Between Saturdays
This week: How childhood trauma reshapes the brain, why naps might slow aging, the surprising allergy-lowering power of pets, and the mental health cost of sleeping after 1 a.m.
Every week, the science shifts a little—and sometimes, it stuns. In this edition of Between Saturdays, I look at what makes our minds more fragile—or more resilient—over time. From the way trauma in childhood can wire a brain like that of a soldier, to the protective power of something as simple as a 1 p.m. nap, the findings are as sobering as they are hopeful. I also explore how our furry companions might quietly be reducing the allergy risks of the next generation, and why staying up past 1 a.m. may be doing more harm than you think—even if you're a natural night owl.
Whether you're a parent, a late-night thinker, or someone just curious about how everyday habits shape long-term wellbeing, this week’s roundup is for you.
Let’s get into it.
Caught My Eye…
Childhood Trauma and the Brain
A remarkable study led by researchers at University College London (UCL), found that children exposed to domestic violence exhibit neural activity similar to that of combat veterans. Specifically, when shown images of angry faces, these children displayed heightened activation in the amygdala and anterior insula—two brain regions central to threat detection and emotional processing.
This pattern of brain activity mirrors that seen in adult soldiers exposed to war-related trauma. In both cases, the brain appears to adapt by becoming hyper-vigilant, scanning for potential threats as a protective mechanism. While this neural rewiring may confer short-term survival benefits—such as being alert to danger in a volatile environment—it comes with long-term costs. Over time, this constant state of vigilance can increase vulnerability to anxiety disorders, depression, and PTSD-like symptoms, even in the absence of ongoing threat.
The good news? There’s evidence that these patterns can be reversed. With consistent support, therapy, and safe environments, neural function can gradually normalize. Interventions aimed at promoting resilience and emotional regulation have shown promise in reshaping even deeply entrenched stress-response systems.
In Summary
The Brain-Boosting Power of Napping
New research from a large Mendelian randomization study using UK Biobank data (nearly 379,000 participants aged 40–69) has uncovered a compelling link between habitual daytime napping and brain health. Individuals with a genetic predisposition to napping were found to have larger total brain volumes, equating to brains that appeared 2.6 to 6.5 years younger compared to non-nappers. While the study didn’t find improvements in memory or reaction time, the preservation of brain tissue alone is a striking marker of healthy aging.
That said, there are important caveats. The study measured genetic tendency toward napping—not nap duration or quality—and most participants were of European ancestry, which limits broad generalization. Additionally, naps were not directly linked to cognitive enhancement in this study, only brain volume. Still, the findings point to naps as a potential protective factor against age-related brain shrinkage.
Napping Smart: What Experts Recommend
Power Naps (10–20 min): Great for alertness and mood; avoid sleep inertia.
Short Naps (20–30 min): Support memory and light cognitive recovery.
Full-Cycle Naps (~90 min): Ideal for memory consolidation and full mental refresh.
Best Time to Nap: Between 1–3 p.m., during your natural circadian dip.
Keep It Regular: Erratic napping can increase dementia risk in older adults, while consistent, early-afternoon naps support better cognitive aging.
Why It Matters
Though naps aren’t a miracle drug for cognition, they may be a powerful, low-cost tool for slowing brain aging. Combined with consistent sleep hygiene, healthy daytime napping may help preserve neural structure, especially when practiced wisely.In other words: a nap done right isn’t laziness—it’s neural maintenance.
Lower Food Allergy Risk with Dogs & Cats
A large-scale study out of Japan—The Japan Environment and Children’s Study—tracked over 66,000 children and uncovered an intriguing link between early-life pet exposure and reduced food allergy risk. Children exposed to indoor dogs or cats during pregnancy and infancy were 15% less likely to develop food allergies by age three.
Breakdown by Pet Type:
Dogs were linked to lower rates of egg, milk, and nut allergies
Cats were associated with reduced egg, wheat, and soybean allergies
Hamsters, however, were connected to increased nut allergy risk—likely due to their proximity to nut-based bedding or feed
Timing Matters
The protective effect was strongest when exposure occurred both during pregnancy and infancy, rather than just one period. This supports theories around immune system “training” during critical developmental windows.The Science Behind It?
Researchers point to the hygiene hypothesis—suggesting that early, diverse microbial exposure helps the immune system develop tolerance rather than hypersensitivity. Pets may also shape the gut microbiome, introducing beneficial microorganisms that promote immune balance. Additionally, pets bring environmental endotoxins indoors—tiny microbial components that may “prime” the infant immune system.While the findings are promising, it’s important to note a few limitations. The study relied on parent-reported allergy diagnoses rather than confirmed clinical testing, which may affect the precision of the results. Additionally, the research was conducted within a Japanese cohort, so the outcomes may not be directly applicable to populations with different genetic, dietary, or environmental backgrounds. Most importantly, this was an observational study, meaning it reveals an association—not a direct cause-and-effect relationship. In other words, having a dog or cat during pregnancy and infancy might help lower the risk of food allergies, but it’s not a guaranteed preventive strategy.
Late Nights, Higher Risk: What the Science Reveals
Emerging research suggests that consistently going to bed after 1 a.m. could be doing more than disrupting your schedule—it might be compromising your mental health. An observational study from Imperial College London found that individuals who habitually sleep past 1 a.m.—regardless of whether they identify as night owls—reported significantly higher rates of depression, generalized anxiety, and other mental health concerns. These findings were echoed by a Stanford University analysis of nearly 75,000 adults in the UK Biobank, which showed that late bedtimes were associated with a 20–40% increased likelihood of being diagnosed with a mental health disorder, even after accounting for sleep duration and chronotype.
The biological mechanisms are just as telling. Staying up late disrupts the brain’s frontal lobe function, which governs emotional regulation and impulse control. It also misaligns the body’s circadian rhythms from the natural light-dark cycle, elevating stress hormones and impairing mood regulation. Moreover, late sleepers often miss out on crucial REM sleep—vital for emotional processing and mental restoration—resulting in cumulative deficits that show up as irritability, anxiety, and depression.
Importantly, this risk isn't limited to people who are forced into late nights due to work or lifestyle pressures. Even natural night owls face the same mental-health toll if they push their sleep into the early morning hours. The takeaway? Going to bed earlier isn’t just good sleep hygiene—it’s a mental-health intervention.
Experts recommend being in bed before 1 a.m. consistently, including weekends, to help safeguard your emotional and cognitive resilience. Incorporating wind-down routines, minimizing evening screen time, and creating a dim, tech-free sleep environment can all support a healthier circadian rhythm. For those with shift work or unpredictable schedules, tools like timed light exposure and preemptive naps can help minimize circadian misalignment.
The bottom line: late nights may feel productive or unavoidable, but your brain is paying the price. Making an effort to turn in earlier could be a deceptively simple way to protect your mental well-being.
If this resonates, you might appreciate this deep dive on how to fix insomnia without medications—especially if you’re struggling to fall asleep despite knowing the risks. It explores science-backed behavioral strategies, cognitive traps that keep you wired at night, and realistic tweaks for moms (and non-moms) alike.
Detailed Readings
Maltreated children show same pattern of brain activity as combat soldiers
Regular naps might keep the brain younger by as much as 5-6 years
How going to bed past midnight could affect your mental health
