The 5 Different Types Of Alzheimer’s Disease, with Dr. Dale Bredesen

Dr Daniel Amen and Tana Amen BSN RN On The Brain Warrior's Way Podcast

Like most brain health diagnoses, Alzheimer’s disease is not just one thing. In fact, this week’s guest Dr. Dale Bredesen has identified 5 major subtypes for Alzheimer’s disease, and they all have different causes and different treatment recommendations. In the third episode of a series with Dr. Bredesen, he defines the characteristics of each of these subtypes and identifies how and why they manifest in the brain.

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Daniel Amen, MD:

Welcome to the Brain Warrior’s Way podcast. I’m Dr. Daniel. Amen.

Tana Amen, BSN RN:

And I’m Tana Amen. In our podcast, we provide you with the tools you need to become a warrior for the health of your brain and body.

Daniel Amen, MD:

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Tana Amen, BSN RN:

The Brain Warrior’s Way podcast is also brought to you by BrainMD, where we produce the highest quality nutraceuticals to support the health of your brain and body. To learn more, go to

Daniel Amen, MD:          Welcome back, everybody. We are here with our friend and colleague, Dr. Dale Bredesen, who is the author of The End of Alzheimer’s and his new book, “The End of Alzheimer’s Program”, to really help you take a deep dive, I mean, how you can really apply it in your own life. And we just adore him and are grateful for his work.

Let’s talk about the different types of Alzheimer’s. Ever since I started imaging in 1991, I’m also a child psychiatrist, my expertise was on ADD or ADHD, and there was this study from NIH and it showed decreased activity in the prefrontal cortex when you try to concentrate. And so in my mind, “Oh, well, that’s what ADD is,” until I scanned a couple hundred ADD patients and I’m like, “Oh, it’s not one thing.” Some people have the classic pattern. A lot of people have other patterns. And ultimately, I described seven types of ADHD. All psychiatric illnesses are not single or simple disorders. They all have multiple types. And the same thing is true for Alzheimer’s disease. Talk a little bit about how you came to that conclusion and what are the different types of Alzheimer’s disease.

Dr. Dale Bredesen:         Yeah, you made a great point there. When you start to ask, “Okay, why?” 20th century medicine was about, “What is it? What’s the diagnosis?” 21st century medicine is about why. Why do you have this? What are the factors that are driving this abnormal biochemistry? And when you look at this thing we call Alzheimer’s, which is just a pathology, it can be driven, as you said earlier, by different factors. And they have a final common pathway, but they can come in from different places.

And so what we found is when we begin to measure these things, just as you said, you’ve got to look, you’ve got to measure. It is so helpful to do so. Then we found that there are some people where the dominant driver of the degenerative process is an inflammatory one, and they may have a leaky gut. You were talking about gingivitis and periodontitis, as they’re now calling it leaky gums. You’ve got leaky gut, leaky gums, things like this where you’re now having this inflammatory process, maybe [crosstalk [00:03:11]-

Daniel Amen, MD:          Which cause leaky brain. I love that. Leaky gut, leaky gums, leaky brain.

Dr. Dale Bredesen:         Brain. That’s exactly right. And of course, the blood brain barrier abnormalities are very, very early in Alzheimer’s disease. That’s type one or inflammatory or hot Alzheimer’s disease. And the typical person is kind of a 65 year old man who’s doing all the wrong things and has an HSCRP of eight, that sort of thing. They have an inflammatory profile.

Then there’s type two. Very different story. You’ve gotten to the same pathology, but you’ve come in this case, not because you’re pushing on it with inflammation, but because you cannot support the network, so you have low vitamin D or thyroid pregnenolone, progesterone, all these things we had talked about before, estradiol, testosterone. All these things are critical nerve growth factor, brain-derived neurotrophic factor, vitamin D, all of these things are critical to support that 500 trillion plus neuron network or synapse network. It’s a tremendous network that you’re supporting there. And if you’re low in these things, you simply cannot afford that network and so you now downsized and Alzheimer’s results from that story. That’s type two. That is atrophic or cold Alzheimer’s. And I should say the Ayurvedic physicians thousands of years ago came to the same conclusion that there are these different subtypes of dementia.

