Music

Angela Guo: So, it's the old adage
on what you eat

when I eaτ sugary or caffeinated food
I often find myself, like unable to focus

So, eating healthier foods
has a significant impact on

how well I can focus, as well as
how quick I can think.

Sanjay Gupta: That's Angela Guo.

She's a 17-year old senior at
Adlai Stevenson High School

in Lincolnshire, Illinois.

And that adage she just cited,
"You are what you eat",

that's been around since the 1800's.

People have known for a long time
just how much food affects us.

But it's not just in term of
long-term health,

but also short-term mood.

AG: Food really helps us maintain
a safe clarity

and so eating healthier foods

has had a significant impact

on how well I can focus, as well as
how quick I can think.

SG: She may only be in high school

but Angela has already made

the crucial connection between
what she puts in her mouth

and how quickly that affects her brain.

She even believes that
simple understanding

gave her a real advantage
when she competed

in the National Science Olympiad
tournament earlier this year.

Announcer: First place: National
champions of the 2023 Science Olympiad

National Tournament: Adlai Stevenson
High School of Illinois, let's go!!

SG: Now at this tournament
earlier this year,

Angela and her team mates went up
against thousands of students

from around the country.

They were competing in events
highlighting chemistry,

and Earth science and biology.

But here is the thing:
the entire time on Angela's team

you really didn't see much sugar around.

Instead,
there were lots of healthy snacks.

AG: So, even at school, I'd bring
my own lunch

and it's just that aspect of
knowing what goes into your meals

is like really important. It kind of
gives you peace of mind.

SG: The team did really well, and now
as they prepare for more tournaments,

Angela, who's now is team captain, says,
"Sure, they do study hard,

but what they eat, how they eat,
that's also top of mind.

AG: When we do travel for Science Olympiad
our coaches always makes sure that

our like bus is well stocked with

fruits and water.

SG: So Angela, seems pretty convinced
that food helps her focus

and perform well academically.

Of course, that makes sense
but the question today,

"What is the empirical evidence
to support that and how does it work?

How exactly does food impact the brain?

And how do we really know when our brain
is well nourished?"

Uma Naidoo: Sugar is not good 
for our brain.

But I also want people to understand
we need sugar for our bodies

and our brain,

so it's where you get the sugar
that's important.

SG: Look, a lot of people worry about
how food influences the way we look,

how much weight we may gain
-- I get that --

or the likelihood we're going to be
high risk for diseases,

like diabetes and hypertension.

But even though it is harder to measure,
food is also deeply connected

to how we feel in the moment
and how well the brain functions.

Even as you listen to this podcast,
your experience, right now,

is likely affected
by what you ate earlier today.

So in this episode, I'm going to find out
what's the best fuel for the brain,

what food we should avoid
and what it really means

to have a well-nourished brain.

I'm Dr Sanjay Gupta, CNN's
Chief medical correspondent

and this is Chasing life.

You know, I love hearing stories
like Angela's.

They're so personal.

She's someone who's paying attention
to her body and then she's figuring out

what makes her feel good and what it takes
to do the activities she loves.

She's being really intentional
with her nutrition

and that may save her from having
health problems later in life

but it could help optimize
her function now.

For me, food is an endless source
of fascination.

The way that I think about it is this:

food is one of the most significant ways
we allow our outside world to influence

and communicate with our inside world,
the world inside of our body and our mind.

That is an awesome task. Food does that.

So, I thought today we would start
with the basics.

We know that all food items have calories
and calories are by definition energy

but, as you just heard, not all calories
are created equal.

Some have more nutrients
and do more to promote

overall health and well-being than others.

And that is especially true
when it comes to the brain.

But the challenge again:
that's hard to measure.

There is no brain scan or blood test 
that indicates that a particular food

promotes brain health.

So how do we really know?

How do you really know what works for you?

To find out, I return to someone
whose work I really respect

both in the clinic and in the kitchen,
someone who knows a lot

about this really intricate connection
between food and brain health.

