Later On

A blog written for those whose interests more or less match mine.

Archive for December 4th, 2019

The Humanoid Stain: Art lessons from our cave-dwelling ancestors

leave a comment »

Barbara Ehrenreich, who wrote Natural Causes: An Epidemic of Wellness, the Certainty of Dying, and Killing Ourselves to Live Longer and her memoir is Living with a Wild God, writes in The Baffler:

IN 1940, FOUR TEENAGE BOYS stumbled, almost literally, from German-occupied France into the Paleolithic Age. As the story goes, and there are many versions of it, they had been taking a walk in the woods near the town of Montignac when the dog accompanying them suddenly disappeared. A quick search revealed that their animal companion had fallen into a hole in the ground, so—in the spirit of Tintin, with whom they were probably familiar—the boys made the perilous fifty-foot descent down to find it. They found the dog and much more, especially on return visits illuminated with paraffin lamps. The hole led to a cave, the walls and ceilings of which were covered with brightly colored paintings of animals unknown to the twentieth-century Dordogne—bison, aurochs, and lions. One of the boys, an apprentice mechanic, later reported that, stunned and elated, they began to dart around the cave like “a band of savages doing a war dance.” Another recalled that the painted animals in the flickering light of the boys’ lamps also seemed to be moving. “We were completely crazy,” yet another said, although the build-up of carbon dioxide in a poorly ventilated cave may have had something to do with that.

This was the famous and touristically magnetic Lascaux cave, which eventually had to be closed to visitors lest their exhalations spoil the artwork. Today, almost a century later, we know that Lascaux is part of a global phenomenon, originally referred to as “decorated caves.” They have been found on every continent except Antarctica—at least 350 of them in Europe alone, thanks to the cave-rich Pyrenees—with the most recent discoveries in Borneo (2018) and the Balkans (April 2019). Uncannily, given the distances that separate them, all these caves are adorned with similar “decorations”: handprints or stencils of human hands, abstract designs containing dots and crosshatched lines, and large animals, both carnivores and herbivores, most of them now extinct. Not all of these images appear in each of the decorated caves—some feature only handprints or megafauna. Scholars of paleoarcheology infer that the paintings were made by our distant ancestors, although the caves contain no depictions of humans doing any kind of painting.

There are human-like creatures, though, or what some archeologists cautiously call “humanoids,” referring to the bipedal stick figures that can sometimes be found on the margins of the panels containing animal shapes. The nonhuman animals are painted with almost supernatural attention to facial and muscular detail, but, no doubt to the disappointment of tourists, the humanoids painted on cave walls have no faces.

This struck me with unexpected force, no doubt because of my own particular historical situation almost twenty thousand years after the creation of the cave art in question. In about 2002 we had entered the age of “selfies,” in which everyone seemed fascinated by their electronic self-portraits—clothed or unclothed, made-up or natural, partying or pensive—and determined to propagate them as widely as possible. Then in 2016 America acquired a president of whom the kindest thing that can be said is that he is a narcissist. This is a sloppily defined psychological condition, I admit, but fitting for a man so infatuated with his own image that he decorated his golf clubs with fake Time magazine covers featuring himself. On top of all this, we have been served an eviction notice from our own planet: the polar regions are turning into melt-water. The residents of the southern hemisphere are pouring northward toward climates more hospitable to crops. In July, the temperature in Paris reached a record-breaking 108.7 degrees Fahrenheit.

You could say that my sudden obsession with cave art was a pallid version of the boys’ descent from Nazi-dominated France into the Lascaux cave. Articles in the New York Times urged distressed readers to take refuge in “self-care” measures like meditation, nature walks, and massages, but none of that appealed to me. Instead, I took intermittent breaks from what we presumed to call “the Resistance” by throwing myself down the rabbit hole of paleoarcheological scholarship. In my case, it was not only a matter of escape. I found myself exhilarated by our comparatively ego-free ancestors who went to great lengths, and depths, to create some of the world’s most breathtaking art—and didn’t even bother to sign their names.

