A stable blood sugar level is key to both health and mental well-being.
Sharp fluctuations in blood glucose can lead not only to fatigue, irritability, and sugar cravings, but also, in the long term, to more serious problems – from insulin resistance through hormonal imbalance and cardiovascular issues to type 2 diabetes, and in the long run even Alzheimer’s disease.
What will you learn in this article?
- Why balanced blood glucose is the key to health
- How blood sugar fluctuations can manifest
- Blood sugar and metabolic health
- Impact on the hormonal system
- Blood sugar fluctuations and aging
- Glycated hemoglobin and why it makes sense to measure it
- Practical tips for stabilizing blood sugar and reducing health risks
- Key takeaways
Why balanced blood glucose is the key to health
Glucose is the preferred source of energy for most cells in our body, especially for the brain and muscles. For the body to use it effectively, blood sugar levels must be maintained within a fairly narrow range, fasting between 3.9–5.6 mmol/l. With balanced glucose, we feel focused, have enough energy, and organs function optimally. Stable blood sugar also protects blood vessels, the nervous system, and influences hormonal balance. Blood glucose, the concentration of “sugar” in the blood, is thus one of the fundamental indicators of metabolic health.
On the other hand, blood sugar fluctuations trigger physical stress and burden the organs, particularly the pancreas and liver, and may also set off a chain of other health complications. Excessive exposure of cells to high blood sugar levels also leads to glycation of tissues and their damage. In this process, sugar molecules bind to proteins and fats, creating harmful substances known as advanced glycation end products (AGEs).
Stable blood glucose levels (also known as glycemia) are achieved through a complex system of hormonal regulation. The main role in maintaining blood sugar balance is played by two hormones secreted by the pancreas: insulin and glucagon. If the glucose regulation system fails and blood sugar levels become too high (hyperglycemia) or too low (hypoglycemia), dysregulation occurs, leading to a cycle of metabolic and hormonal disorders that can result in organ damage and the development of serious diseases.
When blood glucose levels rise, for example after a meal but also as a result of stress, the pancreas begins to secrete the hormone insulin. It acts as a key that unlocks the cells, primarily in the muscles and adipose tissue, but also in the liver, allowing them to absorb glucose from the bloodstream for energy or storage.
At the same time, insulin suppresses the production of new glucose in the liver. When blood sugar levels begin to drop, the pancreas releases glucagon. This hormone signals the liver to break down stored glycogen and release glucose back into the blood (a process known as glycogenolysis). Thanks to this feedback system, the body is prevented from falling into hypoglycemia.
Dysfunction of the entire system and insulin resistance of cells, characterized by the inability to store excess glucose, leads in the long term to a number of diseases and type 2 diabetes.
However, problems may not be apparent at first. If the body suffers from insulin resistance but the pancreas is still able to produce insulin, this only results in increased production of the hormone. Over time, however, pancreatic cells become exhausted and unable to produce insulin. This naturally leads to increased blood glucose levels.
How blood sugar fluctuations can manifest
Blood sugar fluctuations are characterized by a sharp rise in blood glucose after a meal followed by a rapid drop. When monitored with a glucometer, this can be illustrated as the so-called Gothic curve. Fluctuations can then appear in both the short-term and long-term spectrum. This condition occurs primarily after consumption of foods containing simple and rapidly absorbed carbohydrates without fiber, such as sugary soft drinks, sweets, ice cream, but also sweet fruits such as bananas and pineapples, or after consuming pasta and other carbohydrate side dishes such as rice and potatoes.
This can subsequently lead to:
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Short-term symptoms: fatigue, irritability, lack of concentration, headaches, sugar cravings.
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Long-term consequences: repeated overloading of the pancreas, insulin resistance and the inability of cells to respond to it, development of inflammatory processes in the body due to circulating blood sugar, storage of glucose in fat deposits and damage to blood vessels.
The more sugar the body consumes, the deeper the fluctuations become, which increases the risk of chronic diseases. A rapid rise in blood sugar after a sweet meal (especially if the source is simple sugars and industrially processed foods such as sweets and soft drinks) triggers excessive insulin release. Insulin then lowers glucose levels, but often too much – which leads to subsequent hypoglycemia. At this point, the body begins to release the stress hormone cortisol, which supports gluconeogenesis – that is, the stimulation of glucose production from non-sugar sources, particularly in the liver. However, people often also feel a loss of energy and fatigue, which leads to cravings for more “sweets” containing fast sugars. The vicious cycle of blood sugar fluctuations thus deepens further.
These fluctuations are an enormous stress burden for the body, leading to increased production of free radicals, oxidative stress, and microinflammation. All of these factors gradually damage blood vessel walls, accelerate atherosclerosis, and increase the risk of cardiovascular diseases.
Blood sugar and metabolic health
Unstable blood sugar is directly linked to the development of metabolic and cardiovascular diseases for several reasons.
