"News From The Future" with Dr Catherine Ball

I find this dialogue between human biology and microbes fascinating. It was an area I studied for my first doctorate…
Enjoy!
Transcript:
Welcome to News From The Future read to you by the AI Voice Clone of Dr Cath made by eleven labs. Please share this with anyone who sleeps or poops. Yes, poops. We are starting a new series soon on AI, tech, and the microbiome. But we still love the future of sleep as a topic so will be creating some bridging podcasts. Enjoy
Sleep is a cornerstone of life, taking up about a third of our existence. This isn’t just a quirk of biology—it’s a necessity. Sleep is vital for our health, and even animals with challenging lifestyles, like aquatic mammals that must surface for air or birds flying for days without landing, have developed remarkable adaptations to ensure they rest. But while we sleep, there’s another story unfolding inside us. The tens of trillions of microorganisms living in and on our bodies—our microbiota—don’t rest. These microscopic companions, mostly bacteria, weigh around 200 grams and form a biological partnership with us, known as the holobiont. Far from being passive hitchhikers, they actively influence processes critical to our survival, including digestion, immune function, and even sleep.
The relationship between humans and their microbiota is a finely tuned partnership. We provide them with a home and nutrients, and in return, they help regulate numerous biological functions. This balance is increasingly recognized as essential to health, well-being, and possibly even longevity. For instance, studying the gut microbiomes of some of the world’s oldest individuals has offered fascinating insights into how these microorganisms might influence aging.
Interestingly, the connection between sleep and the microbiota is bidirectional. The state of your microbiota can directly affect how well you sleep, and your sleep quality, in turn, impacts the health and diversity of your microbiota. When the microbiota is healthy, it produces beneficial compounds like short-chain fatty acids (SCFAs), such as butyrate. These molecules are linked to reduced inflammation and improved functioning of neuroendocrine pathways, including the hypothalamic-pituitary-adrenal (HPA) axis, which governs the body’s stress response. A well-regulated HPA axis lowers nighttime cortisol levels, leading to deeper, more restful sleep with fewer awakenings.
The gut microbiota also plays a key role in the production of neurotransmitters, including serotonin. Serotonin is widely known for its role in promoting positive mood states, but it also has a significant impact on sleep regulation. This means that a healthy microbiota doesn’t just support physical health; it also contributes to emotional and mental well-being, creating a holistic connection between our gut and our brain.
Maintaining a balanced microbiota is essential, but it’s important to note that there’s no such thing as a “perfect” microbiota. Each person has a unique microbial ecosystem shaped by their genetics, environment, and lifestyle. The goal is to achieve a functional balance that supports health. If imbalances occur, gradual lifestyle changes can often restore harmony. Here are three effective strategies to nurture the relationship between your microbiota and your sleep:
1. **Adopt a fiber-rich diet**: Diet is one of the most powerful tools for shaping your gut microbiota. A diet rich in fiber nourishes beneficial bacteria, reduces inflammation, and improves sleep quality. Foods like vegetables, fruits, pulses, whole grains, and fermented products (such as yogurt, kefir, sauerkraut, or kimchi) are excellent choices. The Mediterranean diet, in particular, is celebrated for its ability to promote microbial diversity. On the flip side, reducing the consumption of ultra-processed foods helps maintain a balanced microbiota. This dietary approach not only supports your gut but also contributes to better sleep.
2. **Stick to a consistent routine**: Your body’s internal clock, or circadian rhythm, thrives on regularity. Exposure to natural light, especially in the morning, is crucial for synchronizing this rhythm. At night, reducing your exposure to bright artificial light can improve sleep quality and help maintain biological balance. Sleep isn’t just a time for rest; it’s also when your body and microbiota work together to restore equilibrium. Even a few nights of poor sleep can disrupt the composition of your gut microbiota, increase inflammatory responses, and impair cognitive and metabolic functions the following day.