Auroch Bites Man

Cave art had a profound effect on its twentieth-century viewers, including the young discoverers of Lascaux, at least one of whom camped at the hole leading to the cave over the winter of 1940–41 to protect it from vandals and perhaps Germans. More illustrious visitors had similar reactions. In 1928, the artist and critic Amédée Ozenfant wrote of the art in the Les Eyzies caves, “Ah, those hands! Those silhouettes of hands, spread out and stenciled on an ochre ground! Go and see them. I promise you the most intense emotion you have ever experienced.” He credited the Paleolithic artists with inspiring modern art, and to a certain degree they did. Jackson Pollock honored them by leaving handprints along the top edge of at least two of his paintings. Pablo Picasso reportedly visited the famous Altamira cave before fleeing Spain in 1934, and emerged saying “Beyond Altamira, all is decadence.”

Of course, cave art also inspired the question raised by all truly arresting artistic productions: “But what does it mean?” Who was its intended audience and what were they supposed to derive from it? The boy discoverers of Lascaux took their questions to one of their schoolmasters, who roped in Henri Breuil, a priest familiar enough with all things prehistoric to be known as “the pope of prehistory.” Unsurprisingly, he offered a “magico-religious” interpretation, with the prefix “magico” serving as a slur to distinguish Paleolithic beliefs, whatever they may have been, from the reigning monotheism of the modern world. More practically, he proposed that the painted animals were meant to magically attract the actual animals they represented, the better for humans to hunt and eat them.

Unfortunately for this theory, it turns out that the animals on cave walls were not the kinds that the artists usually dined on. The creators of the Lascaux art, for example, ate reindeer, not the much more formidable herbivores pictured in the cave, which would have been difficult for humans armed with flint-tipped spears to bring down without being trampled. Today, many scholars answer the question of meaning with what amounts to a shrug: “We may never know.”

If sheer curiosity, of the kind that drove the Lascaux discoverers, isn’t enough to motivate a search for better answers, there is a moral parable reaching out to us from the cave at Lascaux. Shortly after its discovery, the one Jewish boy in the group was apprehended and sent, along with his parents, to a detention center that served as a stop on the way to Buchenwald. Miraculously, he was rescued by the French Red Cross, emerging from captivity as perhaps the only person on earth who had witnessed both the hellscape of twentieth-century Fascism and the artistic remnants of the Paleolithic age. The latter offered no glimpse of an earthly paradise such as modern keto-drunk paleophiles like to imagine, in which our distant ancestors lounged around making up dance tunes and gnawing on ungulate bones. As we know from the archeological record, it was a time of relative peace among humans. No doubt there were homicides and tensions between and within human bands, but it would be at least another ten thousand years before the invention of war as an organized collective activity. The cave art suggests that humans once had better ways to spend their time.

If they were humans; and the worldwide gallery of known cave art offers so few stick figures or bipeds of any kind that we cannot be entirely sure. If the Paleolithic cave painters could create such perfectly naturalistic animals, why not give us a glimpse of the painters themselves? Almost as strange as the absence of human images in caves is the low level of scientific interest in their absence. In his book What Is Paleolithic Art?, the world-class paleoarcheologist Jean Clottes devotes only a couple of pages to the issue, concluding that: “The essential role played by animals evidently explains the small number of representations of human beings. In the Paleolithic world, humans were not at the center of the stage.” A paper published, oddly enough, by the Centers for Disease Control and Prevention, expresses puzzlement over the omission of naturalistic depictions of humans, attributing it to Paleolithic people’s “inexplicable fascination with wildlife” (not that there were any non-wild animals around at the time).

The marginality of human figures in cave paintings suggests that, at least from a human point of view, the central drama of the Paleolithic went on between the various megafauna—carnivores and large herbivores. So depleted is our own world of megafauna that it is hard to imagine how thick on the ground large mammals once were. Even the herbivores could be dangerous for humans, if mythology offers any clues: think of the buffalo demon killed by the Hindu goddess Durga, or of the Cretan half-man, half-bull Minotaur who could only be subdued by confining him to a labyrinth, which was, incidentally, a kind of cave. Just as potentially edible herbivores like aurochs (giant, now-extinct cattle) could be dangerous, death-dealing carnivores could be inadvertently helpful to humans and their human-like kin, for example, by leaving their half-devoured prey behind for humans to finish off. The Paleolithic landscape offered a lot of large animals to watch and plenty of reasons to keep a close eye on them. Some could be eaten—after, for example, being corralled into a trap by a band of humans; many others would readily eat humans.

