One of the quotes that a professor of mine used to repeat is “Measure what can be measured, and make measurable what cannot be”, attribuited to Galileo Galilei (actually everyone of us in STEM, engineers most of all, are obsessed by data). So, once a dear friend of mine suggested me a book that analyzed data to find better evidence on how our body process food, focused on glucose, I quickly took the book and prioritized it on my huge books list. For several reasons: not only because I trust my friends, but because C6H12O6 (glucose, as you probably guessed after reading the title) was one of the first molecular formulas I learned when I was a passionate little child (and many teachers hated and punished me for wanting to study too much, but that’s another story). The book I’m talking about is “Glucose Revolution – The Life-Changing Power of Balancing Your Blood Sugar” By Jessie Inchauspe, a French biochemist.
Before talking about the book (that I really suggest reading), for those unfamiliar with science: medicine is a cross between “art” (in the sense of craftsmanship) and science: it improves with experience and with empirical tests on various clinical cases, but is strongly based on research in chemistry and biology, as well as using their technical application (together with physics, statistics and other fields) with engineering. That’s because we basically have two ways to understand how our body works; making a parallel with computer science, we can read and try to decode our code (in the DNA) or do what is called “reverse engineering“: dealing with a black box (our body), of which we do not know the functioning of the various parts inside (our organs), we can look for correlations between what is produced on the basis of what we give it as input (nutrition, rest, physical activity, external physical-chemical agents and so on). You may argue that, after 10 years of medical studies, a MD should know everything in the specialization taken, but I can guarantee that (with a few exception involving only really “basics” processes, like mechanical movements of our arms and legs) they can’t explain everything in details. Some mechanisms are still too complex and too “mysterious” for us (specially when describing the brain functions) and for all the others simply we can’t be absolutely 100% of results. Medical doctors are simply doing the best with the limited knowledge we have (limited on scientific research and limited on the data and description a patient can provide). That’s the reason why they operate on “best effort” basis and why they say that treatment are not “one size fits all” (as you can also read on (medical) drugs, not supposed to be shared with your friends).
What the author of this book did was measuring the glucose level based on several observations (scientific method), with a glucose sensor to keep track (monitor and log) of glucose in the blood (the equivalent of inserting a measuring probe inside the box to measure a quantity of an intermediate product, such as for example professional cooks who measure the temperature of a portion of food in the oven). By carrying out various measurements, it is possible to try to draw out correlations between what/how much/when/how we eat (and in what order and combination), physical activity, rest (and other factors) and the level of glucose circulating in our blood.
Put like this, it might seem that this book is aimed at diabetics, but in reality, it is of interest to everyone, regardless of their blood sugar level.
Disclaimer
As expected, the author wrote “I’m a scientist, not a doctor, so remember that none of this is medical advice”. Actually, even if the book was written by dozens of medical doctors it would have been no different: each of us is different and lives in a specific context, hardly a doctor will be able to say with certainty what is good or bad for everyone, except for the usual known generic advice (as also beautifully written in a recent Italian book by Dario Bressanini, “Fa bene o fa male?“, click on the related post to learn more – probably I’ll also translate it in English, it really deserves it). The book consists of 3 parts:
- What is glucose (with a fascinating journey starting with plants);
- Why we should worry about glucose spikes in our body;
- How we can avoid/limit those spikes for a better health (actionable “hacks”).
I can never repeat it enough: without understanding the basics, repeating some remedies can be useless or even counterproductive, you may become like those who take antibiotics when they have a virus – in most cases, only creating problems. That’s why I strongly suggest you to read all the whole book, please don’t skip the first 2 parts (they contains also curious and amazing things to know, by the way).
