Commusings: Fiat Lux by Jeff Krasno

Dear Commune Community,

I often say that disease is a normal and expected result of our adaptive mechanisms trying to cope with our modern lifestyle. In short, our culture has hijacked our evolution.

I like to underscore this notion by leveraging my great-great-great-great-great grandfather times 600 who lived as a hunter gatherer in 10,321 BC in the area of East Africa that we now call Kenya.

His name was Ffej Onsark – which is, somewhat unimaginatively, my name spelled backwards.

Ffej’s lifestyle and ecosystem mirrored those of hundreds of generations. And across vast swaths of time, human biology evolved in relationship to its environment.

I have virtually the same exact biology as Ffej but our cultural conditions could not be more different. This change in culture has created evolutionary mismatches. Our hard-wrought advantages have become disadvantageous.

There are many examples of how culture has rendered the adaptive maladaptive.

Today, I explore the human relationship with light and sleep. I dive into some of the ancient health-conferring aspects of being exposed to the right amount of light and the right kind of light at the right times.

I will outline how our modern rapport with light, both artificial and natural, leads to a variety of negative physiological and psychological knock-on impacts. And I will introduce protocols related to deliberate light therapy that can re-align you with your adaptive mechanisms and lead to greater well-being. And I will try to accomplish this in a “light” hearted manner.

Here at [email protected] and swinging from the branches of IG @jeffkrasno.

In love, include me,
Jeff

• • •

Fiat Lux

Watch an extended version of this musings on YouTube or listen on the podcast

 

Let me begin with an admission: I love movies, documentaries and good series.

Schuyler and I were members of Netflix when they used to send you red, DVD-containing envelopes via snail mail. It seems like eons ago that two flirtatious hours of Kate Hudson and Matthew McConaughey would be delivered right to our mail slot. It’s difficult to grok the scale of evolutionary history when I can barely remember the era of mail-order rom coms. At that point, I never dreamed of the day when you could cue up “How to Lose a Guy in 10 Days” or “Fool’s Gold” on a whim. Of course, now there are hundreds of platforms that offer every conceivable movie, documentary, sporting event and TV series on an on-demand, 24-7 basis.

And it’s just too tempting. You’re tired. It’s been a long day. You’re full from dinner. Just one episode of Curb Your Enthusiasm before bed. Or maybe two. After all, it’s pretty… pretty … pretty good.

Watching Larry David hysterically step in his own shit seems innocuous enough. But upon closer inspection, it’s not just his awkward hilarity that might be impeding your sleep.

Let’s go back 12,000 years and examine the conditions in which our bodies were engineered.

The sunrise generally served as Ffej’s alarm clock. This was somewhat dependent on season but it was not uncommon for Ffej to rouse at the first crack of light. Of course, Ffej did not have blackout curtains on his hut and often slept outside, so his exposure to morning light was customary. This habitual contact with early morning sunlight informed certain adaptations.

Light exists across a wave spectrum. Humans can see “visible light” across a sliver of that spectrum between ultraviolet and infrared or between approximately 400 to 700 nanometers in wavelength. In the morning, when the sun is low, there is a greater prevalence of a slice of the visible light spectrum (closer to ultraviolet) known as blue light. Blue light exists between 380 to 500 nanometers in wavelength.

I’ll get deeper into the mechanism of how light impacts physiology in a bit, but here’s a primer.

When humans take in morning light, blue light radiation enters the eye and interacts with specialized neurons in the inferior part of the retina. These cells are known as intrinsically photosensitive retinal ganglion cells. These sensory neurons evolved in the lower part of the retina because light from the sun is coming from above.

These cells then send a message to your body’s timekeeper – two wee nodes just above the roof of your mouth known as the suprachiasmatic nucleus. These nuclei are responsible for setting your “circadian clock.” Circa means “approximately.” Dia means “day.” Circadian means “approximately a day.”

The suprachiasmatic nucleus regulates the flow of hormones in your body across approximately a day. Specifically, it signals the pineal gland to produce and secrete the hormone melatonin at a certain time. Melatonin naturally induces grogginess. When your eyes get blue light in the morning, your circadian clock is set such that about 12-14 hours later, melatonin will begin to pulse through your bloodstream and usher you off into Lala land.

The morning time is generally characterized by a rise in melatonin’s hormonal foil, cortisol, which contributes to the feeling of alertness that you require as you begin your day.

Let me take a brief detour here to explore the yin-yang hormonal relationship between melatonin and cortisol.

