GUY RAZ, HOST:
On the show today, ideas about prevention, the things we can do today to prepare ourselves for tomorrow, even when it comes to something that doesn't seem preventable at all, something like Alzheimer's.
LISA GENOVA: If we're too scared to talk about Alzheimer's to the point where we can make it seem like it doesn't exist 'cause we're not going to talk about it, well, it's awfully hard to cure something that doesn't exist.
RAZ: This is Lisa Genova.
GENOVA: And if we can all think back to when people wouldn't say the word cancer, they called it the big C, and we didn't discuss it. And if your neighbor had cancer, we didn't talk about it. We didn't look at our neighbor anymore. And that person basically got excluded from community. And something changed in the world of cancer. And people began talking about it.
We mentioned the name. We wear the looped ribbons, we go for walks, we bake casseroles and we bring those people back into community. And it's no accident that we have treatments and survivors now for cancer. If we're going to get to a point where we have treatments and survivors for Alzheimer's, we need to be in conversation about it today.
RAZ: Lisa is a neuroscientist turned writer.
GENOVA: I write novels about people living with neurological diseases and disorders.
RAZ: And a couple years ago, she wrote a novel about Alzheimer's. It's called "Still Alice."
GENOVA: "Still Alice" is about a Harvard professor. And she's diagnosed with early-onset Alzheimer's disease. And so the book is about trying to find out what you're worth as if you've placed all of your worth in what you do and what you do is think for a living. And it's very cerebral and intellectual. And if you can no longer be that, the book is about who am I and how can I matter when I have something like Alzheimer's?
RAZ: And as Lisa points out, Alzheimer's is something that will probably impact all of us in one way or another. Here's Lisa Genova on the TED stage.
(SOUNDBITE OF TED TALK)
GENOVA: How many people here would like to live to be at least 80 years old? Yeah, I think we all have this hopeful expectation of living into old age. Let's project out into the future to your future yous and let's imagine that we're all 85. Now everyone look at two people. One of you probably has Alzheimer's disease. And maybe you're thinking, well, it won't be me.
Then, OK, you are a caregiver. So...
GENOVA: ...In some way, this terrifying disease is likely to affect us all. Part of the fear around Alzheimer's stems from the sense that there's nothing we can do about it. Despite decades of research, we still have no disease-modifying treatment and no cure. So if we're lucky enough to live long enough, Alzheimer's appears to be our brain's destiny.
But maybe it doesn't have to be. What if I told you we could change these statistics, literally change our brain's destiny without relying on a cure or advancements in medicine?
RAZ: I mean, so do you think Alzheimer's can be prevented?
GENOVA: I do to an extent. So we think that Alzheimer's begins with the buildup of a protein called amyloid beta. And that buildup can take 10 to 20 years before it reaches a tipping point that then causes the disease to become symptomatic. And so like heart disease - right? - like, so we know that when you go for your physical and you get your blood pressure taken and your cholesterol checked with a blood draw, you're being tested for heart disease.
And the hope is that if they catch it, you can do something about that either through statins, diet, exercise to prevent you from getting a heart attack in 10 years or 20 years. Likewise, with Alzheimer's, there are things that we can do to keep those amyloid plaque levels from reaching the tipping point. And they involve similar things.
GENOVA: Like - so one of the big discoveries in recent years has to do with sleep. So in slow-wave deep sleep, our glial cells rinse cerebral spinal fluid throughout our brains. And this clears away a lot of the metabolic waste that accumulated during the business of being awake. And one of the things it can clear away is amyloid beta. And so you can imagine that while you're sleeping, this is being sort of swept away. It's like a deep cleanse for the brain.
But if you're not getting enough sleep, you're going to wake up in the morning with amyloid beta levels not cleared away. And so it's going to pile up. We know that cardiovascular health is so important. Anything that's good for your heart is also going to be good for your brain. And likewise, anything that's not good for your heart is probably not going to be good for preventing Alzheimer's.
And so you can imagine that if you did nothing, you'll reach that tipping point sooner. So in terms of it preventing the disease, you know, maybe you've bought yourself, you know, an extra 10, 15, 20 years.
RAZ: After the tipping point, what do the symptoms look like?
