The Circadian Rhythm: Far More Than Most People Know
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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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Dancing vs Parkinson’s Depression
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This is a fun study, and the results are/were very predictable, and/but not necessarily something that people might think of in advance. First, let’s look at how some things work:
Parkinson’s disease & depression
Parkinson’s disease is a degenerative neurological disease that, amongst other things, is characterized by low dopamine levels.
For the general signs and symptoms, see: Recognize The Early Symptoms Of Parkinson’s Disease
Dopamine is the neurotransmitter responsible for feelings of reward, is involved in our language faculties and the capacity to form plans (even simple plans such as “make a cup of coffee”) as well as being critical for motor functions.
See also: Neurotransmitter Cheatsheet ← for demystifying some of “what does what” for commonly-conflated chemicals
You can see, therefore, why Parkinson’s disease will often have depression as a comorbidity—there may be influencing social factors as well (many Parkinson’s disease sufferers are quite socially isolated, which certainly does not help), but a clear neurochemical factor that we can point to is “a person with low dopamine levels will feel joyless, bored, and unmotivated”.
Let movement be thy medicine
Parkinson’s disease medications, therefore, tend to involve increasing dopamine levels and/or the brain’s ability to use dopamine.
Antidepressant medications, however, are more commonly focused on serotonin, as serotonin is another neurotransmitter associated with happiness—it’s the one we get when we look at open green spaces with occasional trees and a blue sky ← we get it in other ways too, but for evolutionary reasons, it seems our brains still yearn the most for landscapes that look like the Serengeti, even if we have never even been there personally.
There are other kinds of antidepressants too, and (because depression can have different causes) what works for one person won’t necessarily work for another. See: Antidepressants: Personalization Is Key!
In the case of Parkinson’s disease, because the associated depression is mostly dopamine-related, those green spaces and blue skies and SSRIs won’t help much. But you know what does?
Dance!
A recent (published last month, at time of writing) study by Dr. Karolina Bearss et al. did an interventional study that found that dance classes significantly improved both subjective experience of depression, and objective brain markers of depression, across people with (68%) and without (32%) Parkinson’s disease.
The paper is quite short and it has diagrams, and discusses the longer-term effect as well as the per-session effect:
Dance is thought to have a double-effect, improving both cognitive factors and motor control factors, for obvious reasons, and all related to dopamine response (dancing is an activity we are hardwired to find rewarding*, plus it is exercise which also triggers various chemicals to be made, plus it is social, which also improves many mental health factors).
*You may have heard the expression that “dancing is a vertical expression of a horizontal desire”, and while that may not be true for everyone on an individual level, on a species level it is a very reasonable hypothesis for why we do it and why it is the way it is.
Want to learn more?
We wrote previously about battling depression (of any kind) here:
The Mental Health First-Aid That You’ll Hopefully Never Need
Take care!
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7 Tips To Burn Fat & Build Muscle At The Same Time
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Cori Lefkowith, of “Redefining Strength” and “Strong At Any Age” fame, has her formula to share:
Know your priorities
We’ll not keep the 7 tips a mystery; they are:
- Determine your primary goal: decide whether your main focus is losing fat while building muscle or building muscle while trimming up. This choice will influence your calorie intake, macros, and cardio approach.
- Start tracking: spend 7–14 days logging your current food intake, including calories, protein, carbs, and fats, without taking any particular action to change them yet. Understanding your baseline will help tailor your diet and exercise plan.
- Prioritize strength training: focus on strength work over cardio to build muscle. Avoid turning strength sessions into cardio by rushing between sets—allow adequate rest for muscle progression.
- Center your meals on protein: adjust your protein intake based on your primary goal. For fat loss while gaining muscle, aim for 40-45% of calories from protein. For building muscle while losing fat, aim for 30-40% protein, with attention to maintaining sufficient carbs.
- Set your calories: after adjusting protein, fine-tune your calorie intake. However, make only small changes (e.g. 100 calories up or down) and reassess every 2–3 weeks to avoid extreme deficits or surpluses.