A philosopher (so let’s say not a “person of science”, strictly speaking), Alan Watts, suggested that “the animal tends to eat with his stomach, and the man with his brain”, so actually he got the point I described in another post: Weight management: no quick useless hacks, but the real hard science into practice! (signals from hindbrain (physical feeling from stomach) + strongest signals from cortico-limbic system (from context, emotions and memories) are mixed together in hypothalamus). What/how/how much we eat creates a reaction involving also some of the estimated 30 trillion bacteria within us (yes, we’re a machine controlled by trillions of tiny organisms, scarying uh? :D). Yes, I know someone would say “we don’t have “time to waste in reading books, just gimme those hacks”, but really you should be aware of at least some of the mechanisms in normal (physiological) and not-so-normal (potentially pathological) cases, in author’s words (and you can also find related papers online):
“When our glucose levels are dysregulated, we experience glucose spikes. During a spike, glucose floods into our body quickly, increasing its concentration in our bloodstream by more than 30 milligrams per deciliter (mg/dl) in the span of about an hour (or less), then decreasing just as quickly. […] Dysregulated glucose levels contribute to aging and to the development of chronic diseases such as acne, eczema, psoriasis, arthritis, cataracts, Alzheimer’s disease, cancer, depression, gut problems, heart disease, infertility, PCOS, insulin resistance, type 2 diabetes, and fatty liver disease.“
In a few words: the flatter our glucose curves, the better. And this is something we should really care, since for example a recent study found that only 12% of Americans are metabolically healthy. The author explained why she started investigating glucose activity in her body, but… I prefer to not spoiler, read it 🙂 One last thing before starting: glucose spike isn’t everything: some foods (and even alcohol) doesn’t cause spikes but are quite bad for us (e.g.: industrial processed red meat and trans fat). Also, it’s not only about food: as previously said in La scienza dello stare bene there are other factors (sleep, exercise, stress, meditation, social connections and many others).
Meet the glucose
Everything starts with plants. A famous song for children (here an amateur English version) took an Italian poem to sing that “to make everything you need a flower”. Plants, in fact, have the ability to transform air (not soil, as someone thought few centuries ago) into matter, combining carbon dioxide (from the air) and water (from the soil, but not actually soil), using the energy of the sun, to make a substance (never seen before plants on the Earth) that it uses to construct every part of itself: this is what we now call glucose. Without glucose, there would be no plants and no life. Calvin won a Nobel Prize since he discovered and described what every child learn at school: the photosynthesis. Plants are the ultimate “makers”: they create their own food. In human terms, it would be like being able to inhale molecules from the air, sit in the sun, and create a gourmand soup inside our stomachs without needing to find it, cook it and swallow it. Once created, plants can use glucose as energy (breaking down it) or use it as a building block. Since plants have same problems we have with some renewable energy sources (main issue is how to store energy when we don’t need it, that’s why someone is trying innovative ways like gravity batteries created by Swiss company Energy Vault), they “invented” a way to store glucose: packing it in long chains called starch (from German stark, meaning “strong”); the work is done by enzymes.
Ther reverse process (obtaining again glucose from starch chains) is done by enzyme alpha-amylase. Other enzymes build another structure with glucose: fibers (useful to build “rigid” structure in the plants). Plants can also transform glucose in fructose (to store in fruits, where also seeds are, so animals will be attracted by fruits and then propagate/spread seeds). Finally, plants create also (you guess it, with another enzyme) sucrose to store energy in even smaller space (sucrose is a molecule widely known as “table sugar”).
Glucose is assembled in:
- starch;
- fibers;
- fructose;
- sucrose (fructose + glucose).
Glucose is the prioritized energy source for plants/animals cells (including humans). We use the same alpha-amylase enzyme to break down starch into glucose; most of the process happens in the gut, but if you chow a piece of bread long enough before swallowing (let’s say for a couple of minutes) you can taste it sweet like sugar 🙂 Same for pasta, pizza, …
Fruits, instead, are immediately sweet since they already have available glucose and fructose (even sweeter) and sucrose (a combined form of the previous two); sucrose is immediately broken down into glucose+fructose by another enzyme, while fructose is (in part) turned back into glucose in our small intestine.
Fiber remains fiber, we don’t have enzymes to break it: useful not for providing energy, but for our health (involved mainly in digestion and in keeping a good microbiome state).
So in a few words: plants create glucose from sunlight, air and water and use it to build starch, sugars and fibers; we can’t produce glucose, so we break it down from food through gluconeogenesis in our liver. When there’s glucose shortage, our body can “burn fat” (nutritional ketosis leveraging metabolic flexibility, as enhanced by some low-carb diets).
Sugars and fibers are part of the family of Carbohydrates (named this way since they have Carbo and Hydrate, so carbon and water). But for the common, average person (not the scientist), fibers are not included in the carbs, so the author decided to not consider fibers in carbs group. Usually in nature sugars and fibers are present together (with different percentage, but at least a small amount of fiber is present); when we consume a lot of sugars and really too few fibers (e.g.: extracting juice from fruits) it can be a problem. Fiber is not often present in processed food for many reasons, but mainly for taste (so we can “distill sweetness” from raw food) and because it’s difficult to preserve food with a lot of fiber for a long time (try to freeze a fruit and then unfreeze it: the structure will be heavily damaged).
Before continuing, it’s worth to remember that we can measure sugar in our body, the most common measure is sugar in the blood, measured at “fasting level”, so after few hours without eating. The higher the number (in mg/l), the worst. Some studies found that after 85mg/l there can be more likelihood to develop health problems.