Cortisol is a steroid hormone produced in the adrenal glands. Cortisol levels bottom out around midnight and rise naturally in the morning, triggering a flood of glucose that supplies an immediate energy source to your large muscles. This helps to get your sleepy head out of bed.

Cortisol levels decline across the course of the day, sometimes with mini-peaks in the late afternoon. Cortisol is on a hormonal teeter-totter with melatonin. In a balanced system, melatonin secretion increases soon after the onset of darkness, eliciting a sensation of sleepiness that propels you toward your pajama drawer and recumbency. Melatonin typically summits in the middle of the night, between 2 and 4 a.m., and gradually dips during the second half of the night as cortisol is rising.

The dance between these two hormones is representative of the counterposing forces that exist in so many systems of the body. Equilibrium between cortisol and melatonin is essential for maintaining the wake-sleep cycle.

As the sun set and darkness pervaded, Ffej and his fellow villagers would commune around a roaring fire. The flames of the fire emit amber light waves closer to infrared. And because the firepit is at ground level, light is being received in the superior part of the retina. The morning light triggers an endocrine response that sets our circadian rhythm but the evening light has no impact. This is not by mistake. This mechanism evolved as an advantage to maximize alertness during the day and induce sleep at night.

But, yet again, this adaptive mechanism has been upended by the tantalizing lure of Netflix. The glow discharged from your flatscreen, laptop or iPad is blue light. Viewing blue light at night is upsetting your hormonal balance as the confused suprachiasmatic nucleus doesn’t know morning from night except by dint of the signals it receives from the neurons in your retina.

The result is, as the Beastie Boys rapped, “No Sleep Till Brooklyn” or until anywhere else. One in every three Americans report symptoms of insomnia. Ten percent have a chronic insomnia disorder that occurs at least three times per week for at least three months.

Of course, Larry David cannot be blamed for the global scourge of insomnia. Stress, sleep apnea, alcohol and caffeine over-consumption can also contribute to poor and disrupted sleep.

What are the knock-on impacts of poor sleep? The answer requires an entire article, or five, but here’s a brief glimpse.

The cumulative long-term effects of sleep loss and sleep disorders have been associated with a wide range of deleterious health consequences including an increased risk of hypertension, diabetes, obesity, depression and cardiovascular disease. We also know that memory consolidation appears to take place during REM sleep but don’t completely understand why or we can’t remember the reason ;-). Sleep also activates the glymphatic system, the brain’s version of the lymphatic system, which is responsible for repair of brain tissues. This “glymph” is responsible for cleaning out beta-amyloid proteins that are highly associated with Alzheimer’s disease.

Many mysteries regarding sleep remain. At first glance, it appears maladaptive. We’re not procreating or eating, and, in slumber, we are susceptible to predation. That said, when we disrupt our circadian balance and homeostatic drive, disease knocks at the door. All of the conditions elicited by disrupted sleep, from disease to mere crankiness, should … curb your enthusiasm.

Ok. So, let’s take a deeper look into the nature of light.

Light is measured in “lux” (Latin for light). It’s a relatively quaint and antiquated metric. One lux is equivalent to the illumination that would exist on a surface all points of which are one meter from the flame of one candle.

A fully overcast sky at sunrise has about 40 lux. The brightest midday sunlight has over 100,000 lux. The ambient illumination of the sky at sunrise on a clear day hovers around 400 lux.

Humans evolved with sunlight. Our physiology responds to light in myriad ways depending on the kind of light. Light exists across a wavelength spectrum measured in nanometers (or one billionth of a meter). On one side of the spectrum, there is ultraviolet radiation, commonly referred to as UVC, UVB and UVA, spanning the distance between 100 and 400 nanometers (nm). On the other wing of the spectrum, we have infrared radiation.

Infrared light has wavelengths longer than ultraviolet and visible light, but shorter than those of terahertz radiation. More specifically, infrared light spans a wide array of wavelengths from 760 nm to 1,000,000 nm (or 1 mm).

Stuck in the middle, like the ham in a sandwich, is visible light, the segment of the electromagnetic spectrum the human eye can see. A typical human eye will respond to wavelengths from ~380 nm to ~700 nm.

Each of these light bands has different properties and different human applications.

• • •

 

The Protocols for Optimal Light Exposure

Blue Light & Circadian Rhythm

Blue light is a segment of the visible light spectrum between 380 and 500 nanometers.