Yet despite the tricky and life-threatening relationship between Paleolithic humans and the megafauna that comprised so much of their environment, twentieth-century scholars tended to claim cave art as evidence of an unalloyed triumph for our species. It was a “great spiritual symbol,” one famed art historian, himself an escapee from Nazism, proclaimed, of a time when “man had just emerged from a purely zoological existence, when instead of being dominated by animals, he began to dominate them.” But the stick figures found in caves like Lascaux and Chauvet do not radiate triumph. By the standards of our own time, they are excessively self-effacing and, compared to the animals portrayed around them, pathetically weak. If these faceless creatures were actually grinning in triumph, we would of course have no way of knowing it.


We are left with one tenuous clue as to the cave artists’ sense of their status in the Paleolithic universe. While twentieth-century archeologists tended to solemnize prehistoric art as “magico-religious” or “shamanic,” today’s more secular viewers sometimes detect a vein of sheer silliness. For example, shifting to another time and painting surface, India’s Mesolithic rock art portrays few human stick figures; those that are portrayed have been described by modern viewers as “comical,” “animalized” and “grotesque.” Or consider the famed “birdman” image at Lascaux, in which a stick figure with a long skinny erection falls backwards at the approach of a bison. As Joseph Campbell described it, operating from within the magico-religious paradigm:

a large bison bull, eviscerated by a spear that has transfixed its anus and emerged through its sexual organ, stands before a prostrate man. The latter (the only crudely drawn figure, and the only human figure in the cave) is rapt in a shamanistic trance. He wears a bird mask; his phallus, erect, is pointing at the pierced bull; a throwing stick lies on the ground at his feet; and beside him stands a wand or staff, bearing on its tip the image of a bird. And then, behind this prostrate shaman, is a large rhinoceros, apparently defecating as it walks away.

Take out the words “shaman” and “shamanistic” and you have a description of a crude—very crude—interaction of a humanoid with two much larger and more powerful animals. Is he, the humanoid, in a trance or just momentarily overcome by the strength and beauty of the other animals? And what qualifies him as a shaman anyway—the bird motif, which paleoanthropologists, drawing on studies of extant Siberian cultures, automatically associated with shamanism? Similarly, . . .

Continue reading.

Written by LeisureGuy

4 December 2019 at 3:26 pm

Posted in Art, Daily life, Science

How the Gut Microbiome Helps Regulate Blood Pressure

leave a comment »

The gut microbiome seems to play a much bigger role in our health than we realize, and it is nourished by dietary fiber. The percentage of American men age 18-50 who consume the minimum recommended daily amount of dietary fiber: 0%. Zip. Nada. Bupkis. That means the number is less than 0.5%. That’s pitiful. One of the (many) good things about a whole-food plant-based diet is that whole plant foods provide lots of dietary fiber. I average about 55g-60g per day. Meat, dairy, and eggs have zero fiber, and most refined/processed foods have little or no fiber (but plenty of salt and refined sugar).

The national fiber recommendations are (for ages 18-50) 38 grams a day for men and 25 grams a day for women, and (for ages 51 and older) 30 grams a day for men and 21 grams a day for women. Another general guideline is to get 14 grams of fiber for every 1,000 calories in your diet. – See this article.

Veronique Greenwood writes in Quanta:

Some years ago, when Jennifer Pluznick was nearing the end of her training in physiology and sensory systems, she was startled to discover something in the kidneys that seemed weirdly out of place. It was a smell receptor, a protein that would have looked more at home in the nose. Given that the kidneys filter waste into urine and maintain the right salt content in the blood, it was hard to see how a smell receptor could be useful there. Yet as she delved deeper into what the smell receptor was doing, Pluznick came to a surprising conclusion: The kidney receives messages from the gut microbiome, the symbiotic bacteria that live in the intestines.

In the past few years, Pluznick, who is now an associate professor of physiology at Johns Hopkins University, and a small band of like-minded researchers have put together a picture of what the denizens of the gut are telling the kidney. They have found that these communiqués affect blood pressure, such that if the microbes are destroyed, the host suffers. The researchers have uncovered a direct, molecular-level explanation of how the microbiome conspires with the kidneys and the blood vessels to manipulate the flow of blood.

