Newsletter #63: Enhancing Mitophagy for Better Aging and Healthy Muscle 💪🏽
Hello Friends!
Welcome to the newest edition of the humanOS newsletter! Here, as always, is where we share our work, plus the various studies and media that captured our attention this week. 🤓
This Week’s Research Highlights
🌿 Mixed spices, at culinary doses, have prebiotic effects in healthy adults.
Researchers randomly assigned 29 adults to receive 5 g capsules containing either maltodextrin (placebo) or a spice mixture of 1 g (20%) cinnamon, 1.5 g (30%) oregano, 1.5 g (30%) ginger, 0.85 g (17%) black pepper, and 0.15 g (3%) cayenne pepper. After two weeks, the spice group showed a significant reduction in Firmicutes abundance, and a trend of enrichment in Bacteroidetes, compared to controls. Greater abundance of Firmicutes and a higher Firmicutes/Bacteroidetes ratio is often found in obese individuals, and is thought to be associated with increased capacity of energy harvest.
🏋️ Exercise improves insulin sensitivity in the brain and enhances cognition in overweight individuals.
2 sedentary adults (average BMI of 31) underwent brain scans before and after an 8-week exercise intervention. Brain function was measured before and after using an insulin nasal spray to assess insulin sensitivity in the brain. Participants also underwent testing for cognition and mood. Despite minimal weight loss, the exercise intervention normalized brain function relevant to metabolism, and greater improvement in brain function was correlated with greater loss of visceral fat. In particular, subjects exhibited increased blood flow in regions of the brain related to motor control and reward processes. The striatum showed greater insulin sensitivity after the exercise intervention - comparable to the response of a normal-weight individual. Participants also reported improvements in mood and executive function.
🐭 Alternate-day fasting substantially reduces risk of developing type 2 diabetes in mice on a high-fat diet.
Researchers provided a group of mice that are predisposed to developing diabetes with ad libitum access to high fat food. These mice were then subjected to food restriction every other day. Compared to controls, the alternate-day fasting rodents showed dramatically reduced pancreatic fat - similar to levels found in mice that are naturally resistant to diabetes. They also showed lower blood sugar levels and better islet-cell function.
😪 Inadequate sleep doesn't just harm health. It may also impact civic engagement.
Researchers analyzed data from two large nationally representative longitudinal surveys, both of which included questions about civic participation and sleep. In a complementary experimental design, the team also recruited and surveyed more than a thousand participants via Amazon Mechanical Turk, and randomly assigned them to complete a survey either in the afternoon or at 3am. Through these studies, the researchers found overall that tired people, despite a genuine desire to participate, are less likely to vote, donate money, sign petitions, or vote in elections.
New humanOS Content
In this episode of humanOS Radio, Dan talks to Dr. Davide D’Amico. Davide is a research scientist in the field of metabolism and aging. He was previously a post-doc at the Auwerx Laboratory of Integrative Systems Physiology at the École Polytechnique Fédérale de Lausanne (EPFL), where he investigated the role of mitochondrial function in health, disease, and the aging process.
Most of us associate getting older with a loss of energy. On the molecular level, this is quite literally true, because one of the hallmarks of aging is mitochondrial dysfunction. As we age, mitochondria become less effective at generating the energy we need for various chemical processes. So why does this happen? One likely reason is a failure of quality control. Mitochondrial autophagy (aka mitophagy) declines with age, and our body starts to accumulate broken and dysfunctional mitochondria. This becomes most obvious in tissues that consume a lot of energy, like skeletal muscle. Hence, mitochondrial dysfunction is linked to poor muscular strength in older people. If we could only find a way to ramp up mitophagy, perhaps we could retain excellent mitochondrial function throughout our golden years.
In this interview, we discuss a recently published study from his team, which revealed one of the molecular mechanisms through which defective mitochondria accumulate in cells. Additionally, Davide is a scientific project manager at Amazentis, where he is investigating a naturally derived bioactive from pomegranate (urolithin A) that has been shown in a new clinical trial to reverse age-related decline in mitochondrial function in the muscles of older people. Please check out the interview to learn more about this exciting research!
Podcasts We Loved This Week
- Martin Blaser: Missing Microbes. Via the American Society for Microbiology.
- Sarah Crespi: What antlers can teach us about cancer and regrowing limbs. Via Science Magazine.
- Samantha Jones: Top five strangest and most deadly poisons. Via Reactions.
Products We Are Enjoying
Blue Light Blocking Computer Glasses
Ginny says: These glasses are a lifesaver if you have a job that requires you to read text on computer screens all day, like me. I have personally found that prolonged exposure to blue light emitted from my laptop (not to mention my phone, iPad, lightbox, etc) causes painful eyestrain and makes it hard for me to focus. But I also don’t want to wear amber lenses during the day, because I do want some light to enter the eye for alertness and circadian alignment. These glasses are ideal because they look almost completely clear when you are wearing them, with no discernible orange tint. When I put them on, eyestrain goes away within an hour or so. As an added bonus, they actually look pretty cute. 🤓