The Circadian Rhythm: Far More Than Most People Know
Dr. Satchidananda Panda’s groundbreaking research on the circadian rhythm reveals the importance of timing in eating, exercising, and getting sunlight for optimal metabolic health.
The Circadian Rhythm: Far More Than Most People Know
This is Dr. Satchidananda (Satchin) Panda, the scientist behind the discovery of the blue-light sensing cell type in the retina, and the many things it affects. But, he’s discovered more…
First, what you probably know (with a little more science)
Dr. Panda discovered that melanopsin, a photopigment, is “the primary candidate for photoreceptor-mediated entrainment”.
To put that in lay terms, it’s the brain’s go-to for knowing approximately what time of day or night it is, according to how much light there is (or isn’t), and how long it has (or hasn’t) been there.
But… the brain’s “go-to” isn’t the only method. By creating mice without melanopsin, he was able to find that they still keep a circadian rhythm, even in complete darkness:
Melanopsin (Opn4) Requirement for Normal Light-Induced Circadian Phase Shifting
In other words, it was a helpful, but not completely necessary, means of keeping a circadian rhythm.
So… What else is going on?
Dr. Panda and his team did a lot of science that is well beyond the scope of this main feature, but to give you an idea:
- With jargon: it explored the mechanisms and transcription translation negative feedback loops that regulate chronobiological processes, such as a histone lysine demathlyase 1a (JARID1a) that enhances Clock-Bmal1 transcription, and then used assorted genomic techniques to develop a model for how JARID1a works to moderate the level of Per transcription by regulating the transition between its repression and activation, and discovered that this heavily centered on hepatic gluconeogenesis and glucose homeostasis, facilitated by the protein cryptochrome regulating the fasting signal that occurs when glucagon binds to a G-protein coupled receptor, triggering CREB activation.
- Without jargon: a special protein tells our body how to respond to eating/fasting at different times of day—and conversely, certain physiological responses triggered by eating/fasting help us know what time of day it is.
- Simplest: our body keeps on its best cycle if we eat at the same time every day
This is important, because our circadian rhythm matters for a lot more than sleeping/waking! Take hormones, for example:
- Obvious hormones: testosterone and estrogen peak in the mornings around 9am, progesterone peaks between 10pm and 2am
- Forgotten hormones: cortisol peaks in the morning around 8:30am, melatonin peaks between 10pm and 2am
- More hormones: ghrelin (hunger hormone) peaks around 10am, leptin (satiety hormone) peaks 20 minutes after eating a certain amount of satiety-triggering food (protein does this most quickly), insulin is heavily tied to carbohydrate intake, but will still peak and trough according to when the body expects food.
What does this mean for us in practical terms?
For a start, it means that intermittent fasting can help guard against metabolic and related diseases (including inflammation, and thus also cancer, diabetes, arthritis, and more) a lot more if we practice it with our circadian rhythm in mind.
So that “8-hour window” for eating, that many intermittent fasting practitioners adhere to, is going to do much, much better if it’s 10am to 6pm, rather than, say, 4pm to midnight.
Additionally, Dr. Panda and his team found that a 12-hour eating window wasn’t sufficient to help significantly.
Some other take-aways:
- For reasons beyond the scope of this article, it’s good to exercise a) early b) before eating, so getting in some exercise between 8.30am and 10am is ideal
- It also means it’s beneficial to “front-load” eating, so a large breakfast at 10am, and smaller meals/snacks afterwards, is best.
- It also means that getting sunlight (even if cloud-covered) around 8.30am helps guard against metabolic disorders a lot, since the light remains the body’s go-to way of knowing the time.
- We realize that sunlight is not available at 8.30am at all latitudes at all times of year. Artificial is next-best.
- It also means sexual desire will typically peak in men in the mornings (per testosterone) and women in the evenings (per progesterone), but this is just an interesting bit of trivia, and not so relevant to metabolic health
What to do next…
Want to stabilize your own circadian rhythm in the best way, and also help Dr. Panda with his research?
His team’s (free!) app, “My Circadian Clock”, can help you track and organize all of the body’s measurable-by-you circadian events, and, if you give permission, will contribute to what will be the largest-yet human study into the topics covered today, to refine the conclusions and learn more about what works best.