Then there’s type 1.5, which we named it that way, because it has features of both. It’s glycotoxic. It is sweet Alzheimer’s disease. And it is because you’ve got on the one hand glycation of these various proteins and so they now change their shape. They change their function as well as their form, and you respond to them. They are now abnormal. Of course, we measure it as hemoglobin A1C, but there are lots of other proteins that are glycated just like remoras on a shark.

And so on the other hand, it has some features of type two because it creates insulin resistance. You can literally measure the phosphorylation change on IRS1, which is part of the signaling pathway from the insulin receptor. You’re shutting down your response to insulin, which is an important growth factor for the brain. That’s type 1.5, or sweet Alzheimer’s.

Then there’s type three, which is toxic. And as you know, the toxins come in three groups, metals like mercury and other inorganics, air pollution, things like that. As you know, there was a study out of Mexico City with severe air pollution showing a child that had Alzheimer’s changes in the brain. Just really scary.

It’s the metals and the other inorganics, then it’s the second group, organics. Amazing. We’re finding people who have high levels of propylene oxide, acrolein, glyphosate, all these various organics, again, people don’t typically check for that can contribute to cognitive decline. Then, the third group in there, of course, is the biotoxins, things like trichothecenes and ochratoxin A, mold-related toxins. That’s type three, [inaudible [00:06:32] toxic Alzheimer’s.

Type four is vascular. And of course, the vascular component so important. And this is a critical area for the future because so many people aren’t checking, they’re not checking their oxygenation at night. They’re not getting their blood flow up. They’re not doing appropriate exercise. They’re often having big glucose swings that they don’t know about until they actually do CGM, the continuous glucose monitoring, all of these critical for the vascular status.

And then the fifth one, of course, is one where you are a real expert, which is traumatic, which as you know contributes so commonly to this problem. These are the different ones, and it’s helpful of course, to know what are all the contributors, because then you can go after them.

And I should say, we’re in the middle of the first trial in history for Alzheimer’s. I’m very enthusiastic about this because as you know, all the trials in the past have been where you have to say, “Here’s our predetermined treatment for this problem. It’s going to be this drug or it’s going to be this lifestyle change,” or what have you. In this one, we’re saying the opposite. We’re staying, “For each person who comes in, we’re going to measure all these different variables and then we’re going to address the ones that are contributing to the decline.” And I think moving forward, that’s what we’re all starting to do [crosstalk [00:07:50]-

Daniel Amen, MD:          That’s rational. You’re going to target treatment based on the vulnerability they have. I’m looking at this thinking about my types, infectious Alzheimer’s. There was an editorial in the Journal of Alzheimer’s [crosstalk [00:08:10] but there’s other infections, like Lyme. I bet COVID-19’s going to become part of the future because [crosstalk [00:08:20] we scanned our first COVID-19 positive brain with cognitive symptoms. It was terrible. The scan was terrible. Do you think at some point there may be an infectious type?

Dr. Dale Bredesen:         Oh, absolutely. Right now, this is part of type one, the inflammatory type because of the infections typically drive the inflammation, but I absolutely agree. Many, many people have Alzheimer’s in association with infections. Again, it may just be one. Professor Ruth at Saki has spent her career looking at this. And you’re absolutely right about COVID-19. It’s really concerning because you go back to post-encephalitic Parkinson’s from 100 years ago. Are we going to have post-COVID Alzheimer’s disease?

And one of the most concerning things I heard recently was from someone on the front line saying that a lot of the people who are coming off the ventilators, no anesthesia, no hypoxia, but just not waking up the way they should, which really suggests a significant amount of brainstem pathology, and even though they then ultimately do wake up, what’s their concern down the road? Where are they going to stand? And I’d be interested, Daniel, in your scans COVID-19, do you see brainstem changes?

