Will Alzheimer's Disease Become New Diabetes 3?

Scientists are increasingly finding evidence of diabetic changes in patients suffering from Alzheimer’s disease. There are signs of insulin resistance, which are an early indicator of diabetes. In fact, Dr. Suzanne DeLaMonte a neuro-pathologist from the Brown Medical School found, during autopsy, signs of insulin resistance in the brains of patients with Alzheimer’s disease way back in 1995.

She was the first person to coin the term diabetes type 3. According to her, people with diabetes are increasingly prone to develop cognitive impairment and dementia because of insulin resistance in the brain. Both these features are the hallmark of Alzheimer’s disease.

More and more researches in the recent past have found an association between diabetes and Alzheimer’s disease. The incidence of both the diseases has shown a steady increase and in both the diseases, the age of onset of symptoms has been gradually decreasing.

The increased risk of Alzheimer’s disease in patients of type 2 diabetes and obesity can be attributed to chronic hyperglycemia, and peripheral insulin resistance.  Due to a persistent state of oxidative stress, there is an increased deposition of advanced glycation end products, and an increase in the production of pro-inflammatory cytokines leading to cerebral micro-vascular disease.

The scientists have tried to treat Alzheimer’s disease with rosiglitazone (Avandia), a drug used in the treatment of diabetes, but the results have been mixed. Researchers have postulated that by the time the symptoms of dementia appear, irreversible damage has been done to the brain cells due to increased insulin resistance.

As diabetes is usually associated with the increased intake of calories, one can infer that watching your calories would help in preventing both diabetes and Alzheimer’s disease. It is the excess fat in the body which increases the insulin resistance. 

This has been proven by a number of studies done on people who consume fish regularly, or take a diet high on fruits and vegetables and low on alcohol, or those who adhere to a Mediterranean style diet.

We should also try to limit the intake of nitrates in our diet, according to Dr. DeLaMonte. Nitrates are found in cured meats like salamis and hot dogs and have been associated with neuronal changes. Upon heating, nitrates get converted into nitrosamines, compounds which impair the interaction of brain cells with insulin.

Apart from taking care of your diet, another important aspect that should be taken care of is your physical health. And exercise plays an important role in maintaining your health.

A Single Common Gene May Be Influencing Both Diabetes And Alzheimer’s Disease

Insulin plays an important role in the regulation of signal transmissions between neurons. A recent study by CCNY-CUNY has thrown light on the fact that there may be a single gene involved which influences both diabetes and Alzheimer’s disease.

The gene has an effect on the insulin pathway and a disruption of the pathway may occur in diabetes. The same insulin pathway plays an important part in the brain, keeping the nervous system in good shape. Disruption of this pathway may result in the development of dementia.

Insulin resistance, which is seen in diabetes type 2, results in a problem with the degeneration of amyloid protein in the brain. Accumulation of amyloid in the brain may lead to formation of plaques in the brain, a characteristic feature of Alzheimer’s disease. Also, the amyloid beta configurations, called as oligomers, get attached to the brain cells. These oligomers are responsible for the memory loss seen in Alzheimer’s disease. When the oligomers attach to the brain cells, they make the cells more insulin resistant.

Thus, a vicious cycle is established where insulin resistance of diabetes leads to formation of amyloid oligomers, which when attach to cells, lead to further insulin resistance. Hyperglycemia, associated with diabetes, may also produce some oxygen containing molecules which may be harmful to the neuronal cells. This process is called as oxidative stress.

Damage to blood vessels seen in diabetes, can lead to vascular dementia. Hyperglycemia and increased cholesterol lead to atherosclerosis, which can block the vessels of the brain and cause dementia.

The lowest levels of these factors are seen in areas most ravaged by the disease. Researchers from the Rhode Island have concluded that the impairment in cognitive functions, seen in Alzheimer’s disease, is mediated by the low levels of insulin and insulin like growth factors in the brain and by the secondary loss of neurons which are dependent on these molecules.

Almost 50 to 80 percent of all dementia cases are due to Alzheimer’s disease. It is a progressive disease. In the early stage of Alzheimer’s disease, the memory loss is mild, but as the disease progresses, the patient loses his ability to communicate and fails to respond to changes in his environment. It is the sixth leading cause of mortality in the United States. 

Although the two main causal factors behind Alzheimer’s are age and a positive family history, there is mounting evidence that diabetes may also be playing an important role in the development of the disease.

In view of the association between Alzheimer’s disease and diabetes, experts advise to modify your life style in order to prevent the disease. Steps to be taken to maintain your health and prevent type 2 diabetes include:

• Regular monitoring of blood pressure, blood sugar and cholesterol levels above the age of 45.
• Eating a wholesome nutritious diet which includes a right mixture of green vegetables, fruits, whole grains, lean meat and low fat dairy products.
• Exercising for a minimum of 30 minutes per day for at least four days a week.