Even though insulin resistance can lead to diabetes, hypertension and cancer, conventional medicine is not interested since there is no diagnosis and no treatment.
I was covering medical emergencies on a cold December night when a colleague said, “Dr Ibrahim, should you use your asthma puffer (inhaler) because you are very wheezy?”
That was the first clue that I had hit a serious medical problem. My colleagues had to rush me to the radiology department. They were shocked to see that my windpipe was kinked due to severe compression on my neck.
After urgent surgery, during which half of my thyroid gland was removed, I felt much better. However, at midnight, I deteriorated again with severe asthma-like symptoms. I asked the surgical house officer to remove my stitches immediately, and those were my last words before I went into a deep coma.
I have had a battle with insulin all my life, eventually learning to live with my sugar problems. In this blog, I want to define the importance of insulin sensitivity – and the dangers of insulin resistance. It is a subject dear to my heart, as you can see – and it may catch your attention too!
Why is insulin so important?
When you eat, the pancreas senses sugar in the bloodstream and responds by releasing insulin. This reaches every cell in the body to facilitate sugar delivery. Insulin touches the receptor, as it were, to open the door for sugar to enter.
Insulin resistance occurs when insulin knocks on the door, but the door does not open fully, and a smaller amount of sugar reaches the cell – insufficient to fuel the body. Your cells continue to feel hungry, sending a message to the pancreas to pump more insulin so that more sugar can be delivered.
The pancreas continues compensating for the defect by producing more and more insulin, resulting in high insulin levels.
Do all types of sugar produce the same effect?
Sucrose (Table sugar), produced from sugarcane, comprises equal amounts of glucose and fructose. When you eat table sugar, only the glucose component stimulates the pancreas to produce insulin. The fructose does not.
Other sugars, like lactose (milk sugar), consist of glucose and galactose. The latter is converted to glucose, which raises blood sugar and stimulates the pancreas to produce insulin.
The biggest food sources of glucose are starches in different grains’ flour. We generally refer to these as carbs in creals, bread, rice, pasta, and pizza. These are converted 100% to glucose and can raise your blood sugar to twice the level of table sugar.
Fructose, a fruit sugar, does not stimulate the pancreas to produce insulin but can cause insulin resistance through the back door. This is because it goes straight to the liver, which can process a limited amount of it into energy. However, an excess of fructose results in fat deposition in the liver cells, making them insulin-resistant and eventually causing fatty liver. This can progress to heart disease, stroke, dementia or even cancer.
High fructose corn syrup (HFCS) is made from corn through a chemical process. It is the cheapest but the sweetest sugar on the planet. HFCS has driven the boom in the soft drinks industry, like Pepsi Cola and Coca-Cola. It is also found in cookies, sweets, chocolate bars, bread, and ketchup.
Like fructose, HFCS does not stimulate insulin release but can cause insulin resistance by triggering lipogenesis (fatty liver), leptin resistance (inability to stop eating), and high uric acid, which can cause gout. Studies revealed a strong correlation between uric acid and insulin resistance, the common factor among metabolic diseases.
The importance of fibre and nutrients
The factory processing of carbohydrates involves the removal of fibre and nutrients, such as vitamins and minerals, to give us empty calories (starch.) This process aims to prolong the shelf life of the product. The body digests carbs into glucose. But it would be best to have these nutrients, like B vitamins, iron, and magnesium, to convert glucose into energy (ATP) for fuel. Lack of nutrients compels the body to store excess calories as fat.
Everyone knows that fibre is essential for bowel function. However, it is the missing element in our modern diet, which typically contains 15 grams of fibre per day compared to the 100 grams in the cavemen’s diet.
Fibre is available as soluble and insoluble fibre. Soluble fibre slows down the absorption of glucose and fats, resulting in a slow insulin response. It is fermented by the beneficial bacteria in the colon to produce short-chain fatty acids, which nourish the colon wall and protect against cancer. The insoluble fibre consists of non-glucose carbohydrates, such as cellulose. It is a bulk-forming agent that speeds up food passage through the gut.