The amount of blue light in the sky varies throughout the day. However, due to the way our atmosphere scatters sunlight, blue light is particularly noticeable during the "blue hours" of dawn and dusk. The blue hour refers to the period of twilight in the morning and in the evening when the sun is just below the horizon. At these times, indirect sunlight is evenly diffused and can give the sky a blue shade.

Blue light, as I have described, has a specific impact on human circadian rhythm. Our circadian rhythm is famously associated with the sleep-wake cycle but also bears additional responsibilities. It regulates hormone production and secretion, hunger and satiety, metabolism, antioxidant production and body temperature.

Blue light, specifically in the range between 460 nm and 484 nm, can set your circadian clock. As we have already discussed, when humans get morning light, blue light radiation enters the eye and interacts with specialized neurons in the lower part of the retina (i.e. the part of the retina that sees the sky).

These cells then send a message to your body’s master clock – the suprachiasmatic nucleus. This pair of small nuclei in the hypothalamus of the brain regulates the flow of hormones in your body across approximately a day. Specifically, it signals the pineal gland to produce and secrete the hormone melatonin at a certain time. Melatonin naturally induces grogginess.

When your eyes get blue light in the morning, your circadian clock is set such that about 12-14 hours later, melatonin will begin to pulse through your bloodstream and round your day with a sleep.

What to do in the morning:

The protocol is simple. Within an hour of waking up, get 20 minutes of morning light outdoors. Ideally, you’re up before 9am, though this may be difficult for some shift workers. Do not wear sun glasses. You can just survey the scene, look into the lower sky and, of course, avoid staring directly at the bright ball of gas.

Blue light does not travel effectively through windows. So, steep your tea, put on a jumper and get outside. A bright day with more lux might require a smaller time commitment. An overcast day will require more patience.

If natural light is not an option due to schedule or geographic location, light therapy lamps can be used. The lamps are often dubbed SAD lamps as they help address seasonal affective disorder, which is common in the winter in the farther reaches of the northern and southern hemispheres.

These lamps provide a measured amount of balanced-spectrum light, often around 10,000 lux, and can be used to stimulate a morning light response. Spending 20 minutes approximately 12” away from a SAD light box will mimic the effect of the sun.

What (not) to do in the evening:

• Stop looking at screens at least an hour before bed time. Your isRGC’s are MORE sensitive to blue light at night than in the morning.
• Turn on blue light filters. Most computers and tablets now have a night-time filter. Apple's Night Shift uses geolocation and sunset time data to reduce the amount of blue light your device emits.
• If you can withstand the mockery of your children, you can don blue blocker sunglasses that mitigate blue light.
• If you must binge “Succession” then try to have your eye level above the screen such that you’re looking down your nose at Logan Roy. You may already do this for moral reasons. Your blue light sensitive neurons evolved in the inferior part of your retina. So, while it doesn’t eliminate the impact, it’s better if the screen is in the inferior field.
• Have amber night lights at floor level for mid-evening pees. Avoid turning on a harsh overhead light when nature calls.
• While LED lights are more energy efficient than incandescent bulbs, they also produce more blue light. Many companies now produce “amber” LED bulbs that mitigate some blue light. In general, avoid overhead lighting at night and go dim and amber.
• Black-out curtains or curtains that block overhead light are a solid option for your bedroom.

While we’re at it, here are some other tips for good sleep architecture:

• Try to take your last bite of food three hours before you go to bed. Ideally, you’re going to sleep with your food digested. This helps the body maximize its restoration and repair processes.
• Keep it cool: Turn off the heat if you can or set your thermostat between 60 to 66 degrees Fahrenheit.
• Get regular exercise. Nothing too vigorous close to bed time, though a walk after dinner is key as a glucose sink.
• Meditation. Quiet the mind as you move from the bright, busy yang state of the day into the dark, tranquil yin state of the night. A 4-7-8 pattern, in which you inhale for four counts, hold for seven and exhale for eight will decrease heart and respiratory rate.
• And, yeah, not too much, if any, wine.

Infrared Light & Melatonin

While melatonin is most celebrated as a "sleep hormone," it double-agents as a powerful antioxidant.

An antioxidant is a substance that can prevent or slow damage to cells caused by free radicals, unruly molecules that the body makes as a product of energy creation and in reaction to environmental forces. When unchecked, free radicals badly damage cells and their mitochondria and cause oxidative stress.

Melatonin is a direct scavenger of free radicals and reactive oxygen species (ROS). This means it can neutralize these harmful substances and reduce oxidative stress which is associated with aging and many chronic diseases including cancer, neurodegenerative diseases, cardiovascular disease and diabetes.

