How High Is Your Glucose Spike?

🔗In this Nexus:

📊 Normal Glucose Levels

🩸 Glycated Hemoglobin

📈 What Are Glucose Spikes?

📉 Recognising a glucose spike

🧬 Glucose Spikes, Inflammation and Longevity

⚙️ What is Continuous Glucose Monitoring?

💁♀️ My Personal Experience with CGM

‼️ Precautions When Using CGM

💡 10 Tips How to Control Your Glucose Spikes

📗 Book recommendation

Back to writing, back to longevity. After an intense travel period and a good log off during the holiday period, I am once again back to my Nexus Newsletter. This time I want to discuss something that was initially designed for people with diabetes, and now becomes more and more popular among healthy individuals – continuous glucose monitoring (CGM). And of course, I had to try it myself in order to share my own view and experiences. The whole hype about monitoring glucose levels (even if you are healthy) significantly increased after a French biochemist Jessie Inchauspe has published a book Glucose Revolution (recommendation at the end of this article) and also started trending heavily on social media as a Glucose Goddess.

While I think it is a very important topic, some precautions and awareness are needed for the general public, especially those without background in life sciences. In this Nexus I discuss what are normal glucose levels, the importance of checking your glycated hemoglobin, what are glucose spikes and how to recognize them, how glucose metabolism is related to longevity, what is continuous glucose monitoring and my personal experiences trying CGM, precautions when using CGM, 10 very practical tips how to control your glucose spikes and a book recommendation at the end.

Normal Glucose Levels

To discuss the glucose spikes, first of all we need to understand what are normal glucose levels. There are two types of measurements used: mg/dL or mmol/L. You can easily find converters online if you have received your test results in one or another format. In healthy individuals, glucose levels typically fall within the following ranges (1):

Fasting glucose: 70–100 mg/dL OR 3.9–5.6 mmol/L
Postprandial glucose, 1–2 Hours After Eating: Below 140 mg/dL OR 7.8 mmol/L

The variance of blood glucose levels of a healthy person during the day is shown in the figure below.

Glucose and insulin fluctuations during the day

As you can see, blood glucose level is a very time-sensitive parameter, so you should not panic if you did a morning glucose blood test in the lab and the result came back being outside the normal range. Even such things as chewing gum or brushing your teeth in the morning before the test can somewhat influence the result. However, you should not disregard the result. Dig deeper and consult with your physician, who most probably will recommend to perform additional tests, such as HbA1C.

Glycated Hemoglobin

As mentioned blood glucose levels changes all the time, therefore, if you want to evaluate your metabolic health, another important measurement which shows a longer-term consequences of your lifestyle to your body is glycated hemoglobin or hemoglobin A1c (HbA1c) test, which measures the amount of blood glucose attached to your hemoglobin. HbA1c blood test is performed to diagnose pre-diabetic condition or diabetes itself. Let’s look at the ranges (1):

Normal range for the HbA1c level is between 4% and 5.6%.
HbA1c levels in the range of 5.7%-6.4% means you have pre-diabetes and a higher chance of being diagnosed with diabetes.
HbA1c levels of 6.5% or higher mean you have diabetes.

Glycated hemoglobin (HbA1c) is a form of hemoglobin that has glucose molecules irreversibly attached to it, reflecting average blood glucose levels over the past two to three months. Glycated hemoglobin impairs the ability of red blood cells to efficiently deliver oxygen, exacerbating tissue hypoxia (lack of oxygen) and promoting further cellular dysfunction. HbA1c serves as a valuable marker for long-term glucose control. Elevated levels indicate prolonged exposure to high blood glucose, which has harmful effects (2).

