‘Blood sugar regulation’ and ‘insulin resistance’, are common parlance for Nutritional Therapists and Dieticians, but they can leave some clients slightly baffled. Blood sugar regulation is fundamental to good health and many chronic, lifestyle-related conditions occur after years of poor blood sugar regulation, so I thought I would reproduce a recent dialogue from a clinic consultation which covered this very subject.
Q: What exactly is blood glucose?
A: Blood glucose results from carbohydrates (bread, rice pasta and potatoes), getting digested and broken down to simple sugars that then get absorbed, from the intestine, into the bloodstream. The blood then delivers it to any tissues that need it as a source of energy. Glucose is also stored in our muscles and the liver, so these stores of glucose can be released and used when we’re hungry and can’t get access to food.
Q: What happens when blood glucose is too high?
If a meal consists of a lot of sweet carbohydrates, (sandwiches, biscuits, cakes), blood glucose can become high very quickly. This can be made worse if the muscle tissues are still full of stored glucose, if they’ve not been exercised to burn off the last meal’s stored glucose, then another peak of glucose arriving in the blood stream – in excess of needs – will be converted to fat and shunted off to be stored in fat cells.
Q: What has insulin got to do with it?
A: Insulin is a hormone that regulates and keeps blood glucose levels within an optimum range. When blood glucose rises, typically after a meal, insulin is released to direct that glucose to where its needed. If a meal is mostly refined carbohydrate, i.e. a high percentage of it is bread/pasta/rice/mashed potatoes, this will cause a surge of blood glucose that will trigger lots of insulin and fire up metabolic pathways of ‘storage’. For most of us, (excluding athletes who’s muscles are generally ‘thirsty’ for glucose), chronically raised blood glucose will result in stored fat deposits (predominantly around the abdomen).
Q: So apart from that sort of weight gain, why do we worry about high blood sugar levels?
A: Actually this is quite pertinent, because even slim people and athletes can become insulin resistant from chronically raised blood glucose. When insulin levels are constantly high, tissues and their cells become desensitised to the action of insulin. Sometimes, particularly with sedentary individuals – whose muscles have had no opportunity to ‘spend’ their stored energy (stored glucose) – the cells signal they are still full, and so are ‘unreceptive’ to the action of insulin. Even fat cells can down-regulate their receptivity to insulin after a while, leaving glucose circulating in the blood with nowhere to go, causing yet more insulin to be released.
Q: What are the long-term consequences of insulin resistance?
A: Years of elevated blood glucose can eventually lead to Diabetes, a condition where the body either doesn’t make enough insulin or can’t use its own insulin as well as it should. Unfortunately, chronically high blood glucose will eventually damage blood vessels and heightens risk of heart disease. Damage also occurs to tiny blood vessels, typically in the eyes leading to blindness, and nerve damage leading to a loss of sensation and numbness in the feet and hands. If undiagnosed and untreated, severe cases of diabetes can lead to ulcers on the feet and lower legs with disrupted blood flow causing gangrene in toes and feet, leading to amputations.
Q: Are drugs that replace insulin the only option?
A: No, the good news for type 2 diabetes is that insulin resistance is completely reversible, with changes to diet and an increase in your activity levels. And this is important because it’s the chronically raised blood glucose that damages the veins, arteries and small blood capillaries, so maintaining a low sugar diet, and ensuring you eat some protein with every meal, will keep blood glucose at moderate levels. And a brisk walk each day will not only use up circulating glucose, it has also been shown to re-sensitise our cells to insulin.
Dietary changes and exercise as part of a broad programme of behavioural change are the best way to control blood glucose.
Choosing natural, unrefined, whole foods that digest s l o w l y , converting to glucose in a controlled, steady fashion, provide sustained energy levels throughout the day and won’t cause unhealthy surges of insulin. Concentration will also improve and your risk of many conditions like cardiovascular disease and dementia will reduce. A good rule of thumb is to avoid processed foods and refined, white carbohydrates that digest really quickly causing a surge in glucose. But a consultation with a Nutritional Therapist can help an individual adapt their diet to better manage blood glucose and steer a healthy path away from Diabetes.
Hamilton MT et al (2007) Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes 56(11):2655-67 http://www.ncbi.nlm.nih.gov/pubmed/17827399