The smell receptor, called Olfr78, was an orphan at first: It had previously been noticed in the sensory tissues of the nose, but no one knew what specific scent or chemical messenger it responded to. Pluznick began by testing various chemical possibilities and eventually narrowed down the candidates to acetate and propionate. These short-chain fatty acid molecules come from the fermentation breakdown of long chains of carbohydrates — what nutritionists call dietary fiber. Humans, mice, rats and other animals cannot digest fiber, but the bacteria that live in their guts can.

As a result, more than 99 percent of the acetate and propionate that floats through the bloodstream is released by bacteria as they feed. “Any host contribution is really minimal,” Pluznick said. Bacteria are therefore the only meaningful source of what activates Olfr78 — which, further experiments showed, is involved in the regulation of blood pressure.

Our bodies must maintain a delicate balance with blood pressure, as with electricity surging through a wire, where too much means an explosion and too little means a power outage. If blood pressure is too low, an organism loses consciousness; if it’s too high, the strain on the heart and blood vessels can be deadly. Because creatures are constantly flooding their blood with nutrients and chemical signals that alter the balance, the control must be dynamic. One of the ways the body exerts this control is with a hormone called renin, which makes blood vessels narrower when the pressure needs to be kept up. Olfr78, Pluznick and her colleagues discovered, helps drive the production of renin.

How did a smell receptor inherit this job? The genes for smell receptors are present in almost every cell of the body. If in the course of evolution these chemical sensors hooked up to the machinery for manufacturing a hormone rather than to a smell neuron, and if that connection proved useful, evolution would have preserved the arrangement, even in parts of the body as far from the nose as the kidneys are.

Olfr78 wasn’t the end of the story, however. While the team was performing these experiments, they realized that another receptor called Gpr41 was getting signals from the gut microbiome as well. In a paper last year, Pluznick’s first graduate student, Niranjana Natarajan, now a postdoctoral fellow at Harvard University, revealed the role of Gpr41, which she found on the inner walls of blood vessels. Like Olfr78, Gpr41 is known to respond to acetate and propionate — but it lowers blood pressure rather than raising it. Moreover, Gpr41 starts to respond at low levels of acetate and propionate, while Olfr78 kicks in only at higher levels.

Here’s how the pieces fit together: When you — or a mouse, or any other host organism whose organs and microbes talk this way — have a meal and dietary fiber hits the gut, bacteria feed and release their fatty-acid signal. This activates Gpr41, which ratchets down the blood pressure as all the consumed nutrients flood the circulation.

If you keep eating — a slice of pie at Thanksgiving dinner, another helping of mashed potatoes — Gpr41, left to itself, might bring the pressure down to dangerous levels. “We think that is where Olfr78 comes in,” Pluznick said. That receptor, triggered as the next surge of fatty acids arrives, keeps blood pressure from bottoming out by calling for renin to constrict the blood vessels.

The new understanding of how symbiotic bacteria manipulate blood pressure is emblematic of wider progress in linking the microbiome to our vital statistics and health. While vague statements about the microbiome’s effect on health have become commonplace in recent years, the field has moved beyond simply making associations, said Jack Gilbert, a microbiome researcher at the University of Chicago.

“Everybody goes on about the promise,” he said. But in fact, studies full of mechanistic details, like the ones Pluznick, her collaborators and other researchers have published, have been growing more and more numerous.

In June of last year, the National Institutes of Health convened a working group on the microbiome’s control of blood pressure. Researchers met in Maryland to thrash out what important questions still need to be answered, including what role the host’s genetic background plays — whether, for instance, the microbiome matters more for some hosts than for others.

“There’s a lot of excitement [about] getting more data,” said Bina Joe, a professor of physiological genomics and the director of the Center for Hypertension and Personalized Medicine at the University of Toledo. If you look at PubMed, she continued, there are more reviews of the microbiome literature than research papers. The review articles get new researchers interested — but there are still more details to hammer out.

Understanding those details is key to knowing whether transplanting a certain set of microbes into someone can reshape the recipient’s biology enough to cure a health problem, as some proponents of personalized medicine hope. One famous early study showed that . . .

Continue reading.