High HbA1c is associated with increased oxidative stress and chronic low-grade inflammation, contributing to vascular damage and the development of diabetic complications such as retinopathy (any damage to the retina of the eyes, which may cause vision impairment), nephropathy (kidney impairment), and neuropathy (nerve damage leading to pain, weakness, numbness or tingling in one or more parts of the body). Additionally, persistent elevations in HbA1c also disrupt protein structure and function, exacerbate inflammatory responses, and drive the progression of chronic diseases such as atherosclerosis and cardiovascular disease (3).

Thus, if you want a good indication of your metabolic health, HbA1c test should be included in your prophylactic blood tests routine, as it better reflects a long-term glucose fluctuations.

What does science say?

What Are Glucose Spikes?

Lets get back to where we started. So what is a glucose spike and why it is important?

Glucose spikes refer to rapid increases in blood sugar levels, usually after consuming foods or beverages high in refined carbohydrates or sugars. These include items like sugary drinks, desserts, white bread, and processed snacks, which are quickly digested and absorbed, causing a sharp increase in blood glucose levels. Although these spikes are a natural postprandial response, their magnitude and frequency can significantly affect metabolic processes. Also, not only carbohydrates or sugars can cause a glucose spike:

Large portion sizes can exacerbate glucose spikes, as a higher glycemic load stresses the body’s ability to manage glucose efficiently (4).
Lack of dietary fiber also contributes, as fiber slows glucose absorption in the gut (5).
Lifestyle factors, such as physical inactivity, amplify glucose responses since muscles are less active and therefore less able to uptake glucose (6).
Stress and poor sleep quality can further heighten glucose spikes by increasing cortisol levels, which impair insulin sensitivity (7).

Even for non-diabetic individuals, these factors can disrupt glucose regulation, emphasizing the importance of balanced nutrition, physical activity, stress management and sleep (core elements of longevity), to maintain stable blood sugar levels.

Recognising a glucose spike

Recognising glucose spikes results in better self-awareness and glucose level management. Symptoms of glucose spikes can vary depending on the magnitude of the spike and individual sensitivity but often include feelings of fatigue and lethargy following a rapid rise and fall in blood sugar levels. This “sugar crash” can result from an overproduction of insulin in response to the spike, leading to subsequent hypoglycemia (8).

As shown below, when our glucose levels are in the optimal range, there should be no symptoms related to glucose and insulin fluctuations. However, when we eat sugary foods, the glucose level in the blood raises significantly (hyperglycemia), or in other words a glucose spike happens. Our body releases more insulin to deal with this high level of glucose, and this results in a fast glucose level drop in the blood (hypoglycemia), followed by an energy crash. These high spikes over time results in food cravings (or sugar cravings specifically), increased fat storage and weight gain.

Glucose spikes can cause other symptoms as well:

Headaches. Glucose spikes can contribute to headaches, possibly due to changes in blood flow or inflammation (9).
Increased thirst and frequent urination. The body may attempt to excrete excess glucose through urine, leading to dehydration and heightened thirst (10).
Cognitive symptoms. Symptoms like “brain fog” or difficulty concentrating can result from fluctuations in glucose levels impacting brain energy metabolism (11).
Cravings for sugary or high-carb foods. Glucose spikes can trigger cravings, perpetuating cycles of unstable glucose levels (12).

Overall, managing glucose spikes can not only help avoid the symptoms described, but also in a long term help manage the feeling of hunger and sugar cravings, improve metabolic health, reduce fat storage and even lose weight.

Glucose Spikes, Inflammation and Longevity

Chronic inflammation is one of the 12 currently identified hallmarks of aging, discussed in one of my pervious Nexus editions. Excessive glucose spikes, even in healthy individuals, can promote oxidative stress and chronic inflammation, thus has negative impact on our longevity. Below I have shortly described the core damage glucose spikes can cause to our body:

Oxidative stress. Elevated glucose levels increase reactive oxygen species (ROS) production, which damages cellular components, including lipids, proteins, and DNA (13).

Activation of inflammatory pathways. Persistent glucose elevations can trigger the production of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), which are linked to chronic low-grade inflammation (14).

