A whopping 88% of adults in the US have some degree of insulin resistance. And with a staggering 70% of all calories consumed globally coming from carbohydrates, it’s no wonder the average person spends every waking moment in a state of elevated insulin. Are you unknowingly part of this “hidden epidemic?”
What is Insulin Resistance?
Talk about insulin resistance has been buzzing around the health world, and for good reason. It can affect a lot of people and is linked to some pretty serious health issues. But what exactly is it?
In a nutshell, insulin resistance is when your body’s cells become less responsive to the hormone insulin. Think of it like this: insulin is a key player in managing your blood sugar levels.
Insulin’s Role: The Body’s Glucose Shuttle and More!
Insulin, produced by your pancreas, is like a super-efficient “taxi” or “shuttle,” transporting glucose (sugar) from your bloodstream into cells. These cells then use that glucose for energy or store it for later. Pretty neat, huh?
But insulin’s job doesn’t stop there! It also acts like a “bouncer,” knocking on the door of cells (especially muscle cells) to allow glucose to enter. Think of insulin as the key to unlocking the energy your cells need.
Basically, insulin has a thematic effect on the entire body, telling it what to do with energy in all its forms, including glucose, fats, lactate, ketones, and amino acids.
The Two Sides of Insulin Resistance: A Double Whammy
Now, here’s where it gets interesting. Insulin resistance isn’t just a single issue; it’s more like a coin with two sides:
- Reduced Insulin Sensitivity: This is the first part of the problem. Insulin simply doesn’t work as well as it should. Remember the “taxi” analogy? If your muscle tissue is insulin resistant, insulin tries to pull the sugar-loaded taxi into the muscle, but the muscle is all like, “Nah, I’m good.” It’s like a bouncer knocking on a deaf muscle cell door, struggling to get the glucose in. Some cells or tissues become “deaf” to insulin’s demands, making it less effective at lowering blood sugar.
- Higher Insulin Levels: And here’s the kicker. At the same time that insulin isn’t working well, your blood insulin levels are higher. The body is smart (most of the time). If the muscle cell doesn’t respond to the “bouncer” (insulin), the body adapts by sending an “angry mob of bouncers” (more insulin) to try and get the muscle to open the door for glucose. So, your pancreas starts pumping out more and more insulin to try and force those cells to respond.
So, insulin resistance is a double whammy: your cells are less responsive to insulin, and your body is producing more of it to compensate. Sounds like a recipe for trouble, right? In the next section, we’ll dive into why this happens and what it can lead to. Stay tuned!
What Causes Insulin Resistance?
Alright, so we know what insulin resistance is, but what actually causes it? Turns out, there are multiple paths to this destination, and we can think of them as two main lanes: the fast lane and the slow lane.
The Fast Lane: Quick Onset, (Potentially) Quick Recovery
This type of insulin resistance can pop up pretty quickly, even within a matter of hours! The good news is, if you address the root causes, you can often reverse it just as quickly. Here are the main culprits in the fast lane:
- Stress, Stress, Stress!: We all know stress isn’t good for us, but it can rapidly make your body insulin resistant. When you’re stressed, your body releases hormones like cortisol and epinephrine (adrenaline), which cause your blood glucose levels to rise. This forces insulin to work overtime to lower it. If this stress-hormone elevation becomes chronic (think sleep deprivation upping your cortisol, or excessive caffeine spiking your epinephrine), insulin has to work harder and harder, eventually leading to burnout and resistance.
- Inflammation Nation: Any increase in inflammation in your body can throw a wrench into your insulin sensitivity. Think about it: during infections (like a cold or flu), your glucose levels tend to be significantly higher because insulin is struggling to manage them. Even in autoimmune diseases like rheumatoid arthritis, the degree of insulin resistance can fluctuate with the level of immune system activity. And let’s not forget smoking and vaping – these are HUGE inflammation triggers that can lead to insulin resistance. Cigarette smoke and the superheated molecules from vaping elicit a powerful inflammatory response. There is also evidence that diesel exhaust gas increases levels of inflammation and insulin resistance.
- Too Much Insulin (Paradoxical, I Know): This one’s a bit of a head-scratcher, but high insulin levels can actually cause insulin resistance. It’s like that saying, “Too much of a good thing is a bad thing.” Basically, if a cell is constantly overstimulated, it may try to become resistant to that stimulus. If your insulin levels are constantly high (often due to frequently consuming carbohydrates throughout the day), your cells (like muscle cells) can become less responsive to it, like becoming “deaf” to the constant “knocking” of insulin trying to bring glucose in. Even a continuous, low-level infusion of insulin can quickly make someone less sensitive to it!