Written by LeisureGuy

4 December 2019 at 2:46 pm

Posted in Daily life, Food, Health, Science

How the Gut Microbiome Affects Fear

leave a comment »

Elena Renken writes in Quanta:

Our brains may seem physically far removed from our guts, but in recent years, research has strongly suggested that the vast communities of microbes concentrated in our digestive tract open lines of communication between the two. The intestinal microbiome has been shown to influence cognition and emotion, affecting moods and the state of psychiatric disorders, and even information processing. But how it could do so has been elusive.

Until recently, studies of the gut-brain relationship have mostly shown only correlations between the state of the microbiome and operations in the brain. But new findings are digging deeper, building on research that demonstrates the microbiome’s involvement in responses to stress. Focusing on fear, and specifically on how fear fades over time, researchers have now tracked how behavior differs in mice with diminished microbiomes. They identified differences in cell wiring, brain activity and gene expression, and they pinpointed a brief window after birth when restoring the microbiome could still prevent the adult behavioral deficits. They even tracked four particular compounds that may help to account for these changes. While it may be too early to predict what therapies could arise once we understand this relationship between the microbiome and the brain, these concrete differences substantiate the theory that the two systems are deeply entwined.

Pinning down these mechanisms of interaction with the brain is a central challenge in microbiome research, said Christopher Lowry, an associate professor of integrative physiology at the University of Colorado, Boulder. “They have some tantalizing leads,” he added.

Coco Chu, the new study’s lead author and a postdoctoral associate at Weill Cornell Medicine, was intrigued by the concept that microbes inhabiting our bodies could affect both our feelings and our actions. Several years ago, she set out to examine these interactions in fine-grained detail with the help of psychiatrists, microbiologists, immunologists and scientists from other fields.

The researchers performed classical behavioral training on mice, some of which had been given antibiotics to dramatically diminish their microbiomes and some of which had been raised in isolation so that they had no microbiome at all. All the mice learned equally well to fear the sound of a tone that was followed by an electric shock. When the scientists discontinued the shocks, the ordinary mice gradually learned not to fear the sound. But in the mice with depleted or nonexistent microbiomes, the fear persisted — they remained more likely to freeze at the sound of the tone than the untreated mice did.

Peering inside the medial prefrontal cortex, an area of the outer brain that processes fear responses, the researchers noticed distinct differences in the mice with impoverished microbiomes: Some genes were expressed less. One type of glial cell never developed properly. Spiny protrusions on the neurons associated with learning grew less plentifully and were eliminated more often. One type of cell showed lower levels of neural activity. It’s as if the mice without healthy microbiomes couldn’t learn to be unafraid, and the researchers could see it on a cellular level.

The researchers also set out to learn how the condition of the microbiome in the gut caused these changes. One possibility was that microbes send signals to the brain through the long vagus nerve, which carries sensations from the digestive tract to the brain stem. But snipping the vagus didn’t alter the behavior of the mice. It also seemed possible that the microbiomes might stir up responses in the immune system that affect the brain, but the numbers and proportions of immune cells in all the mice were similar.

But the researchers did pinpoint four metabolic compounds with neurological effects that were far less common in the blood serum, cerebrospinal fluid and stool of the mice with impaired microbiomes. Some of the compounds were already linked to neurological disorders in humans. The team speculated that the microbiome might produce certain substances in abundance, with some molecules making their way into the brain, according to the microbiologist David Artis, the director of the Jill Roberts Institute for Research in Inflammatory Bowel Disease at Weill Cornell Medicine and the senior author on the study.

In many laboratories, there’s a growing interest in tracking specific bacterial substances that are involved in nervous system signaling, said Melanie Gareau, an associate professor of anatomy, physiology and cell biology at the University of California, Davis. Numerous metabolites and pathways are probably involved in such processes.

Research on other disorders like depression has also pointed to the involvement of particular compounds created by microbes, but there’s still no consensus on which ones contribute to any condition, said Emeran Mayer, a professor of medicine and director of the G. Oppenheimer Center for Neurobiology of Stress and Resilience at the University of California, Los Angeles. And although the intestinal microbiome is clearly altered in many people with brain conditions, it’s often unclear if that change is a cause or an effect, he said. Differences in the microbiome might give rise to neurological problems, but the conditions could also change the microbiome.

