Translator: Rhonda Jacobs Reviewer: Tanya Cushman
Hi everybody.
I want to begin with a quick little exercise if you will indulge me.
I want you all to close your eyes -
don't worry, this is not going to be a meditation -
just close your eyes for a few seconds.
And I want you to picture somebody that has dementia.
Okay, what does the term "dementia" evoke for you?
Maybe you have a relative with the disease.
Maybe you've seen a documentary recently.
There's no right or wrong answer.
Just get that image in your mind's eye.
Now I want you to open your eyes, and if the image you had in your head
looks something like the person you see on the screen in front of you,
I want you to raise your hand.
Alright, that's quite a bit of people.
Now I want you to raise your hand if the image you had in your head
looks somebody like the person that you see on screen now.
Okay. Much less people.
This is my mother.
And her name is Kathy, and she has dementia,
and I love her very much.
And when I had to come to terms with the fact
that my mom was showing the initial signs of memory loss
in her 50s a couple of years ago,
it was an incredibly traumatic experience for me,
and it's still, to this day, incredibly heartbreaking
to have to acknowledge.
But because I couldn't chalk up what I was seeing in my mom
to typical aging -
clearly she's not the picture of a person succumbing to the ravages of time -
I decided to learn all that I possibly could
about the ways diet and lifestyle mediate risk for neurological disease,
brain health, and ultimately brain function itself.
Now, what I learned shook me to my core.
You see, I thought, like you guys, that dementia was an old person's disease.
You see, not only is dementia not a normal aspect of aging,
but it begins in the brain decades before the first symptom of memory loss.
If you make it to the age of 85, you have a one in two chance
of being diagnosed with Alzheimer's disease.
That's 50 percent; those odds are not very good.
And unfortunately for my generation, millennials,
we're the first generation in history that's going to reach the age of 90,
according to the Stanford Center on Longevity.
Now, I think I speak for many millennials
when I say that generally we believe science has our back, right?
Ninety is a long ways from now.
By the time I get to that age,
we're going to have some kind of pharmaceutical cure -
ultimately, not something I have to worry about.
Well, unfortunately,
Alzheimer's drug trials have a near 100 percent failure rate.
Let that figure sink in, okay?
That's worse than the failure rate for cancer drugs.
I mean, those are dismal statistics.
Therefore, unless we can prevent this disease,
one in two millennials will have it, which is pretty heartbreaking.
For the past century,
the conversation surrounding Alzheimer's disease,
the most common form of dementia, has been one dominated by doom and gloom.
That's because since 1906,
when Alzheimer's disease was first coined and named
by the physician Alois Alzheimer,
90 percent of what we know about the disease
has been discovered only in the past 15 years.
So that is to say, this is a rapidly evolving field of science.
And while we don't yet have all the answers -
there's still no cure; I wish we had a cure -
we do have enough information to say that today,
for a significant proportion of people, it is a potentially preventable disease.
Here we have a statement written in 2014
by 109 leading scientists and clinicians around the globe
stating very plainly that in 2014, we had enough evidence to say
that dementia and Alzheimer's disease is a preventable disease.
And just this year, for the first time,
at the Alzheimer's Association's International Conference,
it was acknowledged that one third of dementia cases may be preventable.
Depending on what literature you review, even more may be preventable as well.
This is just the statistic that was most recently published
in the journal Lancet,
which is one of the top medical journals in the world.
And here we have coverage from that same event
alluding to the notion
that a field is now looking for hope in an area once thought impossible.
Now, when it comes to our diets and our lifestyles,
and their impact on our health,
it's been said that our genes load the gun while our choices pull the trigger.
So I became obsessed
with trying to understand what it is about the modern world
that makes it so likely for our choices to pull the trigger
on diseases like Alzheimer's disease.
So I did a deep dive into the literature.
And I looked at parts of the world, like in Ibadan, Nigeria,
home of the Yoruba people.
Now, there,
the most common and most well-defined Alzheimer's disease risk gene,
that in the United States puts somebody
at anywhere between a 2- and 14-fold increased risk for developing the disease,
there, has little to no association with Alzheimer's disease.
So in other words, if you live in the United States,
and you are genetically at risk for developing Alzheimer's disease,
you might move to Ibadan, Nigeria, and see that risk disappear.
