Diabetes and Alzheimer’s

There is a strong association between diabetes and the development of Alzheimer’s disease.

Diabetes is a health condition characterized by an abnormality in sugar metabolism and occurs as increased blood sugar levels.

Close to 10% of the Canadian population have been diagnosed with diabetes. The most common form is Type 2, or non-insulin dependent diabetes. Ninety per cent of diabetics have Type 2 diabetes. Type 1, or insulin dependent diabetes, usually occurs in childhood or early adulthood. Approximately 10% of individuals with diabetes have Type 1 diabetes.

Diabetes is due to a problem with the hormone insulin. Insulin is a small hormone produced in the pancreas. It is passed into the blood in response to a rise in blood sugar levels. Insulin promotes the uptake of sugar into cells of the human body. Insulin also increases the uptake of amino acids into cells, increases protein and fat production and inhibits fat and sugar breakdown.

Non-insulin dependent diabetics have an abnormality of insulin production and release and sensitivity of insulin to human cells. Insulin dependent diabetics have a deficiency of insulin production from beta cells in the pancreas. The pancreas simply does not produce enough insulin to meet dietary requirements. It is believed to occur as genetically induced auto-immune disorder.

Non-insulin dependent diabetics are not dependent on insulin supplementation. Although most individuals with Type 2 diabetes are over the age of 40, that type of diabetes can occur at any age. Dietary and environmental factors appear to be involved in the development of diabetes in non-insulin dependent diabetics.

Especially prominent is the role of excessive food intake particularly simple carbohydrate foods like added sugar foods. Insulin levels may be normal or variable. Abnormal response to insulin in the body is common in 60 to 90% of non-insulin dependent diabetics.

Insulin dependent diabetics are dependent on insulin and are prone to acidosis in the body. Insulin supplementation is required. Without insulin the body’s cells start to break down fats in a process called ketoacidosis. Toxic byproducts called ketones are produced that result in acidic blood.

Viral infection and auto-immune disorders have been linked to the development of diabetes in insulin dependent diabetics. There is a strong genetic predisposition in developing diabetes I those people.

Diabetics are at increased risk for the development of atherosclerosis or hardening of the arteries, stroke, heart disease, high blood pressure, kidney failure, optic retinal disorders, infections, ulcers and other serious complications.

Normal fasting blood sugar levels in Canada are considered to be between four and six millimoles per litre. Some labs now even use an upper limit to 5.9 or even 5.7 millimoles per litre.

“Pre-diabetes” is the term used to describe what was previously considered high normal blood glucose levels. A fasting blood sugar level between six and seven millimoles per litre is now considered pre-diabetes. Some labs will use a lower limit between 5.7 to 5.9 millimoles per litre as a cutoff for the diagnosis of pre-diabetes.

Excessive consumption of refined sugars which have been added to processed foods is the main driver of pre-diabetes in non-insulin dependent diabetics. This includes most forms of sugar like glucose, fructose, sucrose, honey, organic raw sugar, turbinado sugar, corn syrup and maple syrup.

Consumption of a large number of fruits and sugary vegetables can also be a driver for diabetes. A large consumption of refined complex carbohydrates like white bread, refined flour and white rice can also contribute to sugar overload. Lack of exercise also contributes to the development of non-insulin dependent diabeties.

Alzheimer’s disease and vascular dementia has been called Type 3 diabetes.

The brain and neurons, or nerve cells, almost exclusively use blood sugar as the main source of fuel for energy. Insulin increases uptake of sugar into the neurons of the brain and nervous system. A decrease in insulin production or a decrease in insulin sensitivity of cell receptors results in abnormal blood sugar fluctuations across the cell membrane. This can result in neurological dysfunction.

Cholesterol is a fat molecule that is transported throughout the body on a protein called lipoprotein. LDL, or low-density lipoprotein, carries cholesterol to cells around the body. HDL, or high-density lipoproteins, carries cholesterol back to the liver for breakdown and reprocessing.

APOe is a variant of LDL that carries cholesterol to the brain and other nerve cells for uptake and processing. Most people have a normal APOe3 protein that works normally. Ten per cent to 15% of individuals carry a mutation called APOe4 that causes the carrier protein to malfunction. The presence of one or two APOe4 genes dramatically increases your risk of atherosclerosis, Alzheimer’s disease and vascular dementia.

The APOe4 protein also interferes with normal insulin receptors on brain and nerve cells. This impairs insulin’s ability to work normally to increase sugar uptake into neurological tissue. As a consequence, the nerve cell is deprived of fuel and doesn’t work normally.

The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.