There’s disagreement within the field not just about the consequences of diseased microbiomes, but also about healthy ones. “For a long time, we’ve been focused on this idea that we could identify specific types of bacteria that provide either risk or resilience to stress-related disorders, and it may be that it doesn’t have to be a particular microbe,” Lowry said. Even in healthy people, microbiomes vary widely. Particular microbes might not matter if a microbiome has enough diversity — just as there are many kinds of thriving forests, and one individual type of tree may not be necessary.

Still, the study of microbial effects on the nervous system is a young field, and there is even uncertainty around what the effects are. Previous experiments reached inconsistent or contradictory conclusions about whether microbiome changes helped animals to unlearn fear responses. What gives extra weight to the findings from Chu and her colleagues is that they can point to evidence for a specific mechanism causing the behavior they observed. Animal studies like this one are especially helpful in cementing a clear connection between the nervous system and the microbiome, even if they don’t point to treatments for humans, said Kirsten Tillisch, a professor of medicine at the David Geffen School of Medicine at UCLA. “The way that humans process emotion, physical sensation and cognition in the brain is just so different than in animals that it’s just very difficult to translate,” she said.

In theory, the presence of certain microbial substances might help predict who is most vulnerable to disorders like post-traumatic stress disorder. Experiments like these could even identify pathways of communication between the brain and the microbiome that could be targeted by treatments. “That’s always the big hope from these mouse experiments, that we’re getting close to interventions,” Mayer said, and the studies often generate striking results through rigorous methods. But the operations of the human brain aren’t fully reflected in mice. Moreover, the interactions of the brain and the gut microbiome differ in humans and mice, and diet-driven differences between their respective microbiomes add to the disparity.

For humans, interventions targeting the microbiome might be most effective in infancy and childhood, when the microbiome is still developing and early programming takes place in the brain, Mayer said. In this new research, the scientists saw a specific window of time in infancy when mice needed a typical microbiome to extinguish fear normally when they grew up. . .

Continue reading.

Written by LeisureGuy

4 December 2019 at 2:37 pm

Posted in Daily life, Food, Health, Science

The other Prince, with The Holy Black SR-71 slant

with one comment

This is a two-band knot and much more resilient than the Prince from day before yesterday.. Still a very pleasant knot, but a very different feel. The lather from the pre-reformulation and pre-outsourced Geo. F. Trumper Sandalwood shaving soap was extremely nice, and The Holy Black slant did an excellent job. It’s basically a Merkur 37BH (Black, Hefty). The hand is thick brass (hollow because it’s a two-piece razor, but with thick walls) and feels substantial in the hand.

A splash of Saint Charles Shave Sandalwood Extract EDT as the aftershave, and the day begins anew.

Written by LeisureGuy

4 December 2019 at 10:30 am

Posted in Shaving

Time-restricted eating has been found to work

with 6 comments

I’m trying this starting today: I’ll continue my current diet, but only in the four-hour window from 10:00am to 2:00pm. Update: So far it’s working fine. See notes below.

And here’s the follow-up:

See also “Effects of Intermittent Fasting on Health, Aging, and Disease” (PDF) from the New England Journal of Medicine. From the article:

Studies in animals and humans have shown that many of the health benefits of intermittent fasting are not simply the result of reduced free-radical production or weight loss. Instead, intermittent fasting elicits evolutionarily conserved, adaptive cellular responses that are integrated between and within organs in a manner that improves glucose regulation, increases stress resistance, and suppresses inflammation. During fasting, cells activate pathways that enhance intrinsic defenses against oxidative and metabolic stress and those that remove or repair damaged molecules. During the feeding period, cells engage in tissue-specific processes of growth and plasticity. However, most people consume three meals a day plus snacks, so intermittent fasting does not occur.

Preclinical studies consistently show the robust disease-modifying efficacy of intermittent fasting in animal models on a wide range of chronic disorders, including obesity, diabetes, cardiovascular disease, cancers, and neurodegenerative brain diseases. Periodic flipping of the metabolic switch not only provides the ketones that are necessary to fuel cells during the fasting period but also elicits highly orchestrated systemic and cellular responses that carry over into the fed state to bolster mental and physical performance, as well as disease resistance. [emphasis added – LG]

UPDATE: The morning after my second day of eating in a 4-hour window, my fasting blood glucose was 5.4 mmol/L (“normal”), and I had  lost 1.1 pounds.