Melatonin is particularly effective in protecting mitochondria, the energy-producing parts of cells which are particularly vulnerable to damage from free radicals. Melatonin can also stimulate the activity of other antioxidant enzymes like glutathione in the body, enhancing the overall antioxidant defense system.

We already aware that melatonin is the “hormone of darkness,” secreted by the pineal gland at night. But free radicals don’t just operate under the cover of night, they are wreaking plenty of day-time havoc. So, how does the body protect itself during the day?

It turns out that near infrared radiation from the sun directly activates the production of melatonin at the sub-cellular level.

You cannot see near infrared radiation radiation, which registers between 760 – 1400 nm on the wave spectrum, as it is outside the parameters of visible light. But your sensory neurons can feel it as warmth – even through a shirt. The longer, low frequency wavelengths of near infrared radiation more easily penetrate objects, just like the low-end frequency waves of the sonic spectrum emanate out of gold-rimmed SUVs.

Infrared radiation penetrates down into your body’s tissue up to eight centimeters into cells and even into your mitochondria. Why is this important?

Your mitochondria are the energy producing organelles in your cells that generate the currency known at ATP. It accomplishes this through a series of highly complex operations. One of the stages of energy production (or cellular respiration) is called the Krebs’ cycle. One of the primary by-products of the Krebs’ cycle is NADH, packaged reduced electrons that subsequently zip around the inner membrane of the mitochondria. At the end of this electron chain, there is an enzyme that catalyzes a reaction in which leftover electrons combine with oxygen to form water. The responsible enzyme is cytochrome C-oxidase (CCO). Like hectic factories can sometimes produce defective products, the process of energy making doesn’t always function to perfection and free radicals like superoxide and hydrogen peroxide are made.

Near infrared radiation penetrates the skin and reacts with CCO. This excitation stimulates the production of melatonin at the mitochondrial level! In fact, 95% of your melatonin is produced on-site in the mitochondria and is consumed locally to blunt the impacts of free radicals. The melatonin stimulated by light is sub-cellular and does not enter the blood stream. By extension, it does not make you sleepy.

The good news is that most of the energy on earth is in the infrared spectrum. And you don’t need to be in the sun to get it. Near infrared radiation is actually stronger when it’s reflected off of leaves or grass. Being outside in green spaces, even in the shade, will upregulate the production of melatonin and, in turn, decrease oxidative stress.

Parenthetically, while sunscreen blocks ultra-violets rays, it does not inhibit near-infrared radiation from penetrating your skin. Also, the trappings of urbanity like buildings, concrete and hot dog stands do not reflect near-infrared radiation to nearly the same degree.

This interplay between near-infrared radiation light and your mitochondria may be one of the primary reasons why people who spend more time in nature have significant reduced risk of type II diabetes and cardiovascular disease as well as a less stress and lower blood pressure. As if we needed yet another reason to be in nature.

UVB (or not to B)

Ultraviolet B radiation is a double-edged sword. It has both beneficial and harmful effects on the body. Thus, finding the right balance of Ultraviolet B is key to health.

UVB radiation stimulates the production of vitamin D in the skin. Vitamin D is a crucial nutrient that has multiple roles in the body, and it is also a hormone in that it controls how cells and organs function.

Vitamin D is required to absorb calcium and phosphate from the gut into the bloodstream. These minerals are critical for the development and maintenance of healthy teeth and bones. Deficiency in vitamin D can lead to a softening of the bones, a condition known as rickets in children and osteomalacia in adults. Long term deficiency can contribute to osteoporosis.

Vitamin D is also important for maintaining muscle function. Deficiency can lead to muscle weakness and falls, particularly in older adults.

Vitamin D helps to regulate the body's inflammatory response. Research suggests that vitamin D may play a role in preventing and treating a number of different conditions, including type 1 and type 2 diabetes, hypertension, glucose intolerance and multiple sclerosis.

Exposure to sunlight, including UVB radiation, can help improve mood and alleviate symptoms of seasonal affective disorder (SAD). There's some evidence to suggest that vitamin D might play a role in mood regulation and may help to ward off depression.

Vitamin D plays a significant role in the immune system, affecting both the innate and adaptive immune responses. Here's a closer look at how vitamin D interacts with immune cells:

The “innate immune system” is the body's first line of defense against pathogens. Immune cells in this system, such as macrophages and dendritic cells, have vitamin D receptors. When these cells are exposed to pathogens, they can increase the expression of the enzyme required to convert the inactive form of vitamin D in the body (25-hydroxyvitamin D) into its active form. Once activated, vitamin D can stimulate the production of antimicrobial proteins that kill pathogens and reduce inflammation.

