Circadian Rhythms, Time-Restricted Eating Impact Our Sleep & Brain Health

Bob Crowther (68) introduces the topic of circadian rhythms, highlights important daily relationships of light, time-restricted eating, physical activity, sleep and optimal brain health presented in the book by Dr. Satchin Panda, The Circadian Code.

I AM CURRENTLY EXPERIENCING

HEALTHY
 DAILY CIRCADIAN RHYTHMS

PARIVRTTA TRIKONASANA

REVOLVED TRIANGLE

[2013, PHOTO BY ERIC LECUYER]

DURING JANUARY, 2020

LOWERED WEIGHT TO 118.8 POUNDS
BY
INCLUDING
TIME-RESTRICTED EATING
&
MORNING & EVENING YOGA SESSIONS
TO
DAILY ACTIVITIES

ALSO REDUCED EXPOSURE 
TO
BLUE-SPECTRUM LIGHT IN EVENINGS
CONTRIBUTING TO IMPROVED SLEEP

I highly recommend this book - it is informative, well written and includes many useful illustrations, charts and references to enhance and further clarify the many topics presented about our circadian rhythms.

Significantly, The Circadian Code is accessible to non-specialists without a biological background interested in learning how to improve the quality of their lives by making relatively easy lifestyle choices to enhance overall health.

Readers of this blog are encouraged to read the entire book to learn about several topics I do not address: various useful self-assessments, evaluations, food sources and details about digestion, inflammation, cancer and other subjects easily found and cross-referenced in the index.

AUTHOR

 SATCHIN PANDA, PhD

• Scripps Research Institute, La Jolla, California, PhD
• Genomics Institute of the Novartis Research Foundation, PostDoc 
• Professor, Salk Institute for Biological Studies
• Founding Executive Member of the Center for Circadian Biology at the University of California, San Diego

Dr. Panda has made significant contributions towards our current understanding of circadian rhythms using various organisms, technologies 

[See pp. xiv - xvii; Google Dr. Satchin Panda for details of his past and current research focus, publications and notable contributions throughout his career]

BOOK TITLE
THE CIRCADIAN CODE
LOSE WEIGHT, Supercharge Your Energy and Sleep Well Every Night

"This book, based on my research, is meant to give you the tools you can use to optimize your clock by making simple lifestyle choices."

 (p. xvii) 

"Circadian lighting, time restricted eating, and restorative sleep sustain our circadian rhythm and prevent or reverse ... diseases." (p. 45)

DEFINING CIRCADIAN

Dr. Panda: from Latin circa (="around", "approximately") and diem (="day")

"Circadian rhythms optimize biological function." (p. 12)

 "The circadian clock is the internal timing system that interacts with the timing of light and food to produce our daily rhythms." (p. 13) 

NOTE

"Erratic lifestyle or aging promotes circadian disruption and various diseases:
 Poor Sleep Quality, Depression/Brain Diseases, Heart Diseases, High Blood Pressure, Fatty Liver Disease, Insulin Resistance/Type 2 Diabetes, Compromised Muscle  (p. 45)

QUOTES  (pp. ix, 28)

"Circadian rhythms are real biological processes that every plant, animal and human exhibits over the course of a day."

"These rhythms are interconnected among species and are governed by internal circadian or biological clocks."

AND

"... almost each and every one of our cells contains one of these clocks, and each is programmed to turn on or off thousands of genes at different times of the day or night."

"These genes influence every aspect of our health." 

"Every gene in our genome has a circadian cycle. However, they don't cycle at the same times and some cycle in one organ."

SCIENCE OF CIRCADIAN RHYTHMS
AUTHOR QUOTES
(pp. ix, x)

"... a multidisciplinary field that includes biologists, exercise physiologists, mathematicians, psychologists, sleep researches, nutritionists, endocrinologists, ophthalmologists, geneticists, oncologists ..."

[Each discipline listed above uses diverse tools of inquiry - many shared, some specific to their speciality; published observations made using various plant and animal models (for example: fruit fly, mouse) may or may not be applicable to humans]

"Working together, we have found that simply adjusting the timing of how we live - and making easy lifestyle changes - is the secret to restoring our rhythm, and it will surely be the next revolution in health care."

"I call this the circadian code, and by adopting these lessons you will make small changes to the way you sleep, eat, work, learn, exercise and light up your home that will make a profound difference in every aspect of your health."

2017
 NOBLE PRIZE IN PHYSIOLOGY OR MEDICINE

RECOGNIZED

Jeffery C. HALL
 Michael Rosbash
 Michael W. Young

FOR

" ... THEIR DISCOVERIES OF MOLECULAR MECHANISMS CONTROLLING THE CIRCADIAN RHYTHMS."