To reap the full benefit, you need to have a mixture of the two types of fibre. Soluble fibre is found in oats, apples, flaxseed, lentils, cucumbers, and berries, while insoluble fibre is found in whole wheat, nuts, celery, carrots, and dark leafy green vegetables.
What causes insulin resistance?
Chronic inflammation is the underlying cause of insulin resistance and metabolic syndrome. It is a 24/7 low-grade inflammation with no apparent purpose except to destroy bodily tissue and cause disease. It’s a no-brainer to pick sugar as the culprit. But which type of sugar is the worst?
Simple sugar causes inflammation and insulin resistance. High fructose corn syrup (HFCS) renders the liver and muscles insulin-resistant, fuels an irresistible appetite and raises uric acid, the new marker of insulin resistance.
Processed and refined carbohydrates, such as bread, highly polished white rice, pasta, pizza, and biscuits, can also cause inflammation. These break down into sugar, which raises blood sugar quickly.
Cheap vegetable oils, such as corn, sunflower, and safflower, all contain the inflammatory omega 6. Together with trans-fat in fast and restaurant food, these are major causes of inflammation and insulin resistance.
Allergens can also trigger inflammation. Gluten is the main offender in this group, but so are dairy, soy, eggs, and peanuts.
Food is a culprit, but belly fat is the most typical source of chronic low-grade inflammation. We will discuss this in another blog.
Smoking is another common cause of insulin resistance. Nicotine makes your cells less sensitive to the action of insulin and raises cortisol, which antagonises insulin and increases triglyceride, the forgotten risk factor for vascular disease.
Studies showed that smoking doubles the risk of having diabetes. But the risk of diabetes starts to drop two years after giving up smoking, reaching non-smoker levels in 10 years.
Sitting is the new smoking
There is compelling evidence that periods of physical inactivity led to insulin resistance and adverse metabolic and vascular consequences.
However, physical activity is a fast and reliable way to enhance insulin sensitivity. Even without insulin, moving your muscles empowers them to suck glucose from the circulation. No wonder a 15-minute walk after lunch flattens the post-meal glucose spike.
Exercise builds muscles and makes them hungry for sugar. You need 60 minutes of moderate activity per day to prevent metabolic conditions.
Thyroxine regulates metabolism; when it’s too low in the underactive thyroid, it slows down metabolism, leading to insulin resistance, weight gain and high blood fat.
Consequences of high insulin
High insulin promotes cell proliferation, resulting in prostate enlargement, a condition known as benign prostatic hyperplasia (BPH), which is highly prevalent in older men and associated with distressing urinary tract symptoms.
Similar changes in the ovaries result in polycystic ovary syndrome (PCOS), usually present with obesity, excessive body hair and infertility in women.
Insulin stimulate HMG COA reductase, the key enzyme in cholesterol synthesis in the liver that raises blood cholesterol levels.
High insulin can cause cysts in various body organs. We see these cysts regularly on scans, but we consider them incidental findings of no clinical significance. This was my impression until I had a life-threatening bleeding into a thyroid cyst.
Inflammation raises blood sugar, damaging blood proteins. The most important are the immune cells, so their damage causes low immunity. This is why patients with sugar problems tend to catch infections, particularly seasonal flu.
Sugar damages proteins through a process known as glycation, resulting in advanced glycation end products (AGES), a common cause of accelerated ageing.
High insulin causes hypertension
The proliferation of cells in the arterial wall causes the thickening and narrowing of arteries. It also promotes build up of cholesterol plaques and calcification along the artery wall. The heart must pump harder to push blood through thick and narrowed arteries, raising blood pressure.
High blood glucose levels damage the endothelium (arterial lining), which secretes nitric oxide (NO), a chemical that relaxes the arterial muscle and maintains normal blood pressure.
