Category Archives: Circadian Rhythm Therapy

The Benefits of Near Infrared Light

We have a great respect for the influence of light upon health. We’ve blogged and spoken about the importance of blue light for circadian rhythm entrainment, and ultraviolet light for production of vitamin D and nitric oxide (for example, in “Nitric Oxide and AO+Mist Skin Probiotic at the Perfect Health Retreat”; use the coupon code phd25 for 25% off AOBiome’s nitric oxide enhancing skin probiotic).

However, red and near infrared light are healthful too. Vladimir Heiskanen (also known as “Valtsu”) is a Finnish blogger and intelligent young scholar who has been researching the effects of red and near infrared light, and he wrote a post on his blog which deserves greater exposure. Vladimir has graciously allowed me to revise his post for PHD readers. – Paul Jaminet

I (Valtsu) used to spend a lot of time reading Ray Peat’s articles, trying to make sense of his ideas. In many of his articles, Peat praised red light. For example (from here):

Old observations such as Warburg’s, that visible light can restore the activity of the “respiratory pigments,” showed without doubt that visible light is biochemically active. By the 1960s, several studies had been published showing the inhibition of respiratory enzymes by blue light, and their activation by red light.

Peat didn’t give many references to justify his claims, but after doing some searches on PubMed, I realized that there are thousands of papers supporting his views.


Activation of cytochrome c oxidase (Cox), the mitochondrial respiratory enzyme discovered by Nobel laureate Otto Warburg, seems to be the primary mechanism by which red light enhances mitochondrial function. [1] [2] [3] [4] [5] [6]

Cox is the centerpiece of the last stage of mitochondrial energy production, Complex IV. Cox utilizes energetic electrons and protons from opposite sides of the inner mitochondrial membrane to turn one molecule of oxygen (O2) into two molecules of water (H2O), in the process contributing the energy required to form ATP.

But a number of small molecules can displace the O2, spoiling the reaction and acting as inhibitors of ATP synthesis. These include cyanide (HCN), carbon monoxide (CO), hydrogen sulfide (H2S), and nitric oxide (NO). If too much oxygen is displaced, as in cyanide or carbon monoxide poisoning, cells die from chemical asphyxiation.

Nitric oxide is a native molecule of crucial importance for health, especially cardiovascular health. Nitric oxide generation by ultraviolet light (UV-A) is probably a major reason for the healthfulness of sunshine. Nitric oxide is commonly generated by stressed cells (for example, during the heat shock response) to support cellular health, in part by increasing blood flow.

However, the binding of NO to Cox, inhibiting mitochondrial respiration, can be an unwanted side effect. It turns out, fortunately, that red and near infrared light photodissociate NO from Cox, leading to its release from mitochondria back into circulation with beneficial effects on blood flow.

Removal of NO from mitochondria appears to be the mechanism by which red light phototherapy enhances mitochondrial respiration [2] [7a] [7b] [8] [9] [10] [11]. Supporting evidence: provision of NO abolishes the cellular effects of red and near infrared light.

Visible light doesn’t penetrate the body well, but infrared light does. Near infrared light is only reduced in intensity by about half after passage through 2 mm of tissue, and in daytime outdoor environments may dissociate NO and promote mitochondrial respiration at a depth of 2-3 cm beneath the skin. [13] [14] [15]

This image, from here, is illuminating:

Valtsu image 01

First, it illustrates the relative transparency of human tissue in the red (and even greater transparency in the infrared). Transparency in this frequency range appears to have been evolutionarily selected, to the point that one molecule – cytochrome c oxidase in mitochondria – absorbs 35% or more of red light. If it was so important to let red light reach mitochondria that other human molecules had to evolve transparency in the red, then it is surely important for us to provide our mitochondria with red light.

Second, when tissues are injured, they release extra nitric oxide, and NO bound to Cox absorbs red light, making the injured tissue more opaque in the red. In this case the middle finger had been jammed; due to the injury it passes significantly less red light than the fingers on either side.