3. **Get moving and manage stress effectively**: Regular physical activity is another critical factor for a healthy microbiota and better sleep. The good news is that you don’t need to engage in intense workouts to see benefits. Moderate activities like walking, cycling, or swimming can positively impact microbial diversity and enhance sleep quality. Stress management is equally important. Chronic stress can harm your gut microbiota and, by extension, your sleep. Practices like yoga, meditation, mindfulness, or even simple activities like spending time with loved ones or walking in nature can help reduce stress. Lower stress levels improve mental health and support a healthier microbiota, creating a positive feedback loop that enhances sleep.
The interplay between sleep, diet, exercise, and stress management highlights the importance of a holistic approach to health. A balanced microbiota contributes to better digestion, lower inflammation, improved mood, and deeper, more restorative sleep. In turn, good sleep supports the health and diversity of your microbiota, creating a virtuous cycle of well-being.
Sleep deprivation, even over a short period, can have profound effects on your microbiota and overall health. Just a few nights of poor sleep can alter the gut microbiota’s composition, increase inflammation, and make the intestinal lining more permeable—a condition often referred to as “leaky gut.” This can lead to a cascade of health issues, including impaired glucose metabolism, increased stress responses, and reduced cognitive performance. These effects underscore the importance of prioritizing both sleep and gut health in our daily lives.
The relationship between humans and their microbiota is a remarkable example of biological interdependence. By making intentional lifestyle choices—such as eating a fiber-rich diet, maintaining a consistent routine, staying active, and managing stress—you can nurture this relationship and reap the benefits it brings to your physical and mental health. Sleep, once seen as merely a passive state of rest, is now understood to be a dynamic and essential process that supports the delicate balance of the microscopic ecosystem within us. By caring for your microbiota, you’re not just improving your sleep—you’re investing in your overall well-being and longevity.
Thank you for listening to this podcast. Please support Dr Cath’s works by buying her books or becoming a paid subscriber to her substack.

"News From The Future" with Dr Catherine Ball is a reader-supported publication. To receive new posts and support my work, consider becoming a paid subscriber.



This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drcatherineball.substack.com/subscribe

Watch this space for the next book coming over the hill…. you’ll definitely be better off after reading it…
For now; here is the podcast transcript for today:
Welcome to News From The Future read to you by the AI Voice Clone of Dr Cath made by eleven labs. Please share this with anyone who sleeps or poops. Yes, poops. We are starting a new series soon on AI, tech, and the microbiome. But we still love the future of sleep as a topic so will be creating some bridging podcasts.
When sleep becomes elusive, people often turn to familiar remedies like counting sheep, taking melatonin, or practicing breathing exercises. However, a recent study has introduced a surprising and unconventional approach to tackling chronic insomnia: fecal microbiota transplantation (FMT). Yes, a poop transplant. This groundbreaking research sheds light on the intricate relationship between gut health and sleep, offering new insights and potential therapeutic options for those struggling with insomnia.
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**The Study and Its Findings**
A study published in the *Journal of Internal Medicine* explored the potential of FMT to improve sleep in adults suffering from chronic insomnia. The results were remarkable. Participants who received the treatment slept longer, woke up less frequently during the night, and maintained these improvements for up to six months. According to the study’s authors, Zhe Wang from the Institute of Brain Science and Brain-Inspired Research in China and Yanping Bao from the National Institute on Drug Dependence in Beijing, the findings provide clinical evidence that the gut microbiota—the diverse community of microorganisms in our digestive system—may be a modifiable factor in regulating human sleep. They further suggest that the gut-brain axis, the communication network between the gut and the brain, could be a promising therapeutic target for chronic insomnia.
The trial involved 80 adults in China who had been diagnosed with chronic insomnia. To prepare participants for the treatment, researchers first administered a short course of antibiotics to reduce their existing gut bacteria, effectively creating a blank slate. Participants were then randomly assigned to receive either an FMT capsule or a placebo. This double-blind study ensured that neither the participants nor the researchers knew who received the actual treatment. The fecal transplant material came from healthy donors with no history of sleep disorders or psychiatric symptoms.
