What is Insulin? A comprehensive guide to insulin

Insulin is a hormone that our body makes in the pancreas (an organ located in the abdomen). Its main job is to control the amount of sugar in our blood. When we eat food, the pancreas releases insulin to help our cells use the sugar, called glucose, for energy. Imagine insulin as a key that unlocks the doors of our cells, allowing the glucose to go inside and provide energy for our body. Additionally, insulin tells our liver to save any extra glucose for later use, helping keep the right amount of sugar in our blood and ensuring our cells get the energy they need.

However, some people develop a condition called insulin resistance, where their cells don't respond properly to insulin. This can cause a problem called prediabetes, which may later develop into diabetes.

The good news is that people with insulin resistance can do things to improve their condition[1], such as making changes to their lifestyle, exercising regularly and controlling their blood sugar levels. This means their cells start responding better to insulin again, which helps prevent or manage diabetes.

In this article, we explore insulin more in-depth, as well as what it means to become insulin-resistant and how you may be able to reverse it. 

Why is insulin important?

When blood sugar levels rise, the body needs insulin to regulate it. Insulin helps maintain blood glucose levels by allowing cells to use glucose as a source of energy. If you become insulin resistant, cells cannot properly use glucose, leading to a glucose build-up in the blood, which causes high blood sugar levels, which can lead to prediabetes, which can then progress to type 2 diabetes.   

Blood sugar levels rise when you consume food, particularly foods high in sugar and high in carbohydrates like bread, potatoes, or pasta. These types of food will immediately spike your blood sugar levels.

Did you know that many adults worldwide suffer from insulin resistance? Studies show that this condition affects around 15.5% to 46.5% of adults globally, with differing rates across countries.

Insulin resistance is a growing problem that many people may not know they have. Experts warn that it's becoming more and more common[1.1]

What are the causes of insulin resistance? 

Exactly what causes insulin resistance is unclear. However, a combination of factors can increase your risk. 

1. Being overweight

Being overweight, particularly having excess fat around the waist, is widely recognized as a significant risk factor for developing insulin resistance. This is because adipose tissue, or fat cells, release various substances known as adipokines. These adipokines can interfere with insulin's ability to function properly, contributing to insulin resistance. Additionally, individuals who are overweight or obese often have higher levels of free fatty acids circulating in their bloodstream, which can further impair insulin's action[2].

However, it is essential to recognise that insulin resistance can occur in individuals who are not overweight. Some people may have a genetic predisposition to developing insulin resistance, regardless of their body weight. 

1. Genetic factors

If one of your parents or siblings has been diagnosed with diabetes, you may be at an increased risk of developing insulin resistance. This is because diabetes can have a genetic component, and having a first-degree relative with the disease can increase your likelihood of developing it[3]. 

1. Lifestyle factors 

Various lifestyle factors can influence insulin resistance, including a sedentary lifestyle, smoking and poor diet. When an individual lacks physical activity, this can contribute to insulin resistance. 

Consuming a diet high in processed foods and sugary beverages can also lead to weight gain and insulin resistance. Over time, this can increase the risk of developing type 2 diabetes.

1. Medical and health conditions 

Certain health conditions increase the risk of developing insulin resistance, such as high blood pressure and abnormal cholesterol levels[4]. A history of gestational diabetes, heart disease, or stroke also puts individuals at a higher risk. Medical conditions like polycystic ovary syndrome and sleep apnea can lead to insulin resistance, which makes it harder for insulin to regulate blood sugar levels effectively. This can further increase the risk of developing prediabetes or type 2 diabetes.

1. Medications and hormonal imbalances

Certain medications like steroids, some blood pressure medications, specific HIV treatments, and some psychiatric medications can cause insulin resistance in your body. In addition, certain hormone disorders such as Cushing's syndrome, Acromegaly, and Hypothyroidism can also impact how well your body utilises insulin[5].