Endothelial dysfunction. Repeated glucose spikes impair endothelial cell function, promoting vascular inflammation and atherosclerosis (15).

These findings underscore the importance of managing postprandial glucose levels to mitigate inflammatory responses and lower the risk of chronic conditions like cardiovascular disease and insulin resistance.

What is Continuous Glucose Monitoring?

Continuous glucose monitoring (CGM) is a cutting-edge technology initially developed for individuals with diabetes to manage their blood sugar levels effectively. Recently, its application has expanded to include healthy individuals seeking to optimize their metabolic health. As shown in the picture below, a regular glucose monitor requires a blood draw to get the results, which is very uncomfortable for those with the disease.

Regular versus continuous glucose monitoring devices

CGM devices continuously measure interstitial glucose levels using a sensor inserted beneath the skin. Unlike traditional glucose meters, CGMs provide real-time data and trend patterns, offering a comprehensive view of glucose dynamics. In healthy individuals, CGM can help identify subtle glucose patterns that may influence metabolic health, even when glucose levels fall within the clinical “normal” range.

My Personal Experience with CGM

I would have to describe my experience with 2 words only it would be interesting and useful. Here are some insights below:

Which CGM? I have tried Dexcom One+ CGM (not an ad). My selection criteria were pretty simple: which provider ships to Lithuania quickly and without customs fees, a reliable brand that has been on the market for some time and the size of the sensor (the smaller, the better). But I am sure you can find other reliable brands as well.

How long? I have bought 3 sensors for a month. One sensor lasts 10 days with a grace period of 12 hours. I have tried wearing the sensor in different routine circumstances, during travel period (when I went to Australia), during regular work from home period and during Christmas holidays, which gave me different insights how my body reacts to different food, stress levels, sleep quality, environment changes, etc.

It doesn’t hurt. When I was about to put on my first sensor, I was surprised how it doesn’t hurt AT ALL! I was sensing it a bit for the first days, but when you get used to it, you just forget about it.

The app. When you put on a sensor you connect it to the app to see the glucose levels in real time. While I got what I needed, the app was very basic, you cant scroll the the history, you just see a 24-hour period maximum. So if insights are important to you, the brand I mentioned is not the best.

I have tried all the junk food. NOT. Before I put on a CGM, I thought I will try everything bad and see what give the highest spike. However, when I put it on and saw my optimal curves, it had an opposite effect and I didn’t want to eat anything, that I would not eat anyway and what is unhealthy. So for me it also really worked as a control mechanism, not to misbalance my perfect curve.

My glucose curves. I confirmed the fact that I am in a good metabolic health. My fasting glucose was in the range of 4–5 mmol/L, and after eating it would raise up to a range of 6-7 mmol/L.

2 highest spikes ever. Throughout the period of 30 days, there were only 2 times when my glucose level raised above 10 mmol/L. First one happened on the last connecting flight to Australia, when I was not sleeping for over 24 hours and I eat a muffin. A second happened during a holiday period, after eating a piece of panettone cake.

What increases my glucose levels apart from food? Glucose levels are very individual and different people can have very different triggers for glucose spikes.

Stress level definitely affect my glucose level. Even in a fasting phase it can increase by 1-2 mmol/L in a stressful situation.
The same for being on a plane (which I think is just a different form of stress to the body). Whenever I was flying my fasting glucose levels were higher and my glucose spikes while eating on the plane were higher as well (even when I was eating a healthy option).
Sleep deprivation is also a factor influencing my glucose levels. On the days when I did not sleep enough my average glucose levels were higher.

