How Memory Works with Dr. James Noble
Is memory loss expected as we age? A neurologist explains the distinction between dementia and Alzheimer’s disease and shares options for treatment and support.
Welcome to Health Matters – your weekly dose of the latest in health and wellness from NewYork-Presbyterian. I’m Faith Salie.
We’ve all experienced forgetful moments, but for some of us, they can become more common as we age. So when does memory loss become a more serious issue?
This week, I talked to Dr. James Noble, a neurologist at NewYork-Presbyterian and Columbia. He shared insights about how memory works, how it may change as we age — and how people can take care of their memory. He also breaks down memory disorders and the differences between Alzheimer’s disease and dementia.
Faith: Hi Dr. Noble. Thank you for joining us.
Dr. Noble: Hi, Faith. Thanks for having me.
Faith: From a cognitive standpoint, what exactly is memory?
Dr. Noble: Memory can be defined many different ways. Sometimes we think about memory kind of being in the moment. There’s a problem with memory that many of us experience that now has a name called Doorway Memory. This is where somebody walks into a room, happens to all of us. We walk into a room and we say, “Oh, gosh, what was I doing? I was coming in here for something.” My coffee cup or something like that. Right. That’s a kind of an in the moment memory, working memory. What is it that I’m doing right now that I just was thinking about?
There is, another form of memory where we think about it being something that has to be or begins to involve long-term storage. And when we think about long-term storage, we can define that as being on the order of minutes or months or years.
There is a key area in the brain called the hippocampus, which is essential for laying down new memories and getting them to last. And so that’s the circuit that begins to get involved when we think, “Okay. What was the conversation I had with my colleague a half an hour ago?” For your capacity to not just remember that it happened, but the details of that conversation.
And then we can think about more long-term memory, which is, you know, things that happened to us from long ago. So the same circuits that were involved in laying down information about that conversation you had, you know, just a half an hour ago, are involved as a first step in laying down information that stays with you for years.
As we know, that information becomes less and less discreet over time. You know, we have general ideas of what happened to us. Maybe we can remember certain conversations if they were really important to us. But by and large, we begin to think about things in kind of broader events rather than, uh, you know, finite sentences or conversations that are held.
And then there’s procedural memory. That is the ability for us to do things like, you know, use a hammer and a nail. It’s the process of putting together something, something we may have learned along the way.
Faith: So we’ve learned there are lots of kinds of memories. Can you describe to us what is going on in our brain when memory is at work?
Dr. Noble: Great question. Well, let’s say for instance, I gave an example a moment ago about hammer and a nail. We, in order to remember how to use that, we might think back to a project that we did some years ago that involved a hammer and a nail, or our brain might be accessing some information in part of our language centers that says that’s a hammer and that’s a nail as we pick it up. And then in another area of our brain might even know, well, what do those things do? What’s the function of that hammer and nail? Well, it’s to fasten something together, and all of those things come together along with the idea of “I want to hammer and nail something together” so that that memory, it’s not just like something is just remembered, it’s your brain is engaging multiple areas of your brain. It’s involving language circuits, visual-spatial circuits, kind of sensory integration circuits of how do I hold and swing and what’s the, what’s the feel of that hammer in my hand?
Faith: How can we take care of our memory? What, what can we do to preserve the memory we have?
Dr. Noble: There is a tendency for saying once somebody has a thinking or memory problem, or once somebody’s of an age to have a thinking and memory problem, that we can in fact reduce somebody’s risk of developing subsequent problems. I don’t think we have great evidence to support that. But there’s very little downside to trying.
We know that those individuals who, throughout their lifetime have done certain things towards their health, including keeping a healthy diet, exercising on a regular basis, keeping themselves socially active, keeping themselves cognitively stimulated in some capacity of whether it be education or work. Those individuals seem to be the most resilient against having some sort of medical or neurological problem like dementia later on in their lives. There’s very little downside to having a healthy diet, very little downside to exercising.
Faith: We hear a lot about how Omega-3s could boost memory. Is that right, and are there other nutrients that can improve memory?
Dr. Noble: I would not say that there’s any one specific micronutrient that seems to be better than another. Generally speaking, you know, adhering or taking supplements, we don’t think that they have that much of a overall benefit. And instead we’d, we’d always recommend a well-balanced diet that maybe adheres to something like the Mediterranean diet. So the Mediterranean diet is one that is low in saturated fats, higher in unsaturated fats. It does seem to be the case that those individuals who have a well-balanced diet that has a long list of primary ingredients and a short list of highly processed ingredients, those individuals are the ones that seem to have the best outcomes.
Faith: I am in the middle of my life if I’m lucky. So I really wanna know, is it possible ever for anyone to entirely prevent memory loss as we age, or is memory decline just a natural part of getting older?
Dr. Noble: So our brains operate differently as we age. But there are plenty of individuals that we follow over time who don’t demonstrate a thinking or memory change over time. And so what you’ve hit upon is this great debate of what is normal aging? What is expected aging? Is even Alzheimer’s disease part of somebody’s normal life? Maybe it was going to happen anyways. And so there’s been a reframing of what we think of as normal.
On the other hand, I think most of us still would say Alzheimer’s disease is something that is a disease. It’s something that we are aiming to try to minimize, hopefully even eliminate someday. I think we’re far from that, but maybe getting closer to understanding a lot of its biological underpinnings. But until we can make a definitive change in somebody’s trajectory before they develop memory problems, we still think that memory changes, thinking changes are part of the normal process of aging, or at least part of the aging process. Whether it’s expected or normal, I think remains of some debate.