The History of Red Light Therapy

There is nothing new under the sun, and when a simple activity is beneficial for health, we often find that somebody discovered the effect long ago. So it is with red light.

Niels Ryberg Finsen won the Nobel Prize for Medicine in 1903 for his explorations of the therapeutic effects of light, notably the use of ultraviolet light to treat lupus and other diseases; but he had also found that red light could be beneficial, and had published an article titled “The Red Light Treatment of Smallpox” in 1895.

The idea of using red light for therapy was picked up by John Harvey Kellogg, who published a 200-page book titled Light Therapeutics in 1910. Kellogg had long been famous as one of the first vegetarian doctors, leader of the Battle Creek Sanitarium for the Seventh Day Adventist Church from 1876 until 1933, and as the inventor of corn flakes breakfast cereals (in 1878). Kellogg recommended light therapy for diabetes, obesity, chronic fatigue, insomnia, baldness, and cachexia. [18]

After the invention of lasers, it was found that red laser light could accelerate wound healing in animals, and in the 1970s similar results were obtained in humans. [2]

The most interesting work on phototherapy, however, has been conducted recently. It is becoming a hot field: a Pubmed search for LLLT (an acronym for “low-level laser therapy” or “low-level light therapy”) generates about 10 papers per year in the 1990s, 100 per year in the 2000s, and 400 per year in the 2010s.

Therapeutic Benefits from Local Application of Red Light

Therapeutic benefits from local application of red or near infrared light to injured tissues have been reported for several conditions:

  • Age-related macular degeneration. The eyes of 200 elderly subjects with age-related macular degeneration were exposed to near infrared light of wavelength 780 nm. Visual acuity was improved in 95% of the subjects; most were able to see two rows lower on an eye chart. Results achieved in two weeks of treatment were maintained three to thirty-six months. [65]
  • Knee osteoarthritis. Application of near infrared (830 nm) light to the knees of osteoarthritis patients dramatically reduced knee pain scores. [73]
  • Herpes labialis. Cold sores around the lips caused by herpes simplex virus 1 were treated with red laser light. Time to recurrence was a median 37.5 weeks in the treatment group, 3 weeks in the placebo group. (Subjects wore masks and couldn’t tell which group they were in.) [61]
  • Hypothyroidism. Hashimoto’s hypothyroidism patients were exposed to near infrared (830 nm) radiation of the skin over the thyroid gland. Nine months later, 48% of the treatment group had been able to stop taking thyroid hormone, and the average T4 dose had dropped from 93 mcg to 39 mcg. In the control group, the average T4 dose had increased from 90 mcg to 107 mcg. [37] Similar results have been reported in other studies. [36] [37] [38] [40]  [41] [42] [43]
  • Cognitive dysfunction following traumatic brain injury. Eleven patients with continuing cognitive dysfunction following traumatic brain injury (from motor vehicle accidents, sports injuries, and an improvised explosive device detonation) were treated with red and near-infrared light to the scalp. They experienced improvements in executive function, learning, and memory, as well as improved sleep and fewer post-traumatic stress disorder symptoms.
  • Cellulite. This is more speculative, but there are indications that red and near infrared light can help reduce cellulite.
  • Hair loss. Use of a laser hair comb led to fuller and thicker hair in hair loss patients.

Systemic Benefits of Phototherapy

Even when light is applied locally, some of the benefits may be shared systemically.

For instance, exposure to light causes release of NO from mitochondria and also an increase in NO levels due to photoactivation of nitric oxide synthase. Elevation of NO anywhere increases blood flow throughout the body. In one experiment, one hand was irradiated with white light; blood flow rate increased 45% in the irradiated hand and 39% in the non-irradiated hand.

Irradiation with white light has been found to increase antibody production, presumably improving immune function.

Light exposure has also been found to have anti-inflammatory effects. For example, white light exposure reduces levels of the pro-inflammatory cytokines TNF- α, IL-6, interferon-gamma, and interleukin-12 and increases levels of anti-inflammatory cytokines interleukin-10 and TGF-beta.

