Myths About Blood Sugar and Insulin, Debunked by Experts

17 Sep 2025 By Vinaya Simha, M.B.B.S., M.D.

Myths About Blood Sugar and Insulin, Debunked by Experts

Blood sugar and insulin – two terms that are often shrouded in confusion and misinformation. Understanding how these biological components work together is crucial for maintaining overall health, particularly for those managing diabetes or insulin resistance. Unfortunately, numerous myths persist, clouding people’s judgment and potentially leading to inadequate or even harmful health practices. In this article, we'll debunk some of the most common myths about blood sugar and insulin, with insights from leading health experts and scientific research. Decoding Your Blood Sugar Range What The Numbers Really Mean

Why Clearing Up These Myths Matters

The prevalence of misinformation can have serious consequences. People might avoid necessary medical treatments, follow ineffective diets, or develop anxiety around food and blood sugar levels. Education and factual information are paramount. By dispelling these myths, we aim to empower individuals to make informed decisions about their health, fostering a proactive and positive approach to managing their well-being.

Myth 1: Sugar is the Sole Cause of High Blood Sugar

One of the most pervasive myths is that sugar alone is responsible for elevated blood sugar levels. While it’s true that consuming sugary foods and beverages can lead to rapid spikes in blood glucose, the reality is far more complex.

The Role of Carbohydrates

The primary source of glucose in the body comes from carbohydrates, which break down into sugar during digestion. This includes not only refined sugars found in sweets but also complex carbohydrates present in starchy foods like bread, pasta, rice, and potatoes. The impact on blood sugar depends on several factors:

Type of Carbohydrate: Simple carbs are quickly digested, leading to rapid blood sugar spikes, while complex carbs are broken down more slowly, resulting in a more gradual rise.
Glycemic Index (GI) and Glycemic Load (GL): GI measures how quickly a food raises blood sugar levels, while GL considers both the GI and the amount of carbohydrate in a serving. Foods with high GI and GL can significantly impact blood sugar levels.
Portion Size: The amount of carbohydrates consumed also plays a significant role. Even healthy complex carbohydrates can raise blood sugar if consumed in excessive amounts.
Presence of Fiber: Fiber slows down the absorption of sugar into the bloodstream, helping to moderate blood sugar levels.

Beyond Carbohydrates: Other Influencing Factors

Besides carbohydrates, several other factors can influence blood sugar levels:

Protein and Fat: While they don’t directly convert to glucose as carbohydrates do, protein and fat can influence insulin sensitivity and glucose metabolism. Some studies suggest that high-protein diets, especially when combined with low carbohydrate intake, can improve blood sugar control. High-fat meals can sometimes delay glucose absorption, leading to a later, more prolonged blood sugar rise.
Stress: Stress hormones like cortisol and adrenaline can raise blood sugar levels by stimulating the liver to release stored glucose.
Physical Activity: Exercise increases insulin sensitivity, helping the body use glucose more efficiently and lowering blood sugar levels.
Illness: Infections and illnesses can trigger the release of stress hormones, leading to elevated blood sugar.
Medications: Certain medications, such as corticosteroids, diuretics, and some antidepressants, can affect blood sugar levels.

| Factor | Impact on Blood Sugar | Example | | ----------------- | ---------------------------------------------------------------------------- | --------------------------------------------------------------------------------- | | Simple Carbs | Rapid increase | Candy, soda | | Complex Carbs | Gradual increase | Whole grains, vegetables | | Fiber | Slows absorption, moderates increase | Legumes, fruits with skin | | Protein & Fat | Influences insulin sensitivity & glucose metabolism | Meat, nuts, avocados | | Stress | Increases due to hormone release | Workplace pressure, emotional distress | | Physical Activity | Decreases, improves insulin sensitivity | Brisk walking, weightlifting | | Illness | Increases due to stress response | Common cold, flu | | Medications | Can increase or decrease depending on the type | Corticosteroids (increase), insulin (decrease) |

Expert Insight: "Focusing solely on sugar intake can be a misguided approach. A balanced diet that considers the types and amounts of all carbohydrates, along with other factors like stress and physical activity, is key to effective blood sugar management," says Dr. Emily Carter, an endocrinologist specializing in diabetes management.

Myth 2: Insulin is Only for People with Type 1 Diabetes

While it's true that insulin is essential for individuals with Type 1 diabetes—whose bodies do not produce insulin—it's a misconception that it's exclusively a Type 1 diabetes medication. Insulin plays a crucial role in the management of Type 2 diabetes and certain other conditions as well.