Daniel Amen, MD:          We’ll have to look. We just starting that work. But with Lyme, for example, initially … because there are a lot of COVID-19 people without symptoms or they just have mild flu-like symptoms, but if you’re losing your sense of smell, that’s-

Tana Amen, BSN RN:      And how do you know? How do you know if you’re having cognitive changes [crosstalk [00:10:06]-

Daniel Amen, MD:          And will we see some later on-

Tana Amen, BSN RN:      Right, down the road.

Daniel Amen, MD:          … like Lyme. You actually put a map of the United States with the highest incidence of schizophrenia, it’s the northwest, the north Midwest and the west coast. And then you overlay the highest instance of Lyme in the United States, it’s almost identical.

Tana Amen, BSN RN:      Identical.

Daniel Amen, MD:          And so I think like your subtypes for Alzheimer’s, I think it’s also true for serious psychiatric illnesses. It’s just curious. We’re going to be paying attention really closely to COVID-19. And quite frankly, it’s one of the reasons I don’t want to … I know there’s a lot of controversy in society. They’re having COVID-19 parties. It’s like, I just don’t think that’s the smart thing. The smart thing is wash your hands and avoid it if you can.

Dr. Dale Bredesen:         Yes. I’ll pass this time around. Thank you.

Tana Amen, BSN RN:      Yeah, exactly.

Daniel Amen, MD:          Oh my goodness. I love these types. And I think one that’s often overlooked is your type five, is the having a traumatic brain injury. And I think Tana and I had this discussion-

Tana Amen, BSN RN:      We talked a lot about that.

Daniel Amen, MD:          … when we first met. I asked her if she ever had a brain injury, because that’s part of my dating ritual.

Tana Amen, BSN RN:      Okay. But in my defense, I’m a neurosurgical ICU nurse. What do you think we think a brain injury looks like?

Dr. Dale Bredesen:         Yeah, of course.

Tana Amen, BSN RN:      You’ve got a brain drain, you have a skull flap. I’ve never had that. I walked away from a car accident. I walked away.

Daniel Amen, MD:          And what happened?

Tana Amen, BSN RN:      We rolled two and a half times at 75 miles an hour, but I walked away.

Dr. Dale Bredesen:         Yeah, Daniel, that’s a great pickup line. Have you ever had a brain injury? That’s [crosstalk [00:11:53].

Tana Amen, BSN RN:      The best pickup line ever, “Can I see your naked brain?”

Dr. Dale Bredesen:         That’s different than the chemists’ pickup line is, “Tell me if this smells like chloroform.”

Tana Amen, BSN RN:      Right, exactly. But really when he brought that up and he pointed out, he just stared at me when I mentioned the car accident, because he had to ask me over and over and over and he’s like, “Ever been in a car accident?” I’m like, “Yeah, but I walked away from it,” and he just kept staring at me. And then I had to think about it. I’m like, “You know, I am a nurse. Shaken baby syndrome is a thing,” right? Basically that’s what I had was probably shaken baby syndrome, right? [inaudible [00:12:29]

Daniel Amen, MD:          [inaudible [00:12:33]. The book is called “The End of Alzheimer’s Program”, Dale Bredesen. Groundbreaking. You should buy this book and then you should buy it for people you love because [crosstalk [00:12:46] get your brain right, yes, your memory will be better, but your mood will be better, your focus will be better, you relationships will be better because ultimately that’s [inaudible [00:13:01]. Stay with us. When we come back, we’re going to talk about more ways [inaudible [00:00:13]:09]. Stay with us.

Tana Amen, BSN RN:      If you’re enjoying The Brain Warrior’s Way Podcast, please don’t forget to subscribe so you’ll always know when there’s a new episode. And while you’re at it, feel free to give us a review or five star rating as that helps others find the podcast.

Daniel Amen, MD: If you’re considering coming to Amen Clinics or trying some of the brain healthy supplements from BrainMD, you can use the code podcast 10 to get a 10% discount on a full evaluation at or a 10% discount on all supplements at For more information, give us a call at 855-978-1363.