Other studies have found that UV radiation increases TNF-α, IL-6 and other pro-inflammatory cytokines. [90] [91] So it is likely that the anti-inflammatory effects of the white light were chiefly due to its red and near infrared components.

These anti-inflammatory effects may shed light on the improvements hypothyroid subjects experienced from near infrared phototherapy. TNF-α and IL-6 suppress peripheral thyroid hormone metabolism by decreasing T3 and increasing rT3. [92] [93] Inflammation seems to commonly trigger hypothyroidism, while anti-inflammatory strategies are almost always therapeutic for hypothyroidism.

Epidemiological evidence suggests that light exposure improves serum lipid profiles. At mid-latitudes, serum cholesterol levels typically rise 5% to 10%, but HDL cholesterol levels decrease, in winter. Blood pressure is also higher in winter. [97] [98] [99] [100] [101] [102] Lack of red light may be the reason. In a pilot study, red light exposure reduced serum cholesterol levels in 84% of subjects.

Widespread Deficiencies in Light Exposure

It’s likely that our modern environments lead to systemic deficiencies in light exposure. It’s common for health to worsen in low-light locations or seasons, as Ray Peat observed:

Many people who came to cloudy Eugene to study, and who often lived in cheap basement apartments, would develop chronic health problems within a few months. Women who had been healthy when they arrived would often develop premenstrual syndrome or arthritis or colitis during their first winter in Eugene.

Since the last ice age ended, humanity has populated more northerly latitudes and moved indoors. We are getting far less light than our ancestors. The evolutionary mismatch principle suggests that humans will be optimized for ancestral light levels, and that we moderns can improve our health by getting more light.

Health Risks of Blue-Only Light

While red light tends to enhance mitochondrial function, high intensities of blue light can damage mitochondria by triggering oxidative stress. Blue-only light can kill retinal cells. Exposing rats to blue-only light or to “white” LED light that peaks unnaturally strongly in the blue led to retinal damage. LED lights are the worst, due to their concentration at single frequencies, but compact fluorescent lights which have peaks in the blue can also generate mild to moderate retinal damage. A commentary on the research is here.

Reactive oxygen species are generated in mitochondria when they can’t dispose of electrons in the manufacture of ATP. For this reason, NO binding to Cox promotes oxidative stress, and release of NO from Cox by red and infrared light reduces oxidative stress. It is probably by this mechanism that red and near infrared light protects against retinal injury.

Because of this research, we don’t recommend using blue-only light boxes for circadian rhythm entrainment; rather, use full spectrum white light.

Incandescent lights, which produce a smooth spectrum including red and near-infrared wavelengths, are probably safest for eye health. Some researchers, such as Richard Funk and Alexander Wunsch, who appeared in the Bulb Fiction documentary, assert that increased CFL usage may be harmful to eyes. Of course, governments are here to help us, and have banned incandescent lighting.

Circadian Rhythm Considerations

There are hints that bright red and near infrared light exposure should occur in the daytime.

Night-time levels of melatonin, but not day-time levels, have been shown to abolish the effects of red and infrared light on cellular function, just as nitric oxide does.

This shows that melatonin, a circadian rhythm hormone, evolved to inhibit red light influences at night. If our “night hormone” is trying to block the influence of red light, we probably shouldn’t willfully expose ourselves to bright red light at night.

What to Do

If fluorescent lights are problematic, how should we get adequate red and near infrared light, while getting sufficient blue in the daytime to entrain circadian rhythms?

The general lighting types that provide the most red and near-infrared are incandescent lights, heat lamps, and LEDs.

Heat lamps by Philips or Osram  generate little blue light but, thanks in part to their high power levels (up to 250 W), provide significant red and near-infrared light. However, only ~12% of the power is emitted at therapeutic wavelengths (600-1070 nm); most of their power is emitted at the warming IR-B wavelengths. In fact, these lamps emit so much heat that they can substitute for central heating in the winter. Most people will find they produce too much heat for summer use. Although we recommend using red or orange lighting at night, heat lamps are not really suitable for night use; ambient temperature is a zeitgeber and our exposure to warmth should occur in the daytime. Moreover, as noted above, it might be best to get red light exposure in the daytime, when melatonin levels are low. So heat lamps are best used in the daytime as a complement to other broad-spectrum lighting.