Does Glucose Goddess practices work? I have mentioned you already a book Glucose Revolution where you can find very simple practices to better control your glucose levels. So I have tried those in practice. Below are the ones that worked for me while using CGM:

Start meals with vegetable. Eat fiber-rich foods first to slow glucose absorption. Green salad with apple cider vinegar before any meal can do miracles.
Pair carbs with protein and fat. Adding healthy fats or proteins to foods like bread or pasta can reduce glucose impact.
Move after eating. Any physical activity quite close after eating can significantly reduce your glucose spike, as it helps muscles use glucose effectively.
Use vinegar before meals. A tablespoon of vinegar in water before eating can reduce post-meal spikes.
Use a “glucose-friendly” sequence. Vegetables first, then protein and fats, and save carbs for last.

Precautions When Using CGM

If you would ask me if it is worth trying a CGM yourself, my immediate response would be YES. However, while using CGMs can provide valuable insights, but certain precautions must be taken to avoid misinterpretation of data or unnecessary stress:

Get used to it and only then look for insights from the data you get. I have fried who have tried it and started panicking due to glucose levels being too low or too high. First of all, understand you daily averages and spikes and only then try to
Understand that glucose levels are individual, and don’t try to compare yourself with a friend using a CGM at the same time as you do. Compare yourself only with yourself after different meals or changes of the circumstances.
There are certain limitations of interstitial glucose monitoring. CGMs measure glucose in interstitial fluid, not in blood, which may lag behind blood glucose changes during rapid fluctuations (16).
Consult with your physician how to interpret the results if they are worrying or if you don’t understand something. In the end it is medical data.
Don’t go wild. Don’t try to change your routine drastically after or while using a CGM. It won’t work and it won’t stay. Do one change at the time.
Don’t over-consume vinegar. Not related to CGM itself, but it was so much promoted in the book I’ve mentioned, that I see some people using it in illogical amounts. Overconsumption can cause tooth enamel erosion, digestive issues, low potassium levels, bone loss, throat irritation and interactions with medications, particularly diuretics and insulin.

10 Tips How to Control Your Glucose Spikes

Here are some very short but scientifically proven ways how to manage glucose spikes and keep your metabolic health in a good state:

Low glycemic index foods. Consuming foods with a low glycemic index (e.g., vegetables, legumes, whole grains) slows glucose absorption (17).
Balance macronutrients. Pairing carbohydrates with protein, fat, or fiber helps moderate glucose responses (18).
Eat smaller, more frequent meals. Avoid large meals that can lead to significant glucose surges (19).
Avoid sugary drinks. Liquid sugars can cause rapid glucose spikes due to their high absorption rate (20).
Post-meal movement. Engaging in light physical activity after meals enhances glucose uptake by muscles, reducing postprandial spikes (21).
Regular exercise. Consistent aerobic or resistance training improves insulin sensitivity over time (22).
Manage stress. Chronic stress elevates cortisol levels, which can impair glucose regulation (23).
Optimize sleep. Poor sleep quality negatively affects glucose metabolism and increases the risk of insulin resistance (24).
Stay hydrated. Adequate hydration aids glucose metabolism.
Consume carbohydrates timely. Consuming high-carb meals earlier in the day aligns with natural insulin sensitivity rhythms (25).

Book recommendation

I think many of you have read this already, but if you didn’t and you want to dig deeper into this topic, Glucose Revolution is an easy and a good way to do it. I listened to an audio version and what triggered me a bit was that the author mentioned her Instagram profile like 1000 times… Otherwise, I really enjoyed it.

Continuous glucose monitoring offers valuable insights into your glucose dynamics. Understanding and managing glucose spikes is essential for reducing inflammation and optimizing your long-term metabolic health. While CGM technology provides a wealth of data, interpreting it requires care to avoid overreaction or misinterpretation. For anyone considering CGM, I recommend a consultation with a healthcare provider to tailor its’ use effectively and interpret data meaningfully. Monitoring glucose is not about numbers, it’s about understanding the body’s responses and making informed decisions to enhance your overall well-being. Hope you have enjoyed this Nexus edition. I really enjoyed getting back to writing! More on longevity, healthspan and health optimization coming soon! Stay tuned and do not hesitate to engage!