26/08/2025
Insulin Resistance: The Silent Health Threat
Insulin is a vital hormone produced by the pancreas’s beta cells. Its primary role is to regulate blood glucose (sugar) levels and support energy storage and utilization. Here are two of insulin’s main functions:
1. It lowers blood sugar by binding to receptors on cells, particularly in muscles, liver, and fat, allowing glucose to enter for use as energy, storage as glycogen (carbohydrates), or conversion to fat.
2. It works with glucagon, another pancreatic hormone produced by alpha cells, which raises blood glucose to maintain a healthy range.
These hormones should work harmoniously, but insulin resistance (IR) disrupts this balance. In IR, cells become less responsive to insulin, leading to high blood insulin and glucose levels. This condition contributes to type 2 diabetes, cardiovascular disease, cognitive decline, and even increased cancer risk due to chronic inflammation. As IR worsens, cells struggle to absorb glucose, impairing energy production and potentially causing organ dysfunction. IR also reduces blood vessels’ ability to dilate, raising blood pressure and contributing to metabolic dysfunction, a state underlying many chronic diseases.
As blood vessels become insulin resistant they are less responsive to insulin’s vasodilatory effects, so they lose the ability to dilate, expand and carry more blood. Normally insulin causes blood vessels to dilate, but as IR increases this doesn’t occur but an increase in blood pressure does. So what are the consequences of this happening - a very unhealthy state called “metabolic dysfunction”, which means the body’s normal processes for generating and using energy are not working properly. This underlies many chronic diseases often leading to death. It is happening at ever increasing numbers in our communities.
Most adults today have some degree of IR, often caused by excessive consumption of sugar, refined carbohydrates, and fast foods. Carbohydrates raise blood glucose, triggering insulin release. Over time, persistently high insulin levels lead to IR.
Interestingly, IR affects tissues differently: fat cells may remain insulin-sensitive and store excess fat, while muscle cells become resistant, starving them of energy. This imbalance causes calories to be stored as fat rather than burned, increasing the risk of obesity and chronic diseases.
IR’s story isn’t cut and dried, some tissues can remain sensitive to insulin while others become unresponsive. For example, fat cells can be sensitive and store fat, whilst muscle cells can be resistant and be starved of energy.
This results in energy contained in the calories you are eating being mainly stored in the body and not burned for energy. Fat accumulates, which again is bad for your health and raises your chance of succumbing to chronic diseases.
Mitochondrial Uncoupling (MU) - Thermoregulation
MU is a fancy name but has very interesting connotations. MU is a healthy state whereby fat and other substrates including glucose, are used to produce heat instead of producing cellular energy called ATP. Most of this heat comes from brown adipose tissue because it is rich in mitochondria and contains an uncoupling protein (UCPI) which is very efficient at producing heat.
The problem arises when Insulin levels become too high, slamming the brakes on mitochondrial uncoupling and resulting in only energy use when you need it, and not wasting it on heat. This is a problem because shedding heat energy is crucial for keeping us lean and healthy. This is why cold immersion baths and subjecting your body to very cold temperatures can have healthy benefits.
When insulin levels are low and MU is working, it has been shown you can burn up to 300 more cals a day. High insulin not only stops healthy thermoregulation but inhibits fat loss and raises the likelihood of contracting disease states.
Insulin resistance and Vitamin D (Vit D)
Optimal vitamin D levels are crucial for reducing IR and improving overall health. Benefits include:
1. Enhancing insulin receptor function and signaling, improving cellular communication.
2. Upregulating glucose transporter 4 (GLUT4), increasing glucose uptake by cells.
3. Reducing inflammation associated with IR.
4. Protecting pancreatic beta cells, slowing IR and diabetes progression.
5. Supporting cardiovascular health by reducing related risks.
To combat IR, try these steps:
1. Reduce sugar and refined carbohydrates (e.g., white bread, pastries). Choose complex carbs like whole grains, legumes, and vegetables to lower the glycemic index and insulin spikes.
2. Eat smaller portions to avoid overloading your plate.
3. Time meals before physical activity, not before sedentary activities like watching TV or sleeping.
4. Consider a ketogenic diet if obese, as it can reduce insulin levels and lower IR.
5. Increase vitamin D through sunlight, foods (e.g., fatty fish), or supplements.
6. Exercise regularly to improve insulin sensitivity.
Conclusions
Insulin resistance is a widespread and dangerous condition that increases with age and poor lifestyle habits. Fortunately, it can be managed or reversed through simple changes. Eat natural, unprocessed foods like vegetables, fruits, proteins (meat and Fish) and healthy fats. Avoid sodas, fruit juices, sugars, and refined flours, which spike insulin. Fiber-rich foods slow nutrient absorption, reducing insulin surges. By adopting these habits, you can improve insulin sensitivity, lower chronic disease risk, and enhance your health and longevity. Graeme