Incandescent lights (including halogen lights), which produce a blackbody spectrum, can generate a significant amount of red and near infrared and are excellent daytime light sources. A color temperature of 5500 K mimics the sun and provides substantial amounts of red and near infrared; a color temperature of 4100 K is also excellent in the red and near infrared, but is rather weak in the blue and ultraviolet for daytime circadian rhythm entrainment. A look at blackbody spectra as a function of color temperature:

Valtsu image 02

LEDs are another possibility. One of their virtues is that it’s possible to obtain monochromatic LEDs with frequencies optimized for Cox-NO photodissociation (680 and 820 nm work best; inexpensive LEDs are available at 630, 660, 850, and 880 nm. Here is a video of a fellow who created a homemade LED helmet:

A variety of commercial light devices have been used in LLLT/light therapy studies: AnodyneBioptronHairMax LaserCombOmniluxNoveon NaiLaserBiolightQuantum WarpSyrolight BioBeamHIRO 3.0Picasso LiteHELBO® TheraLite Laser and Mustang 2000.


Exposure to sunshine on bare skin, which was common in our ancestral environment, is something we need to obtain or mimic if we want optimal health.

Unfortunately, it’s hard to reproduce the many facets of sunshine in indoor environments. Blue light (for daytime circadian rhythm entrainment), UV-A light (for nitric oxide), UV-B light (for vitamin D), red light (for nighttime circadian rhythm entrainment), and now red and near infrared light in the daytime (for mitochondrial respiration) all seem to be important.

Awareness is the first step toward optimization. Thank you, Vladimir, for sorting through this research for us!

Beyond Standing Desks: Portable Outdoor Workstations

A note from Paul: I’m happy to introduce Kamal Patel’s first post on PHD! Kamal is the funniest and maybe smartest guy in the ancestral health movement. A Ph.D. candidate in nutrition and a leader in the Ancestral Health Society, you may know him from PaleoHacks or For more, check out Kamal’s bio on our About Us page. Welcome Kamal!

Goal: Do some computer work outside a couple times a week. Get maximal benefits from the sun in a minimum amount of time, while fitting all the necessary gear inside a backpack.

Resources: Tiny budget, free Amazon Prime shipping, access to a sunny park.

Why do computer work outside?

Hi, Kamal here (see below Shou-Ching for a short bio). I love sunlight. You probably love sunlight too. Turns out the sun is important for things outside of just vitamin D production. Ever wonder why indoor cats gravitate towards sunlight, even though they get their vitamin D from food? Probably not, since it just makes intuitive sense that animals want to be outdoors. The desire to be free of inside confines applies not just to indoor cats but also to indoor humans. Yet indoor humans sometimes need to see peer-reviewed articles before changing their habits. Don’t fret, we’ll start with a couple of those before delving into five specific steps for creating an outdoor workstation.

Escape plot foiled by hammock

My kitty’s escape to sunlight, foiled by a vicious hammock

Sun exposure increases production of endorphins and nitric oxide, which can translate into benefits for both pyschological well being as well as disease prevention. Light boxes benefit not only seasonal affective disorder but also non-seasonally linked depression. Brief but regular exposure to ultraviolet light from tanning beds can help the mysterious and painful chronic condition called fibromyalgia, and sunlight may benefit pain after surgery. The draw of UV radiation is so powerful that frequent tanners can literally get addicted to catching rays. Unfortunately, the “pro-sunshine” lobby isn’t pouring billions into research on sun exposure, so the specific mechanisms of sunlight benefit will likely remain more mysterious than the mechanisms of blockbuster medications like Viagra and Prilosec.

Step 1: Dress for success

Look at your skin. Does it look more like Paul’s, or does it look more like Kamal’s?