GENOVA: So the symptoms change from, like, so for example, there's this phenomenon called tip of the tongue where you're trying to think of someone's name or a word and you're like, oh, what is it? What is it? I know it begins with S or I know it has two syllables but can't come up with it.
And maybe you're driving in your car four hours later and suddenly the word or the name pops into your head - oh, it's Sarah (ph). And we all experience this tip of the tongue. In fact, the average 25-year-old experiences 3 to 4 tips of the tongue a week. And this does increase a little bit with age. But with something like Alzheimer's, when a word drops out, you don't have the first letter and you don't know the number of syllables and it doesn't come back in a couple of hours.
So the beginning symptoms of Alzheimer's will often be words that are lost and not found. It is having trouble remembering what happened a few minutes ago. So short-term memory gets compromised. So it's language, it's memory, it's cognition, it's being able to think through complex tasks so you're making mistakes at work.
If there's a procedure that involves 10 steps, you might not get through all the way to the 10th step but you'll be unable to complete it. So those mistakes start happening with Alzheimer's.
RAZ: OK, but what happens, you know, if you've already reached that tipping point?
GENOVA: Yeah, so in thinking about Alzheimer's, it's helpful to think of synapses. So synapses are the places where neurons communicate. And that's what's under attack in this disease. And the good news for us humans is that we've got a lot of these synapses. The average brain has 100 trillion. So while they're under attack with Alzheimer's, we've got sort of a lot of backup connections that we could potentially take advantage of.
(SOUNDBITE OF TED TALK)
GENOVA: We gain and lose synapses all the time through a process called neuroplasticity. Every time we learn something new, we are creating and strengthening new neural connections, new synapses. In the nun study, 678 nuns all over the age of 75 when the study began were followed for more than two decades. They were regularly given physical checkups and cognitive tests.
And when they died, their brains were all donated for autopsy. In some of these brains, scientists discovered something surprising. Despite the presence of plaques and tangles and brain shrinkage, what appeared to be unquestionable Alzheimer's, the nuns who had belonged to these brains showed no signs of having the disease while they were alive.
How can this be? We think it's because these nuns had a high level of cognitive reserve, which is a way of saying that they had more functional synapses. People who have more years of formal education, who have a high degree of literacy, who engage regularly in mentally stimulating activities all have more cognitive reserve. They have an abundance and a redundancy in neural connections.
So even if they have a disease like Alzheimer's compromising some of their synapses, they've got many extra backup connections. And this buffers them from noticing that anything is amiss.
RAZ: So you can do those things like have social connections and engage your brain in stimulating activities and potentially slow down and maybe even prevent Alzheimer's from getting worse?
GENOVA: Well, you're not going to prevent the actual disease with these things. So the exercise, the good sleep, those are actually going to prevent the disease from happening, the actual pathological neurobiology of Alzheimer's. The idea of learning Italian or staying socially engaged or learning to play piano or just reading a book, how that can help, it's not going to stop the disease but it's going to build backup neural connections so that when the other ones go defunct because Alzheimer's has killed them off, you've got these detoured roads.
It's sort of like, you know, if you're driving down the street and there's been a car accident and you can't go straight down that road anymore, it's blocked off, well, if you've paved other roads to drive around it, you can still get to where you're trying to go.
RAZ: So do you, I mean, when you think of the word Alzheimer's, do you think, is this something that in 20 years from now we will say, man, we've just made incredible leaps and strides in preventing this or improving the lives of people who have some of this disease?
GENOVA: Yeah, I do. I see a future without Alzheimer's. I don't think it's that far-fetched. I think, you know, if we look back to HIV is a great example. So, you know, that disease struck in the '80s and we had never seen it before. And there was no science around it yet. And, you know, today it is 100 percent treatable. We have HIV survivors now.
There are a lot of cancer survivors now. There are real examples of diseases that were not understood and lethal, which are now managed well. And that possibility, I think, is there for Alzheimer's in our near future, certainly within 20 years.
RAZ: Lisa Genova is a neuroscientist turned writer. She's the author of the book "Still Alice," which was also made into a movie starring Julianne Moore. You can see Lisa's full talk at ted.com. On the show today, ideas about prevention. I'm Guy Raz, and you're listening to the TED Radio Hour from NPR.
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