So I started thinking a lot about evolution
and the kinds of diets that our ancestors might have consumed
during the time in which our brains evolved -
the magnificent supercomputer that each one of us is heir to,
this incredible legacy -
and I realized that for two million years,
our ancestors ate in a way that led to the evolution of our brains.
That's pretty amazing.
But then, 10,000 years ago, something happened.
We turned our backs on that diet.
We went from being hunter-gatherers, eating according to seasonal availability,
the world was our buffet,
we got our nutrients from the 50,000 edible plant species
that there are around the world,
and we became settlers,
essentially becoming slaves
to the few crops that we could domesticate.
Over time, our brains lost the volumetric equivalent of a tennis ball.
So let me just rephrase that so you really get it.
We ate a certain way for two million years that led to the evolution of our brains,
then we turned our backs on that diet.
This ultimately paved the way for the fact that today,
60 percent of the calories that we consume worldwide
come from three plants.
Three plants.
Wheat, corn, and rice.
Perhaps even worse, 50 years ago,
these crops became the basis of our dietary guidelines,
where for the first time in human history, human beings were told how to eat.
We were told to base our diets on healthy whole grains.
I mean, I grew up, the Food Pyramid - which is now debunked - existed,
telling me that if I wanted to be healthy,
I needed to load up on anywhere between 6-11 servings of grains per day.
And today, the advice is still given
that to be healthy, we need to incorporate grains in every meal.
Well, when we look at research,
like what was recently published by Cochrane,
which is an organization
that has a partnership with the World Health Organization
and is known for their unbiased, systematic reviews of medical research,
we see that there is no evidence to suggest that eating grains,
including whole grains,
improve our health.
Now, in this research review, they looked at a certain kind of a trial:
they looked at a randomized controlled trial.
Now, randomized controlled trials
are the only kinds of trials that can show cause and effect,
which is why this research is so important.
But perhaps the most insidious thing about these three grains
is that today they're pulverized and packaged and sold to us
in processed foods that line our supermarket aisles.
These ultraprocessed foods
now make up 60 percent of the calories that we consume worldwide.
When we consume these exact kinds of foods,
they set off the equivalent of a forest fire in the body.
And the brain sits directly downwind of that fire.
That fire that I'm talking about, that's called inflammation.
And inflammation directly accelerates brain aging
and worsens pre-existing disease states.
Now, our bodies have an incredible capacity to heal from inflammation.
That's what's so great about being a biological entity.
Our bodies are so smart.
But the problem is our bodies need the proper ingredients
to be able to repair from inflammation.
Unfortunately today,
90 percent of Americans are now deficient in at least one vitamin or mineral.
Why do you think that is?
Well, that's because we're basing our diets
around not only these ultra-processed foods,
but processed foods made from these three crops,
which are pretty scarce when it comes to nutrients.
They're calorically dense,
but they are not nutrient dense, which is a key differentiator.
Another thing that these foods do very well
is they send levels of blood sugar through the roof.
And when blood sugar is elevated,
an ancestral hormone in our bodies also becomes elevated.
That hormone is called insulin,
and insulin is the body's chief fat-storage hormone.
The fact that we're relying so much on these kinds of foods
is why for the first time in history,
there are more overweight people walking the earth than underweight.
Now, the other thing that insulin does really well
is it turns your fat cells
into the equivalent of a subway turnstile in midtown Manhattan during rush hour.
Basically, calories can flow into your fat cells,
but they can't come out.
Now, this is very problematic
because there are certain organs in our body
that have evolved to use fat,
and use it remarkably well - in particular, the brain.
The brain loves to use fat for fuel.
In fact, I call fat our body's birthright fuel.
You see, when we're born,
human babies come packaged with an unusual amount of fat.
Our fatness rivals that of baby seals, actually.
We come packaged with a really high percentage of body fat.
I don't mean to make any babies in the audience insecure.
If there are any babies in the audience, I apologize,
but it's actually fascinating
why it's believed we come packaged with so much fat.
You see, the human baby is born with a half-baked brain.
We complete our development in the world.
This is often referred to as the fourth trimester.
If we were born cognitively
with the skills that some of our simian ancestors are born with,
our gestation would be twice as long.