[FOR DETAILS: GOOGLE 2017 NOBLE PRIZE]

IDENTIFIED CIRCADIAN CELLULAR ACTIVITIES

THEY OCCUR IN A CYCLIC MANNER
(pp. 28 -29)

1. Nutrient - or energy sensing pathway - think of cell hunger and satiety pathways
2. Energy metabolism pathway - affects cellular functions and metabolism of all key nutrients
3. Cellular maintenance mechanisms - author mentions "reactive oxygen species", formation of free radicals
4. Repair and cell division - includes blood vessel, gastro-intestinal epithelium, external skin
5. Cell communication - consider example of fat cells (adipocytes) make hormone leptin signals brain to stop eating
6. Cell secretion - includes production and secretion of molecules
7. Almost every drug target - there are optimal times when to take medications

THE BODY'S DAILY RHYTHMS 
(from p. 11)
 DURING DAY

• Melatonin declines, cortisol rise, high alertness
• Better glucose regulation, muscle primed for exercise, motor coordination peaks
• Improved immune response, bowel movement likely

VS.

DURING NIGHT

• Melatonin begins to rise, deep sleep, memory consolidation
• Growth hormone rises, gut lining and skin repair
• Saliva production and gut mobility slows down, stomach acid production peaks

CIRCADIAN DISRUPTION OVER TIME

(p. 48)

SHORT TERM ( 1 - 7 Days)

Sleepiness/insomnia, lack of focus, migraine, irritation, fatigue, moodiness, indigestion, constipation, muscle ache, stomach pain, bloated stomach, blood glucose rise, susceptibility to infection

CHRONIC CIRCADIAN RHYTHM DISRUPTION

(WEEKS, MONTHS, YEARS)

IN COMBINATION WITH

GENETIC PREDISPOSITION/POOR NUTRITION

 Gut, immune, metabolic, affective mood, neurodegenerative diseases and chronic inflammation, various cancers

LIGHT, BRAIN CONNECTION

MELANOPSIN
(pp. 19 -22)

"Visible light includes all the colors of the rainbow. Each color has a different wavelength. ... When all the waves are seen together, they make white light, or sunlight."

"Different colors within the white light activate three different types of opsin proteins (red, green, blue), which in turn identify these colors individually and collectively (as white light)."

A new light sensing protein (melanopsin) is present in approximately 5,000 cells outside the 100,000 neural retinal rod and cone cells - discovered by three independent lab groups in 2002 including the Panda lab. 

AND 

Melanopsin is "the light sensor that entrains the daily sleep-wake cycle to light" and "is most sensitive to blue light waves" ... It takes a lot of blue spectrum light to activate it.

Melanopsin tells brain to stop producing the sleep hormone melatonin in the pineal gland and for the adrenal gland to start producing the stress hormone cortisol, to become more alert.

The bright light synchronizes the brain clock to daytime so circadian rhythms in learning and memory will begin to rise.

IDENTIFYING

THE MASTER CLOCK

The Suprachiasmatic Nucleus
(SCN)

"The SCN is the link between light and timing, because it receives information about light from the outside world and shares it with the rest of the body."

"The melanopsin cells of the retina make direct connection with the SCN, which is why our master clock is most sensitive to blue light."

"When melanopsin is activated by registering blue light, it sends a signal to the brain that any light is present, and the brain responds by thinking it is daytime, regardless of what time it really is."

NOTE

The SCN is located at the hypothalamus (the center of the base of brain), composed of 20,000 cells

• It "houses command center for hunger, satiety, sleep, fluid balance,the stress response and more"

• Indirectly connected to many glands within body (pituitary, adrenal, thyroid, pineal, gonads) 

• "The other clocks in the body, like the liver clock and gut clock, create their circadian rhythm from a combination of the SCN signal and the timing of the foods we eat."

THE AUTHOR IDENTIFIES
 THREE CORE RHYTHMS
(p. 32)

"The clocks in different organs work like an orchestra to create three major rhythms that form the essential foundations of health - sleep, nutrition, activity

CIRCADIAN LIGHTING
TYPE AND INTENSITY OF *LIGHT MATTERS

(pp. 18, 129, 158)

• Light impacts daytime activities, sleep and optimal brain health

• Bright light in the morning also synchronizes your brain clock to the daytime so that your circadian rhythm in learning and memory will begin to rise and you will reach optimum productivity a few hours later."

