The Circadian Code is a short book that sheds light on the importance of the circadian clock. By explaining how the body works as a coordinated system, not only by itself, but alongside the ...
The Circadian Code is a short book that sheds light on the importance of the circadian clock. By explaining how the body works as a coordinated system, not only by itself, but alongside the natural rhythm of the day (sunrise and sunset), it becomes impossible to think of the body in isolation.
The reason why we need to sleep early and get enough sunlight and eat at orderly intervals (time-restricted-eating) is because if we don’t, our circadian rhythm goes out of sync with our habits. We effectively swim against the tide by choosing to ignore the circadian clock – we prevent our bodies from performing essential tasks, such as cellular renewal, counteracting oxidative stress, and proper metabolism. Not to mention our mood and psychology. In a concise and important book, Dr. Panda tells us truths that few want to hear, but desperately need to.
Germ theory—and its related breakthroughs of sanitation, vaccination, and antibiotics—was the groundbreaking health development of the past century. It prevents infectious disease and led to the most dramatic rise in longevity in any century in human history. Yet living longer does not always mean living healthier. Chronic diseases of the mind and body proliferate among modern people, who’s lifestyles disrupt a deeply ingrained, primordial, and universal code to being healthy.
Circadian comes from circa, meaning “around” (or approximately”) and diēm, meaning “day.”
Which Kind of Shift Worker Are You?
Anyone who stays awake for more than 3 hours between 10:00 pm and 5:00 am, for more than 50 days a year, is classified a shift worker, according to the official European definition. But many people are shift-workers simply because of lifestyle choice – musicians, college students, new mothers, performing artists. Others are part of the gig economy – freelancers, part time drivers for ride-share services, flexible workers. Jet lag can also have the same effect. So can social jet lag (staying up on weekends with friends) and digital jet lag (chatting with friends in different time zones). Finally, the shift worker effect is experienced by people who live in extreme north and south latitudes.
The Rhythm of Daily Life
Metabolism, cognition, and other physiological processes follow a circadian rhythm. Evening activities affect circadian rhythm. It is most important to monitor your activity between 6:00 pm and midnight.
Even before we wake up in the morning, our internal clock prepares our body for waking up. It begins to shut down the production of the sleep hormone melatonin from our pineal gland. Our breathing becomes slightly faster and our heartbeat picks up a few beats per minute as our blood pressure rises slightly. Our core body temperature notches up half a degree even before we open our eyes.
Our sense of health is determined by our daily rhythms. Feeling good in the morning comes from having sufficient sleep, and healthy bowel movements to eliminate the toxins we collected at night.
Shortly after we open our eyes, the adrenal glands produce more cortisol (stress hormone) to get us through the morning routine. The pancreas becomes primed to release insulin to handle breakfast.
After breakfast, the brain is primed for learning and problem solving in the first half of the day. In the afternoon, we feel healthy if we have accomplished enough work to feel satisfied with our efforts. Without a good night’s sleep, you have an overwhelming feeling that you are wasting the day. As time passes, muscle tone peaks. And as evening comes, body temperature drops, and the production of melatonin (sleep hormone) rises – and the body prepares for sleep.
Circadian rhythms optimize biological functions.
A Brief History of Harnessing Light
Human history can be summed up as our attempt to beat the clock. Our primordial rhythms were natural, they were derived from natural phenomenon (sun rise, sun set). Modern rhythms are out of sync with nature. They are aligned with an artificial environment, where sleep and eating schedules have become random and out of sync with our biology.
The Genetics of the Circadian Clock
The health of our organs, and susceptibility to illness, depends on which genes we have and whether they are turned on or off, or if it is a normal gene or mutant. Some people can eat anything, while others complain that some foods (like dairy) cause digestive discomfort which result in gas, bloating, or constipation. Those that suffer have a mutation in the gene that helps break down and absorb nutrients from milk.
Every Organ Has Its Own Clock
Scientists took it for granted that there was only one clock that controlled the entire body (in the brain) until this was disproven. Now we know that there are many circadian clocks, each pertaining to different parts of the body. The clocks in different organs work like an orchestra to create three major rhythms that form the essential foundations of health—sleep, nutrition, and activity. When they all work perfectly, we have ideal health. When one rhythm is thrown off, the others are ultimately upset, creating a downward spiral of poor health.
Rhythm 1. Sleep: The Myth of Morning Larks and Night Owls
There is no such thing as genetic night owls or morning larks. As we get older, we naturally revert to waking up early. Post-puberty, females tend to wake up earlier than males, but with time, as the effect of hormones wear off, there is no longer a difference.
Rhythm 2. When You Eat Affects Your Clock
When food is available at the wrong time, our system will be affected. If rodents are only given food during the day, when they are supposed to fast and sleep, they learn to wake up an hour before the food arrives to find the food.
In other words, their SCN clock, controlling the daily sleep-wake cycle, continues to work fine, except for a brief period during the day when they wake up to eat food
You feel hungry around the same time every morning regardless of what you ate for dinner the night before because our brain clock or the clock in the hunger center tells us when we should be hungry. At the same time, the brain and gut talk to each other, and the clock in the gut tells the brain to get ready for a rush of breakfast. The pancreas is also ready to secrete some insulin, the muscles are ready to soak up some sugar, and the liver is ready to store some glycogen and make some fat and send it off for storage.