When we discover a “pre-diabetic” level (range: 100-126) is already too late. In her book, Jessie Inchauspe define “glucose spike” every increase in glucose in our body of more than 30mg/dl. It’s important to limit spikes of glucose in the blood, since years of repeated spikes can increase the base fasting glucose level. Not all spikes are equal: if you get a sweet breakfast with table sugar (sucrose = glucose + fructose), spike is higher/worst than the one made up by starchy food.
Well, but what happens with glucose inside us?
Glucose’s primary biological purpose in a cell is, combined with oxygen, to provide energy: mitochondria are the responsible microscopic organelles for this transformation. So far, everything good; but, when the glucose accumulate way too much, compared to the mitochondria speed and to the quantity needed by the cell, it can create issues in the normal functioning: glucose spike = too much velocity (speed) of delivered glucose. According to the Allostatic Load Model, mitochondria struggling with this glucose overload create (from glucose in excess) free radicals and fat. Free radicals lead to possible DNA mutation, activation of harmful genes and eventual cancer development; when the free radicals are “too much” to be neutralized, body is considered in a state of “oxydative stress” (leading to heart disease, type 2 diabete, congnitive decline, general aging and more) – fructose is even worst than glucose. Our body is actually “browning” exactly like biscuits or meat during the Maillard reaction: the molecules will be “glycated” (and damaged), it’s part of aging, but we can slow the process. As just wrote: fructose is worst than glucose (it glycates 10x faster) and once a molecule of our body is glycated, you can “un-toast” it, it will remain damaged, no way (so far) to revert effects like wrinkles, cataracts, Alzheimer’s disease. There’s a way to measure how much we are browning: HbA1c (hemoglobin A1c) test: the higher the level, the more glucose is circulating, the more the chronic inflammation and the more we are aging. Glucose excess, combined with alcohol, smoking, stress, substances released by body fat and many other factors, is the reason why 3 out of 5 people will die of an inflammation-based disease.
The body tries its best to reduce glucose circulation: pancreas sends a hormone called insulin to stash excess glucose in storage units (people that can’t produce insuline, like in type 1 diabet, must inject it to survive). Store, but where? First storage is the liver, where glucose become glycogen (like plants transform glucose in starch), so it will not harm our body (no oxydative stress, no glycation), but in a normal person it can store approx. 100g of glucose. Second storage units are muscles, in a healthy average person they can store up to 400g. The eventually remaining glucose will be transofrmed in fat. Where is the fat? Firstly, in the liver (leading to nonalcoholic fatty liver disease), then in fat cells everywhere (hips, thighs, face and between organs… so we get fat) and in the blood (the famous LDL, low-density lipoprotein or “bad cholesterol). Too much glucose will call too much insulin and too much (chronic) insulin is the root cause of many problems like type 2 diabete. It’s extremely difficult to burn fat when insulin level is high.
So, in the short term: usually people, when facing a glucose spike (and consequent dip) face different symptoms like dizziness, nausea, heart palpitation, sweats, food cravings, stress, brain fog and many others. The constant hunger is another effect linked to high insulin level: leptin (hormone signalling we’re full) is blocked and ghrelin (hormone signalling we are hungry) takes over. And if we’re reaching junk food, more spikes, so we get trapped in a vicious cycle; so, please, avoid “energetic food”, they usually do the opposite, embrace the counter-intuitive mindset that actually it’s opposite: more probably, when we feel tired, we need less food; also, glucose spikes can impair memory and cognitive function. And (as I think everyone knows) avoid glucose spikes also before sleeping.
In the long term: skin conditions (avoiding glucose spikes can be a more effective solution compared to abundance of expensive local skin lotions), overall aging, arthritis, Alzheimer’s and dementia, increase cancer risk, depressive episodes, gut issues, heart diseases (that can be measured with triglycerides-to-HDL ratio for LDL pattern B levels and C-reactive protein for inflammation levels), infertility, type 2 diabete, wrinkles, cataracts, and nonalcoholic fatty liver (same of what is obvserved in alcoholic, but cause of fat here is fructose rather than alcohol; so common that 70% over overweight people has it, leading to liver failure and cancer). Hope now you’re scared enough, how I was when I started researching on impact of food and sleep on our health. You can see a lot of posts I wrote about these topics.
Scaring, OK. But what we can do?
Remembering that we are a complex system (so don’t focus just on the glucose, as the author does), let’s start with the tips: it’s not only what we eat, but also how we eat. Talking about the order, forget about what you learned as a child. The “right order” is: Fiber; Protein and fat; Starches and sugar (including fruit). So, it turned out that the order followed in mediterranean countries (pasta/pane, meat/fish and salad it’s not “the right one”).