This is one of the reasons human beings are so smart.
We complete our development in the world.
And it's thought the fat that we come packaged with
serves as a sort of Mophie for the developing brain.
The developing brain is incredibly energy hungry too.
This is why that's so useful.
The newborn brain uses 90 percent of the baby's metabolic rate.
So that means that 90 percent
of the oxygen and calories that the baby is consuming
goes to fuel its brain.
But the baby couldn't possibly consume enough calories to support that,
therefore, fat.
In the human adult brain, the ability to use fat for fuel is not lost.
In fact, as adults, our brains still love to use fat.
It could almost be said - almost -
that when the brain is using fat for fuel, it's not aging.
And the fact that we constantly, chronically deny the ability of the brain
to use fat for fuel due to our chronically high-carbohydrate diets,
well, this might be one of the most detrimental aspects of the modern diet.
And this could, partly, explain why it's thought
that 40 percent of Alzheimer's cases
may be attributable to chronically elevated insulin alone.
Again, insulin is the hormone
that turns our cells into that subway turnstile.
And this was a figure published in the Journal of Alzheimer's Disease,
which is one of the leading dementia journals worldwide.
So knowing what I know about the brain and how to properly feed it,
I've become obsessed with what I like to describe
as resetting my brain to its factory settings.
So I like to spend more time with my body and brain in a low insulin state.
And the quickest way, the best and most efficient way,
of getting your body and brain into a low insulin state is via fasting.
Luckily, we all fast every single day.
This is when we're asleep.
So what I like to do is I like to pad my sleep
by two or three hours on each side
with an additional time frame in which I'm not eating.
A lot of people call this intermittent fasting.
But essentially, one of the main goals of intermittent fasting
is to allow your body and brain to spend more time in a low insulin state.
When it's time for me to eat, I opt for nutrient density,
which describes foods
that have a very high ratio of nutrients to calories.
And there's no better example of that
than dark, leafy greens, like kale and spinach.
They have tons of nutrients that protect your brain cells
and help your brain cells create energy,
and they have very few calories.
In fact, the consumption of dark, leafy greens
is associated with reduced aging by up to 11 years.
I eat lots of eggs.
You see, I learned that when an embryo is developing,
the first structure to develop is the nervous system,
which includes the brain.
Therefore, an egg yolk is literally designed by nature
to contain all of the necessary ingredients
required to grow a healthy brain.
I also eat two to three servings
of humanely-raised grassfed red meat per week.
If I was a pre-menopausal woman, I would probably eat three to four
because red meat contains an abundance of highly bioavailable micronutrients.
And in fact, a lot of people today
say that there's no place for meat in a healthy diet.
But to that, I invoke a quote from one of my heroes, Carl Sagan,
who said that extraordinary claims require extraordinary evidence.
And researchers believe
that it's not just access to meat, but cooked meat
that catalyzed the growth of our brains during our evolution.
I eat lots of fatty fish:
salmon, wild salmon, and sardines.
And this is actually my perfect plate.
It's half, if not more, filled with colorful, fibrous vegetables
and a piece of protein that's not just protein.
It's got a ton of essential micronutrients,
like DHA fat,
which is one of the most important structural building blocks of the brain.
We now know that the adult brain can grow new brain cells up until death.
But the impetus there is that we need to supply our brains
with the appropriate building blocks to do so.
I also eat tons of fruit.
But not all fruits, okay?
I eat lots of avocados.
Avocados have the highest percentage of fat-protecting antioxidants
of any fruit or vegetable.
This is really important and really key for brain health
because your brain is constructed of fat.
Sixty percent of the brain by weight is fat,
but it's a kind of fat that is highly vulnerable
and prone to oxidation.
We need to supply our bodies with fat-soluble antioxidants
like vitamin E -
I eat lots of avocados, an avocado a day.
And I avoid, for the most part, modern, cultivated sweet fruit.
I'm not going to stand up here, guys,
and tell you that the banana on the right is toxic.
It's not toxic!
But today, our modern fruits are bred to contain more starch and sugar
than ever before in history because we like the way it tastes.
Compare the modern banana to the wild banana on the left,
and you'll see the contrast is stark.
And the research on fruit, okay, might surprise you.