The Slow Lane: Gradual Development, Slower Resolution
This type of insulin resistance develops more gradually and takes longer to resolve. It’s primarily linked to changes in fat tissue.
- Large Fat Cell Size (Hypertrophy): The size of your individual fat cells is a critical factor here. While the total mass of fat might not be the sole determinant of metabolic health, when fat cells become excessively large, they kick off a cascade of events leading to insulin resistance. Large fat cells become dysfunctional and less insulin sensitive. They may even reach a point where they can no longer grow efficiently and signal insulin to stop trying to make them bigger, leading to insulin resistance.
- Insulin’s Role in Fat Storage: Insulin is the primary hormone that tells fat cells to grow and store energy. In the absence of insulin (as seen in untreated type 1 diabetes), it’s nearly impossible to gain or even retain fat, regardless of calorie intake. When insulin levels are frequently high (often due to a diet high in carbohydrates), fat cells are constantly signaled to grow.
- Calories and Fat Cell Growth: While insulin provides the signal for fat cells to grow, calories (energy from food, particularly fats and glucose) provide the building blocks for this growth. Both high insulin and sufficient calories are necessary for significant fat cell enlargement.
- Visceral Fat: The Deeply Unhealthy Fat: The fat stored around your organs (visceral fat) seems to be more strongly associated with insulin resistance compared to subcutaneous fat (the fat just beneath your skin). Visceral fat accumulation can lead to the release of factors that promote insulin resistance. One study showed that moving visceral fat from an obese animal to a lean animal immediately caused insulin resistance in the lean animal.
Other Players Contributing to Insulin Resistance
- Dietary Habits: A diet packed with refined carbohydrates and sugars leads to frequent spikes in blood glucose and, consequently, in insulin levels, contributing to insulin resistance over time. Frequent snacking, even of starchy or sugary treats between meals, keeps insulin levels elevated for most of the day, preventing cells from regaining insulin sensitivity.
- Genetics and Ethnicity: Sadly, some of us may be predisposed. Different ethnicities may have variations in fat cell number and distribution, which can influence their susceptibility to insulin resistance and related metabolic issues.
- Environmental Toxins: Exposure to certain environmental toxins, both inhaled and ingested, can contribute to insulin resistance and fat cell growth. Diesel exhaust particles, cigarette smoke, vaping, and potentially microplastics and chemicals from plastics like BPA have been implicated in promoting fat cell enlargement and insulin resistance.
- Lack of Physical Activity: Moving your body is super important! Lack of muscle mass and physical inactivity reduce glucose utilization, potentially contributing to insulin resistance over time.
It’s important to note that in some physiological states like puberty and pregnancy, the body intentionally becomes more insulin resistant to support growth and development. However, if this insulin resistance becomes excessive, as in gestational diabetes, it can have negative consequences for both the mother and the baby.
The Devastating Domino Effect: Consequences of Insulin Resistance
Okay, we’ve covered what insulin resistance is and how it happens. Now for the not-so-fun part: the consequences. Let me be frank, folks: insulin resistance is a big deal. Dr. Benjamin Bikman calls it a “hidden epidemic” with “devastating consequences,” and he’s not exaggerating. Think of it as a core problem underlying many chronic diseases that are major causes of death. It’s like a metabolic domino effect, where one issue triggers a cascade of others.
Here’s a rundown of the major consequences you should be aware of:
- Increased Risk of Most Chronic Diseases: This is the umbrella statement. Insulin resistance is identified as the fundamental issue for a wide range of chronic illnesses. So, if you want to stay healthy long-term, addressing insulin resistance is key.
- Alzheimer’s Disease: “Insulin Resistance of the Brain”: This is a scary one. Alzheimer’s is sometimes called “type 3 diabetes” because it’s essentially “insulin resistance of the brain.” Brain cells become resistant to insulin, affecting their ability to use glucose for energy. This leads to brain glucose hypometabolism, a reduction in the amount of glucose the brain uses. In short, your brain isn’t getting the fuel it needs.
- And the numbers are staggering. Worldwide, there is a new case of dementia every 3.2 seconds. Alzheimer’s disease has gone from not being on the radar to being a top 10 killer. One study found insulin resistance at approximately 40% of individuals with Alzheimer’s, while another study found it to be as high as 70 to 80% in Alzheimer’s patients. The total number of people living with dementia globally is expected to reach 139 Million by 2050, up from around 55 million in 2020.
