The Three Types of Alzheimer’s Disease


How much do you know about the three different types of Alzheimer’s disease? Do you know your risk factors? Find out here!


Type 1: Inflammatory

Alzheimer’s disease type 1 is inflammatory. This type of Alzheimer’s disease occurs in people who carry one or two alleles (variants) of APOE4, which often runs in families. This inflammatory gene mutation is also a causative factor in cardiovascular disease, arthritis, aging in itself and many other disorders.

Under normal conditions inflammation is part of our immune system reacting to foreign invaders and protecting us from serious infections. As we age, ongoing inflammation may lead to the diseases mentioned above including Alzheimer’s disease.

25 percent of Americans (about 75 million people) carry a single copy of APOE4 (apolipoprotein-e 4) which put them at 30 percent risk for developing Alzheimer’s disease. People who carry two copies of the APOE4 gene have a 50 percent chance for developing Alzheimer’s disease.

Inflammatory Alzheimer’s Symptoms

What are some of the early symptoms related to this inflammatory type of Alzheimer’s?

Difficulty storing new information is often one of the first signs of inflammtory Alzheimer’s. Long-term memory, the ability to speak, write, and calculate generally stay intact.

The symptoms of whom carry two copies of APOE4 can begin as early as late forties and early fifties. People without any copy of the APOE gene often don’t develop symptoms until early sixties or seventies.

Inflammatory Alzheimer’s Biomarkers

We can determine the different types of Alzheimer’s disease by their biomarkers, in blood test and others. What kind of inflammatory biomarkers can we see in type 1?

  • Elevated C-reactive protein blood level. It is a protein produced by the liver in response to inflammation like infection.
  • Decreased ratio of albumin to globulin blood level. (Albumin is a protein responsible of removing molecules including toxins and amyloid)
  • Increased Interleukin-6 (IL-6) in response to inflammation
  • Increased tumor necrosis factor (TNF) in response to inflammation

According to Dr. Bredesens research the inflammatory type of Alzheimer’s responds to the ReCODE protocol quickly.


Type 2: Atrophic

Alzheimer’s disease type 2 is atrophic. Again, people who carry one or two copies of the APOE4 gene are at a greater risk for developing Alzheimer’s type 2. However, people who present with type 2 generally have a later onset of symptoms — often a decade later than type 1.

Atrophic Alzheimer’s Symptoms

The symptoms of atrophic Alzheimer’s a fairly similar to the inflammatory type,  but there is no the evidence of inflammation. Often the inflammatory biomarkers are normal or below normal. Instead, the overall brain synapses support has drastically diminished.

Atrophic Alzheimer’s Biomarkers

What are the markers in Alzheimer’s type 2?

  • Suboptimal blood levels of hormones, ie. Thyroid, adrenal, sex hormones (estrogen, progesterone, testosterone, and pregnonolone.
  • Low Vitamin D blood levels.
  • Evidence of insulin resistance or decreased insulin.
  • Elevated blood homocysteine (type 1 may have an elevated level as well)

Often the atrophic type of Alzheimer’s responds more slowly to the ReCODE protocol.


Type 1.5: Glycotoxic

Alzheimer’s disease type 1 and 2 can occur together. People with this combination have the inflammatory characteristics of type 1 and diminished brain synapses support of type 2. Dr Bredesen defines this type of AD as the 1.5 glycotoxic type.

Glycotoxic Alzheimer’s Symptoms

Symptoms of Alzheimer’s type 1.5 are the same as type 1 and 2.

Glycotoxic Alzheimer’s Biomarkers

What markers are relevant in type 1.5?

  • Chronic glucose levels which increase different blood proteins causing glycocation and inflammation.
  • Insulin resistance which lowers the neurotrophic factor and therefore causing a loss of trophic support.


Type 3: Toxic

Alzheimer’s disease type 3 is toxic. This type of Alzheimer’s most often occurs in people who carry the common APOE3 allele, and it does not run in families.

Toxic Alzheimer’s Symptoms

Type 3 often presents in younger people – those their late forties to early sixties, often after experiencing tremendous stress. Unlike the other types of Alzheimer’s, the type 3 symptoms usually begin with difficulties related to speech, numbers, or organization. Often people lose recent and old memories, including memories related to speech, how things work, difficulties with calculation, figuring out bills, word finding, spelling, or reading. Depression and attention deficits are also common.

Since people with this atypical presentation of Alzheimer’s responded the poorest to conventional treatment they were the main drives for the ReCODE protocol development.

Toxic Alzheimer’s Biomarkets

What are the biomarkers of type 3?

  • Affected multiple brain areas on MRI, not only involving the hippocampus that have shrunk.
  • Multiple abnormal small white spots on MRI related to neuro-inflammation and vascular leakage.
  • Low zinc blood levels, high copper and high ratio copper to zinc.
  • Often diagnosed with frontotemporal dementia or depression prior to PET scan confirming Alzheimer’s.
  • Hormonal abnormalities in responds to stress, HPA axis dysfunction with low pregnenolone, DHEA-S, low cortisol, increased reverse T3 and low free T3 (thyroid test), low sex hormones: low estradiol, low testosterone, and other hormonal abnormalities.
  • High blood toxin levels, especially mercury and mycotoxins (mold). Best to perform a chelating agent for mercury which pulls it out of the tissues compared to the blood test by itself not representing the total toxic level. In addition, HLA-DR/DQ genetic test is associated with multiple biotoxin sensitivities.
  • High serum C4a, TGF-b1, or MMP9, or low MSH all indicative of exposure to biotoxin or mycotoxin.
  • Diagnosis fo CIRS (chronic inflammatory response syndrome) with cognitive decline.
  • Symptoms often occur around menopause or andropause and before age 65.

Being able to differentiate between the types of Alzheimer’s disease is extremely helpful in being able to develop the right treatment plan.

If you like help in figuring out yours or your loved ones cognitive decline or just want more information you can schedule a free consultation with me. I am a certified functional medicine and Bredesen’s ReCODE practitioner, so I can help! You can also send me an email at

Dale Bredesen MD (2017). The End of Alzheimer’s. The first program to prevent and reverse cognitive decline, p. 177-212

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