Insulin and diabetes

 

There are different types of diabetes, each with a unique relationship to insulin. Either the body doesn't produce enough insulin or doesn't use it correctly. This article mostly refers to type 2 diabetes and prediabetes, but here’s an outline of all four of them. 

1. Type 1 Diabetes

Type 1 diabetes is when the body's immune system mistakenly attacks and destroys cells in the pancreas that make insulin. As we know, Insulin helps regulate the amount of sugar in our blood. So, when these cells are damaged or destroyed, the body can't produce enough insulin or any at all. This lack of insulin causes problems because it means the body can't properly control the blood sugar levels.

Risk factors for type 1 diabetes

When it comes to understanding the things that increase the chances of developing type 1 diabetes, there isn’t a clear picture like there is for prediabetes and type 2 diabetes. However, we know a few factors can contribute to the risk of developing type 1 diabetes[6]. These factors include:

• Family history: Having a first-degree relative, such as a parent, brother, or sister, who already has the condition. This means that if someone in your immediate family has type 1 diabetes, you may be at an increased risk of developing the disease yourself.
• Age: This condition can affect people of any age, although it is most commonly diagnosed in children, teenagers, and young adults. 

Prevention and cure for type 1 diabetes

Medical professionals do not know how to prevent type 1 diabetes, and there is no known cure[7]. 

1. Type 2 Diabetes

Type 2 diabetes is when the body's cells do not respond properly to insulin, resulting in insulin resistance. This causes an inability to efficiently utilise sugar (glucose) for energy, leading to high blood sugar levels if left untreated[8].

Risk factors for type 2 diabetes

If you exhibit any of the following risk factors, then you may be at a higher risk for developing type 2 diabetes:

• Have prediabetes
• Are overweight, especially around the waist 
• Are 45 years of age or older
• Have a direct family member, such as a parent, brother, or sister, with type 2 diabetes.
• Engage in physical activity fewer than three times a week
• If you have had gestational diabetes (diabetes during pregnancy) or given birth to a baby weighing over 9 pounds. 
• If you have non-alcoholic fatty liver disease 

Prevention and cure for type 2 diabetes

You can reduce your risk of developing type 2 diabetes by making lifestyle changes such as losing weight, eating a healthy diet, and engaging in regular physical activity.

Once a person develops type 2 diabetes, it cannot be cured. However, it’s possible to achieve complete remission (glucose levels return to the non-diabetic range) or partial remission (glucose levels return to the pre-diabetic range)[9]. 

1. Prediabetes

Prediabetes is when blood sugar levels are higher than normal but not yet high enough to be considered type 2 diabetes. If left untreated, prediabetes can progress to type 2 diabetes within a decade[10].

Risk factors for type Prediabetes

Certain factors can increase your risk of developing prediabetes. These include: 

• Being overweight, especially around the waist 
• Are 45 years of age or older
• Have a direct family member, such as a parent, brother, or sister, with type 2 diabetes.
• Engage in physical activity fewer than three times a week
• If you have had gestational diabetes (diabetes during pregnancy) or given birth to a baby weighing over 9 pounds. 

Prevention and cure for Prediabetes

You can prevent or reverse prediabetes by making lifestyle changes. These include losing weight if you’re overweight, eating a healthy diet, and exercising regularly[11].

1. Gestational diabetes 

Gestational diabetes is a type of high blood sugar that can occur during pregnancy. If someone has gestational diabetes, it means their blood sugar levels are higher than normal. 

This can be a problem because it puts them at a higher risk of getting type 2 diabetes in the future. However, most of the time, there are no signs or symptoms of gestational diabetes, so getting a blood sugar test during pregnancy is important. This test will help doctors diagnose gestational diabetes and take necessary steps to keep mum and baby healthy.

Risk factors for type gestational diabetes

Here are a few factors that increase the risk of developing gestational diabetes: 

• If you’ve had gestational diabetes during a previous pregnancy
• If you’ve given birth to a 9-pound or heavier baby 
• Are overweight
• Are 25 years of age or older
• Have a family history of type 2 diabetes
• Have polycystic ovary syndrome (PCOS), a hormone disorder. 