- Cardiovascular Problems (Hypertension and Heart Disease): Insulin resistance is considered a major contributor to hypertension (high blood pressure), which in turn is a major risk factor for heart disease. It’s all connected!
- Type 2 Diabetes: This is probably the most well-known consequence. The link between obesity, growing fat tissue, and the increased risk of type 2 diabetes was an early concept that drew attention to insulin resistance. Gestational diabetes is also described as essentially “type 2 diabetes of pregnancy,” where insulin resistance goes too far, leading to high glucose levels.
- Infertility (in Both Men and Women): Insulin resistance is a heavy contributor to common forms of infertility.
- Erectile Dysfunction (in Men): Insulin resistance affects the blood vessels, preventing them from expanding properly in response to insulin, leading to insufficient blood flow. It can even be an early manifestation of insulin resistance.
- Polycystic Ovary Syndrome (PCOS) (in Women): Insulin resistance affects the ovaries and their ability to produce proper sex hormones, which is the most common form of female infertility. Women with PCOS are often insulin resistant and may gain weight easily due to this. Dietary changes can potentially reverse PCOS by addressing insulin resistance.
- Fatty Liver Disease (Liver Failure): Insulin resistance is linked to fatty liver disease, which can eventually lead to liver failure. Your liver is a vital organ; keep it healthy!
- Increased Risk of Cancer: Yikes! Tumor tissue, such as breast cancer tissue, can have significantly more insulin receptors (e.g., seven times more in breast tumors) than normal tissue. High insulin levels, a consequence of insulin resistance, can accelerate the growth of these tumor cells as insulin promotes growth. The rising incidence of breast cancer in younger women is potentially linked to the rising incidence of insulin resistance.
- It’s worth noting that cancer incidence amongst women up to 49 years old has seen a really significant rise over the last 20 years, while cancer amongst men in the same age group has been pretty flat. Also, breast cancer is the main cancer for women.
- Neurodegenerative Disorders Beyond Alzheimer’s: Brain glucose hypometabolism, linked to insulin resistance in the brain, is also associated with depression, migraines, epilepsy, and Parkinson’s disease.
- Increased Likelihood of Obesity and Metabolic Complications in Offspring: If a mother has gestational diabetes, she creates a hyperglycemic and hyperinsulinemic environment for her developing baby, hardwiring them to potentially prefer this state after birth, leading to a significantly higher chance of being obese and developing metabolic complications like type 2 diabetes later in life (a 40% higher chance is mentioned).
- Impaired Metabolic Flexibility: Prolonged insulin resistance, especially from a long-term ketogenic diet adaptation, can temporarily reduce the body’s ability to efficiently switch back to burning glucose after a carbohydrate-rich meal.
- Potential for Increased Insulin Resistance with Very Low Salt Intake: Ironically, drastically reducing salt intake can make the body more insulin resistant as insulin tries to retain more salt and water.
- Accelerated Aging (in the Brain): Chronic insulin resistance may accelerate the aging process in the brain.
Conclusion: Reclaim your health
So, we’ve journeyed through the complex world of insulin resistance, uncovering its definition, delving into its causes (both fast and slow!), and facing the stark reality of its potential consequences. Remember, insulin resistance isn’t just a minor inconvenience; it’s a foundational issue linked to a cascade of chronic diseases, from Alzheimer’s and heart disease to type 2 diabetes and even certain types of cancer.
We learned that a shocking 88% of adults in the US have some degree of insulin resistance! Highlighting a critical health concern for almost all Americans.
But don’t lose hope! The fact that you’ve read this far means you’re already taking the first step toward better health: awareness. Understanding what insulin resistance is, what causes it, and what it can lead to empowers you to make informed choices and take proactive steps to improve your metabolic health.
The good news is, insulin resistance is often manageable, and in some cases, even reversible! It’s not a life sentence, but a wake-up call. From managing stress and reducing inflammation to tweaking your diet and getting more active, there are many strategies you can employ to improve your insulin sensitivity and reduce your risk of these devastating consequences.
Now that you understand the what, why, and how of insulin resistance, the next step is to explore specific strategies for reversing it. Lucky for you, we have a wealth of resources right here on this site! Click here to discover our top tips for treating insulin resistance and reclaiming your health.