Insulin in Type 2 Diabetes

In Type 2 diabetes, the body becomes resistant to insulin, meaning that the cells don't respond as effectively to the hormone's signals. Over time, the pancreas may also gradually lose its ability to produce enough insulin to overcome this resistance. As a result, blood sugar levels remain elevated.

Insulin therapy is often considered when lifestyle changes (diet and exercise) and oral medications are no longer sufficient to maintain target blood sugar levels. Starting insulin does not mean someone has failed at managing their Type 2 diabetes. It simply means the condition has progressed, and the body requires additional support to regulate blood glucose.

Situations Where Insulin is Used in Type 2 Diabetes

Insufficient Control with Other Medications: When oral medications and other injectables are not enough to manage blood sugar effectively.
Pancreatic Exhaustion: In advanced stages of Type 2 diabetes, the pancreas may become exhausted and unable to produce sufficient insulin.
Temporary Use: During pregnancy (gestational diabetes) or times of significant stress or illness, insulin may be used temporarily to achieve optimal blood sugar control.
Severe Hyperglycemia: In cases of severely high blood sugar, insulin is used to quickly lower glucose levels and stabilize the patient.

Other Conditions Where Insulin Might Be Used

Gestational Diabetes: Pregnant women with gestational diabetes may require insulin to manage blood sugar levels and ensure the health of both mother and baby.
Post-Pancreatectomy: After surgical removal of the pancreas (pancreatectomy), individuals may become insulin-dependent.
Certain Pancreatic Disorders: Conditions like chronic pancreatitis or cystic fibrosis can damage the pancreas and impair insulin production.

Benefits of Insulin Therapy

Improved Blood Sugar Control: Insulin is a highly effective way to lower blood sugar levels and maintain them within the target range.
Reduced Risk of Complications: Proper blood sugar control with insulin can help prevent or delay the onset of long-term diabetes complications, such as nerve damage, kidney disease, and vision problems.
Flexibility in Diet: Insulin therapy can provide greater flexibility in meal planning, allowing individuals to adjust their insulin doses to match their carbohydrate intake.
Improved Quality of Life: By effectively managing blood sugar, insulin can help reduce symptoms like fatigue, excessive thirst, and frequent urination, improving overall quality of life.

Expert Insight: "It's crucial to dispel the stigma around insulin use in Type 2 diabetes. Insulin is a vital tool that can help people achieve optimal blood sugar control and prevent long-term health problems," says Dr. Mark Thompson, a diabetes specialist at the American Diabetes Association. "It should be viewed as a proactive step in managing the condition, not as a sign of failure."

Myth 3: Fruit is Bad for Blood Sugar

Fruits often get a bad rap due to their natural sugar content. However, demonizing all fruits as "bad" for blood sugar is an oversimplification and overlooks the significant health benefits they offer.

The Nutritional Value of Fruits

Fruits are packed with essential nutrients that are vital for overall health:

Vitamins and Minerals: Rich sources of vitamins (such as Vitamin C and Vitamin A) and minerals (like potassium).
Fiber: Helps regulate blood sugar levels by slowing down the absorption of glucose.
Antioxidants: Protect cells from damage caused by free radicals.
Phytonutrients: Plant compounds with various health benefits, including anti-inflammatory and anti-cancer properties.

Impact of Fruit on Blood Sugar

The impact of fruit on blood sugar depends on several factors:

Type of Fruit: Fruits with a lower glycemic index (GI) and glycemic load (GL) have a smaller impact on blood sugar levels. Berries, apples, and pears tend to have lower GI values, while fruits like watermelon and ripe bananas have higher GI values.
Portion Size: Eating large quantities of fruit at one time can lead to a more significant rise in blood sugar.
Form of Fruit: Whole fruits are preferable to fruit juices, as they contain fiber that helps slow down glucose absorption.
Combination with Other Foods: Eating fruit with protein or healthy fats can also help moderate its impact on blood sugar.