I never felt hungry in limiting eating to the 4-hour window. I did notice that I have an eating habit: when I walk through the kitchen, I look for some food to put into my mouth. When I stifled the impulse, I could tell it was habit rather than hunger — just being in the kitchen made me look for something to eat. The impulse by now (10 days after starting the 4-hour window practice) has been pretty much extinguished.

I received an email from a friend, asking whether (since I have type 2 diabetes) eating only in a 4-hour window would trigger hypoglycemia (low blood sugar, causing what medical professionals refer to as “wooziness,” and sometimes also the shakes).

Because I follow a whole-food plant-based diet, I don’t eat any quickly digested foods — that is, I eat no refined foods (no refined sugar or foods that contain it, no foods made from flour, no grain other than intact whole grain) and no “product foods,” manufactured using industrial processes from refined ingredients and sold packaged under a brand name.

Because I eat only whole plant-based foods, my diet naturally contains a good amount of dietary fiber (around 60g/day) — and not as a dietary supplement but in whole foods (fresh fruit, dried beans and lentils, intact whole grain, vegetables, and nuts). I suspect that it’s the fiber that helps extend satiation and prevents hypoglycemia by causing a slow and steady blood glucose level. Plus, of course, whole foods are digested more slowly than refined foods.

I am familiar with hypoglycemia and how it feels, and indeed I keep some glucose tablets around (somewhere) but haven’t needed them for years. The times I suffered from hypoglycemia were when I was still regularly eating refined and processed foods — a bad idea for anyone.

I bet that if I still ate refined/processed food and ate only within a 4-hour window I would indeed experience hypoglycemia because the food would be more quickly digested, lacking ballast (as it were). And I bet I would be ravenous by bedtime. This brief video explains why refined foods quickly leave you hungry:

And to some extent refined/processed foods quickly leave you hungry again because that is what they are designed to do. The manufacturer isn’t making money if you not consuming the product. Note this: “Study Finds Ultra-Processed Foods Drive Weight Gain”  — such foods drive weight gain because they are not satisfying for very long, thus you are driven to eat more, a boon to the manufacturer.

It’s 9:40am as I write this so I’ve had no food for 19 hr 40 min, and while I feel mildly peckish, I have no signs whatsoever of hypoglycemia —  and I don’t feel  ravenous at all. I am just hungry enough that eating in another 20 minutes is a pleasant prospect, but it doesn’t feel urgent or life-saving.

UPDATE: The mechanism by which dietary fiber (including resistant starch) stifles hunger—the ileal brake—is explained in this post. /update

A side note: It’s pleasant that, having now been on this whole-food plant-based diet for 7 months, I can prepare a meal on the fly without giving it much thought. The learning has been assimilated and internalized at this point.

I figured out one reason I like this 4-hour-window approach. First, though, note that a 10-hour window also works. But a 4-hour window has the advantage that I don’t have to fool with food after 2:00pm until the next day. (And being able to skip breakfast and dinner food preparation and dishes and clean-up gives me much more free time in the mornings and evenings.)

What I like is that it’s simple: don’t eat except between 10:00am and 2:00pm (the 4-hour window I picked— I talked to someone else who chose 11:00am to 3:00pm). No judgment call required: if it’s food, and if the time is not between 10:00 and 2:00, it doesn’t go into my mouth.

It’s the same appeal that the simplicity of a whole-food plant-based diet has for me: if the food is meat, dairy, eggs, or refined/processed, I don’t eat it. No need to figure out exactly what “in moderation” means in each particular instance. (Is eating one egg “moderate”? How about two? Three-egg omelets are pretty common — how about a three-egg omelet without the sides? Is that “in moderation”? And so on.)

It’s much easier just not to eat any. That’s simple, and the clarity and ease of making the decision (to eat or not to eat) appeals to me. (In the case of the WFPB diet, it obviously helps a lot that the foods I do eat have tremendous variety and taste good and are filling and satisfying.)

Written by LeisureGuy

4 December 2019 at 8:44 am

Posted in Daily life, Food, Health, Science

%d bloggers like this: