Dangers of High Blood Glucose

The medical literature provides an abundance of evidence to show that high blood glucose causes cardiovascular disease. Commercial interests in the cholesterol hypothesis have prevented this information from reaching us, and this information also provides a significant challenge to current dietary advice.

The presence of diabetes (a condition characterised by high blood glucose) increases the risk for cardiovascular disease. For example, women in the UK with diabetes are three to five times more likely to have heart disease than the general population. However, of particular significance is the fact that high blood glucose increases the risk for cardiovascular disease in people who do not have diabetes as well as those who do have diabetes.

A study published in The Lancet collated data on blood glucose and cardiovascular disease from 52 countries - the total number of deaths related to higher than optimum blood glucose was comparable to the number of deaths from smoking.

Another investigation found that high blood glucose levels (still lower than the threshold for a diagnosis of diabetes) are associated with a 27 percent greater risk for cardiovascular disease.

High blood glucose kills people. A study published in the journal Diabetes Care included a national sample of 3,092 American adults. After the 16 year follow up period, people with high blood glucose had a two-fold increased risk of dying. High blood glucose increased the death rate for all causes and cardiovascular causes.

Overall, there is a linear progression in the risk for heart disease, cardiovascular disease and death as blood glucose levels increase. This is illustrated below:

                                        

A Current Problem

This evidence concerning the risks associated with high blood glucose is extremely important. Many countries have changed their diet in line with recommendations based on the food pyramid (a low fat/high carbohydrate based diet). For example, in the UK, there have been significant reductions in the amount of fat that is eaten and an increase in carbohydrate. 

One of the most striking changes is associated with a huge increase in the amount of pasta, rice and other cereals that are eaten. These foods have a high glycemic index and cause blood glucose levels to rise rapidly. The consumption of these foods went from an average of 236 grams per week in 1987 to 507 grams per week in 2001.

In 2009, the consumption of grains and cereals is likely to be even higher than in 2001.

These dietary changes cause the glycemic load of our diet to be much higher than it ever was before. The consequence can only be higher blood glucose levels and an increased risk for cardiovascular disease in the general population.

It is ironic that the low fat/high carbohydrate diet has been chosen to prevent many of the things that it actually causes.

Heart Disease

There is direct evidence that high blood glucose can cause cardiovascular disease. The same cannot be said about cholesterol. The idea that cholesterol causes heart disease is just that, an idea, and this idea has not been proven. On the other hand, high levels of blood glucose are known to cause damage to the arteries and blood vessels.

Our blood vessels and arteries are dynamic. They are in a constant state of change and adapt to the demands that are put upon them. The changes that occur are controlled by endothelial cells. These cells line the inside wall of the blood vessels and arteries and perform a wide range of different tasks. They generally keep everything within vessels and arteries balanced and under control. 

The presence of too much glucose in the blood can actually impair the normal functioning of the endothelial cells. In particular, high blood glucose can prevent blood vessels from dilating (widening). This, of course, has very important implications for the flow of blood and oxygen through the blood vessels to the heart.

Endothelial cells synthesise a substance called nitric oxide. This substance actually causes blood vessels to widen so that blood can flow through more easily. High levels of blood glucose can actually inhibit the ability of endothelial cells to manufacture nitric oxide. 

Furthermore, nitric oxide is also involved in a number of other functions that protect against heart disease.

Overall, problems with the functioning of endothelial cells form a key step in the progression of heart disease. It is well established that people with diabetes have an impaired endothelial cell function, but studies have also shown that these problems can occur in people who have just slightly high blood glucose levels, considerably lower than the levels associated with diabetes.

This is an extract from Justin Smith's article that was published on PTontheNet.com, which is the world's leading educational resource for personal trainers and fitness professionals. To receive a copy of the full article, please email info@29billion.com.