Under modern medical practice, insulin resistance often goes undiagnosed. However, it can progress to many chronic diseases, including heart attack, stroke, cancer and dementia, even without causing diabetes.
But the solution is within our grasp.
A 72-year-old lady came to see me. She had recently lost her husband. She reported chronic back and neck pain and felt her shoulders almost touching her ears. I believed her stress was related to her bereavement and that she would benefit from counselling and stress-relieving techniques, such as deep breathing, meditation, and yoga.
She returned to see me three weeks later, saying she had implemented my advice without improvement. I thought I must have missed something major, so we delved more deeply into her lifestyle.
She admitted that she was not really looking after herself. She could not be bothered to cook and relied on convenience food, such as biscuits, crackers, and crisps. She felt lethargic, had gained weight, and said she no longer enjoyed a good night’s sleep.
I did routine blood tests, and, to my amazement, she had a major problem processing sugar – beyond diabetic levels. Her fasting insulin was 26 (normal is 5 or less.) I worked with her to control this. Her shoulders settled into a normal position, her energy returned, and she lost significant weight. The only clue to her problem had been a very high insulin level.
In this blog, I will discuss the blood sugar problem known as insulin resistance, which raises insulin levels, explore why such an increase is detrimental, and describe what we can do to bring the levels down to prevent many chronic diseases from happening, often not including diabetes.
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 into the cells. Insulin touches the receptor, as it were, to open the door for sugar to enter when insulin does this, a protein known as GLUT4 moves towards the cell membrane to allow the entry of glucose into the cell.
Insulin knocks on the door, and GLUT4 opens it! This happens every time you eat.
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 receptor sensitivity defect by producing more and more insulin, resulting in high insulin levels (hyperinsulinemia).
High fructose corn syrup (HFCS) is often responsible
HFCS, in many popular foods, does not stimulate insulin release. Instead, it goes straight to the liver to trigger a process of lipogenesis (making fat). This also causes insulin resistance but through a different mechanism. It results in fat deposition into the liver, causing fatty liver. This can progress to heart disease, stroke, dementia or even cancer.
Changing from being insulin sensitive to insulin resistant takes time. Without having the diagnostic power to identify insulin resistance early on, we miss a great opportunity to prevent these diseases.
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 craving and frequent hunger. Affected people usually see their energy levels fluctuate around meals, often resulting in a significant afternoon slump and interrupted sleep at night. And it leads to excessive weight gain.
Patients can display certain features, such as patches of dark skin, usually in the armpit, neck or face, and skin tags anywhere. More common are pot bellies in men and facial hair in obese ladies.
Routine tests usually show normal blood sugar, only rising to high in late stages of insulin resistance, HbA1C may be slightly off range, high triglyceride, and low HDL (the good guy) cholesterol are common. Specialised tests include high-sensitivity CRP (hs-CRP), and the vascular risk factor homocysteine may be raised.
A fasting insulin test is the gold standard – the earliest opportunity to confirm hyperinsulinemia.
What causes insulin resistance?
Eating a lot of sugar and carbohydrates, particularly those with a high glycaemic index and glycaemic load, results in insulin resistance. This, together with eating frequently (three meals and three snacks daily), can increase insulin levels.
I meet many patients who found it hard to appreciate that smoking is a common cause of insulin resistance. Nicotine makes your cells less sensitive to the action of insulin, raises cortisol which antagonises insulin and increases triglyceride, the forgotten risk factor for vascular disease. Studies showed that diabetics who smoke need more insulin, and smoking doubles the risk of having diabetes. The risk of diabetes starts to drop two years after giving up smoking, reaching non-smoker levels in 12 years.
Thyroxine regulates metabolism; when it’s too low in the underactive thyroid, it slowdown metabolism leading to insulin resistance, weight gain and high blood fat.
Hyperinsulinemia increases your appetite, particularly for energy-dense foods, locks body fat stores, favours energy storage over usage, and drives obesity.
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.
High insulin damage many cells in the body by oxidative stress (rusting) due to associated raised glucose and impairment of cellular antioxidant barriers.
I always explain oxidative stress to my patients by saying that free radicals are generated in every cell while burning fuel (glucose or fat) to produce energy. Sparks emerge from the metabolic fire, and if they are not neutralised immediately by antioxidants, they fall onto the cell parts and damage them.
Hyperinsulinemia promotes hypertension in three ways
The proliferation of cells in the arterial wall cause thickening and narrowing of arteries, raising blood pressure. The heart must pump harder to push blood through thick and narrowed arteries.