One month after the treatment, participants returned to a sleep lab where researchers measured several key factors, including how long participants slept, how often they woke up, and their sleep efficiency (the percentage of time spent asleep while in bed). The results were striking. For those who received the fecal transplant, sleep efficiency increased from about 79% to 93%. In contrast, the placebo group showed only a slight improvement, going from 85% to 87%. Additionally, participants in the FMT group spent 42 fewer minutes awake after initially falling asleep compared to those in the placebo group. Follow-up questionnaires revealed that these improvements persisted for up to six months.
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**Limitations and Open Questions**
While the findings are promising, the study does have its limitations. With only 80 participants, the sample size is relatively small, and the results need to be replicated in larger and more diverse populations. Moreover, the researchers have yet to identify which specific microorganisms or microbial functions are responsible for the observed benefits. Questions also remain about whether different donor preparations would produce similar effects and how long the improvements might last beyond six months. Wang and Bao acknowledge these gaps and stress the need for further research to uncover the precise biological mechanisms at play.
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**The Gut-Brain-Sleep Connection**
The study highlights the fascinating relationship between gut health and sleep, often referred to as the gut-brain axis. Chronic insomnia, which affects about one-third of adults, involves persistent difficulties in falling or staying asleep at least three nights a week for three months or longer. While the idea that gut health can influence sleep isn’t entirely new, this study takes the concept a step further by demonstrating the potential of FMT as a therapeutic option.
Erica Jansen, MPH, PhD, an assistant professor of nutritional sciences at the University of Michigan, explains that there is ongoing “cross-talk” between the gut and the brain. A healthier gut microbiome could positively impact brain function and, by extension, sleep. Certain bacteria, such as *Lactobacillus* and *Bifidobacterium*, are believed to promote sleep by enhancing serotonin production—a key neurotransmitter involved in regulating sleep cycles. Conversely, sleep deprivation can disrupt the balance of beneficial gut bacteria, creating a vicious cycle.
Probiotics, prebiotics, and now fecal transplants are emerging as potential tools to restore this balance and improve sleep quality. However, as Jansen points out, other digestive-related processes, such as acid reflux or gastrointestinal discomfort, can also interfere with sleep. This underscores the complexity of the gut-brain-sleep relationship and the need for more targeted studies.
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**Diet and Sleep: What to Eat (and Avoid)**
While FMT offers a cutting-edge approach, there are simpler, more accessible ways to support sleep through diet. Research consistently shows that a balanced diet can improve sleep quality and make it easier to fall asleep. Foods rich in melatonin, tryptophan, antioxidants, and other essential nutrients are particularly beneficial. Jansen highlights the following as sleep-supporting foods:
- **Fruits**: Berries, kiwifruit, bananas, and tart cherries
- **Vegetables**: Spinach and sweet potatoes
- **Whole grains**: Oatmeal
- **Protein sources**: Turkey, chicken, eggs, and peanuts
- **Fatty fish**: Such as salmon and mackerel
- **Dairy products**
These foods provide compounds that help regulate sleep-wake cycles and promote relaxation. For example, tryptophan is an amino acid that the body converts into serotonin and melatonin, both of which are critical for sleep. Tart cherries, on the other hand, are a natural source of melatonin.
Jansen cautions against focusing too heavily on any single food. Instead, she recommends aiming for a balanced diet while avoiding items that could disrupt sleep. Foods high in saturated fat, sugar, and refined carbohydrates—like desserts—can interfere with sleep quality, as can alcohol and caffeine. Timing also matters. Eating heavy meals too close to bedtime can make it harder to fall asleep, while maintaining consistent meal times can help regulate your body’s internal clock.
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**Looking Ahead**
The idea that gut health could hold the key to better sleep is both exciting and somewhat unconventional. The recent study on fecal microbiota transplantation opens up new possibilities for treating chronic insomnia, but it’s clear that more research is needed to fully understand the mechanisms and potential applications. In the meantime, focusing on a balanced diet and maintaining good sleep hygiene remain practical and effective ways to improve sleep quality. Whether through cutting-edge science or simple lifestyle changes, the connection between the gut and sleep is a fascinating frontier that’s only beginning to be explored.
Thank you for listening to this podcast. Please support Dr Cath’s works by buying her books or becoming a paid subscriber to her substack.
"News From The Future" with Dr Catherine Ball is a reader-supported publication. To receive new posts and support my work, consider becoming a paid subscriber.