Uma Naidoo: if you want, you know,

your brain to really be optimized

lean into the foods you like,
but the healthy versions of that.

SG: That' Dr Uma Naidoo;
she's a nutritional psychiatrist.

Such a cool field.
She's at Harvard medical school.

What she does is that she works
with patients to improve

their mental health with the help
of medication and food.

She's also a professional chef.
She's the author of the books

"This is Your Brain on Food" and
"Calm Your Mind with Food."

That one's going to be released
later this year.

I should tell you, this is actually
Dr Naidoo's second time on the show.

We spoke a few years ago about
the broader concept of food as medicine.

And I was so fascinated by
the conversation, so affected by it,

I asked her to come back and discuss
how food impacts brain health specifically

and brain function.

I have long said that I think food

can be medicine, I also think 
just philosophically,

we consciously decide what signals
we're going to give to the inside

of our body through food.

What the discussion has primarily
focused on has been calories and energy,

and are you going overweight or not.

UN: Correct
SG: So what are those foods that are both

good for the brain and can actually
get to the brain.

UN: What I think is good, and I think
what is helpful for people,

especially in the U.S., is that most
people are consuming

the standard American diet

which, as you know, is called sad
for a reason.

So any time that we can add those lipid
grains and those actual whole foods

onto our plate, you know, and think
about it that way and step away

a little bit from those processed 
fast foods

the healthier we are going to become
as a country and I think that that is

because processed, ultra-processed foods
are engineered, as you know,

to trick our brain.

So we eat more, we can't stop ourselves.

SG: Yeah, maybe I'm being audacious here
in doing a podcast about how to achieve

a most optimally nourished brain.

As you correctly point out, we have
a lot of work to do as a country to just

stop doing the bad things, maybe even
before we can, uh, really, really focus

on the good things.

But the idea that food itself can be
medicine and that can be quantified,

maybe even to the point, for someone like
you, prescribed. Are we to the point,

with what we know, data-wise that food
can be thought of prescriptive,

like we think of medicine?

UN: So I can't yet say to you, you need
to eat ten blueberries over this amount

of time to improve your mood.

But what we do know from pretty large
population-based studies that

if you were consuming extra-dark natural
chocolate, that it improved depression

by 70% in over 12,000 participants. 
We know and it was in the candy bars

it was extra dark natural chocolate, 
which contains serotonin, magnesium,

um, some fiber. So we're not at a point
where I can say this number

of blueberries in order to improve 
your mood,

but we are definitely emerging and
growing in the scientific evidence

to be able to say you can construct
a nutritional psychiatry plate

for your mood.

You can lean into those leafy green
vegetable, 3-5 cups a day. Um, things like

arugula, spinach all contain folate. 
A low folate is associated with low mood.

So, we can give people guidance around it
and really have them understanding that

food is moving in that direction.

SG: Now before we hear more food 
recommendations, I want to note something

that's, I think, really important here.
the term "brain food."

That gets thrown around a lot. But, true
brain food meaning any food that actually

impacts the function of the brain has to 
do something really important.

Its got to get past the blood-brain 
barrier.

Now, I don't want to get to wonky or
technical, but I think it's important

for you to understand this point.
Think of the blood-brain barrier as sort

of a body guard for the brain. 
This barrier prevents the entry of toxins

and pathogens and other molecules
that could be harmful to the brain.

What it looks like is a system of blood 
vessels around the brain and the central

nervous system that sort of keep tight
over which molecules and which

nutrients are allowed to get in.

UN: We know this, for example
a lot of serotonin that's manufactured

in the gut and some in the brain
but the more peripheral serotonin

doesn't cross over the blood brain
barrier, so why not look at the foods

which are the precursors to the 
neurotransmitters, that then

interact with the gut microbes,
I'm fascinated by the gut microbes.

The impact of the gut microbes and 
then they are able to cross over

the blood brain barrier and then form
the substances that we need

in the brain. So I'm thinking about
things we need like serotonin

and dopamine.