NOTE

• Poor daylight exposure to blue spectrum light reduces alertness, promotes depression and affects all aspects of brain health 

• Blue-spectrum light that keeps us alert during daytime can contribute to insomnia at night, foggy brain in morning

[*Author uses term lux to refer to light intensity - "a lux is a unit of measurement that signifies the amount of light that is received by the eye"]

 INSUFFICIENT EXPOSURE TO LIGHT INDOORS
CAN DISRUPT CIRCADIAN RHYTHMS
&
"PREDISPOSE US TO A RANGE OF BRAIN DISORDERS"
(p. 18)

Anxiety . Migraine . Irritation . Depression . Postpartum Depression . Autism Spectrum Disorder . Attention Deficit and Hyperactivity Disorder . PTSD . Manic Disorder . Alzheimer's Disease . Delirium . Psychosis

Being exposed to bright light during daytime is important

[See p.158: Author provides a list of different types of light that are rich or poor sources of blue light including color temperature, light color composition and which promotes alertness during day, is best for evening hours]

EATING

AUTHOR QUOTES

"Now we know that in addition to what we eat and how much, when we eat matters." (p. xvi)

" In 2017, the American Heart Association released their first recommendation on meal timing and frequency in almost 70 years that corroborates our research, showing how eating patterns might be used as a way to prevent or reduce cardiovascular disease." (p. xvii)

&

"The first bite of the day resets organ clocks, "food timing can be a powerful cue to override the the master signal from the SCN master clock" (p. 38)

ABOUT FAT

"Our cells cannot make and break up body fat at the same time." (p.40) ... "... when eating occurs at random times throughout the day and night, the fat-making process stays on all the time." (p. 41)

ABOUT GLUCOSE
"At the same time, glucose created from digested carbohydrates floods our blood and the liver becomes inefficient in its ability to absorb glucose. If this continues for days, blood glucose continues to rise and reaches the the danger zone of prediabetes or diabetes." (p. 41)

[See illustration on p. 197: Author notes blood glucose reaction to eating the same meal at different times of the day - in the morning, the glucose levels are in the safe zone but as the day progresses the same meal causes the blood sugar levels to rise higher and stay high for a longer period of time]

GUT MICROBIOME

Our gut microbiome is circadian, affects our food-mood axis (see pp. 181 - 184)

OBSERVED BENEFITS

 OF

 TIME-RESTRICTED EATING
(modified from chart, p. 237)

• Reduced fat mass, increased lean mass instead of obesity
• Normal glucose, not glucose intolerance and insulin resistance
• Normal, not high cholesterol values

AND

• Improved cardiac function, reduced arrhythmia
• Reduced inflammation vs. increased inflammation
• Healthy liver and not fatty liver disease
• Reduced cancer risk, better treatment outcomes  not increased cancer risks
• Better sleep quality vs. poor sleep

PLUS

• Increased endurance instead of compromised muscle function
• Healthy gut microbiome, not harmful contributing to inflammation
• Regular bowel movement, not irregular
• Healthy kidney function not kidney disease
• Better motor coordination

 FOR MORE DETAILED INFORMATION
READ

Chapter 9: The Clock, the Microbiome, and Digestive Concerns

 &

Chapter 10: The Circadian Code for Addressing Metabolic Syndrome: Obesity, Diabetes, and Heart Disease

ALSO

[See Index - pp. 261 - 287 - for more details on time-restricted eating associations with brain health optimization, children, digestion, eating, immune system, inflammation, learning and work optimization, medications, production of melatonin, metabolic syndrome, obesity, physical activity, sleep, snacking, teenagers]

SLEEP
(pp.70 -72)

"Great sleep is created when there are cycles of quiet sleep and active sleep."

The quiet sleep takes place in three stages that occur in a specific sequence : N1 (drowsiness), N2 (light sleep) and N3 (deep sleep).

These three stages of quiet sleep alternate with periods of active sleep, which is referred to as REM sleep (= rapid eye movement sleep).

FOR INDIVIDUALS MY AGE

In the first four hours after falling asleep, you get some of your best sleep.

The next three hours or more go toward nurturing your brain and body, giving it the additional time it needs for repair and rejuvenation.

NIGHT BRIGHT LIGHT
 COMPROMISES SLEEP,
ENABLES BAD HABITS
(from flowchart pp.  80 - 82)

Bright light at night reduces sleep hormone melatonin, keeping you awake at night, leading to poor or insufficient sleep and low production of growth hormone and increases hunger, poor food choices with late-night eating.

Low growth hormone production impacts daylight activities: lack of attention, sleepiness & mind fog, reduction of damaged-cell repair.

Late night eating contributes to indigestion, high blood glucose, reduction of fat burning.