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Development of insulin resistance and type 2 diabetes – this occurs because cells stop responding to insulin and are unable to store circulating glucose. As a result, chronically elevated blood glucose remains in the bloodstream, which causes oxidative stress in the body and leads to the development of inflammatory processes.
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Development of cardiovascular diseases – this is a consequence of elevated blood sugar and insulin resistance, which promote inflammation in the blood vessels and the formation of atherosclerotic plaques due to the action of cholesterol, which also contributes to the development of high blood pressure.
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Overweight and obesity – caused by blood sugar fluctuations, which increase appetite and promote fat storage, especially in the abdominal area. Excess amounts of glucose and fructose that are not used in energy processes are stored in fat deposits and liver tissue, gradually leading to non-alcoholic fatty liver disease. Excess body fat further promotes a chronic inflammatory state in the body.
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Chronic hyperglycemia can ultimately cause irreversible and extensive damage to nerves, blood vessels, tissues, and organs, affecting both microvascular and macrovascular health of the entire body. Microvascular complications primarily affect small vessels and include, for example, retinopathy (damage to the retina), nephropathy (kidney damage), and neuropathy (nerve damage). Macrovascular complications mainly affect large vessels and can lead to serious conditions such as ischemic heart disease or stroke.
Impact on the hormonal system
Unstable blood glucose is closely related to hormonal balance and can be the cause of various types of health problems.
Which hormones are most affected by blood sugar fluctuations?
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Cortisol (stress hormone):
Blood sugar fluctuations have a direct impact on cortisol levels, the main stress hormone. When blood glucose drops sharply, the body responds to this stressful situation by producing a greater amount of cortisol.
This is followed by processes associated with the release of glucose into the blood. This repeated cycle of excessive cortisol stimulation leads to fatigue, disrupted sleep, increased inner tension, and poorer recovery of the body. In the long term, unstable blood sugar weakens not only metabolic health but also the body’s overall resilience to stress.
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Female hormones (estrogen, progesterone, and hormones from the androgen group):
Blood sugar fluctuations affect not only energy and mood but also women’s hormonal balance.
Unstable blood sugar is associated with worsening premenstrual syndrome (PMS) and painful menstruation, primarily due to increased inflammation.
For some women, blood sugar fluctuations may also contribute to irregular menstrual cycles, impaired ovulation quality, or a condition known as PCOS.
In PCOS (polycystic ovary syndrome), stable blood sugar plays a significant role. Fluctuating glucose levels further aggravate this problem, raise androgen levels, and worsen symptoms such as irregular menstruation, acne, or excessive hair growth. Maintaining stable blood sugar is therefore one of the key steps in supporting women’s health, fertility, and hormonal balance.
Blood sugar fluctuations and aging of the body
Unstable blood sugar also accelerates aging processes – both the more visible ones (skin aging and loss of elasticity) and the less obvious ones (atherosclerosis, protein glycation). The main causes are increased oxidative stress, formation of glycated proteins, and chronic inflammation.
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Oxidative stress: caused by an excess of unused glucose in the body, which leads to increased production of free radicals. These then damage DNA and other cellular structures.
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Glycated proteins (AGEs): with chronically elevated glucose levels, glycation occurs (“binding” of sugar molecules to proteins), which reduces tissue elasticity and damages blood vessels, skin, and nerves. All of these factors contribute to accelerated aging and greater oxidative stress.
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Chronic inflammation: high blood sugar fluctuations also maintain an inflammatory environment in the body, which is one of the main factors of accelerated biological aging and further health damage.
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High blood sugar also negatively affects the gut microbiome: it leads to microbiome imbalance and may cause intestinal permeability – a condition known as “leaky gut.”
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In the long term, the formation of advanced glycation end products (AGEs) also contributes to decline in cognitive functions and the ability to retain information. AGEs thus play a significant role not only in diabetes and cardiovascular diseases but also in neurodegenerative disorders, such as Alzheimer’s disease. A high burden of AGEs contributes to faster brain aging, memory loss, and worsens the course of neurodegenerative diseases.
Glycated hemoglobin and why it makes sense to measure it
Excessive intake of simple carbohydrates and free sugars in the diet, which are not bound to fiber and not used, for example, during physical activity, results in large amounts of unutilized glucose circulating in the body. Sugar molecules then bind to proteins such as collagen and elastin.
Protein glycation is also a major factor contributing to microvascular and macrovascular problems. Tissue damage is particularly evident in the kidneys, the retina, and peripheral nerves. A large amount of these sugar-damaged proteins also impairs the uptake of glucose by cells and contributes to insulin resistance.
The cycle of oxidative stress and glycation also damages the pancreatic beta cells, which are responsible for insulin production. This fact further accelerates the onset of type 2 diabetes mellitus. The scientifically proven connection between glycated proteins and type 2 diabetes is clearly reflected in measured levels of glycated hemoglobin.