Debating who has worse posture

If it looks like Kamal’s, you might be getting vitamin D not-at-alls (PS: that’s a rhyming mnemonic). Let me explain. I first got my vitamin D tested in 2008, and it came in at a whopping 19 ng/ml…even with taking a multivitamin most days and getting sunlight at lunchtime! As you probably know, pigmented and/or tanned skin serves as sunscreen, making it tough for darker people to synthesize vitamin D without very long sun exposure times. Indians may also produce less active vitamin D (calcitriol) from a given amount of sun exposure due to genetic predisposition.

But my problems apply to you lighter-skinned folk as well — my outdoor lunch excursions were done while wearing business casual clothing with short sleeves. This means covered torso and legs, leaving only about 25% of my skin exposed for vitamin D production. If you factor in things that can lower vitamin D production further, such as cloud cover, not laying down horizontally, higher BMI, and increased age, then it might be worth it to create a “sunlight maximization” strategy. 

How serious are you about getting that extra sunlight? If you’re moderately serious, consider small changes like taking off your shoes and rolling up your pantlegs a bit while sitting in the park. If you’re extremely serious and okay with looking strange, consider occasional use of…mesh basketball jerseys! Yup, those cheapo mesh tops are made of thin material covered with tiny holes. One day I’ll buy a UV meter and check the actual numbers, but my suspicion is that wearing such a jersey would greatly increase skin exposure to the sun, perhaps doubling it or more. I bought my jersey for about $10 on Amazon, and sometimes change into it before leaving for the park. If you don’t already have blue-light blocking glasses to ratchet down light exposure before bedtime, you can buy a pair of those plus a jersey on Amazon in order to level up to free shipping.


Step 2: Acquire tiny chair and tiny laptop

Now that you’ve freed up enough skin to get some substantial sunlight, the next step is to assemble your outdoor office. This part is fun. Eventually you’ll want a small chair, especially if you’re planning on spending many hours working outside. To get a chair that you can stuff in your backpack, just head to REI or any place that sells camping gear. I chose a collapsible model at REI called “Flex Lite” that weighs only 1.75 pounds and folds down to 14×4 inches. 


Tiny chair and tiny laptop fit into backpack with plenty of room to spare.

Laptops are expensive, so you can totally just use whichever model you have. BUT…if you have a few bucks to spare or your current model is in need of replacement, I’d recommend getting an ultra-light laptop, at under 3 pounds. That way, you can fit the tiny laptop and tiny chair along with a hearty lunch in your backpack. Just remember that a laptop with a matte screen works much better than a glossy screen for outdoor use.

Step 3: Optimize ergonomics

The name of the game when working at a computer is to avoid repetitive stress injuries. Simply by being outside, it will give you more incentive to get up and walk around once in a while. But there are other ways to introduce some structured change-of-posture. You can set a timer for every 20 or 30 minutes or get an app on your phone that reminds you to get up. You could also take a break from sitting in the chair to sit on the grass. Note that sitting with feet in contact with the earth (aka “earthing” or “grounding”) is speculated to have some health benefits, which is another bonus for getting in some outdoor office time.

For those with wrist problems, consider switching up your input method every now and then. Switching from right to left hand on occasion is the easiest way to do this. Other ways are switching from trackpad to mouse or trackball and using keyboard shortcuts more. Later this summer, a motion-detecting input device called “Leap Motion” is coming out that will allow you move the cursor with your MIND! Just kidding, not with your mind. But it does allow you to move the cursor with your hands in the air, Minority Report style, reducing much pressure from overstressed wrist tendons and ligaments. Fancy gadgets aside, if you’re going to spend more time outside, it’s a perfect opportunity to think more about varying your working position and revisiting ergonomics.

Step 4: Get pumped

This is going to sound cheesy, but so be it. Working outside can make you feel more alive. The transition from typical cubicle to standing desk is exciting. Work typically takes up the majority of one’s adult life, and standing cracks the mold of being a robotic office cubicle worker. Incorporating some outside work time removes so much of the drudgery aspect from work that it can confuse the most pessimistic of brains.