- Adjust your cardio: prioritize strength training but use walking as low-impact cardio. Avoid excessive cardio that may hinder muscle gains, and use strategic HIIT sessions if needed.
- Ditch the scale: avoid using the scale as your sole measure of progress. Instead, rely on measurements, progress photos, and how your clothes fit to track body recomposition effectively.
For more on all of these, enjoy:
Click Here If The Embedded Video Doesn’t Load Automatically!
Want to learn more?
You might also like to read:
Can You Gain Muscle & Lose Fat At The Same Time? ← we got this question in our Q&A day not long back, and here was our answer. We went for a less numbers-based approach, and a more principles-based approach. Both ways work, so by all means pick whichever method you personally find better suits how you like to do things!
Take care!
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Heart Attack: His & Hers (Be Prepared!)
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Heart attack symptoms vary by sex. This is governed by hormones, so if you are for example a postmenopausal woman and not on HRT, your symptoms might be nearer that of men.
The following symptom list is intended as a rough “most likely” guide. You may not get all of the symptoms you “should”. You could get symptoms from the “wrong” category. So don’t sweat the minutiae, but do be aware of…
Symptoms for everyone:
- Jaw, neck, and/or back pain
- Nausea and/or vomiting
- Shortness of breath
- Feeling of impending doom ← heart attack survivors assure us that you’ll know this one if you experience it
Additional symptoms (mostly) just for men:
- Pressure and/or pain in the upper chest
- Discomfort and/or tingling in the arms
- Sudden cold sweat
Additional symptoms (mostly) just for women:
- Pressure and/or pain in the lower chest and/or abdomen
- Feeling of fullness and/or indigestion
- Fatigue, dizziness, possibly fainting
In the event of experiencing symptoms…
Call 911 or your local equivalent.This is not the time to wait to see if it goes away by itself. If unsure, call. Better safe than sorry/dead.
If you are not alone, or if it is someone with you who is having the suspected heart attack, it may be quicker to go to the Emergency Room by car, than wait for an ambulance.
Even if you choose to do that, you should still call 911 anyway, as the responder will be able to instruct you in real-time, not something we can do in a newsletter.
Note that if available, this means three people in the car is ideal:
Driver, patient, and third person on the phone giving information and following instructions.
Emergency situations rarely go entirely by-the-book, but with a little foreknowledge and at least one person with a calm head, preventable deaths can be avoided.
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Making Friends With Your Gut (You Can Thank Us Later)
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Gut Health 101
We have so many microorganisms inside us, that by cell count, their cells outnumber ours more than ten-to-one. By gene count, we have 23,000 and they have more than 3,000,000. In effect, we are more microbe than we are human. And, importantly: they form a critical part of what keeps our overall organism ticking on.
Read all about it: The role of the gut microbiota in nutrition and health
Our trillions of tiny friends keep us alive, so it really really pays to return the favor.
But how?
Probiotics and fermented foods
You probably guessed this one, but it’d be remiss not to mention it first. It’s no surprise that probiotics help; the clue is in the name. In short, they help add diversity to your microbiome (that’s a good thing).
Read from the NIH: Probiotics: What You Need To Know
As for fermented foods, not every fermented food will boost your microbiota, but great options include…
- Fermented vegetables (sauerkraut, pickles, etc)
- You’ll often hear kimchi mentioned; that is also pickled vegetables, usually mostly cabbage. It’s just the culinary experience that differs. Unlike sauerkraut, kimchi is usually spiced, for example.
- Kombucha (a fermented sweet tea)
- Miso & tempeh (different preparations of fermented soy)
The health benefits vary based on the individual strains of bacteria involved in the fermentation, so don’t get too caught up on which is best.
The best one is the one you enjoy, because then you’ll have it regularly!
Feed them plenty of prebiotic fibers
Those probiotics you took? The bacteria in them eat the fiber that you can’t digest without them. So, feed them those sorts of fibers.