Prevention of gestational diabetes

If you're planning to get pregnant, it's important to take steps to prevent gestational diabetes. You should eat a healthy diet and get regular physical activity to prevent this. If you’re overweight, it can also help to lose some weight. However, losing weight is not recommended if you are already pregnant. In fact, you will need to gain some weight during pregnancy, but not too fast. It's best to talk to your doctor about how much weight you should aim to gain to have a healthy pregnancy[12].

Gestational diabetes typically resolves after childbirth but increases the risk of developing type 2 diabetes. Additionally, babies born to mothers with gestational diabetes are more likely to develop obesity and type 2 diabetes later in life.

The difference between prediabetes and insulin resistance

Prediabetes and insulin resistance are related conditions, but they are different.

Prediabetes is when blood sugar levels are higher than normal but not high enough to be classified as type 2 diabetes. It’s considered an intermediate stage between normal blood sugar levels and diabetes. Prediabetes is diagnosed when the fasting blood sugar level is 100-125 mg/dL (5.6-6.9 mmol/L), or the hemoglobin A1C level is 5.7-6.4%[13].

Insulin resistance, on the other hand, is a condition in which the body's cells become less responsive to the effects of insulin. Insulin is a hormone that helps regulate blood sugar levels by allowing glucose to enter the cells, which can be used for energy. When cells become resistant to insulin, glucose cannot enter properly, leading to higher blood sugar levels. Insulin resistance is often a precursor to prediabetes and type 2 diabetes.

What are the Symptoms of insulin resistance?

If you have insulin resistance, this can lead to various symptoms, including[14]:

1. Weight gain or difficulty losing weight.
2. Increased hunger or cravings, especially for sugary foods.
3. Fatigue or low energy levels.
4. Frequent urination.
5. Increased thirst.
6. Darkened skin patches, especially around the neck or armpits.
7. Polycystic ovary syndrome (PCOS) in women is characterised by irregular periods, excessive hair growth, and fertility issues.
8. High blood pressure.
9. High cholesterol levels.
10. Skin tags, which are small, soft growths on the skin.
11. Slow wound healing.

It's worth mentioning that not everyone with insulin resistance will experience the same symptoms. In fact, some people may not even notice any symptoms at all. If you think you might have insulin resistance, it's best to talk to a doctor so they can give you a proper diagnosis and help you manage the condition.

How is insulin resistance diagnosed? 

Here are some common methods used to diagnose insulin resistance:

Medical history: your doctor will ask about your symptoms, family history of diabetes or insulin resistance, and any other relevant medical conditions.

Physical examination: your doctor may perform a physical exam to check for signs of insulin resistance, such as excess weight, particularly around the abdomen.

Fasting blood sugar test:  measures the amount of glucose (sugar) in your blood after fasting for at least 8 hours. Higher than normal fasting blood sugar levels may indicate insulin resistance.

Oral glucose tolerance test (OGTT): involves drinking a sugary solution and measuring blood sugar levels before and after a specific period. Elevated blood sugar levels after the test may indicate insulin resistance.

Haemoglobin A1c (HbA1c) test: provides an average estimate of blood sugar levels over the past 2-3 months. Higher HbA1c levels may suggest insulin resistance.

Insulin levels: measuring fasting insulin levels can help determine if the body produces excessive amounts of insulin in response to insulin resistance.

How does insulin resistance affect my body?

 If you become insulin resistant, over time, this can lead to several health consequences, including[15]:

Type 2 diabetes: Insulin resistance is a major risk factor for developing type 2 diabetes. When the body cannot use insulin effectively, the pancreas produces more insulin. Eventually, the pancreas may be unable to keep up with the increased demand, leading to elevated blood sugar levels and diabetes.

Cardiovascular disease: Insulin resistance is associated with an increased risk of developing cardiovascular diseases such as heart disease and stroke. High blood sugar levels and insulin resistance contribute to forming plaques in the arteries, narrowing the blood vessels and impairing blood flow.

