Microsoft word - bitter sweet

“YOU HAVE A TOUCH OF SUGAR.” Not an unusual comment to hear from a physician. Especially if you are over fifty and starting to have trouble seeing your toes. Most people don’t pay much attention. Why should they? They feel fine. And after all, a “touch” isn’t diabetes. They may think about cutting back on eating sweets for a few days, and then they’ll forget about that “touch of sugar.” But their bodies won’t. That little extra sugar is likely to become a lot of extra sugar, which heralds the presence of type 2 diabetes with all of its complications. And there is more bitter news about that “touch of sugar.” Even if it doesn’t evolve into diabetes, it still increases the risk of a heart attack or a stroke. Chemically, the term “sugar” refers to a class of simple carbohydrates that have a sweet taste. Sucrose, lactose, fructose and mannose are all sugars. But that “touch of sugar” refers to one specific sugar: glucose. And it is an important one. Without it, you can’t move a muscle. Without it, you can’t think. But unfortunately, it can also kill you. Glucose, when properly absorbed into a cell, is burned as fuel to supply the body’s energy needs. But if it runs wild in the bloodstream, it reacts with various proteins and fatty substances (lipids) to form advanced glycation end products (AGEs), nasty substances that can wreak havoc with the workings of the kidneys, the eyes, the nervous system and the coronary arteries. Indeed, a high level of glucose in the bloodstream is a recipe for disaster. A disaster called diabetes. And it is reaching epidemic proportions, particularly the variety known as type 2, which makes up about 90 per cent of all cases. Predictions are that if we don’t do something about it, we will soon be looking at more than thirty million North Americans afflicted with type 2 diabetes, most of whom will die from some complication of the disease. Luckily, there are ways to curb the carnage. In many cases, it comes down to a simple matter of losing weight. Unfortunately, that “simple” refers to the concept, not to the practice. Ancient Chinese physicians already knew that if ants gathered around spilled urine, it was a bad sign for the urinator. Ants like sweets, and glucose fits the bill. The compound ends up in the urine when the kidneys do their best to remove excessive amounts from the blood. In fact, one of the first signs of diabetes is frequent urination (polyuria) as the kidneys struggle to eliminate glucose. With all that loss of urine, extreme thirst develops (polydipsia), another indicator of the disease. While these symptoms are no more than annoyances, serious problems may lie just around the corner. Blurry vision, fatigue, sores that don’t heal, burning sensations and numbness in the extremities soon signal that glucose is engaging in reactions with essential biomolecules, impairing their performance. Where does this double-edged sword, this glucose, come from? We eat it. Lots of it. Not directly, but as a component of a wide array of carbohydrates. Starches, table sugar (sucrose) and milk sugar (lactose) all yield glucose when broken down by enzymes in the small intestine. From here, glucose is absorbed into the bloodstream and, in turn, into cells. That is, if all goes well. In diabetes, it does not. The problem is not the influx of glucose into the blood from the intestine—if that were the issue, we would all be suffering from the disease. The problem lies in the entry of glucose into cells. In type 1 diabetes, which usually strikes early in life, the pancreas stops producing insulin, the hormone that cells (other than those that make up the nervous system) need to absorb glucose. In this case, the only recourse is the injection of insulin. Type 2 diabetes appears later in life, and is usually associated with being overweight. The pancreas still produces insulin, but cells cannot use it properly; they become insulin resistant, and glucose levels in the blood climb. As the pancreas struggles to churn out more and more insulin in an attempt to force glucose into cells, it eventually falters and full blown diabetes sets in. Why are some people affected, and others not? What causes the destruction of insulin-producing cells in the pancreas in type 1 and the failure of cells to respond to insulin in type 2 diabetes? Let’s get one thing straight. Eating sweets or the wrong kind of foods does not cause diabetes. Poor dietary habits, however, can lead to obesity, which is a risk factor for type 2 diabetes. There are theories aplenty about the causes of diabetes, but they are just theories. Perhaps a virus or bacterium triggers an immune reaction that spins out of control and ends up attacking the pancreas. Perhaps some sort of toxin is involved; this theory is gathering steam with the increasing incidence of type 2 diabetes. A few studies have found an association between diabetes and exposure to chemicals such as PCBs, dioxins, methyl mercury or bisphenol A. These may have a direct effect on either insulin production or use, or perhaps they increase fat retention and lead to obesity, which in turn leads to diabetes. While researchers have not been able to unravel the causes of diabetes, it is clear that heredity plays a part. If one of a set of identical twins develops type 1 diabetes, the chance that the other one also will is about 50 per cent. With type 2, the odds rise to 80 per cent. But clearly, environmental factors such as diet, infections or toxins play a role. While the causes of diabetes remain somewhat of a mystery, we have learned one thing for sure. The physical damage to the body is caused by excess glucose in the blood. This is not as obvious as it may seem. After all, wrinkles and osteoporosis go hand in hand, but wrinkles do not cause the condition. Similarly, there was a possibility that high levels of glucose were associated with diabetes, but that glucose was not responsible for the symptoms of the disease. In the early ‘90s the Diabetes Control and Complications Trial settled that question once and for all. Some fifteen hundred patients with type 1 diabetes were divided into two groups. Half the volunteers took their regular insulin shots and monitored their blood glucose once a day. They made no adjustments as long as they felt well. The others tested their blood sugar at least four times a day, sometimes even in the middle of the night, and were given a specific range of numerical values to shoot for (below 6.7 millimoles per litre of glucose before meals and no more than 10 millimoles per litre). Diet and insulin doses were adjusted to meet this goal. Results were so remarkable that the trial was stopped earlier than planned to allow participants to take advantage of the benefits of careful monitoring. In the group that strictly controlled blood glucose, vision problems were reduced by 76 per cent, kidney disease by 50 per cent and neurological complications by 60 per cent. Obviously, monitoring sugar levels is critical in diabetes, but what can you do to keep the levels under control? And what can you do to prevent type 2 diabetes from developing in the first place? Let’s get down to some numbers. There’s only one way to know the status of sugar (glucose) in your blood: measure it. If after an overnight fast the concentration of glucose is more than 7.0 mmol/L, you’ve got diabetes. If it is between 6.0 and 6.9 (5.5 and 6.9 in the U.S.), you’re dealing with prediabetes, sometimes referred to as glucose intolerance or insulin resistance. Another way to measure blood glucose is by means of a glucose tolerance test, which involves testing two hours after drinking a glucose-laced solution. Above 11.0 mmol/L indicates diabetes, between 7.8 and 11.0 is prediabetes. These tests provide an important snapshot of blood glucose, but a different kind of test is needed to determine average glucose levels over a period of time. The hemoglobin AIc test is based on the reaction of glucose with proteins that are part of hemoglobin, the oxygen-carrying molecule in red blood cells. The more glucose in the blood, the greater the chance that these proteins are glycated. Since red blood cells have a lifetime of three to four months, determining the percentage of hemoglobin that is glycated gives a picture of glucose control over several months. More than 6 per cent glycation signals a problem. That “touch of sugar” the doctor talks about is prediabetes. And it isn’t rare. We’re talking about fifty million people in the U.S. and Canada, most of whom will go on to develop full-blown diabetes unless they take action. And thanks to a landmark study published in the New England Journal of Medicine in 2002, it is clear what that action should be. The Diabetes Prevention Program (DPP) enlisted more than three thousand prediabetics with an average age of fifty-one. Almost all were overweight and sedentary, which wasn’t surprising since elevated blood sugar has long been associated with these characteristics. A third of the subjects were treated with metformin (known by the brand name Glucophage), a medication that lowers blood sugar, a third with a placebo and a third were given a lifestyle-modification program. This last group exercised two and a half hours a week and was instructed in ways to reduce body weight by cutting the fat content of their diet. The results were so dramatic that the study was halted a year earlier than planned. After just three years, 30 per cent of the subjects on placebo had developed diabetes—compared with 22 per cent of those on metformin, but only 14 per cent of those who had modified their lifestyle! And the average weight loss of the third group was only about four kilograms! The conclusion is obvious: type 2 diabetes is preventable, as are the risks that go along with it. High blood sugar damages the eyes, the nervous system, the kidneys and the cardiovascular system. But now for the truly scary part. The risk of heart disease and stroke kicks in well below the blood levels of glucose that define diabetes. That surprising finding came from a fascinating study by researchers at the Harvard School of Public Health who gathered data on blood sugar from fifty-two countries, along with information about the incidence of heart disease and stroke. Sophisticated number-crunching revealed that blood glucose in the prediabetic range was a leading cause of cardiovascular death. Higher-than-optimal blood sugar accounts for more than three million deaths a year. Obviously, controlling blood sugar is very important, even for non-diabetics. Especially so for anyone diagnosed with metabolic syndrome, a collection of disorders that often culminates in diabetes and heart disease. Metabolic syndrome encompasses high blood pressure, high triglycerides, low levels of “good” cholesterol (HDL), elevated blood sugar, and a waist size greater than 40 inches for men and 35 inches for women. All right then, we have to control our blood sugar, but how do we do it? Intuitively, we immediately think of reducing our sugar intake. Not a bad idea, but too simplistic. Other foods can actually drive up blood glucose more effectively than sugar. What really matters is the total carbohydrate content of a food, and the rate at which it releases glucose into the bloodstream. The glycemic index measures the degree to which blood sugar is elevated in response to eating an amount of a food that contains 50 grams of carbohydrate. But alone, this is not very meaningful. Watermelon has a high glycemic index, but you have to eat a lot of melon to consume 50 grams of carbohydrate. Potato chips have a lower glycemic index, but you can easily consume 50 grams of carbs. That’s why the best measure in terms of controlling blood glucose is the glycemic load, which takes into account the glycemic index and the available carbohydrates. Which, then, are the foods with high glycemic loads that we should curtail? Potato chips, for sure. Unfortunately, other types of potatoes too. Candy bars. Anything made with white flour. These flood the blood with glucose, which then reacts with various proteins to form those advanced glycation end products (AGEs), which as we have seen cause the health problems. Recently we have also learned that grilling, broiling or frying foods causes similar reactions in the food itself, and that the AGEs can be absorbed into the bloodstream. The moral of the story is exercise, reduce fats, reduce cooking temperatures and reduce the consumption of anything “white” (low-fat dairy products excluded— these actually may reduce the risk of diabetes), and you’ll reduce that “touch of sugar” in your blood. And you’ll increase your chances for a sweet life.

Source: http://blog44.ca/maurice/files/2013/11/Bitter-sweet-2i4jlnt.pdf