Faith: You’ve referenced Alzheimer’s. I’d, I’d like to pause and ask you to define it or differentiate it from dementia.
Dr. Noble: Yeah, that’s a, great question. Dementia. What’s the difference between that and Alzheimer’s disease? It is one of the main questions we get in the office. Dementia is an umbrella term, describing somebody who has some sort of thinking or memory problem to the point that they need help in their day-to-day lives. They need help with managing their schedule or their appointments or their medications. But it doesn’t really get to the why. It’s really more of a descriptive term, and that stands in contrast to somebody who has so-called normal aging, where they may have some minor thinking and memory changes with aging, but not demonstrably changed on some sort of formal testing and having no real impact on their day-to-day life.
There is a middle ground called MCI, or mild cognitive impairment, where somebody is having some demonstrable change on testing or they perceive it, but not to the point that they’re having to need help or ask for assistance in their day-to-day lives. Many people pass through MCI on the way to dementia. Those terms, however, don’t get to the biology of disease, and that’s really what we’re trying to understand right now. Why is this happening?
Alzheimer’s disease is a change that we can detect microscopically. We can also identify it on special brain scans and even in fluids like the spinal fluid. And increasingly we’re able to help identify it through blood tests. There are two main changes that we can identify.
One is the accumulation of this protein called amyloid, and the other is this accumulation of a protein called tau. These are both proteins that we all have in our bodies. They have nothing to do with protein that we may have in our diet, but we think that those clumping or accumulated proteins may be a signal that something has happened or that the brain is becoming sick.
Because we’ve gotten to the point of being able to biologically diagnose Alzheimer’s disease, we’re hopeful that we’re going to be able to biologically diagnose other forms of dementia. About half of all forms of dementia are due to Alzheimer’s disease, but about half of them are due to something else or maybe a mix of other things, things like stroke or another common condition that doesn’t get nearly enough discussed about it, and it’s called Lewy body dementia.
Further, we have uncommon, or rare forms of disease, but ones we see in our practice all the time, things like frontotemporal dementia, and then there are other forms of dementia that are far less common than those.
Faith: What are some of the risk factors for Alzheimer’s disease?
Dr. Noble: The risk factors that are established for Alzheimer’s disease include things like, uh, rare genetic causes or maybe a multitude of common genetic causes. We know about things like high blood pressure, diabetes, sedentary lifestyle, maybe even things like hearing loss. But even after we take all of those things into account, we also know that about 50% of all people who develop Alzheimer’s disease have no traditional risk factor for Alzheimer’s disease beyond just aging itself. We do not think that Alzheimer’s disease is bound to happen to everybody, but it happens to many.
Faith: With all these groundbreaking revelations about Alzheimer’s and other forms of dementia, what sort of treatments, let’s look at Alzheimer’s, what are patients receiving right now?
Dr. Noble: So for the last, uh, 20 plus years, we have had a very small list of medications to offer. These are medications that are usually pills once or twice a day. We also have a patch that is basically the same drug, and these are medications that help to boost some of the, what we call neurotransmitters. These are the small chemicals within the brain that help to kind of talk from one nerve cell to the next. We’ve been looking for the last, you know, few, you know, not just years, but decades for new therapies that might not be able to just help with those neurotransmitters, but actually affect the biology of disease.
The newer therapies that have been approved by the FDA, and we expect that there may be others coming down the line, are ones that begin to actually take those proteins that cause things like Alzheimer’s disease and remove them from the brain.
It’s been a greatly debated topic as to whether or not that will actually make a difference in somebody’s clinical course. And right now we think that some of these medications in appropriately selected individuals, those medications may slow the process by which people become more and more forgetful or more and more dependent on others.
It’s not a cure. It actually just slows the progression. But that’s a first step. We hope to actually bring it back up to maybe, uh, an arrest of progression and a recovery back to where somebody was is really our, our ultimate goal. But I think a long way from it.
Faith: If someone has dementia that is not diagnosed as Alzheimer’s, how are you treating that?
Dr. Noble: So we use symptom-based therapies for all patients, whether they have Alzheimer’s disease or something else. That is, if they have a problem with, uh, memory, we’ll use a medication that may help boost memory in some regard. These are not permanent fixes or medications that ultimately cure a disease, but they may offer some symptomatic relief. Similarly, if somebody has problems like, uh, depression or sadness or insomnia, we use medications to help treat that.
Faith: How can we support family members and loved ones who are struggling with memory, or, or showing signs of dementia and Alzheimer’s?
Dr. Noble: The thing that really has struck me throughout my career is that we in the office tend to focus on what somebody cannot do, and it makes them very uncomfortable. It makes us uncomfortable too, but we have to know so we can help, you know, provide some sort of therapy to address those issues.
But really what I like to focus on is what somebody can do. And most people are able to kind of go out and about in their community, especially in the earlier phases of disease, and they can enjoy life, enjoy being with one another. And engage in with other individuals in a meaningful way.
Unfortunately, there aren’t enough opportunities for that. And so one of the initiatives that I’ve been involved with, is this nonprofit Arts and Minds where we offer museum-based art-centered experiences for persons with dementia and their care partners. Often a spouse or adult child or professional caregiver where people go to an art museum for an hour, hour and a half on, on a weekly or monthly basis.
They talk about art, make art, and do things that they wouldn’t ordinarily do, and have, uh, you know, some quality time with one another. Enjoying the moment.
Faith: Dr. Noble, thank you so much for joining us today.
Dr. Noble: My pleasure, Faith.
Our many thanks to Dr. James Noble.
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