Scientific Studies and Data

Several studies have investigated the relationship between fruit consumption and blood sugar control:

A study published in the Journal of the American College of Nutrition found that higher fruit intake was associated with a lower risk of developing Type 2 diabetes.
Research in the British Medical Journal showed that certain fruits, particularly blueberries, grapes, and apples, were linked to a reduced risk of Type 2 diabetes.

| Fruit | Glycemic Index (GI) | Glycemic Load (GL) | Fiber Content (per serving) | | ------------- | ------------------- | ------------------ | --------------------------- | | Apple | 36-50 | 5-6 | Approximately 4g | | Banana | 51-73 | 11-22 | Approximately 3g | | Blueberries | 53 | 5 | Approximately 4g | | Grapes | 49-59 | 7-11 | Approximately 1g | | Watermelon | 76 | 5 | Approximately 1g |

Tips for Including Fruit in a Diabetes-Friendly Diet

Choose Low-GI Fruits: Opt for fruits like berries, apples, pears, cherries, and grapefruit.
Control Portion Sizes: Stick to moderate portions (e.g., one medium-sized apple or a cup of berries).
Eat Whole Fruits: Choose whole fruits over fruit juices to benefit from the fiber content.
Combine with Protein or Fat: Pair fruit with a source of protein (such as nuts or Greek yogurt) or healthy fats (such as avocado) to help stabilize blood sugar levels.
Monitor Blood Sugar Levels: Pay attention to how different fruits affect your blood sugar and adjust your intake accordingly.

Expert Insight: "Fruit can absolutely be part of a healthy diet for people with diabetes," says registered dietitian, Sarah Miller. "The key is to choose wisely, control portions, and pair fruits with other nutrient-rich foods. Focusing on the overall dietary pattern is more important than eliminating entire food groups."

Myth 4: High Insulin Levels Are Always a Sign of Diabetes

While high insulin levels are commonly associated with insulin resistance and Type 2 diabetes, they are not always indicative of the condition. In some cases, elevated insulin levels can occur for other reasons or as a compensatory mechanism in the early stages of insulin resistance.

Understanding Insulin's Role

Insulin is a hormone produced by the pancreas that helps glucose enter cells to be used for energy. When blood sugar levels rise after a meal, the pancreas releases insulin to facilitate glucose uptake. In individuals with normal insulin sensitivity, the amount of insulin needed to regulate blood sugar is relatively low.

Insulin Resistance

Insulin resistance occurs when cells become less responsive to insulin, requiring the pancreas to produce more insulin to maintain normal blood sugar levels. Over time, this can lead to chronically elevated insulin levels (hyperinsulinemia) and, eventually, Type 2 diabetes.

Causes of High Insulin Levels Other Than Diabetes

Pre-Diabetes/Early Insulin Resistance: In the early stages of insulin resistance, before blood sugar levels become consistently elevated, the pancreas may overproduce insulin in an attempt to compensate for the reduced insulin sensitivity.
Polycystic Ovary Syndrome (PCOS): PCOS is a hormonal disorder that often involves insulin resistance, leading to hyperinsulinemia.
Obesity: Excess body weight, particularly abdominal fat, is associated with insulin resistance and elevated insulin levels.
Certain Medications: Some medications, such as corticosteroids, can increase insulin resistance and lead to higher insulin levels.
Genetic Factors: Genetic predispositions can influence insulin sensitivity and insulin production.
Fructose Consumption: Diets high in fructose can lead to insulin resistance and increased insulin levels.
Insulinoma: Although rare, an insulinoma is a tumor of the pancreas that produces excessive amounts of insulin, leading to hypoglycemia and high insulin levels.

Diagnosing the Cause of High Insulin Levels

If you have elevated insulin levels, it's important to work with a healthcare provider to determine the underlying cause. Diagnostic tests may include:

Fasting Blood Sugar Test: Measures blood sugar levels after an overnight fast.
Oral Glucose Tolerance Test (OGTT): Measures blood sugar levels at various intervals after consuming a sugary drink.
Hemoglobin A1c (HbA1c) Test: Provides an average of blood sugar levels over the past two to three months.
Lipid Panel: Measures cholesterol and triglyceride levels, which can be affected by insulin resistance.
Insulin Levels Test: Measures the amount of insulin in the blood, often taken in conjunction with a glucose test.
C-Peptide Test: Measures C-peptide levels, which are produced when insulin is made. This can help differentiate between insulin produced by the body and insulin injected as medication.

| Condition | Potential Impact on Insulin Levels | Other Diagnostic Clues | | -------------------------------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------ | | Pre-Diabetes/Insulin Resistance | Elevated insulin levels (hyperinsulinemia) to compensate for reduced insulin sensitivity | Normal or slightly elevated blood sugar levels; may have other risk factors like obesity | | PCOS | Insulin resistance and hyperinsulinemia | Irregular menstrual cycles, ovarian cysts, hirsutism | | Obesity | Increased insulin resistance and elevated insulin levels | High BMI, increased waist circumference | | Certain Medications | Increased insulin resistance due to medication side effects | Recent or current use of medications known to affect insulin sensitivity | | Fructose Consumption | Can lead to insulin resistance and increased insulin levels | Dietary history of high fructose intake | | Insulinoma | Markedly elevated insulin levels, even when blood sugar is low | Hypoglycemia, weight gain |

Expert Insight: "High insulin levels can be a complex issue, and it's important not to jump to conclusions," explains Dr. Susan Davies, an endocrinologist specializing in metabolic disorders. "A thorough evaluation is necessary to determine the underlying cause and develop an appropriate management plan. Focusing solely on lowering insulin levels without addressing the root cause can be counterproductive."