Obesity and weight gain: Insulin resistance can lead to weight gain and difficulty in losing weight. Insulin plays a role in regulating fat metabolism, and when the body becomes resistant to its effects, it becomes more challenging to burn stored fat.

Polycystic ovary syndrome (PCOS): Insulin resistance is closely linked to PCOS, a hormonal disorder affecting women of reproductive age. Insulin resistance contributes to hormonal imbalances, leading to symptoms such as irregular menstrual cycles, infertility, and excessive hair growth.

Non-alcoholic fatty liver disease (NAFLD): Insulin resistance can lead to fat accumulation in the liver, resulting in non-alcoholic fatty liver disease. If left untreated, it can progress to more severe conditions such as non-alcoholic steatohepatitis (NASH) and liver cirrhosis.

Sleep apnea: Insulin resistance is associated with an increased risk of developing sleep apnea, a sleep disorder characterised by interrupted breathing during sleep. This can lead to daytime sleepiness, fatigue, and an increased risk of cardiovascular problems.

Cognitive decline: Some studies suggest a link between insulin resistance and cognitive decline, including an increased risk of developing Alzheimer's disease and other forms of dementia. The exact mechanisms behind this association are still being studied.

It is important to note that not everyone with insulin resistance will experience all the related health problems. Having said that, it’s important to take insulin resistance seriously and consult a healthcare professional if you think you might have it.

How to manage insulin levels

Detecting and managing insulin resistance early on is important in preventing prediabetes or type 2 diabetes. 

Regular physical activity, a balanced diet, weight loss (if overweight), stress reduction, and sufficient sleep are all important in preventing, reversing, and managing insulin resistance and promoting overall health.

If you want to reduce the amount of insulin in your body as per your doctor's advice, here are some simple tips that you can follow:

• Consume less sugar 

This one might be obvious, but eating too much sugar can make your body less able to control your blood sugar levels[16]. However, what’s less obvious is the foods that are sugar bombs. Here is a list of the most common culprits: 

• Breakfast cereals 
• Breakfast smoothies 
• Fruit juice
• Honey 

Related article: Six foods that are making you insulin-resistant

• Add physical activity to your daily routine

Unsurprisingly, being active can benefit you in many ways, like helping your brain, managing weight, and reducing the risk of disease. But did you know that regular physical activity can also help lower insulin levels in your body?[17] 

If you're not keen on the idea of going to a gym, you can still stay active and healthy by incorporating physical activities into your everyday routine. For instance, you can take daily walks, use the stairs instead of escalators, follow workout routines that you can do at home, join a social sports team, or simply turn on some music and dance while doing household chores. There are many ways to increase your physical activity without signing up for a gym membership. Who knows, once you become more active, you might feel more confident about joining a gym in the future!

Related article: How to stay active without a gym membership 

• Incorporate intermittent fasting

Studies have shown that intermittent fasting could be just as effective, or even more effective, than daily calorie restriction in reducing insulin levels[18].

There are different ways to practice intermittent fasting, but all of them include periods where you don't eat followed by periods where you do.

One of the most popular ways of intermittent fasting is known as the 16/8 method or the Leangains protocol. This method involves skipping breakfast and limiting your eating to an 8-hour period. For example, you could eat from 1 pm to 9 pm and fast for 16 hours until 1 pm the next day.

• If advised, concentrate on weight loss

Having too much fat around your belly, also known as visceral or abdominal fat, can lead to various health problems. Visceral fat can cause inflammation and make it difficult for your body to handle insulin properly[19]. 

When you lose weight, you lose not only the fat you can see and pinch but also the harmful fat surrounding your organs. Even though you cannot target this specific type of fat, losing weight can help you eliminate it too.

• Manage stress levels

Taking care of your stress levels can be really helpful in managing insulin resistance. When you're constantly stressed, your body produces a hormone called cortisol which can interfere with your insulin function and make it harder for your body to process sugar. By managing your stress levels, you can help regulate your cortisol levels and potentially improve your body's sensitivity to insulin. This can be really beneficial for your overall health and well-being!