Let me hit pause here to 
explain a couple of things about

the gut. You probably know this
but the gut contains trillions

of micro organisms. Bacteria,
viruses, fungi. Collectively

they are referred to as the gut
microbiome. Now these micro organisms

or microbes aren't just hanging out,
they play an important role in

our health and they are constantly
interacting with each other and

the rest of our body. While a few of
those bacteria or pathogens are

potentially harmful, many are helpful.
For example, what they will do is

they will break down food, they will
then interact with our immune system,

they will synthesize vitamins and amino
acids. And then they communicate with

other parts of the body. And that brings
me to the second thing about the gut.

It is sometimes called the second brain,
and I think that is a good title. And

that's because it uses many of the same
chemicals and cells as the brain to do

its job and to communicate.
In fact, there is an extraordinary amount

of cross talk between the gut and the 
brain. This makes the gut very

sensitive to emotions. Anger, fear,
anxiety. Those things can cause

problems in the gut, vise versa.
When the gut feels bad, it can

cause anxiety and other emotional
issues. Understanding that might

give new meaning to phrases like,
having butterflies in your stomach

when you're nervous. Or a quote, unquote
gut feeling about a person or a situation.

This is why Doctor Niudu's work is so 
important and intriguing. She says,

"It is possible for food to impact how
well our brain functions and how we

feel mentally." For example, some ultra
processed foods have been linked to

disrupting the gut microbiome in a way
that increases the risk for depression.

In contrast, whole foods such as
bananas help trigger the production

of important chemicals in the gut
such as the molecule, serotonin.

But again, remember this point
much of the serotonin made

in the gut cannot cross the blood
brain barrier and that is why

doctor Nidu says we need to
focus on the precursors to

serotonin. Which can then cross
more easily and be assembled

in the brain. Think of it like this,
there are certain foods, for example,

ones that are rich in the amino acid
tryptophan, that when eaten interact

with the gut microbiome. You
with me?

And they become then the precursor
or building blocks for serotonin.

And then these building blocks cross
into the brain and get converted to

serotonin and exert their influence. 
The reason that I'm repeating this

so many times is because it
is so important. What does

this all mean? Eating foods like, 
salmon or pineapple ones that

are loaded with tryptophan could
help you feel happier and calmer.

That is a better definition of brain
food.

UN: Another fascinating but odd
research that is coming through is

several microbiome companies testing
the microbiome. So they are looking

more deeply into what's in the 
microbiome and what you may need

to eat versus what I might need to eat
because our microbiome is so

sort of unique. Whether you take that
substance as a supplement or you

take it as a guidance around food, it
can really help us more finely tune

the way that we can be eating.

SG: What level of evidence to you rely
on to make your recommendations

when it comes to food? How do you
collect that data and that evidence?

UN: So I try to keep current with 
whatever the new research is. For

example, there was a fascinating study
done recently and all of these years

I've been encouraging my patients to
eat foods that are rich in vitamin A.

And this particular study show that 
actually vitamin A rich foods are not

that helpful for mode of your
brain health. Another interesting

study.

SG: What are those foods? Not to cut you
off, but what kinds of foods are we

talking about?

UN: So, you know, eggs, milk, fish oils
beef liver, tomatoes, red bell pepper.

Now does it mean that those foods
are foods I will tell my patients not

to eat? Absolutely not. Uh like the
new research about serotonin. It's

more that I would have emphasized
eating vitamin A rich foods along with

that nutritional psychiatry plate. 
And I most importantly feel that

what's been my secret sources has
been integrating the actual literature

the research and what I do 
clinically with seeing patients and

being able to monitor them you know
and see how they do. Because I think,

please know that I come at this with 
great humility. I don't feel that

because whatever I've studied that
you know, that I have the way to make

everyone feel better. But I can still 
see my patients improve.

SG: You know, when I was growing up
um maybe you heard this as well

when you were a child. But there
were certain foods that were

"brain foods." Fish for example
was sort of considered a brain food.

UN: Nuts, almonds.
SG: Nuts, you know. And my

mom would always you know
"If you eat this, you'll be smart