Myth 5: Once You Start Insulin, You Can Never Stop

A significant misconception surrounding insulin therapy is that once you start taking it, you are committed for life. This belief can create unnecessary fear and hesitation, preventing people from embracing a treatment that could significantly improve their health. The truth is, for some individuals, insulin therapy can be temporary or adjusted based on changes in their condition. How To Manage Blood Sugar With A Smart Diabetic Diet

Insulin Use Can Be Reversible in Certain Cases

Type 2 Diabetes Management: In Type 2 diabetes, insulin is often initiated when other treatments, like oral medications and lifestyle changes, no longer effectively control blood sugar. However, if a person makes significant lifestyle improvements, such as weight loss, regular exercise, and dietary modifications, their insulin sensitivity can improve. As a result, they may be able to reduce or even discontinue insulin under the guidance of their healthcare provider.
Gestational Diabetes: For women with gestational diabetes, insulin is frequently used to manage blood sugar levels during pregnancy. After delivery, blood sugar levels typically return to normal, and insulin therapy is no longer needed.
Temporary Conditions: During periods of illness, stress, or recovery from surgery, insulin may be used temporarily to manage elevated blood sugar levels. Once the underlying condition resolves, insulin can often be discontinued.
Medication Changes: If a person is taking medications that increase blood sugar, adjusting or discontinuing these medications can sometimes improve blood sugar control enough to reduce or eliminate the need for insulin.

Factors Influencing the Ability to Stop Insulin

Lifestyle Modifications: Significant improvements in diet, exercise, and weight management can enhance insulin sensitivity and reduce the need for insulin.
Diabetes Duration and Progression: The longer a person has had diabetes, and the more advanced the condition, the less likely they are to be able to discontinue insulin completely.
Pancreatic Function: If the pancreas is still producing some insulin, lifestyle changes and other treatments may be able to support and improve its function, potentially reducing the need for external insulin.
Adherence to Treatment Plan: Consistent adherence to a comprehensive diabetes management plan, including regular monitoring of blood sugar levels, can increase the likelihood of successful insulin reduction or discontinuation.
Individual Health Profile: Factors such as age, overall health, and the presence of other medical conditions can influence the ability to stop insulin.

The Importance of Medical Supervision

It's crucial to emphasize that any adjustments to insulin therapy should be made under the close supervision of a healthcare provider. Abruptly stopping insulin without proper guidance can lead to dangerously high blood sugar levels and serious health complications.

A healthcare provider can assess individual circumstances, monitor blood sugar levels, and provide personalized recommendations for safely reducing or discontinuing insulin, if appropriate. This may involve gradually decreasing the insulin dose while monitoring blood sugar levels, making adjustments to other medications, and providing ongoing support and education.

Expert Insight: "The idea that insulin is a life sentence is simply not true for everyone," explains Dr. James Oliver, a diabetes specialist and researcher. "While some individuals may require insulin permanently, others can successfully reduce or discontinue it through lifestyle changes and other interventions. The key is to work closely with your healthcare team to develop a personalized plan that meets your specific needs and goals." How Persons With Diabetes Can Achieve Stable Blood Sugar Control

Summary: Key Takeaways

By debunking these common myths, we hope to provide clarity and empower individuals to make informed decisions about their health. Remember these key points:

Sugar is not the sole cause of high blood sugar; carbohydrates, stress, physical activity, and other factors play a role.
Insulin is not only for Type 1 diabetes; it's also used in Type 2 diabetes and other conditions.
Fruit can be part of a healthy diet; choose wisely, control portions, and combine with protein or fat.
High insulin levels are not always a sign of diabetes; other conditions can cause elevated levels.
Starting insulin is not necessarily a lifetime commitment; in some cases, it can be reduced or discontinued with lifestyle changes and medical supervision.

Staying informed and consulting with healthcare professionals will pave the way for better management of blood sugar levels and improved overall well-being.