This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drcatherineball.substack.com/subscribe

Podcast Transcript:
Hello and Welcome to News From The Future, spoken by the eleven labs audio clone of Dr Catherine Ball.
In this new short series we will be focussing on Sleep. We all do it, and we all recognise when we have not had enough of it.
Dr Cath’s new book The Future of Sleep is out now and available globally in paperback, audiobook, and ebook formats.
We think you’ll get something life changing from it.
Today we are talking about something currently trending: Dark Showers
Enjoy!
Somewhere in the evolving world of wellness trends, a new sleep ritual has emerged that’s as low-effort as it is intriguing—dark showering. This minimalist approach to better sleep has captivated social media, promising a more restful night by doing less: less light, less stimulation, and more alignment with the body’s natural rhythms. The concept is straightforward: turn off the bathroom lights during your evening shower and let the darkness guide you into a state of calm.
This trend comes at a time when sleep deprivation is a growing concern, particularly in the UK, where studies reveal that British women are among the most sleep-deprived in Europe. One in five women reportedly gets less than six hours of sleep per night. Could something as simple as showering in the dark really make a difference? Let’s explore what makes this practice so compelling.
Dark showering is designed to help you wind down, unlike a morning shower that energizes you for the day. Experts recommend taking a dark shower 60 to 90 minutes before bed to reduce light exposure, regulate body temperature, and signal to your body that it’s time to rest. Ada Ooi, an integrative Chinese medicine clinician, explains that this practice aligns with principles from Traditional Chinese Medicine (TCM). According to TCM, nighttime is when the active, outward energy of the day (yang) transitions to the quieter, inward energy of the night (yin). A warm, dimly lit shower calms the senses, allowing the body’s qi (energy) to settle and the mind to relax.
Science supports some of these claims. Research shows that exposure to standard room lighting between dusk and bedtime can reduce melatonin levels by 70% and shorten its release duration by about 90 minutes. Since melatonin is a hormone crucial for sleep, this lighting delay can leave you feeling alert at a time when your body should be preparing to rest. Bathrooms, often the brightest rooms in the house, are particularly problematic. Harsh overhead lights and illuminated mirrors may be great for morning routines but are counterproductive at night. Turning off these lights eliminates one of the strongest signals your brain receives to stay awake.
Jane Ollis, a medical biochemist, emphasizes that the key isn’t the shower itself but the absence of light. Light entering the eyes directly affects the hypothalamus, suppressing melatonin and keeping the brain alert. When you remove that light, you’re removing one of the brain’s primary “stay awake” signals. Darkness also reduces cognitive load, as vision is one of the brain’s most demanding systems. Without visual input, the brain has less to process, creating a calmer state.
Temperature plays a significant role as well. Studies suggest that spending about 10 minutes in water heated to 40-42°C, one to two hours before bed, can improve sleep onset and quality. This isn’t because the experience is spa-like, but because it alters the body’s thermal dynamics. A warm shower raises your skin temperature, promoting heat loss when you step out. This drop in core body temperature is a physiological cue that helps initiate sleep.
However, Ollis points out that dark showering isn’t a groundbreaking discovery in neuroscience. Instead, it repackages well-established principles of neurobiology into a simple, novel ritual. The practice aligns your environment with what your nervous system is already trying to do at the end of the day: prepare for rest. While many people may notice a sense of calm or find it easier to fall asleep after their first attempt, the effect is subtle. It’s a state shift, not a transformation.
Personal experiences with dark showering reveal both its appeal and its challenges. Initially, the experience can feel unsettling—perhaps due to cultural associations with darkness and vulnerability. But once the eyes adjust, the absence of light can be calming. The sound of running water becomes more pronounced, and the mental clutter of daily life begins to fade. Practical challenges, like locating the right bottles in the dark, can be mitigated by pre-arranging items or using a candle for soft lighting. Some even find that keeping the lights dim throughout the house enhances the overall effect.