Add fiber before anything else, since: reduces the action of alpha-amylase (the enzyme that breaks starches down into glucose); slows down the gastric emptying; creates a viscous mesh in the small intestine, making harder for glucose to go into the bloodstream. In a few words: fiber helps in making absorption slower. It affects also the levels of ghrelin (the “hunger” hormone): after eating in a correct order, ghrelin stays suppresed for much longer (compared to the approx. 2h measured when people eat “normally”).
The amount of fiber (recommended by USDA) should be more or less 14g per 1.000 Kcal of food, but fiber is almost disappearing, due mostly to the food processing. We can choose however dark dense bread (the classic German one), wholemeal pasta and so on; plus: add salad, yes, we’re not talking about replacing something else, but simply adding salad to the meal. Ideally, try to eat the same quantity of salad as the starches that follow. When you know you’re going to a place with friends that don’t order salad, you can eat it before going out. Remember that calories are not all the same, exactly like a studio album of 1h by the british rock band Queen is not the same of an album of 1h by Justin Bieber; like in the example, some molecules con heal our body, others can harm (we are what we eat). If we follow the right order, we can even add (slightly) more calories, as long as we mantain the glucose curve flat; same is for the opposite: if we take less calories, but mainly sugar and before all the rest, it can be worst than eating more.
Starting with breakfast, one of the most common habit is to eat cereals (one of the most popular ones in US is Honey Nut Cheerios, which contains 3 times as much sugar as the cereal used in a Standford study that proves that eating cereals lead to a pre-diabetic or even diabetic spike levels). So, if you care about your health, you should consider to replace sugars with something like eggs, bresaola, salmon, goat cheese, olive oil and any vegetable you like. Prefer whole fruit instead of fruit juice and remember that sugar is sugar, regardless of the main source, including honey (a concept well explained in book by italian chemist Dario Bressanini “Fa bene o fa male?”); in Nassim Taleb’s “Antifragile” words: there’s a reason if fruit in nature comes to us packed in this way, with fiber. In any other form, you can think of fruit as a dessert, just as a piece of cake (well, a cake without strange/processed ingredients).
Some artificial sweeteners produce same effects of sugar, others are bad, for others we still don’t know much, but so far it seems that (pure extract of) Stevia can be recommended as a substitute; better stay out from aspartame, maltitol, sucralose, xylitol and acesulfame-K. Of course, soda is the same as food: strongly consider to avoid it.
Another popular belief to disrupt is “eating 5 or 6 small meals a day”; actually, it’s proved that periods of intermittent fasting (that’s it: up to 16h from one meal until the next one) are beneficial for us, for many many aspects (I won’t write it here, but it’s considered also key for healthy longevity); so, eat slightly larger/filling meals and, if you want something sweet, much better at the end of a large meal, instead of a “stand alone” snack.
Anyway, if you really can’t resist a snack, at least try it savory (greek yogurt, nuts, cheese).
Another tip suggested by the author is to drink water and vinegar a few minutes before eating a large meal (specially if there are desserts), the most popular among participants in her community is apple cider vinegar. Acetic acid in vinegar temporaly inactivates alpha-amylase and activate muscle (making them produce glycogen faster, so “absorbing” glucose faster). As every substance, of course there’s a limit in vinegar (don’t drink 16 tablespoons of vinegar per day…).
After eating, move. The concept here is straightforward: the more and the harder a muscle is told to contract (consciously or not), the more energy it needs (technically: the more ATP, adenosine triphosphate, they need), up to 1.000x compared with sitting on a couch. There’s no urge to quickly run just after the last bite, it’s fine up to 1h after. Same benefits making exercise up to 30min before eating.
Last tip: instead of eating carbs alone, add something (fiber, protein, but it can be also fat: eating fat before carb-rich meal can decrease the amount of insulin produced).
Then, the author concludes with few other small tips, like better drink wine than beer (and better ale and lager instead of stout and porter) and stay clear of chips. Try to resist 20min your urge to eat a snack and consider to add it as a dessert in your next meal. Don’t be fooled about labels: doesn’t matter if gluten-free, vegan, organic, bio or whatever: same general rules apply. Never go shopping hungry. And the last chapter is about her daily eating routine, to provide examples and inspirations.
Hoping that nobody will directly jump to this image (really, if you are reading this, be sure you read also what I wrote before!), here’s a recap of the “tips” to limit glucose spikes:
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