Great options include:
- Bananas
- Garlic
- Onions
- Whole grains
Read more: Effects of Probiotics, Prebiotics, and Synbiotics on Human Health
Don’t feed them sugar and sweeteners
Sugar and (and, counterintuitively, aspartame) can cause unfortunate gut microbe imbalances. Put simply, they kill some of your friends and feed some of your enemies. For example…
Candida, which we all have in us to some degree, feeds on sugar (including the sugar formed from breaking down alcohol, by the way) and refined carbs. Then it grows, and puts its roots through your intestinal walls, linking with your neural system. Then it makes you crave the very things that will feed it and allow it to put bigger holes in your intestinal walls.
Do not feed the Candida.
Don’t believe us? Read: Candida albicans-Induced Epithelial Damage Mediates Translocation through Intestinal Barriers
(That’s scientist-speak for “Candida puts holes in your intestines, and stuff can then go through those holes”)
And as for how that comes about, it’s like we said:
❝Colonization of the intestine and translocation through the intestinal barrier are fundamental aspects of the processes preceding life-threatening systemic candidiasis. In this review, we discuss the commensal lifestyle of C. albicans in the intestine, the role of morphology for commensalism, the influence of diet, and the interactions with bacteria of the microbiota.❞
Source: Candida albicans as a commensal and opportunistic pathogen in the intestine
The usual five things
- Good diet (Mediterranean Diet is good; plant-based version of it is by far the best for this)
- Good exercise (yes, really)
- Good sleep (helps them, and they’ll help you get better sleep in return)
- Limit or eliminate alcohol consumption (what a shocker)
- Don’t smoke (it’s bad for everything, including gut health)
One last thing you should know:
If you’re used to having animal products in your diet, and make a sudden change to all plants, your gut will object very strongly. This is because your gut microbiome is used to animal products, and a plant-based diet will cause many helpful microbes to flourish in great abundance, and many less helpful microbes will starve and die. And they will make it officially Not Fun™ for you.
So, you have two options to consider:
- Do it anyway, and sit it out (and believe us, you’ll be sitting), get the change over with quickly, and enjoy the benefits and much happier gut that follows.
- Make the change gradual. Reduce portions of animal products slowly, have “Meatless Mondays” etc, and slowly make the change over. This—for most people—is pretty comfortable, easy, and effective.
And remember: the effects of these things we’ve talked about today compound when you do more than one of them, but if you don’t want to take probiotics or really hate kombucha or absolutely won’t consider a plant-based diet or struggle to give up sugar or alcohol, etc… Just do what you can do, and you’ll still have a net improvement!
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- Fermented vegetables (sauerkraut, pickles, etc)
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Celery vs Chard – Which is Healthier?
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Our Verdict
When comparing celery to chard, we picked the chard.
Why?
In terms of macros, chard has more fiber, carbs, and protein, making it the more nutrient-dense option and thus the winner of the macros category.
In the category of vitamins, celery has more of vitamins B5 and B9, while chard has more of vitamins A, B1, B2, B3, B6, C, E, K, and choline—another win for chard.
When it comes to minerals, celery is not higher in any minerals, while chard has more calcium, copper, iron, magnesium, manganese, phosphorus, potassium, selenium, and zinc. One more very clear win for chard!
Looking at polyphenols, celery has very little to boast, about 3mg/100g furanocoumarins and nothing else, while chard has an impressive array of polyphenols, with 9mg/100g kaempferol and 7.5mg/100g quercetin atop the list of 12 polyphenols. Yet another win for chard.
Adding up the sections is not difficult arithmetic today: chard sweeps every category. But by all means enjoy either or both; diversity is good!
Want to learn more?
You might like:
Dr. Greger’s Daily Dozen ← the “dozen” in question includes getting a good amount of of leafy greens per day
Enjoy!
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Mythbusting Moldy Food
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Most Food Should Not Be Fuzzy
In yesterday’s newsletter, we asked you for your policy when it comes to mold on food (aside from intentional mold, e.g. blue cheese etc), and the responses were interesting:
- About 49% said “throw the whole thing away no matter what it is; it is dangerous”
- About 24% said “cut the mold off and eat the rest of whatever it is”
- The remainder were divided equally between “eat it all; keep the immune system on its toes” and “cut the mold off bread, but moldy animal products are dangerous”
So what does the science say?