There are various ways to manage stress that can be helpful for everyone. These include things like getting regular exercise, making sure to get enough sleep, trying relaxation techniques such as deep breathing or meditation, seeking support from family and friends, and doing activities that help you feel happy and calm.

Foods to eat if you suffer from insulin resistance 

We talked earlier about the foods you should avoid. So here’s a list of foods and drinks you can add to your diet to combat insulin resistance. 

Related article: Foods to eat if you have insulin resistance  

Related article: Top 10 foods to naturally lower blood sugar

• ACV (Apple Cider Vinegar) 

ACV may help keep your blood sugar levels stable after you eat[20]. However, if the thought of drinking apple cider vinegar doesn’t appeal to you, try making ACV lollies and consuming them half an hour before every meal. 

Related recipe: Apple Cider Lollies

• Consume adequate protein 

Starting your day with a breakfast that's high in protein can help with controlling your blood sugar. However, eating too much protein for prolonged periods might cause your blood sugar levels to rise. 

Research suggests that eating more plant-based proteins will help you lower the risk of developing type 2 diabetes. On the other hand, eating a lot of red meat increases your chances of getting type 2 diabetes[21]. So, it's essential to eat a variety of proteins that are good for you and to avoid processed protein.

Related recipe: Chicken Breakfast Patties

• Fatty fish

Eating fatty fish like salmon, sardines, mackerel, herring, and anchovies can be really good for you. They have lots of high-quality protein and contain long-chain omega-3 fats, which are very healthy. 

Research has shown that these omega-3s may help people with conditions like obesity, gestational diabetes, and PCOS by reducing insulin resistance[21].

• Increase your intake of soluble fibre

Soluble fibre is a type of fibre that can be easily dissolved in water and has many health benefits. It can help you lose weight by making you feel full for longer and also helps to regulate your blood sugar levels. After you eat, the soluble fibre in food mixes with water to form a gel-like substance that slows down digestion. This helps you feel fuller for longer and prevents blood sugar spikes that can happen after eating[22]. 

Here are some other foods you should consider incorporating into your diet if you suffer from insulin resistance. 

• Cruciferous vegetables
• Fermented food
• Avocado 
• Cinnamon
• Green tea

Sources and cites 

[1]Recent Advances in the Treatment of Insulin Resistance Targeting Molecular and Metabolic Pathways: Fighting a Losing Battle? | 2022 

[1.1]Obesity, insulin resistance and diabetes--a worldwide epidemic | 2000 

[2]Obesity and insulin resistance | 2000 

[3]Genetics of Insulin Resistance and the Metabolic Syndrome | 2016 

[4]Insulin Resistance | Cleveland Clinic 

[5]]Insulin Resistance | Cleveland Clinic 

[6]Diabetes Risk Factors | Centres for Disease and Prevention 

[7]The Future of Type I Diabetes | Gavan Institue of Medical Research 

[8]Diabetes | World Health Organization 

[9]Can Type 2 Diabetes Be Reversed? | Joslin Diabetes Centre  

[10]Prediabetes | Mayo Clinic 

[11]Prediabetes – Your Chance to Prevent Type 2 Diabetes | Centres for Disease and Prevention 

[12]Gestational Diabetes | Centres for Disease and Prevention 

[13]Prediabetes | Mayo Clinic 

[14]Insulin Resistance | Healthline 

[15]Insulin Resistance | Cleveland Clinic 

[16]Sugar consumption, metabolic disease and obesity: The state of the controversy | 2016   

[17]Short-term HIIT and Fat max training increase aerobic and metabolic fitness in men with class II and III obesity | 2015 

[18]Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings | 2014  

[19]Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings | 2015 

[20]Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin Resistance or Type 2 Diabetes | American Diabetes Association 

[21]Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin Resistance or Type 2 Diabetes | 2015 

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