- Is age associated cognitive decline inevitable?
Because I think, I think maybe,
do people think that it's inevitable?
Raise your hand if you think it's inevitable.
Okay, so a smattering of people, yeah.
That's what I thought for a long time,
even after I entered the field,
at least at, you know, in our current
state of the art for medicine.
And I think that comes from these sorts of plots,
where here on the bottom, the x-axis is age,
and from 35 to 85.
And then here is estimated memory change,
and they're measuring two types of memory,
episodic and semantic memory.
You can see it looks like it's pretty much downhill
from 35 onwards.
(audience laughs)
So that's not good.
But as it turns out, that's for a population.
If you look at any particular individual,
the curve could look like this.
Actually, at age 35, that's not even yet the peak.
There's a peak of memory in this individual
at age 60, and then with aging, at age 85,
it kind of, you go back down to where you were
when you were when you were 35.
So that is optimism inducing, right?
So how do we go from this sort of
relentless downhill trajectory
to what we would want, the individual change?
So in order to understand that,
scientists, and epidemiologists,
and public health, public health investigators,
for years have tried to understand
what actually contributes to cognitive decline.
And we know that age is one of the contributors.
We also know that having less education,
from an epidemiological point of view, makes it more likely
that you'll have cognitive decline with age.
Co-morbid medical conditions, like heart condition,
vascular disease, inflammatory conditions,
those can also contribute to cognitive decline.
A big one that's in the news a lot now
is repetitive head injuries, or concussions,
and there's this idea of this thing
called chronic traumatic encephalopathy now,
which is still a little bit,
I mean, I think it's true but there's still
a little bit of controversy around it.
And then more recently,
we understand that there's a big genetic contribution
to sort of cognitive and brain health over time.
So then the natural follow-up question is
how can one increase the odds of successful cognitive aging?
That's why you're all here, right? (chuckles)
(audience laughs)
So I'm gonna give you some good news.
There are ways that we can enhance our likelihood
of successful cognitive aging.
The first one is education, both through the,
through sort of elementary school, through college.
Like I said, if less education
can predispose to the, to increased likelihood
of cognitive decline, then more education
is actually protective.
We're not sure why that is,
it may be that they are more redundant connections,
or synapses, and one develops a cognitive reserve,
we're not sure.
Number two, social engagement somehow
is good for brain health,
as well as mental activity.
Now, none of these are surprising,
but I thought that I should congratulate you all
because at the Mini Medical School,
you're getting all three of these, right?
You're getting education, and social engagement,
and some mental activity, hopefully.
I'll try not to bore you.
And minimizing stress is also good for brain health.
So I'll tell you right now, there's no test
at the end of this lecture, okay?
So we can all relax.
Other things that are good for brain health.
Good sleep, there's some secret sauce in sleep
that helps to consolidate memories,
to modulate sort of our brain circuits.
So optimizing sleep is important.
Moderation in food and alcohol.
I never say, you know, just eat a plant-based diet
because I think even though it's good for you,
we gotta live a little bit.
And there are some studies that alcohol in moderation
can actually be protective for brain health.
Probably the most important thing on this list, though,
and I'm gonna make no bones about it,
is physical exercise.
If I could pick one of these things,
I'd say go run marathons, or, you know,
go do exercise everyday.
I really can't emphasize enough
how important regular physical exercise is
for brain health.
And scientists have been trying for years
to try and understand what it is about physical exercise
that protects the brain, and there's some idea
that exercise causes a neuroprotective chemical
to be released into the brain,
and there's actually a study that's based out of Stanford
where they're trying to, they're in phase one,
or phase two trials now, to activate the receptor
for that brain chemical.
But physical exercise, just do it naturally,
why take a pill when you can go out
for a walk on Crissy Field, right?
And then of course comes the question,
are there any medicines that can improve brain health?
And I'm gonna tell you right now,
my patients send me articles, and links,
and questions about all kinds of these nutriceuticals
that are on the market right now,
and none of them are placebo-controlled trials.
And what I usually say is, "I can't recommend this."
I worry that it's someone taking advantage of,
preying on our fears of losing brain health.
If it's not super expensive and it's not harmful,
I'm not gonna stop you from taking it,
but right now there's nothing out there
that I think is actually worth the money.
And there are even, you know, I mean,
there are all these books written,
and for the, you know, the ones that say,
"Exercise and stay active," those are good.
But the ones that say, "Buy a hundred pills
that I'm gonna sell you," those are not good, okay?