Published in the Journal of the Alzheimer's Association,
it was found when looking at older adults
that higher fruit consumption was associated with shrinkage of the cortex,
which is your brain's grey matter.
Now, researchers in this journal wrote -
they compared that eating foods with high glycemic load,
whether as fruit or highly refined carbohydrates,
may have the same detrimental effect on the brain.
Now, this research is really fascinating
because fruit is usually associated with an overall healthy dietary pattern,
but rather than just looking at diets as a whole in this research,
they looked at individual dietary components as well,
where they came to this finding, which is very striking.
I also consume lots of fruit juice,
but only one kind of fruit juice:
extra virgin olive oil, which is actually a fruit juice.
Extra virgin olive oil is a staple of the Mediterranean diet.
It's one of the main features of the Mediterranean diet,
adherence to which is associated with a robust risk reduction
for Alzheimer's disease and dementia.
No talk about preventing dementia and cognitive decline,
which is the most important topic I think there is,
would be complete without a little bit of a chat on exercise.
So aerobic exercise is really important.
I don't do my aerobic exercise in the gym, I do it in the real world.
I try to imbue my day with as much movement as possible.
I'm always walking, I take the stairs whenever given the opportunity,
and I bike-ride whenever I can.
I know you guys in Venice love bike-riding.
The best thing about aerobic exercise
is that it boosts something called BDNF in the brain.
Remember this acronym; it's very important.
Brain-derived neurotrophic factor.
It's a guardian protein.
It's a guardian molecule
that not only ensures the survival of your existing neurons,
but promotes the growth of new ones as well.
It's key for neuroplasticity.
And aerobic exercise is the best way to stimulate BDNF.
I also love to lift weights.
Aside from making me look better naked, which it does,
having stronger muscles
is really important for brain function and brain health.
Why?
Because the same exact stimulus required to grow your muscles
and make them stronger
also acts on your brain cells to make them more efficient.
So where is the research to show
that making all of these changes in your lifestyles and diets
is going to be worth your time?
Where's the hard data? Right?
Well, to answer that question, I refer to the incredible FINGER study,
which was led by Dr. Miia Kivipelto
at the Karolinska Institute in Stockholm, Sweden.
I had the pleasure of visiting the Karolinska Institute
and interviewing Miia Kivipelto,
and what's so great about the FINGER trial
is that it's the world's first-ever large population, long-term,
randomized controlled trial.
Randomized controlled trials, remember, are the kinds of trials required
to prove cause and effect.
And what she found in this incredible trial
was that in her older adult at-risk population,
that by adhering to a battery of dietary and lifestyle interventions,
many of which I've described already,
she was able to improve executive function in her subjects by 83 percent
and improve processing speed by 150 percent.
Now, this is incredible,
and it's also particularly poignant for me in regards to executive function
because my whole life I've struggled with executive function.
Here's a letter written by my guidance counselors
in elementary school, in the days before e-mail, to my parents
suggesting that I see a psychologist because I had a lot of trouble
focusing my attention and tuning out distraction.
And that's why all throughout my academic career,
my grades were never good.
That's why I went into film instead of going to med school,
which is actually what I really wanted to do.
If only I knew then what I know now.
So in closing, thanks to research performed by AARP,
we know that brain health is important to 93 percent of Americans.
That is awesome.
What's less awesome is that very few people
know how to maintain or improve brain health.
So I'm trying to fill this knowledge gap for people.
Because every three seconds a new dementia case is diagnosed.
Let that sink in.
I mean, that's, like, heartbreaking.
In fact, since I began speaking to you guys,
400 people around the world were diagnosed with dementia.
But for me, this is not about statistics.
This is about a person who I love very much:
my mother.
And truthfully, I would do anything that I could to get her back
into the state she was before the monster that is dementia took over.
But it's made me incredibly passionate about spreading this message of prevention
out to people of all ages.
Our cognitive health might be a choice that we make
with every bite that we take.
And I want to be very clear that there's no person walking the earth
who's not at risk.
The brain is highly delicate
and vulnerable to the many insults thrown at it by the modern world.
You're never too young or too old to make a brain-healthy choice.
And our brains really make possible
all that it is that we love to do in the world.
So for that reason, I hope that you'll all agree with me
when I say that it's worth protecting.
Thank you.
(Applause)