Normalizing circadian rhythm is an essential part of the health equation, and a complementary factor is being outdoors in the sun. “Sick building syndrome” doesn’t get a ton of research attention, but it’s a very real thing. One reason outdoorsy vacations provide a sense of well-being could be a lack of droning artificial light, stale air with concentrated indoor pollutants, and disgruntled coworkers. Even an office full of windows isn’t perfect. Office windows filter out UVB rays (meaning no vitamin D production or improved mood through endorphin release) but allow some UVA through (meaning staying indoors behind a window doesn’t keep you risk-free from skin damage and cataracts).

Step 5: Get outside already!


Directions: Stuff into backpack, leave for park while whistling CCR’s “Lookin’ Out My Back Door”.

Above are my typical outdoor office supplies, all of which easily fit into a normal-sized backpack with room to spare. From the top left, there’s a travel-sized sunblock, laptop, collapsible chair, flipflops, coconut chips plus sardines in olive oil, and mobile wifi device. If you don’t want to get a mobile wifi device, you can usually get free or cheap mobile wifi from your smartphone.

In terms of practical recommendations, I advise people with school or office work to gradually spend more time working outside. If you find yourself able to be productive working outside, only then consider buying a chair or other outdoor accouterments. Wearing a mesh jersey might seem drastic, but it has a couple benefits. For darker-skinned individuals, it can substantially decrease the prolonged time needed to produce vitamin D. Very light-skinned individuals who are at higher risk of skin cancer could wear sunblock on parts of the body that are more prone to skin damage (like the face) and couple that with producing vitamin D from a jersey-clad torso.

To reiterate because of its importance, a critical concept for office work is VARIATION. The capital letters are to show that I’m not joking around. Combining typical indoor seated work with at least occasional standing work and occasional outdoor seated work is a solid ergonomic base. Increasing the standing to a few hours a week may result in weight loss of several pounds a year. When indoors, a “microbreak” of under a minute could be spent grabbing some water, taking a lap around the office, or climbing a set of stairs. These microbreaks have been shown to reduce muscular discomfort without compromising productivity. When outdoors, microbreaks are pretty much just awesome. Breathe in some fresh air, stare at the clouds, say hello to the doggies at the park. All the studies in the world can’t relay just how nice it is to work outside a couple times a week.

Faces Therapy

I’ve discussed Seth Roberts’s idea of “faces therapy” – looking at human faces during the day, especially the morning, in order to normalize circadian rhythms. See Seth Roberts and Circadian Therapy, Mar 22, 2011, and Around the Web; It’s Anthropology Week!, May 21, 2011.

Then Kris gave us a great video she used for faces therapy; that appeared in a post last year (CrossFit NYC: 20 Tips for Optimal Health & Fitness, Nov 22, 2011).

Well, here’s another video so therapeutic I had to share. Enjoy!

Seth Roberts and Circadian Therapy

A while back I noted that hypothyroidism is a circadian rhythm disorder and that dietary steps that restore circadian rhythms, like intermittent fasting and daytime eating, should be therapeutic (“Intermittent Fasting as a Therapy for Hypothyroidism,” Dec 1, 2010).

Many other disorders besides hypothyroidism feature disturbed circadian rhythms:

  • Sleeplessness and poor sleep
  • Depression, bipolar disorder, and other psychiatric disorders
  • Dyslipidemia, metabolic syndrome and obesity.
  • Neurodegenerative disorders

Circadian rhythm disruption also suppresses immune function and increases vulnerability to infectious disease.

Restoring or strengthening circadian rhythm may be therapeutic for all of these conditions. Even for healthy people, tactics for enhancing circadian rhythms may improve health.

Which brings us to Seth Roberts.

Seth Cured a Sleep Disorder With Circadian Therapy

Seth is a well-known blogger, a Paleo dieter and psychologist, author of  The Shangri-La Diet, and a great self-experimenter.

