Diabetes mellitus (also called DM or diabetes for short) refers to a health condition where your body has difficulty converting sugar to energy. Typically, we think of three kinds of diabetes:

  • Type 1 diabetes (T1DM) is a chronic health condition in which your body’s endocrine part of the pancreas doesn’t produce enough of the hormone insulin, and your blood sugar (glucose) level becomes too high.
  • Type 2 diabetes (T2DM) is a chronic condition in which your body develops resistance to insulin, and your blood sugar level becomes too high as a result.
  • Gestational diabetes (GDM) is DM that occurs during a pregnancy, and the blood sugar level is too high during this time.

Some research studies have proposed that Alzheimer’s disease should also be classified as a type of diabetes, called type 3 diabetes.

This “type 3 diabetes” is a term that has been proposed to describe the hypothesis that Alzheimer’s disease, which is a major cause of dementia, is triggered by a type of insulin resistance and insulin-like growth factor dysfunction that occurs specifically in the brain.

This condition also has been used by some to describe people who have type 2 diabetes and are also diagnosed with Alzheimer’s disease dementia. The classification of type 3 diabetes is highly controversial, and it’s not widely accepted by the medical community as a clinical diagnosis.

The above “type 3 diabetes” medical condition isn’t to be confused with type 3c diabetes mellitus (also called T3cDM, pancreatogenic diabetes, and type 3c diabetes).

The pancreas has both endocrine and exocrine glands, and they have their respective functions. Insulin is one of the hormones that beta-islet cells in the Islets of Langerhans, which is endocrine pancreas tissue, produce and secrete.

When the exocrine pancreas becomes diseased and then causes a secondary insult to the endocrine pancreas that ultimately leads to DM, this is T3cDM. Exocrine pancreatic diseases that may lead to T3cDM include pathology such as:

  • chronic pancreatitis
  • cystic fibrosis
  • exocrine pancreatic cancer

Keep reading to find out what we know and what we don’t know about “type 3 diabetes.” And please keep in mind that this isn’t to be confused with type 3c diabetes.

According to the Mayo Clinic, there’s already an established link between Alzheimer’s and type 2 diabetes. It’s been suggested that Alzheimer’s may be triggered by insulin resistance in your brain. Some people say that Alzheimer’s is simply “diabetes in your brain.”

This claim has some science behind it, but it’s a bit of an oversimplification.

Over time, untreated diabetes can cause damage to your blood vessels, including vessels in your brain. Many people who have type 2 diabetes don’t know that they have the condition, which may delay diagnosis and appropriate treatment measures.

Therefore, those with type 2 diabetes, especially undiagnosed diabetes, have a higher risk of this kind of damage.

Diabetes may also cause chemical imbalances in your brain, which may trigger Alzheimer’s. Also, high blood sugar levels lead to inflammation, which may damage brain cells.

For these reasons, diabetes is considered a risk factor for a condition called vascular dementia. Vascular dementia is a stand-alone diagnosis with symptoms of its own, or it can be a warning sign of what will develop into an overlap with Alzheimer’s disease.

The science of this process is uncertain. For now, what’s been established is that there are cases of Alzheimer’s disease and other forms of dementia that don’t have any demonstrated link to insulin resistance.

According to a 2016 study, people who have type 2 diabetes may be up to 60 percent more likely to develop Alzheimer’s disease or another type of dementia, such as vascular dementia.

This study involved more than 100,000 people living with dementia. It showed that women with type 2 diabetes had a higher probability of developing vascular dementia than men.

Risk factors for type 2 diabetes include:

The symptoms of type 3 diabetes are described as the symptoms of dementia, such as those seen in early Alzheimer’s disease.

According to the Alzheimer’s Association, these symptoms include:

  • memory loss that affects daily living and social interactions
  • difficulty completing familiar tasks
  • misplacing things often
  • decreased ability to make judgements based on information
  • sudden changes in personality or demeanor

There’s no specific test for type 3 diabetes. Alzheimer’s disease is diagnosed based on:

  • a neurological examination
  • medical history
  • neurophysiological testing

Your healthcare provider will ask several questions about your family history and your symptoms.

Imaging studies, such as MRI and CT scans of the head, may give your healthcare provider a picture of how your brain is working. Cerebrospinal fluid testing can also look for indicators of Alzheimer’s.

If you have symptoms of type 2 diabetes and Alzheimer’s and haven’t been diagnosed with either one, your healthcare provider may order a fasting blood sugar test and a glycated hemoglobin test.

If you do have type 2 diabetes, it’s important that you begin treatment for it immediately. Treating type 2 diabetes could minimize damage to your body, including your brain, and slow the progression of Alzheimer’s or dementia.

There are separate treatment options for people who have:

  • pre-type 2 diabetes
  • type 2 diabetes
  • Alzheimer’s

Lifestyle changes, such as making changes to your diet and including exercise in your daily routine, may be a big part of your treatment.

Here are some additional treatment tips:

If you’re living with overweight, try to lose 5 to 7 percent of your body mass, according to the Mayo Clinic. This can help stop organ damage caused by high blood sugar and may prevent the progression of pre-DM2 to DM2.

A diet low in fat and rich in fruits and vegetables can help improve symptoms.

If you smoke, quitting smoke is recommended because it can also help manage your condition.

If you have both type 2 diabetes and Alzheimer’s, treatment for your type 2 diabetes is important to help slow the progression of dementia.

Metformin and insulin are an anti-diabetes drugs that may also reduce the risk of developing diabetes-induced brain damage, according to a 2014 study.

Prescription medications are available to treat cognitive symptoms of Alzheimer’s dementia, but there’s uncertainty about whether they have a noticeable impact on the symptoms of Alzheimer’s disease.

Acetylcholinesterase inhibitors like donepezil (Aricept), galantamine (Razadyne), or rivastigmine (Exelon) can be prescribed to improve the way that your body’s cells communicate with one another.

Memantine (Namenda), an NMDA-receptor antagonist, may also help to reduce symptoms and slow the progression of Alzheimer’s disease.

Other symptoms of Alzheimer’s and other dementia types, like mood swings and depression, may be treated with psychotropic drugs. Antidepressants and anti-anxiety medications are part of treatment in some cases.

Some people may need a light dose of antipsychotic therapy later in the course of the dementia process.

Type 3 diabetes is a way of describing Alzheimer’s that’s caused by insulin resistance inside the brain. So, your outlook will vary according to several factors, including your diabetes treatment and the severity of your dementia.

If you can treat your diabetes with diet, exercise, and medication, researchers who promote the diagnosis of type 3 diabetes suggest that you may be able to slow the progression of Alzheimer’s or vascular dementia, but evidence is uncertain.

Your outlook will also vary according to how soon your symptoms were discovered and what your healthcare provider thinks about your specific case. The sooner treatment begins, it’s likely the better your outlook will be.

According to the Mayo Clinic, the average life expectancy for a person with Alzheimer’s is around 3 to 11 years from the time that they’re diagnosed. But some people with Alzheimer’s can live as many as 20 years post-diagnosis.

If you already have type 2 diabetes, there are ways that you can better manage it and lower your risk for developing type 3 diabetes.

Here are some of the proven methods for managing type 2 diabetes and minimizing organ damage: