The Harmful Effects of High Glycemic Load Diets
For many years now, many leading nutrition xperts?have been telling us to follow a low-fat diet and emphasize complex carbohydrates, such as breads, pasta, rice, and potatoes. In fact, those foods are the foundation of the current government dietary recommendations as laid out by the Food Pyramid.
For many years now, many leading nutrition xperts?have been telling us to follow a low-fat diet and emphasize complex carbohydrates, such as breads, pasta, rice, and potatoes. In fact, those foods are the foundation of the current government dietary recommendations as laid out by the Food Pyramid.
However, these recommendations have been largely responsible for the systematic fattening of our country. We eat less fat today than 30 years ago, yet we are much, much fatter as a nation.
Furthermore, diabetes rates have skyrocketed over the past couple of decades, and the incidence of heart disease has not decreased, despite the fact that fewer people smoke today than any time in the past 50 years (smoking is a risk factor for heart disease).
The obsession with cutting out fat from the diet has led to us consuming large amounts of processed, refined carbohydrate rich foods. Not all carbohydrate rich foods are unhealthy. However, the ones consumed most frequently by Americans most definitely are. How can you tell if a carbohydrate rich food is harmful or not? It used to be thought that complex carbohydrates, which come from starchy foods, are better than simple carbohydrates. However, the distinction between the two is meaningless. All carbohydrates we consume are broken down into glucose in our bodies. They get broken down at different rates, and this is what is important. For example, a potato, which is a complex carbohydrate, is broken down into glucose much faster than an apple, which contains simple carbohydrates. When a carbohydrate is broken down into glucose, that glucose enters our bloodstream. The body senses the rise in blood glucose, and our pancreas secretes the hormone insulin. Insulin has many functions. It helps the glucose from our cells enter the liver, muscle cells, and fat cells. It also initiates the production of insulin like growth factors (IGFs), which have anabolic properties, promoting growth in the body. Insulin also shuts down fat burning pathways and the pathways that use protein for energy (gluconeogenesis). It promotes fat storage, and induces the production of triglycerides (fat molecules in the blood). The faster the carbohydrate enters the bloodstream as glucose, the more insulin is required to deal with that glucose.
Herein lies the problem. Since insulin blocks fat burning, promotes fat storage, and increases production of triglycerides, which are a risk marker for heart disease, too much insulin leads to health problems. The speed at which a carbohydrate enters the blood stream as glucose is known as its glycemic index. Foods with no carbohydrates in them such as steak, eggs, fish, etc. don't induce much insulin secretion when consumed. Fruits, vegetables, nuts, and legumes for the most part have low glycemic indexes. That is, when you eat an orange or some almonds, it takes a long time for the carbohydrates in them to be broken down into glucose. On the other hand, most grains, sugars and tubers, including candy, bagels, breads, potatoes, rice, and of course all refined grains such as breakfast cereals, many baked goods, crackers, pretzels, and other white flour products have higher glycemic indexes. Many factors affect glycemic index, amongst them the actual form of carbohydrate found in the food, its fiber content, and its fat content, the latter two decreasing a food glycemic index.
Fiber is indigestible, and so prolongs the time it takes for the carbohydrate in the digestive tract to become digested. Fat slows down digestion, and therefore the carbohydrate takes a longer time to be broken down into glucose and enter the blood.The glycemic index isn't the only thing that counts. For example, if you ate a tiny piece of candy, although the sugar in that candy may be digested rapidly, there is very little sugar, so it would not induce much insulin secretion. On the other hand, some pastas have glycemic index values which are not too high.
However, because they contain a large amount of carbohydrates, even if those carbohydr
ates are digested more slowly, there are so many of them, that a large amount of insulin is required. Thus, we use what called the glycemic load, which is defined as the glycemic index of a food, multiplied by the amount of available carbohydrates per serving of that food. Several new studies have linked high carbohydrate diets, particularly those with high glycemic loads, to heart disease, as well as certain cancers, diabetes, and obesity. The foods with the highest glycemic loads are the starches such as pasta, rice, bagels, and potatoes. Of course, the highly refined versions of those foods (e.g. white flour products), as well as heavily sweetened food, carry an even greater glycemic load. Legumes have an average glycemic load, and most fruits, all vegetables, and all nuts have a very low glycemic load.
