(Health Secrets Newsletter) Type 2 diabetes mellitus is a condition in which the body fails to utilize insulin produced by the pancreas. Insulin is necessary to carry glucose into body cells where it is used as fuel. When there is not enough insulin or when there is insulin resistance, glucose stays in the blood, causing blood sugar to rise. In turn, this high blood sugar causes extensive damage to all parts of the body. While it has long been known that diabetes can lead to heart attacks and strokes, there is now clear evidence that diabetes, especially Type 2, can lead to Alzheimer’s disease.
One of the original studies showing this link was completed in 1997. It concluded that: “The finding of an association between diabetes and the composite outcome of Alzheimer’s disease and cognitive impairment without dementia (without stroke) is consistent with prior reports of a modest relation between diabetes and Alzheimer’s disease.”
In Japan, scientists recently reviewed patients who had been followed since 1961 for heart disease and stroke to see if there was a link between Alzheimer’s and diabetes. In 1988, over 1000 of these adults took a glucose tolerance test to see how well their bodies processed glucose, and they were then followed for 15 years. 232 of these patients developed dementia. The study found that those with diabetes had a 74% greater chance of developing some form of dementia, and the risk of actual Alzheimer’s was slightly more than double the risk of those with normal glucose tolerance tests. Those not meeting all diagnostic criteria to be classified as diabetic but who showed impaired glucose tolerance had a 60% increased risk of Alzheimer’s. The authors concluded that there is a need to consider diabetes as a significant risk factor for all forms of dementia.
Although there is a clear link between the two conditions, how they are related is not known. Multiple hypotheses include:
Genetics: The presence of the ApoE-4 genotype indicates a person may be at higher risk of late onset Alzheimer’s but which carriers will be affected is unknown. However, those patients having diabetes and carrying this genotype have over twice the risk of developing Alzheimer’s than those with the genotype but no diabetes. Diabetes seems to increase amyloid deposition and neurofibrillary tangles in those with this genotype.
- Insulin resistance: Studies have shown small to moderate reductions in insulin sensitivity in patients with Alzheimer’s which may lead to atherosclerosis and micro-vascular disease in the brain. Both of these conditions limit blood flow to the brain.
- Insulin resistance/glucose intolerance can lead to increased oxidative stress and metabolic problems in the brain.
Increased blood glucose levels appear to be linked with increased inflammation. This inflammation in turn, can damage the brain.
The Veteran’s Administration recently completed a study showing that inhaled insulin can actually improve short term memory and slow the rate of decline in Alzheimer’s patients. Insulin is critical for normal brain function and brain cells actually produce insulin. This insulin is used for the production of neurotransmitters which are responsible for the communication that occurs between nerves. While this study was short, other human studies and animal studies have also indicated a benefit.
The steps you need to take to lower your risk of Alzheimer’s disease would be the same steps needed to lower the risk of Type 2 diabetes. Considering that there is now evidence that organ damage can occur long before blood sugar levels reach the numbers used to diagnose diabetes, it is imperative that you do whatever it takes to keep blood glucose normalized. Dr. Bernstein (a physician who is an expert on the dietary management of both Type 1 and Type 2 diabetes) recommends that you strive for an average blood glucose of 85 or a HgA1C of 4.3 to 4.5! HgA1C (hemoglobin A1C) is a measure of average blood sugar over a 3 month period of time although the result is weighted toward the past 2 to 3 weeks. You may also want to:
Lose weight: Even a 7% weight loss leads to a significant reduction in risk.
Exercise: You don’t have to work out at a gym. Any increase in activity is beneficial.
Eat a low carb diet: Dr. Bernstein recommends no more than 30 grams of carbohydrates per day. You can find the right level for yourself by getting a blood glucose meter and checking fasting blood glucose levels as well as blood glucose levels at 1 and 2 hours after eating. Note the amount and type of carbs you ate and your body’s blood sugar response. Amazingly the American Diabetes Association continues to recommend a high carbohydrate diet! While Dr. Bernstein’s recommendation goes far beyond what you will typically find in conventional medicine, this one step has been proven time and time again to WORK, curing many with Type 2 diabetes and allowing those with Type 1 to decrease insulin, lower HgA1C dramatically and maintain stable blood glucose.
Eat only healthy fats from uncontaminated sources. More information on healthy fats can be found in other articles on this site.
Eliminate hard alcohol and limit wine/beer.