A similar process can occur in our bodies as the one we know from the kitchen when baking bread or roasting meat – the so-called Maillard reaction creates the brown “crust” and distinctive aroma. In relation to our health, however, this is a negative manifestation of glucose excess. In the body, this reaction leads to the formation of advanced glycation end products (AGEs), which accumulate in tissues, damage proteins so they stop functioning properly, accelerate cell aging, and contribute to the development of complications in diabetes, cardiovascular, and neurodegenerative diseases.
Direct measurement of AGE levels from blood is not common, and the measurement of glycated hemoglobin (HbA1c) therefore serves as a simple indicator of the body’s exposure to excess glucose. It shows how much the body is currently exposed to sugar, while AGE formation is the long-term and harmful consequence of this state.
For this reason, we recommend regular measurement of glycated hemoglobin (HbA1c) from blood. This is one of the simplest and at the same time very useful preventive examinations, thanks to which it is possible to determine the average blood glucose levels over the past 2–3 months.
If the HbA1c value rises above 37 mmol/mol, it signals the first signs of prediabetes. At this stage, it is still possible to reverse the process by changing lifestyle (adjusting diet, exercise, quality sleep, etc.) and thus prevent the subsequent development of type 2 diabetes.
Practical tips for stabilizing blood sugar and reducing health risks
The composition of meals, the ratio of macronutrients (proteins, fats, carbohydrates), and a simple change in the order of food consumption can have a major impact on blood sugar stability after eating.
Proteins have minimal impact on raising blood sugar levels after a meal. The advantage is that when consuming a complex meal based on quality protein sources, along with healthy fats, the rise in blood glucose is not as significant even when carbohydrates are consumed together.
Dietary fats also slow down glucose absorption by delaying stomach emptying. It is recommended to focus mainly on consuming healthy fats, such as avocado, olive oil, or fatty fish, regularly and in reasonable amounts, ideally combined with quality proteins and complex carbohydrates.
The main macronutrient that breaks down into glucose and thus directly affects blood sugar levels is carbohydrates. The amount of carbohydrates consumed and their type (simple vs. complex) significantly influence the rise in blood glucose after meals.
Another key factor in blood sugar regulation is fiber. Its sufficient intake in the diet slows down digestion and carbohydrate absorption, improves insulin sensitivity, and protects against sharp blood sugar fluctuations, thereby supporting a lower long-term risk of type 2 diabetes and cardiovascular diseases. The optimal daily intake of fiber for an adult is 25–35 grams.
How to reduce the risks associated with blood sugar fluctuations:
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Diet:
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When eating, start with vegetables or proteins, consume carbohydrates at the end and combine them with healthy fats. This leads to a slower rise in blood glucose after meals, less energy drop, and more stable blood sugar levels.
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Choose foods with a low to medium glycemic index and a higher fiber content.
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Avoid simple sugars and industrially processed foods that contain them.
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A simple trick that helps stabilize blood sugar after meals is drinking a spoon of apple cider vinegar in a small amount of water shortly before eating, which supports digestion.
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We also recommend limiting foods rich in AGEs – grilled, fried, and industrially processed foods.
Lifestyle:
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Regular physical activity improves the sensitivity of cells to insulin.
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Quality sleep and stress management help maintain stable hormones and blood glucose.
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Supplementation:
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Magnesium, chromium, zinc, or berberine support the proper functioning of sugar metabolism.
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Omega-3 fatty acids reduce inflammation and support metabolic health.
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We also recommend supporting the body’s natural antioxidant capacity – sufficient antioxidants (vitamin C, E, polyphenols, astaxanthin) help neutralize free radicals produced by AGEs.
Key takeaways
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Stable blood sugar is not only important for diabetes prevention – it is a cornerstone of overall health. It affects our energy, hormonal balance, mental well-being, and the aging process.
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Blood sugar fluctuations gradually damage blood vessels, nerves, and metabolism, opening the way to lifestyle diseases. The good news is that each of us can support our glucose balance – with a balanced diet, physical activity, quality sleep, and mindful self-care.
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Sharp blood sugar fluctuations overload the pancreas, increase stress in the body, promote inflammation, and accelerate aging.
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Unstable blood sugar is linked to insulin resistance, type 2 diabetes, obesity, cardiovascular, and hormonal issues.
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Simple carbohydrates cause a rapid rise in blood sugar, while complex carbohydrates and fiber ensure a steady energy supply.
Maintaining healthy glucose levels is supported by a balanced diet rich in quality proteins and healthy fats, regular exercise, quality sleep, and stress management. -
As a preventive measure, it makes sense to monitor glycated hemoglobin (HbA1c), which reflects the body’s long-term sugar load.
Sources:
https://www.verywellhealth.com/stages-of-type-2-diabetes-6503545
https://pmc.ncbi.nlm.nih.gov/articles/PMC4384119/