ates are digested more slowly, there are so many of them, that a large amount of insulin is required. Thus, we use what called the glycemic load, which is defined as the glycemic index of a food, multiplied by the amount of available carbohydrates per serving of that food. Several new studies have linked high carbohydrate diets, particularly those with high glycemic loads, to heart disease, as well as certain cancers, diabetes, and obesity. The foods with the highest glycemic loads are the starches such as pasta, rice, bagels, and potatoes. Of course, the highly refined versions of those foods (e.g. white flour products), as well as heavily sweetened food, carry an even greater glycemic load. Legumes have an average glycemic load, and most fruits, all vegetables, and all nuts have a very low glycemic load. However, some dried fruits, especially dates, figs, and raisins, have a quite high glycemic load. Bananas are also a bit on the high side. Dairy products for the most part have low glyemic loads. Replacing fat in the diet with carbohydrates, more specifically those carbohydrates with a high glycemic load, produces a number of harmful changes.
Although total cholesterol levels tend to fall, HDL (the so called good cholesterol) levels drop as well, and LDL (the so called bad cholesterol) levels shift to a larger proportion of small dense molecules, which are very prone to lead to clogged arteries. In fact, the cluster of high insulin levels, low HDL levels, high triglyceride levels, and a high proportion of small, dense LDL molecules puts a person at a very high risk for heart disease. High glucose levels by themselves also cause damage in the body.
Glucose is sticky in the blood, binding to many proteins and other molecules in the blood, leading in fact to premature aging. For example, glucose can bind to LDL molecules, rendering them unrecognizable and leading to the same sequence of events as the free radical damage to the LDL molecule described above As an aside, this might be one of the reasons that too much saturated fat is not a good idea for many Americans who follow a high processed food diet. The LDL levels can increase after increased intake of certain saturated fats, and the glucose levels produced from eating refined foods can glycate those excess LDL molecules.
These glycated molecules cannot be recognized by the LDL receptors and thus stay in circulation. Eventually, immune cells known as macrophages engulf these altered LDL molecules, along with their cholesterol cargo. The macrophages cannot rid themselves or break down the cholesterol and become what are known as foam cells, which lodge in the artery walls, clogging them. By contrast, eating a large amount of saturated fat in the absence of foods with high glycemic loads is probably innocuous.
Eating a high glycemic load diet may lead to diabetes as well. When the body is faced with chronically elevated levels of insulin, the insulin receptors in the body recognize the insulin less and less. The insulin can exert its main effect of taking the glucose out of the blood and into the cells, and so the pancreas has to kick out more and more insulin to get rid of the same amount of glucose.
A vicious cycle then ensues, and after several years, the pancreas cannot keep up with the ever larger demands for insulin, and thus the new fasting blood glucose levels become higher, and you have diabetes. The pancreas may also turn out after lengthy periods of producing such high amounts of insulin, which will also result in high glucose levels and diabetes. The complications of type 2 diabetes (the most common type of the disease), which is characterized by high insulin and blood glucose levels, include damage to most of the blood vessels and many of the nerves in the body, leading to heart disease, blindness, kidney disease, susceptibility to infections, limb pain, and amputations.
The bottom line is that the human body does not deal well with high levels of insulin and glucose. Of note, the human body has only one hormone, insulin, to lower glucose levels, but four hormones (glucagon, growth hormone, epinephrine, and norepinephrine) to raise blood glucose levels. This reinforces how unnatural high glycemic load diets are, and how unprepared our bodies are for dealing with chronically elevated levels of glucose.A high glycemic load diet may also lead to cancer.
Several studies have shown a strong link between starch consumption (which is roughly equivalent to glycemic load since most starchy food have high glycemic loads), and several different cancers, including colon cancer and breast cancer. The high levels of IGF formed may encourage the growth of tumors. In addition, high glucose and triglyceride levels in and of themselves provide nutrition for the tumors.As we have seen, following a typical Western diet with a high glycemic load can be very harmful to the body. In addition to the unhealthy effects of the high glycemic load itself, there are two additional ways in which a high processed carbohydrate diet harms your health. One is that most processed, packaged foods contain trans fatty acids, which lower your good cholesterol, raise your bad cholesterol, and induce calcification of the arteries.
Second, a Swedish research team recently discovered that carbohydrate rich, starchy foods, which are fried or baked, may contain dangerously high levels of a substance called acrylamide, which the U.S. government lists as a probable carcinogen. The highest levels were found in potato chips, but moderate to high levels were found in French fries, breakfast cereals, crackers, and breads as well. In conclusion, by following a hunter-gatherer type diet such as the TBK Diet, you will be consuming a low dietary glycemic load and thus protecting your body from many diseases.
