomly assigned undergraduate students to one of four conditions: 1) hands-on animal visitation (ten minutes of petting cats and dogs), 2) animal observation (watching others pet animals), 3) animal slideshow (viewing images of cats and dogs, or 4) waitlist (control).

Sure enough, the students who petted cats and dogs had lower cortisol levels after the interaction, compared to the other groups. In another study from the same research group, students were randomly assigned to stress-management programs that either incorporated interaction with therapy dogs or evidenced-based academic stress management. After four weeks, the students in the 100% animal interaction group showed greater improvements in executive function - meaning skills related to planning, organizing, and concentrating on a goal - than those assigned to the traditional stress management approach, and the benefits persisted up to six weeks after the conclusion of the program.

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Summary: These two recent studies that found interacting with dogs and cats can lower physiological stress and boost cognitive performance. In the first study, undergraduate students who petted cats and dogs had lower cortisol levels than those who observed or viewed images of animals. In the second study, students who participated in a stress-management program that incorporated interaction with therapy dogs showed greater improvements in executive function than those in a traditional stress management program.

Random Trivia Question of the Week

🤔 Why do zebras have stripes?

Researchers outfitted horses in zebra print to tease out the answer to this elusive question

💡 Answer

Podcasts We Loved This Week

Jenny Etnier: Exercise to boost the brain. Via The LLAMA Podcast.

Gary Bennett: How do we overcome vaccine hesitancy? Via Science Friday.

Products We Are Enjoying

Ginger Tea

This tea is super tasty, and some preliminary research suggests that bioactive compounds in ginger may exert an array of beneficial health effects, with especially intriguing findings related to managing nausea /motion sickness and allergies. Of course, you can also make ginger tea pretty easily just by peeling and slicing up some fresh ginger root and steeping it in hot water.

humanOS Catalog Feature of the Week

https://mailchi.mp/humanos.me/newsletter-161