High insulin levels also enhance the absorption of sodium in the kidneys, increasing blood volume and promoting the development of hypertension.
40% of people with insulin resistance have it for the rest of their lives, without it causing diabetes, but 60% progress to the metabolic disease’s continuum.
How do I know if I am insulin-resistant?
Changing from insulin-sensitive to insulin-resistant takes time. Without the diagnostic power to identify insulin resistance early on, we miss an excellent opportunity to prevent metabolic diseases.
High risk group should be vigilant. The risk for insulin resistance include smoking, a sedentary lifestyle, obesity and overweight, a family history of diabetes or high blood pressure, gestational (during pregnancy) diabetes, giving birth to a large baby of more than 9 Ib, menopausal women and those with PCOS.
Insulin resistance is also called a silent disease, as it usually has no specific symptoms beyond subtle ones, such as general tiredness, brain fog, food cravings and frequent hunger. Affected people typically see their energy levels fluctuate around meals, often resulting in a significant afternoon slump and interrupted sleep at night.
Patients can display certain features, such as patches of dark skin, usually in the armpit, neck, or face, known as acanthosis nigricans, and skin tags anywhere. Potbellies in men and facial hair in obese ladies are more common.
Routine tests usually show normal blood sugar, which rises in the late stages of insulin resistance. Inflammatory markers like high-sensitivity CRP (hs-CRP) and the vascular risk factor homocysteine may be raised. HbA1C may be slightly off range, and high triglyceride (TG), and low HDL (the good guy) cholesterol are common.
The surrogate markers of insulin resistance include HOMA-IR, TG, and the ratio TG/HDL. A ratio of >2.5 also suggest high vascular risk.
However, a fasting insulin is the gold standard test – the earliest opportunity to document and confirm high insulin.
Why don’t we discover insulin resistance early?
Conventional medicine is not interested in insulin resistance because the condition is silent, with no symptoms, and therefore, there is no overt disease to treat and cure. Conventional medicine ignores the area between health and disease and waits until a disease is fully formed before any treatment is offered. This is an area where function medicine could complement conventional medicine.
The hospital protocol allowed for only two tests – blood glucose (BG) and haemoglobin A1C (HbA1C) – and, of course, both remain normal until late in the disease’s development.
Management
Insulin resistance can be managed by combining a high-fibre anti-inflammatory diet—that includes fish oil—regular exercise, and a healthy lifestyle.
Restful sleep, good physical activity, and a lower level of stress can improve your sensitivity or manage your resistance naturally. Losing 5 to 10% of your body weight enhances your insulin sensitivity. Ensure a high soluble fibre intake and add colourful fruit and vegetables to a diet low in carbohydrates and sugar.
Let me be a bit more specific about exercise. Aerobic exercise such as walking, running, and swimming helps you improve your heart and lung fitness. However, muscle strength training increases your muscle mass, which increases your basal metabolic rate (BMR – the speed at which you burn calories at rest). This acts like a sponge to suck up excess energy to prevent obesity and metabolic diseases.
So, my friends, you can see that, whilst diagnosis of insulin resistance is difficult, it can be achieved—we offer the ‘gold standard’ fasting insulin test at The Vitality Clinic—and avoiding or managing the condition is straightforward. Please share your thoughts and questions by commenting on this piece, and subscribe to the newsletter so that you don’t miss further vital information. Thank you!
References
Physical inactivity induces insulin resistance and microvascular dysfunction in healthy volunteers
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2596308/
Insulin: too much of a good thing is bad
Hepatic insulin, clearance: mechanism and physiology
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734066/
The Role of Insulin Resistance/Hyperinsulinism on the Rising Trend of Thyroid and Adrenal Nodular Disease in the Current Environment
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5867563/
Mechanically Different Effects of Fat and Sugar on Insulin Resistance, hypertension, and Gut Microbiome, in Rats
https://pubmed.ncbi.nlm.nih.gov/29351480/