It’s important to note that dark showering isn’t a cure-all for insomnia or chronic sleep issues. Ollis clarifies that it doesn’t directly stimulate the vagus nerve, a key player in relaxation and recovery. Instead, it removes the sensory “noise” that keeps the body in an alert state. For those seeking a more immersive experience, other methods like flotation therapy or technologies such as pulsed electromagnetic field (PEMF) mats may offer more comprehensive sensory reduction and relaxation.
Flotation therapy, for example, minimizes multiple streams of external stimulation—light, sound, temperature variation, and even gravity—creating a more profound sense of calm. PEMF mats, though still emerging in evidence, aim to promote relaxation through low-frequency electromagnetic stimulation. Even a candlelit bath, a more traditional approach, can be effective. Research published in the *Journal of Physiological Anthropology* found that participants who took a long soak fell asleep faster and experienced better-quality sleep than those who showered. The underlying neuroscience remains the same; the difference lies in the behavior, not the biology.
Dark showering’s simplicity is ultimately its greatest strength. It doesn’t promise to revolutionize your sleep patterns or solve deep-seated issues, but it offers an intuitive, low-effort way to end the day. By aligning your environment with your body’s natural rhythms, you might just find yourself drifting off a little easier—and enjoying the process of unwinding along the way.
Please share this podcast with anyone you know who sleeps.
Thank you for supporting my work. Please follow me on LinkedIn or subscribe to my substack for more News From The Future
And please buy my book: The Future of Sleep.
Thank you.
Thanks for reading "News From The Future" with Dr Catherine Ball! This post is public so feel free to share it.



This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drcatherineball.substack.com/subscribe

Hello and Welcome to News From The Future, spoken by the eleven labs audio clone of Dr Catherine Ball.
In this new short series we will be focussing on Sleep. We all do it, and we all recognise when we have not had enough of it.
Dr Cath’s new book The Future of Sleep is out now and available globally in paperback, audiobook, and ebook formats.
We think you’ll get something life changing from it.
Today we are talking about something a bit controversial - Social Apnea
Enjoy!
The term “social apnea” has been introduced as a new concept in sleep health by researchers from Flinders University. This phenomenon describes the weekend spike in the severity of Obstructive Sleep Apnea (OSA), which is being linked to lifestyle choices and irregular sleep patterns. The research, published in the American Journal of Respiratory and Critical Care Medicine, analyzed data from over 70,000 individuals worldwide and found a consistent increase in OSA severity on weekends. The findings highlight how behaviors such as staying up late, consuming alcohol, smoking, and sleeping in on weekends contribute to this trend.
Dr. Lucia Pinilla, a lead author and Research Fellow at FHMRI Sleep Health, explains that the impact of sleep apnea may be underestimated due to the current diagnostic approach. Most clinical tests for OSA are conducted on a single weekday night, which could miss the weekend effect now termed “social apnea.” The study found that participants were 18% more likely to experience moderate to severe OSA on Saturdays compared to mid-week (Wednesdays). This weekend surge in sleep-disordered breathing is concerning because it may elevate the risk of serious health conditions, including heart disease, depression, dementia, extreme fatigue, and accidents.
One of the key findings of the study is that sleeping in for an additional 45 minutes or more on weekends increases the risk of worsening OSA by 47%. Demographic variations were also observed, with men being 21% more likely to experience a weekend-related increase in OSA severity compared to a 9% increase in women. Age also plays a role, as younger adults under 60 showed a 24% higher risk of worsened OSA on weekends, while those aged 60 and above exhibited only a 7% increase. These statistics underscore how factors such as age, gender, and behavioral habits contribute to the weekend exacerbation of sleep apnea.
Matthew Flinders Professor Danny Eckert, Director of FHMRI Sleep Health and senior author of the study, emphasized that this is the first evidence showing OSA severity increases on weekends. Although the exact mechanisms are not fully understood, alcohol consumption, lighter sleep, and inconsistent use of OSA therapies on weekends likely contribute to the issue. The research team suggests that current diagnostic practices relying on single-night sleep studies may lead to underdiagnosis or misclassification of OSA severity. Multi-night sleep assessments and personalized approaches to treatment are recommended to address this gap.