Anything you eat after dinner interrupts your fat burning process.
When (and How) You Wake Up Is the Most Important Event of the Day
It is better to wake up without an alarm and get enough sleep.
It is not true that our ancestors woke up in the middle of the night, they just slept really early.
Expose yourself to enough sunlight during the day (2 hours).
Turn down the temperature before you sleep. Avoid screens 2 hours before sleep. Do not stress if you do not sleep well. Stick to routine.
After waking up, the first thing you should do is expose yourself to sunlight.
Coffee is bad for your circadian rhythm. And it affects digestion of glucose.
Fasting produces ketones which leads to higher endurance.
Try blue-light-filtering eyeglasses. They help with migraines, less eye strain, and prevent circadian rhythm disruptions. If you want to adopt blue-light-filtering glasses, make sure that you have a separate pair of glasses only for the evening. Put them on only for 3 to 4 hours before going to bed.
Lastly, pay attention to the color of the lenses. The orange/pink–hue filters out the most blue light; other colors filter out only 5 to 15 percent of blue light, too small to make a real difference.
Gut Function Affects Overall Health
If good nutrition is the key to optimally fueling our body, then the gut is the gateway through which nutrition gets into our system. Most diseases of the gut compromise its core function of absorption of all nutrients, minerals, and vitamins for our body.
An allergy to the gluten protein (in wheat, barley, rye) creates an inflammatory response in the gut. Untreated, this can cause long-term digestive problems. Bad digestion affects sleep, productivity, and the will to exercise. When the guy cannot absorb a specific nutrient or mineral, the whole body suffers (ex: anemia from low protein absorption, fractures from insufficient calcium).
Choose Foods That Protect the Microbiome
Food preservatives can corrode the protective mucosal lining that separates microbes from the cells that line the gut. When these unwanted microbes make contact with the cells in the gut lining, it can cause inflammation, such as colitis. TRE (Time-restricted-Eating) promotes repair of the gut lining and may counteract the negative effects of a bad diet.
A mix of different types of food that includes lots of different fresh fruits and vegetables promotes the healthiest gut microbiome.
Eating Patterns and Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a type of gastrointestinal disorder. IBS symptoms and signs include:
- Abdominal pain
- Altered bowel habits (more or less)
- Bloating
- Cramping
- Gas
Mice, when fed highly processed food and allowed to eat all the time they pooped all the time as if they had IBS. TRS took care of their frequent pooping and restored the daily bowel movement cycle. This suggests that people with IBS may benefit from TRE. IBS is rapidly rising among teens and young adults. We don’t know for sure, but it’s likely that sleep and circadian rhythm disruption beginning in middle school is the problem.
Some practitioners of TRE have reported they do see improvement in their IBS symptoms after just a few weeks.
The Circadian Clock Controls the Immune Response at the Cellular Level
The most common threat inside a cell is oxidative stress, which occurs as a direct result of additional oxygen molecules entering the cell. Oxidative stress has been shown to be an important factor in many diseases because it leads to chronic and systemic inflammation. In fact, the number one biological mechanism that seems to underlie most chronic disease states is oxidative stress, and the results can include cancer, heart disease, dementia, arthritis, muscle damage, infection, and accelerated aging.
The circadian clock plays an important role in controlling oxidative stress. After eating, when every cell in our body uses nutrition to make energy, cells produce reactive oxygen species. The clock acts as a sensor of this oxidative state inside the cell and coordinates antioxidant defense mechanisms to clean up the damage.
Since eating used to happen predictably during the daytime for millions of years, this function of the clock is very fundamental to cellular health. Scientists believe this predictable rise and fall of oxidative stress between day and night might have been one of the primary instigators of the evolution of the circadian clock.
Another cellular activity is autophagy, the controlled digestion of bits and pieces of a cell, which helps to reduce some of the damage from oxidative stress. Cells recycle their stray bits and pieces through autophagy as their immune system puts them in a garbage disposal system, which is the lysosome.
The lysosome digests cellular garbage with acid. When the garbage is broken down, the raw material is used to build new cellular parts. Autophagy is more active hours after your last meal (after hours of fasting and before the first bite of the day). This process slows down when you eat. TRE increases autophagy for a few hours during the fasting period.
Having a healthy circadian rhythm under TRE serves several important functions in reducing systemic inflammation. A strong circadian rhythm supports better repair of the skin and gut lining so that there is less opportunity for undigested food particles, disease-causing bacteria, or allergy-causing chemicals to enter our body and activate the immune system.
A stronger circadian rhythm reduces oxidative stress and the production of inflammatory chemicals. With a reduction in external agents gaining access to our body and a reduction of our body’s own inflammatory chemicals, the immune cells are less activated and thereby create less systemic inflammation under TRE.
The Role of Light
Lack of light is linked to depression, and short winter days with less than 6 hours of sunlight is a major culprit. SAD (seasonal affective disorder) is a form of depression with symptoms including fatigue, hopelessness, and social withdrawal. Getting at least an hour of daylight exposure rebalances the brain chemicals.
Focusing on Depression
Stress or a sad event causes people to feel low. This causes them to stay indoors and brood in a dark room. And this affects the circadian clock, resulting in an imbalance that pushes them further into depression.
To manage depression, one should simplify life in a very disciplined way. Good habits beget more good habits.