Some molds are safe to eat: True or False?
True! We don’t think this is contentious so we’ll not spend much time on it, but just for the sake of being methodical: foods that are supposed to have mold on, including many kinds of cheese and even some kinds of cured meat (salami is an example; that powdery coating is mold).
We could give a big list of safe and unsafe molds, but that would be a list of names and let’s face it, they don’t introduce themselves by name.
However! The litmus test of “is it safe to eat” is:
Did you acquire it with this mold already in place and exactly as expected and advertised?
- If so, it is safe to eat (unless you have an allergy or such)
- If not, it is almost certainly not safe to eat
(more on why, later)
The “sniff test” is a good way to tell if moldy food is bad: True or False?
False. Very false. Because of how the sense of smell works.
You may feel like smell is a way of knowing about something at a distance, but the only way you can smell something is if particles of it are physically connecting with your olfactory receptors inside you. Yes, that has unfortunate implications about bathroom smells, but for now, let’s keep our attention in the kitchen.
If you sniff a moldy item of food, you will now have its mold spores inside your respiratory system. You absolutely do not want them there.
If we cut off the mold, the rest is safe to eat: True or False?
True or False, depending on what it is:
- Hard vegetables (e.g carrots, cabbage), and hard cheeses (e.g. Gruyère, Gouda) – cut off with an inch margin, and it should be safe
- Soft vegetables (e.g. tomatoes, and any vegetables that were hard but are now soft after cooking) – discard entirely; it is unsafe
- Anything else – discard entirely; it is unsafe
The reason for this is because in the case of the hard products mentioned, the mycelium roots of the mold cannot penetrate far.
In the case of the soft products mentioned, the surface mold is “the tip of the iceberg”, and the mycelium roots, which you will not usually be able to see, will penetrate the rest of it.
“Anything else” seems like quite a sweeping statement, but fruits, soft cheeses, yogurt, liquids, jams and jellies, cooked grains and pasta, meats, and yes, bread, are all things where the roots can penetrate deeply and easily. Regardless of you only being able to see a small amount, the whole thing is probably moldy.
The USDA has a handy downloadable factsheet:
Molds On Food: Are They Dangerous?
Eating a little mold is good for the immune system: True or False?
False, generally. There are of course countless types of mold, but not only are many of them pathogenic (mycotoxins), but also, a food that has mold will usually also have pathogenic bacteria along with the mold.
See for example: Occurrence, Toxicity, and Analysis of Major Mycotoxins in Food
Food poisoning will never make you healthier.
But penicillin is safe to eat: True or False?
False, and also penicillin is not the mold on your bread (or other foods).
Penicillin, an antibiotic* molecule, is produced by some species of Penicillium sp., a mold. There are hundreds of known species of Penicillium sp., and most of them are toxic, usually in multiple ways. Take for example:
Penicillium roqueforti PR toxin gene cluster characterization
*it is also not healthy to consume antibiotics unless it is seriously necessary. Antibiotics will wipe out most of your gut’s “good bacteria”, leaving you vulnerable. People have died from C. diff infections for this reason. So obviously, if you really need to take antibiotics, take them as directed, but if not, don’t.
See also: Four Ways Antibiotics Can Kill You
One last thing…
It may be that someone reading this is thinking “I’ve eaten plenty of mold, and I’m fine”. Or perhaps someone you tell about this will say that.
But there are two reasons this logic is flawed:
- Survivorship bias (like people who smoke and live to 102; we just didn’t hear from the 99.9% of people who smoke and die early)
- Being unaware of illness is not being absent of illness. Anyone who’s had an alarming diagnosis of something that started a while ago will know this, of course. It’s also possible to be “low-level ill” often and get used to it as a baseline for health. It doesn’t mean it’s not harmful for you.
Stay safe!
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