Prolonged elevated insulin and associated high glucose levels damage the endothelium (arterial lining), which secretes nitric oxide (NO), a chemical that relaxes the arterial smooth muscle and maintains normal blood pressure. Damaged endothelium suppresses NO production and promotes calcium influx into the artery muscle, resulting in stiff arteries.
High insulin levels also enhance the absorption of sodium in the kidney, increasing blood volume and promoting the development of hypertension.
High insulin damages nerve cells in the brain, resulting in cognitive decline and numbness or loss of sensation in the limbs (peripheral neuropathy).
Promoting cell division and DNA oxidative damage, high insulin is the underlying cause of many cancers.
Unfortunately, conventional medical practice does not work in the gap between health and disease, where early warning signs may be spotted. Medics are not interested in insulin resistance because the condition is silent, so there is no explicit disease to treat. Conventional medicine waits until a disease is fully formed before any treatment.
The solution: fasting and food, but NOT fast food
The most effective way to avoid hyperinsulinemia and, thus, insulin resistance is to restrict the pancreas’s islet cells’ exposure to high glucose by actively reducing your calorie intake or fasting. Exclude high glycaemic index food of simple sugars and processed carbohydrates, and instead eat high fibre in fruits, vegetables, beans, nuts, and seeds.
Everyone knows that fibre is important for bowel function. Some assume fibre is a waste product of food and hence a waste of time. But fibre is the missing element in our modern diet, which typically contains 15 grammes of fibre per day compared to the 100 in the cavemen’s diet.
Soluble fibre slows down the absorption of glucose and fats, resulting in a slow insulin response. You find soluble fibre in oats, apples, flaxseed, lentils, cucumber, and berries, while insoluble fibre exists in whole wheat, nuts, celery, carrots, and dark leafy green vegetables.
A wealth of reports confirm that the Mediterranean diet improves insulin sensitivity.
Excess fat, or fructose, accumulates fat in muscle cells. This activates free radical damage to impair insulin sensitivity. Unlike fat, excess fructose also raises uric acid and blood pressure. Combining excess fat and sugar (Mac and Coke) is more detrimental than excess fat or sugar alone. I recommend the Paleo diet of healthy fat and low-calorie veggies rather than Atkin’s ketogenic diet, which is high in animal proteins and dairy products.
I have met many people who were unsuccessful in increasing their insulin sensitivity, despite a healthy diet simply because they ate all the time. Reducing the number of times you eat (meals or snacks) plummets your insulin level.
I recommend intermittent fasting; 16 hours of fasting and 8 hours of eating is the most popular pattern, but you can also have one meal a day (OMAD) or eat normally for five days and fast or 500 calories a day for two (5:2).
What is the role of exercise?
Aerobic exercise such as walking, running, and swimming improves your insulin sensitivity, speeds up your metabolism and helps you burn more fat. However, equally important is strength training, which increases your muscle mass, crucially increasing your basal metabolic rate (the speed at which you burn calories at rest.)
I also want to stress the impact of restful sleep, lowering stress levels, enjoying more sunshine, having a purpose in life, and loving relationships.
Bariatric surgery and gastric bypass force people to limit their calorie intake, leading to rapid falls in insulin levels and wonderful health outcomes.
Metformin sensitises your cells and makes them more sensitive to the action of insulin but at a high cost of side effects. Berberine, the nutraceutical, is safer and has a similar effect. Patients with underactive thyroids benefit from thyroxine therapy.
Continuous blood sugar (CBS) monitoring is a non-invasive but invaluable technique to help you understand sugar trends, find effective solutions, and motivate you to reach your goals.
So, my friends, insulin resistance may stay with you for life without turning into pre-diabetes or diabetes. It could progress to heart attack, stroke, cancer, and dementia, but, like many threats to our health, it is manageable by adopting simple, straightforward lifestyle changes.
Please share your thoughts and ask any questions on this subject – in the Comment section below is always best so that I can respond most quickly – and please subscribe to the newsletter so you don’t miss further vital information. Thank you!
Insulin: too much of a good thing is bad
Hepatic insulin, clearance: mechanism and physiology
The Role of Insulin Resistance/Hyperinsulinism on the Rising Trend of Thyroid and Adrenal Nodular Disease in the Current Environment
Mechanically Different Effects of Fat and Sugar on insulin resistance, hypertension, and gut microbiome, in Rats