AI-powered
podcast player
Listen to all your favourite podcasts with AI-powered features
Huberman Lab
Dr. Samer Hattar: Timing Your Light, Food, & Exercise for Optimal Sleep, Energy & Mood
Oct 25, 2021
02:12:51
Episode guests
AI Summary
Highlights
AI Chapters
Episode notes
Podcast summary created with Snipd AI
Quick takeaways
- Light exposure at different times of the day can affect mood and learning independent of the circadian clock.
- Getting exposure to bright light in the morning helps regulate the sleep-wake cycle and improves mood and energy levels.
- Consider both intensity and duration of light exposure throughout the day to regulate the circadian clock and support bodily functions.
- Creating a dimmer environment in the evening prepares the body for sleep and promotes a healthy sleep-wake cycle.
- Aligning meal times with the circadian rhythm positively impacts hunger regulation and overall health.
Deep dives
The Direct Effects of Light on Mood and Learning
Exposure to light at different times of the day can have significant effects on mood and learning, independent of its impact on the circadian clock. Research has shown that even when sleep-wake cycles are not disrupted, improper timing of light exposure can lead to changes in mood and deficits in learning. This suggests that there is a direct relationship between light and these non-circadian effects. It has been found that different brain regions are involved in these processes, demonstrating that they are distinct from the effects on sleep and wakefulness.
The Importance of Morning Light Exposure
Getting exposure to bright light in the morning, preferably from natural sunlight, is crucial for setting the circadian clock and aligning the body with the natural light-dark cycle. This exposure should be for around 10-15 minutes, or longer if the light is not very bright, and should be done daily. Morning light not only helps regulate the sleep-wake cycle but also has positive effects on mood, energy levels, and overall well-being.
The Need for Light Intensity and Duration
It is essential to consider both intensity and duration of light exposure throughout the day. Bright light exposure during the day, in addition to morning light, can help regulate the circadian clock and provide the necessary light hunger for various bodily functions. The exact duration and intensity may vary depending on each individual's needs and the light conditions. Dimming light in the evening and avoiding bright screens can help prepare the body for sleep and maintain a healthy sleep-wake cycle.
Appropriate Light Viewing Behavior in the Evening
In the evening, it is important to reduce the intensity of light and create a dimmer environment to signal the body's preparation for sleep. Reducing overall light levels and avoiding bright screens can help in this regard. It is necessary to find the minimum required light level to see comfortably without overstimulating the system. By gradually reducing light exposure in the evening and allowing time for adaptation, individuals can create an optimal environment for a good night's sleep.
The Tripartite Model: Light, Sleep, and Feeding Behavior
The podcast episode discussed the tripartite model that highlights the interconnectedness of light, sleep, and feeding behavior. Light exposure plays a significant role in regulating the circadian clock, impacting sleep and wakefulness, mood, and cognitive function. Bright light in the morning helps set the circadian clock, while avoiding bright light in the evening supports quality sleep. Additionally, the episode highlighted the direct effects of light on mood, showing that getting bright light throughout the day can improve mood and overall well-being. The importance of aligning meal times with the circadian rhythm was also emphasized, with regular meal times positively impacting hunger regulation and overall health.
The Role of the Perihabenular Nucleus
The podcast episode introduced the role of the perihabenular nucleus, a brain region involved in receiving light input and projecting to mood-regulating areas of the brain like the ventral medial prefrontal cortex. This discovery challenges previous understanding of the brain regions involved in mood regulation and highlights the importance of light on human behavior. The episode discussed how the perihabenular nucleus and its impact on the prefrontal cortex can be influenced by light exposure, potentially affecting executive function, stress levels, and mood. Understanding this connection can inform the development of daily protocols for optimizing mood and cognitive function.
Adjusting to New Time Schedules and Seasonal Effects
The podcast episode provided insights into adjusting to new time schedules and the effects of seasonality on human behavior. It emphasized the role of light exposure in aligning the circadian clock to new time zones when traveling and the importance of avoiding light at specific times to prevent clock misalignment. Additionally, the episode touched upon seasonal effects, highlighting how humans can experience changes in energy levels, mood, and sleep patterns throughout the year. The disruption of natural light due to artificial lighting was discussed, underscoring the need to prioritize exposure to natural light to maintain a robust and healthy circadian rhythm.
The Influence of Circadian Rhythms on Sleep and Productivity
Circadian rhythms play a crucial role in determining our sleep-wake cycles and overall productivity. People have different natural inclinations towards being morning or night individuals, and these preferences can have genetic and environmental influences. Morning people tend to have peak productivity in the early hours of the day, while night owls may be more alert and productive in the evening. It is important to align our daily routines with our natural circadian rhythms to maximize productivity, avoid sleep disruptions, and maintain overall well-being.