The concept of social apnea aligns with findings from another study, published in Nature Communications Medicine, which explored seasonal variability in OSA severity. Led by Dr. Bastien Lechat, this research revealed that OSA tends to worsen during summer and winter, with severity increasing by 8–19% compared to spring and autumn. Higher temperatures in summer disrupt sleep by causing lighter sleep stages, which are associated with more frequent apnea events. In winter, longer sleep durations and later wake-up times increase time spent in REM sleep, a phase linked to worsened OSA. These seasonal factors, combined with the weekend effect described in social apnea, highlight the complex interplay between environmental and behavioral influences on sleep health.
To combat social apnea, experts recommend maintaining a consistent sleep schedule throughout the week, including weekends. Professor Eckert advises aiming for the recommended 7–9 hours of sleep per night, keeping a fixed wake-up time, and using prescribed OSA therapies consistently, even on weekends. Going to bed only when feeling sleepy can also help ensure restorative sleep and reduce the weekend spike in OSA severity.
OSA is a common sleep disorder affecting around one billion people globally. It is characterized by repeated airway collapse during sleep, which can lead to serious health consequences if left untreated. These include an increased risk of heart disease, diabetes, cognitive decline, depression, and even death. The weekend exacerbation of OSA, as described in the social apnea study, underscores the importance of addressing lifestyle factors and ensuring accurate diagnosis and treatment.
The study, titled “Social apnea: Obstructive sleep apnea is exacerbated on weekends,” was published in the American Journal of Respiratory and Critical Care Medicine on August 13, 2025. The Nature Communications Medicine article, “Obstructive sleep apnea severity varies by season and environmental influences such as ambient temperature,” was published on July 29, 2025. Both studies were conducted by a team of international researchers, including Dr. Lucia Pinilla, Dr. Bastien Lechat, and Professor Danny Eckert, among others.
Acknowledgments for the research include support from various fellowships and grants, such as the National Health and Medical Research Council (NHMRC) of Australia and the Australian Research Council. These contributions highlight the collaborative effort behind advancing our understanding of OSA and its contributing factors.
In summary, the discovery of social apnea sheds light on how weekend habits and environmental factors can exacerbate sleep apnea severity. By adopting consistent sleep routines and addressing lifestyle choices, individuals can help mitigate the risks associated with this newly identified phenomenon. For those concerned about their sleep health, consulting with a healthcare professional is strongly recommended.
Please share this podcast with anyone you know who sleeps.
Thank you for supporting my work. Please follow me on LinkedIn or subscribe to my substack for more News From The Future
And please buy my book: The Future of Sleep.
Thank you.
Thanks for reading "News From The Future" with Dr Catherine Ball! This post is public so feel free to share it with anyone who sleeps.



This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drcatherineball.substack.com/subscribe

Podcast transcript:
Hello and Welcome to News From The Future, spoken by the eleven labs audio clone of Dr Catherine Ball.
In this new short series we will be focussing on Sleep. We all do it, and we all recognise when we have not had enough of it.
Dr Cath’s new book The Future of Sleep is out now and available globally in paperback, audiobook, and ebook formats.
We think you’ll get something life changing from it.
Today we are talking about something a bit controversial - Blue Light
Enjoy!
For over a decade, warnings about blue light from our screens have dominated conversations about poor sleep. The narrative is simple: the blue glow of our devices disrupts our circadian rhythm, delaying sleep and leaving us groggy the next day. However, Hana Mendel’s deep dive into the science behind these claims reveals that the story is far more nuanced. The issue isn’t just about blue light—it’s about how modern life, in its entirety, disrupts our exposure to light and dark. Let’s unpack the details of her findings.
The blue light panic began in 2014 with a small study that compared participants reading on an iPad before bed to those reading physical books. The iPad users took longer to fall asleep, produced less melatonin (a hormone critical for sleep), and felt more tired the next day. Researchers attributed these results to the blue-enriched light emitted by the iPad, which mimics daylight and interferes with our body’s natural clock. The study launched a wave of concern about blue light, with many people blaming their phones, tablets, and TVs for their sleepless nights.