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Stop Cancer 20 Years Ago
Dr. Jenn Simmons shares vital tips on preventing cancer and inflammation, advocating for lifestyle changes and proactive health management at any age.
Get Abreast And Keep Abreast
This is Dr. Jenn Simmons. Her specialization is integrative oncology, as she—then a breast cancer surgeon—got breast cancer, decided the system wasn’t nearly as good from the patients’ side of things as from the doctors’ side, and took to educate herself, and now others, on how things can be better.
What does she want us to know?
Start now
If you have breast cancer, the best time to start adjusting your lifestyle might be 20 years ago, but the second-best time is now. We realize our readers with breast cancer (or a history thereof) probably have indeed started already—all strength to you.
What this means for those of us without breast cancer (or a history therof) is: start now
Even if you don’t have a genetic risk factor, even if there’s no history of it in your family, there’s just no reason not to start now.
Start what, you ask? Taking away its roots. And how?
Inflammation as the root of cancer
To oversimplify: cancer occurs because an accidentally immortal cell replicates and replicates and replicates and takes any nearby resources to keep on going. While science doesn’t know all the details of how this happens, it is a factor of genetic mutation (itself a normal process, without which evolution would be impossible), something which in turn is accelerated by damage to the DNA. The damage to the DNA? That occurs (often as not) as a result of cellular oxidation. Cellular oxidation is far from the only genotoxic thing out there, and a lot of non-food “this thing causes cancer” warnings are usually about other kinds of genotoxicity. But cellular oxidation is a big one, and it’s one that we can fight vigorously with our lifestyle.
Because cellular oxidation and inflammation go hand-in-hand, reducing one tends to reduce the other. That’s why so often you’ll see in our Research Review Monday features, a line that goes something like:
“and now for those things that usually come together: antioxidant, anti-inflammatory, anticancer, and anti-aging”
So, fight inflammation now, and have a reduced risk of a lot of other woes later.
See: How to Prevent (or Reduce) Inflammation
Don’t settle for “normal”
People are told, correctly but not always helpfully, such things as:
- It’s normal to have less energy at your age
- It’s normal to have a weaker immune system at your age
- It’s normal to be at a higher risk of diabetes, heart disease, etc
…and many more. And these things are true! But that doesn’t mean we have to settle for them.
We can be all the way over on the healthy end of the distribution curve. We can do that!
(so can everyone else, given sufficient opportunity and resources, because health is not a zero-sum game)
If we’re going to get a cancer diagnosis, then our 60s are the decade where we’re most likely to get it. Earlier than that and the risk is extant but lower; later than that and technically the risk increases, but we probably got it already in our 60s.
So, if we be younger than 60, then now’s a good time to prepare to hit the ground running when we get there. And if we missed that chance, then again, the second-best time is now:
See: Focusing On Health In Our Sixties
Fast to live
Of course, anything can happen to anyone at any age (alas), but this is about the benefits of living a fasting lifestyle—that is to say, not just fasting for a 4-week health kick or something, but making it one’s “new normal” and just continuing it for life.
This doesn’t mean “never eat”, of course, but it does mean “practice intermittent fasting, if you can”—something that Dr. Simmons strongly advocates.
See: Intermittent Fasting: We Sort The Science From The Hype
While this calls back to the previous “fight inflammation”, it deserves its own mention here as a very specific way of fighting it.
It’s never too late
All of the advices that go before a cancer diagnosis, continue to stand afterwards too. There is no point of “well, I already have cancer, so what’s the harm in…?”
The harm in it after a diagnosis will be the same as the harm before. When it comes to lifestyle, preventing a cancer and preventing it from spreading are very much the same thing, which is also the same as shrinking it. Basically, if it’s anticancer, it’s anticancer, no matter whether it’s before, during, or after.
Dr. Simmons has seen too many patients get a diagnosis, and place their lives squarely in the hands of doctors, when doctors can only do so much.
Instead, Dr. Simmons recommends taking charge of your health as best you are able, today and onwards, no matter what. And that means two things:
- Knowing stuff
- Doing stuff
So it becomes our responsibility (and our lifeline) to educate ourselves, and take action accordingly.
Want to know more?
We recently reviewed her book, and heartily recommend it:
The Smart Woman’s Guide to Breast Cancer – by Dr. Jenn Simmons
Enjoy!