The Impact of Light on Sleep and Health
Light exposure has a significant impact on our sleep patterns, mood, and overall health. The body's sensitivity to light varies among individuals, with factors such as eye color potentially influencing light sensitivity. Light-colored eyes may be more sensitive to light, requiring less exposure to have the same effect as individuals with darker eyes. The timing and intensity of light exposure are critical for maintaining proper sleep-wake cycles. A consistent exposure to natural light and avoiding bright lights close to bedtime can help regulate sleep and improve overall well-being.
In this episode, I host Dr. Samer Hattar, Ph.D., Chief of the Section on Light and Circadian Rhythms at the National Institute of Mental Health. Dr. Hattar is a world-renowned expert on how viewing light at particular times adjusts our mood, ability to learn, stress and hormone levels, appetite, and mental health. We discuss how to determine and use your individual light sensitivity to determine the optimal sleep-wake cycle for you. We also discuss how to combine your light viewing and waking time with the timing of your food intake and exercise in order to maximize mental and physical functioning. Dr. Hattar is credited with co-discovering the neurons in the eye that set our circadian clocks and regulate mood and appetite. He explains why even a small shift in daylight savings leads to outsized effects on our biking because of the way that our cells and circadian clocks integrate across many days. And he offers precise tools to rapidly adjust to jet lag, shift work, and reset your clock after a late night of work or socializing. This episode is filled with cutting-edge data on the biological mechanisms of human physiology and practical tools for people of all ages.
Read the full show notes for this episode at hubermanlab.com.
Thank you to our sponsors
AG1: https://athleticgreens.com/huberman
LMNT: https://drinklmnt.com/hubermanlab
Waking Up: https://wakingup.com/huberman
Momentous: https://livemomentous.com/huberman
Timestamps
00:00:00 Introducing Dr. Samer Hattar, Ph.D.
00:02:33 Sponsors: AG1, LMNT & Waking Up
00:06:15 Light, Circadian (24-hour) & Circannual (365-day) “Photoentrainment”
00:14:30 Neurons in Our Eyes That Set Our Body Clocks: Similar to Frog Skin
00:18:55 What Blind People See
00:20:15 When, How & How Long to View Light for Optimal Sleep & Wakefulness
00:30:20 Sunlight Simulators, Afternoon Light Viewing, Naps
00:33:48 Are You Jet Lagged at Home? Chronotypes & Why Early Risers Succeed
00:38:33 How to Decide Your Best Sleep-Wake Schedule; Minimal Light Test
00:42:16 Viewing Light in Middle of Day: Mood & “Light Hunger”
00:44:55 Evening Sunlight; Blueblocker Warning
00:48:57 Blue Light Is Not the Issue; Samer’s Cave; Complete Darkness
00:53:58 Screens at Night
00:56:03 Dangers of Bright Light Between 10 pm and 4 am: Mood & Learning
01:01:05 The Tripartite Model: Circadian, Sleep Drive, Feeding Schedules
01:05:05 Using Light to Enhance Your Mood; & The Hattar-Hernandez Nucleus
01:07:19 Why Do We Sleep?
01:08:17 Effects of Light on Appetite; Regular Light & Meal Times
01:18:08 Samer’s Experience with Adjusting Meal Timing
01:22:51 Using Light to Align Sleep, Mood, Feeding, Exercise & Cognition
01:30:15 Age-Related Changes in Timing of Mental & Physical Vigor
01:31:44 “Chrono-Attraction” in Relationships; Social-Rhythms
01:33:40 Re-setting Our Clock Schedule; Screen Devices Revisited
01:37:50 How Samer Got into the Study of Light
01:39:33 Clock Gene mRNAs & More Accurate Biomarkers
01:41:08 Light as Medicine
01:42:48 ADHD (Attention-Deficit Hyperactivity Disorder)
01:43:35 How to Beat Jet Lag: Light, Temperature, Eating
01:50:44 Vigor: The Consequence of Proper Timing
01:52:15 Waking in the Middle of the Night: When Your Nightly Sleep Becomes a Nap
01:54:10 Melatonin, Pineal Calcification
01:55:25 Our Seasonal Rhythms: Mood, Depression, Lethargy & Reproduction
01:59:08 Daylight Savings: Much Worse Than It Might Seem
02:05:27 Eye Color & Sensitivity to Light, Bipolar Disorder
02:09:28 Spicy Food, Genetic Variations in Sensory Sensitivity
02:10:52 Synthesizing This Information, Samer on Twitter, Instagram
02:13:00 Conclusions, Ways To Support the Huberman Lab Podcast & Research
Get the Snipd
podcast app
Unlock the knowledge in podcasts with the podcast player of the future.
AI-powered
Discover
highlights
Listen to the best highlights from the podcasts you love and dive into the full episode
Save any
moment
Hear something you like? Tap your headphones to save it with AI-generated key takeaways
Share
& Export
Send highlights to Twitter, WhatsApp or export them to Notion, Readwise & more
AI-powered
podcast player
Listen to all your favourite podcasts with AI-powered features
Discover
highlights
Listen to the best highlights from the podcasts you love and dive into the full episode