But experts like Jamie Zeitzer, a professor of psychiatry and behavioral sciences at Stanford University, caution against oversimplifying the issue. While it’s true that blue light can affect sleep, the light emitted by our screens is minimal compared to other sources. Modern screens and LED light bulbs do emit more blue light than older technologies because they use blue LEDs coated with yellow phosphor to simulate white light. But the amount of blue light from these devices is trivial compared to the blue light we receive from the Sun. One study found that 24 hours of exposure to screens amounts to less than one minute of sunlight exposure. Another review of 11 studies showed that screen light delays sleep by just nine minutes at worst—not exactly the catastrophic impact many fear.
So, if blue light from screens isn’t the main culprit, what is? Mendel’s exploration points to a broader issue: the way modern lighting and lifestyles disrupt our natural exposure to light and dark. Our bodies are designed to respond to the contrast between bright daylight and dim evenings, but many of us spend our days indoors under artificial light that’s far dimmer than natural sunlight. This lack of exposure to bright light during the day makes us more sensitive to light at night, whether it’s blue or not.
To test these ideas, Mendel embarked on an extreme experiment to eliminate blue light from her evenings. She wore industrial-grade orange goggles designed to block blue light completely, covered her windows with blackout curtains, and replaced all her lamps with candles. While effective, the goggles were impractical and uncomfortable—better suited for industrial work than everyday life. The candlelit evenings, however, became a calming ritual that Mendel grew to appreciate.
Experts like Håvard Kallestad, a sleep researcher, emphasize that avoiding blue light at night is only part of the solution. The real key is managing your total light exposure throughout the day. Bright light in the morning, especially light that’s rich in blue wavelengths, helps regulate your circadian rhythm and makes your body less sensitive to light in the evening. Mendel experimented with a bright light therapy lamp each morning, designed to treat seasonal depression. While sitting in front of the lamp wasn’t particularly enjoyable, it helped anchor her body clock.
Zeitzer highlights the importance of contrast in light exposure. During the day, brighter lighting signals to your body that it’s daytime. In the evening, gradually dimming your lights helps cue your body to start winding down. Even a 30-minute walk outside in the morning can make a significant difference, as natural sunlight is far more intense than indoor lighting. On a cloudy day, outdoor light intensity can reach 10,000 lux, while a sunny day can hit 100,000 lux. In contrast, indoor lighting typically measures around 100 lux, and your phone emits only 50-80 lux at full brightness.
Interestingly, the content we consume on our devices may be more disruptive to sleep than the light itself. Engaging in stimulating activities like scrolling through social media or watching intense shows can keep your brain alert, making it harder to fall asleep. This suggests that what we do on our screens matters more than the light they emit.
Mendel’s experiment didn’t dramatically improve her sleep quality, but it did lead to some positive changes. By the end of her two-week trial, she found it easier to fall asleep and wake up at consistent times. The psychological cues from her candlelit evenings and other bedtime rituals seemed to help her body recognize when it was time to wind down. This aligns with Zeitzer’s observation that such routines can act as “Pavlovian conditioning” for sleep, signaling to your brain that bedtime is approaching.
While blue light isn’t entirely blameless, it’s not the sleep saboteur it’s often made out to be. The real issue is our overall exposure to light and how it aligns with our natural rhythms. To improve your sleep, focus on getting plenty of natural light during the day, dimming your lights in the evening, and creating calming bedtime rituals. If you’re tempted to try blue-blocking glasses or phone filters, know that their biggest benefit might be the psychological signal they send to your brain that it’s time to unwind.
Mendel’s findings highlight the complexities of light’s impact on sleep and the importance of looking beyond simple solutions. While you probably won’t be rushing to stock up on candles or orange goggles, her experiment offers practical advice for anyone looking to improve their sleep in a world that’s increasingly lit up 24/7.
Please share this podcast with anyone you know who sleeps.
Thank you for supporting my work. Please follow me on LinkedIn or subscribe to my substack for more News From The Future
And please buy my book: The Future of Sleep.
Thank you.
Thanks for reading "News From The Future" with Dr Catherine Ball! This post is public so feel free to share it with anyone who sleeps.



This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drcatherineball.substack.com/subscribe