The “adaptive immune system” involves T cells and B cells that respond to specific antigens and have memory capabilities, meaning they can provide long-term protection against specific pathogens. Vitamin D can help to regulate the adaptive immune system, promoting a balance between different types of T cells. This can help to prevent overactive immune responses and reduce inflammation.

Vitamin D can also inhibit the proliferation of B cells (which produce antibodies) and reduce the production of pro-inflammatory cytokines, which are substances secreted by immune cells that can cause inflammation.

Vitamin D keeps the porridge of the immune system “just right,” enhancing the body's natural defenses against pathogens while preventing overactive immune responses that could lead to chronic inflammation and autoimmune diseases.

Most of us enjoy a day frolicking on the beach, sun-bathing and perhaps sipping a tropical drink from a bamboo tumbler, but there are some significant cons to getting too much UVB radiation.

Excessive exposure to UVB radiation increases the risk of skin cancer, including melanoma, the most dangerous type of skin cancer. UVB radiation also accelerates skin aging, leading to wrinkles, age spots, and loss of skin elasticity. UVB radiation can cause damage to the eyes, increasing the risk of conditions like cataracts and corneal sunburn. Yes, your eyes can get sunburned along with the rest of your body.

So, what is the proper amount of time to spend in the sun? Well, oddly, it’s completely bio-individual and determined largely by how much melanin you have. Melanin is the pigment responsible for the color of the skin, hair, and eyes in humans.

Melanin plays a critical role in protecting the skin from the harmful effects of UV radiation from the sun. However, melanin's protective property also influences the synthesis of vitamin D in the skin.

Melanin absorbs UV radiation and dissipates it as heat, providing a natural protection against sunburn and skin cancer. The more melanin in the skin, the darker the skin color and the more protection there is against UV radiation.

While melanin's ability to absorb UV radiation protects the skin from damage, it also reduces the skin's capacity to produce vitamin D. When UVB rays hit the skin, they interact with a form of cholesterol in the skin, which starts the process of vitamin D synthesis. But if those UVB rays are absorbed by melanin, fewer of them are available to start the vitamin D production process. This means that individuals with darker skin, i.e. those who have more melanin, are at a greater risk of vitamin D deficiency if they don't get enough sun exposure, don't consume enough vitamin D in their diet or don't take a vitamin D supplement.

This is a prime example of the trade-offs in human biology. The advantage of having more melanin is greater natural protection against sun damage and skin cancer, but the disadvantage is a higher risk of vitamin D deficiency, particularly in regions with less sun exposure. Conversely, individuals with less melanin (lighter skin) can synthesize vitamin D more readily, but they are at higher risk of sunburn and skin cancer.

For example, if you have darker skin and live in a high latitude climate, you will almost certainly be vitamin D deficient. Of course, humans co-evolved with their climates, so high concentrations of melanin, for example, in most of Africa or India was an adaptive advantage. However, through migration and other more nefarious means, the world has gotten a lot “smaller” and multi-ethnic. This has led to evolutionary mismatches.

Once again, it’s a balance. The need for sun exposure to produce vitamin D versus the risk of skin damage from the sun. The UV index can serve as your beach time planner. You can test to determine where or not you have a vitamin D deficiency. Optimal levels fall between 50 – 100 ng/mL (nanograms per milliliter). Levels below 20 ng/mL are considered deficient. Fortunately, supplementation of vitamin D is easy and relatively cheap. The recommended maximum daily limit of vitamin D in healthy people is 4000 - 5000 IU. That said, it’s hard to overdose. Vitamin D toxicity, also called somewhat ridiculously hypervitaminosis D, is a very rare but potentially serious condition that occurs when you have excessive amounts of vitamin D in your body.

Human are completely dependent on the sun. Without its electromagnetic energy there would be no photosynthesis, and, by extension, no plant growth. And animals need plants for food and oxygen. Our last great extinction, 65 million years back, was caused by the Chicxulub meteor crashing into the Yucatan Peninsula. The impact triggered a nuclear winter that blocked the sun’s rays and wiped out 80-90% of living species.

Alongside this reliance, humans have also evolved with the sun. We developed adaptive mechanisms in relationship with our solar system’s only star. Our circadian rhythm and our endogenous antioxidant and vitamin D production are examples of our evolutionary rapport with chemical reactions occurring 93 million miles away.