Seth recently gave a talk that tells the history of his self-experimentation.

It turns out he suffered from disturbed sleep for many years. He experimented to find cures for 10 years; nothing worked. But then he got a lead.

When a student suggested he eat more fruit, he started eating fruit for breakfast. His sleep got worse! This was exciting to Seth because it was, in 10 years, the first thing he tried that changed his sleep.

He had the idea of trying no breakfast. It turned out that skipping breakfast improved his sleep. One of his slides:

This directly supports our idea that intermittent fasting (confining eating to an 8-hour window each day) should be therapeutic for circadian rhythm disorders such as disturbed sleep and hypothyroidism.

But what’s exciting is that Seth continued his experiments to find other ways to improve his sleep. As a psychologist, he knew that human contact controls when we sleep: people are most awake at the times they have contact with other people, and asleep when isolated.

He knew that watching TV can have effects similar to socializing. So he tried watching Jay Leno one morning. He slept very well the next night.

It turns out that looking at human faces is almost as good as real socializing. Here is Seth’s data relating mood to whether he looked at faces:

Seth also tracked his mood over the course of the day. The response of mood to seeing pictures of human faces clearly followed a circadian (24-hour) rhythm:

Another thing that relates to circadian rhythms is exercise: we normally exercise during the day and rest at night.

For a scholar, the easiest way to exercise is to stand rather than sit (for instance, by working at a standing desk). Seth tried standing 9 hours a day – and it cleared his sleep problem!

Of course, standing is not a very strenuous exercise. Seth found that if he just stood on one leg, the effect was much more intense, and he could fix his sleep problem with only minutes of one-legged standing per day.

He also found that eating more animal food improved his sleep. It’s possible that animal fat may enhance circadian rhythms more than other foods.


I found this fascinating – because it adds more evidence regarding the centrality of circadian rhythms in health – and exciting, because it shows that simple tactics can be therapeutic for circadian rhythm disorders.

In the hypothyroidism post, I suggested the following tactics for improving circadian rhythms:

  • Light entrainment: Get daytime sun exposure, and sleep in a totally darkened room.
  • Daytime feeding: Eat during daylight hours, so that food rhythms and light rhythms are in synch.
  • Intermittent fasting: Concentrate food intake during an 8-hour window during daylight hours, preferably the afternoon. A 16-hour fast leading to lower blood sugar and insulin levels, and the more intense hormonal response to food that results from concentration of daily calories into a short 8-hour time window, will accentuate the diurnal rhythm.
  • Adequate carb intake: Eat at least 400 “safe starch” carbohydrate calories daily during the afternoon feeding window. Relative to a very low-carb diet, this will increase daytime insulin release and, by increasing insulin sensitivity, may reduce fasting insulin levels. It will thus enhance diurnal insulin rhythm.

To these, we can add several more based on Seth’s findings:

  • Looking at human faces: If you work at a computer, keep a window up that cycles among photos of faces, or shows a video of a talk show; keep photos of your family near your screen.
  • Standing: Work at a standing desk or, failing that, get in the habit of standing on one leg rather than two.
  • Animal fat: Eat a diet high in animal fats.

These tactics cured Seth’s sleep disorder. Might these tactics also cure or greatly improve other circadian rhythm disorders – including hypothyroidism and psychiatric disorders like depression and bipolar disorder? Could looking at human faces help the obese lose weight and improve their lipid profiles?

I don’t know but I’d certainly give these techniques a try before pharmaceutical drugs. I believe these techniques deserve clinical testing as therapies for all diseases associated with disrupted circadian rhythms. I believe that they may be just as beneficial for the healthy: by improving immune function, they may delay aging and extend lifespan.

A few weeks ago, when I posted a video of Don Rumsfeld defending the use of a standing desk (the same video was later linked by John Durant and Mark Sisson), I brashly stated, “There are few single life adjustments more likely to improve your health than working at a standing desk.”

Perhaps that statement wasn’t as exaggerated as it may have seemed!

Seth’s Talk