SLEEP
 & 
OPTIMAL BRAIN HEALTH

(pp. 227 - 228)

"Having too much exposure to light in blue spectrum at night reduces sleep, which is when most of the clean up of damaged cell protein occurs."

[Amber bulbs, wearing orange glasses reduces exposure to the blue spectrum light]

NOTE

Author cites *study noting ideal hours of sleep required in Newborns (14 - 17 hours), Infants (12 - 15 hours), Toddler (11 - 14 hours), Pre-schoolers (10 - 13 hours), School-aged children (9 - 11 hours), Teenagers (8 - 10 hours), Young adults (7 - 9 hours) , Adults (7 - 9 hours), Older adults (7 - 8 hours).

[*See chart on p. 75: Recommended Hours Of Sleep Across the Lifespan - author cites M. Ohayon et. al. "National Sleep Foundation Sleep Quality Recommendations: First Report," Sleep Health 3, No.1 (2017): 6-19.]

"..., even in adults, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are now linked to going to bed very late in the evening, not getting enough sleep, and then staying indoors most of the day." (p. 33)

PLUS

The author lists 65 diseases impacting our entire body linked to circadian rhythm disruption on p. 6 

"During the daytime brain cells absorb and process nutrients creating unwanted toxic by products". ... "At night the brain detoxifies" (p. 12)

"These toxins are cleared up as we sleep, and new brain cells are created through the process of neurogenesis." ... new synapses (connections between neurons) are established (p. 11) 

At night, the brain is "consolidating memories based on the sensory information we took in during the day and backing up information." (p. 11)

 BRAIN DYSFUNCTION

(pp. 222 - 224)

"Although we do not completely understand how brain dysfunction starts or develops, the mechanisms of these diseases primarily involve  four themes, and the circadian clock is involved in all of them:"

1. Lack of emergence of new brain cells (neurons) that replace damaged or dead brain cells, causing a gradual decline in the number of healthy neurons
2. Poor wiring of neurons, causing misconnections/miscommunication between brain regions ... need balance of right amount of light and sleep
3. The accumulation of damage, or lack of sufficient repair, and death of neurons ... circadian clock that regulates the genes involved in reducing neuronal stress, promoting repair so neurons remain healthy
4. A brain chemical imbalance - neurotransmitters(messages between nerve cells) include dopamine, serotonin, noradrenaline and GABA (gamma-aminobutyric acid) ... they modulate various aspects of brain function including being alert or active, being calm, and responding to motivation or rewards

["Too much dopamine make both mice and men manic" (p. 221)]

PHYSICAL ACTIVITY
FROM FIRST PARAGRAPH (p. 138)

"Physical activity is just as important as sleep and good nutrition when it comes to good health."

"Daily movements improves muscle mass, muscle strength, bone health, motor coordination, metabolism, gut function, heart health, lung capacity, and even enhances how your brain functions."

"What's more, exercise has a circadian effect, improving sleep and mood. Exercise literally relaxes the brain, reducing depression and anxiety and increasing our ability to experience happiness."

"Exercise is one of the best medicines."

NOTE

Studies on mice and humans demonstrate physical activity improves sleep.

Time-restricted eating and physical activity: under most circumstances, engaging in some form of whole body movement will help us sleep at night.

"Among older adults (50 - 75 years old), moderate physical activity or even regular stretching improved sleep onset, sleep quality, and sleep duration and reduced dependence on sleep medications." (p. 42)

[For more information see Chapter 7: Syncing Your Exercise to Your Circadian Code, pp. 138 - 154]

SIGNIFICANT 
TAKEAWAY QUOTES

"Addressing your circadian clock is more than a diet. In fact, it's not a diet at all. It's a lifestyle. It begins with knowing when to eat and when to turn of the lights." (p. xviii)

"A healthy lifestyle includes what and when you eat and how much you sleep, an when and how often you move." (p. 44)

"By focusing on the when, you are harnessing the power of your circadian code." (p. 44)

"Correcting habitual behaviors is the key to improving your circadian code." (p. 36)

MY EXPERIENCES

I have benefitted from daily lifestyle choices recommended by Satchin Panda in The Circadian Code:

• Paying attention to my daily nutrition - lowering and maintaining weight at teenage levels from calorie restriction, intermittent fasting /time-restricted eating (most recently, from 5-6 and 7-8 hours during January)

• Engaging in daily am and pm yoga sessions - physical activities involving whole body movements addressing strength, balance, flexibility, breathing and mindfulness

• Improving quality of sleep by minimizing blue-spectrum light exposure during evenings - installing amber bulbs

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