When you think about how to be more healthy, one of the things you might think about is your body weight. When our body weight is higher than what is considered healthy for our height, we might be described as overweight or obese and some common health issues come to mind when we think about being overweight: Type 2 diabetes, heart disease, and some cancers.

But body weight and related metabolic conditions like diabetes are also linked to our brain health and, in particular, our risk for Alzheimer's disease. With obesity at epidemic proportions, high economic costs of health-related issues, and an increasingly aging population, understanding the connection between obesity and brain health is critical. Thankfully, researchers are investigating obesity and cognitive decline and what might be done to protect our brains as we age.

Guest Notes: Dr. Catrina Robinson is an Associate Professor in the Department of Neurology in the MUSC College of Medicine. Her research focuses on understanding the role of metabolic disorders (such as prediabetes, diabetes, and obesity) on brain health and aging, as well as understanding the pathways involved in developing novel therapeutic targets to improve brain health.

Show Reference Links:

Robinson Research Lab at MUSC

Can diabetes lead to cognitive impairment? - National Institute of Diabetes and Digestive and Kidney Disease

Diabetes Impact in South Carolina Fact Sheet - Diabetes Initiative of South Carolina

♪

From the Medical University of South Carolina,

this is Science Never Sleeps

where we explore the science, people, and stories

behind the scenes of biomedical research

happening at MUSC.

I'm your host, Gwen Bouchie.

When you think about how to be more healthy,

one of the things you might think about

is your body weight.

When our body weight is higher

than what is considered healthy for our height,

we might be described as overweight or obese

and some common health issues come to mind

when we think about being overweight:

Type 2 diabetes, heart disease,

and some cancers.

But body weight and related metabolic conditions

like diabetes are also linked to our brain health

and, in particular, our risk for Alzheimer's disease.

With obesity at epidemic proportions,

high economic costs of health-related issues,

and an increasingly aging population,

understanding the connection

between obesity and brain health is critical.

Thankfully, researchers are investigating obesity

and cognitive decline

and what might be done to protect our brains

as we age.

In this episode of Science Never Sleeps,

we're chatting with Dr. Catrina Robinson,

an associate professor in the MUSC Department of Neurology,

about her research to better understand

the impact of metabolic disorders

on both normal and pathological brain aging.

Stay with us.

♪

Dr. Robinson, welcome to Science Never Sleeps.

Thank you. It's a pleasure to be here.

I'd like to start today by asking you about your path

to becoming a basic science researcher.

What brought you to science

and your particular interest in being in biomedical research?

So I think my interest probably started really young.

I grew up in a family where my grandmother

had diabetes, stroke, and dementia.

And also, my mother had breast cancer.

So seeing the health issues that were impacting my family,

I always had lots of questions.

I wanted to understand the why,

why things were happening to their body

and really trying to just understand

what are some things that we can do

to possibly make it better.

So that was my initial dive into my interest

in the sciences.

Also, I am from Tuskegee, Alabama,

and my grandparents were part of the Tuskegee Syphilis Study

and so there was a lot of talk always in my family

about the study.

And I was always curious about well, what happened

to their bodies when they had syphilis?

Like I was really curious about the process in general.

And so that's how I knew

that science was near and dear to my heart

and I wanted to pursue a career in science.

Starting out in college,

the only way that I thought that I could, you know,

have an impact in science

was to be a medical doctor.

So that was my goal

was to go to medical school, get an MD.

However, I started my journey in undergrad,

struggled with a class, biochem,

and had a tutor who was actually in graduate school

pursuing a PhD.

So I started volunteering in a lab,

literally washing dishes for the laboratory,

and I fell in love with research.

Started working in the laboratory,

transitioned to a master's program,

and ultimately ended up getting a PhD

and I've never turned back ever since.

And you mentioned that there was diabetes in your family

and it's one of the things that you wanted to understand

and as a researcher

it's one of the areas that you are working in

because you're working in metabolic disorders.

Can you tell us a little bit about

what metabolic disorders are

and why research to understand them

is so important?

Metabolic disorders are a group of disorders

such as diabetes, insulin resistance,

high cholesterol, hypertension,

and these disorders ultimately can lead to

changes within the body that impacts the brain

and places it at risk for cognitive disorders

or stroke later in life.

So my research focus is really trying to understand

what is it about metabolic disorders

and the changes that happen early on

that ultimately has early changes in the brain.

So what contributes to some of these things in the body?

You mentioned things like

insulin resistance, hypertension,

what are some of the things that we know

contributes to this?

One interesting thing and one thing

that I like to always show people

when I talk about my research

is if you look at the map of the U.S.,

and look at the incidence of diabetes,

obesity, insulin resistance,

any of those metabolic disorders,

one thing you'll notice is that the Southeast

has the highest percentage of all of these disorders.

And so when I think about the South

and what's really great here is the food.

So is our Southern diet really driving

some of these changes that we see

or leading to the disorders that are here?

And that's what my research is really focused on.

I'm really focused on the high-fat diet

and trying to recapitulate the Southern diet.

And one thing that I can always remember

that my grandmother taught me

is that to make any vegetable taste great,

you just add a little bit of pork fat.

And so that's what we use in our diet

in the lab is a high pork diet.

That's really interesting.

So in your lab, you're using an animal model.

Yes, correct.

And so in your animal model,

you're working with feeding them the same types of foods

that humans are often eating

that you believe are leading to these disorders.

Yes, that's correct.

So we're feeding them a high-fat diet.

It's actually 54% fat

and I'm often asked,

"Can I really consume 54% fat?"

And yes, you can. It's really easy to do.

If you forget breakfast in the morning,

you stop at McDonald's

and get a bacon, egg, and cheese biscuit

and for lunch, perhaps you just get a Subway tuna,

and for dinner, you just eat iceberg lettuce

and ranch dressing.

You've consumed 54% fat.

So it's pretty easy.

Wow, that's incredible.

What is the connection between diabetes and memory?

So you mentioned that this is something

that you're particularly interested in your research.

What is the connection there?

So there is a link between individuals

who have diabetes.

They are at an increased risk

for developing Alzheimer's later in life.

So this risk can go up to 80%.

And so what my research is focused on

is really trying to understand why is that the case?

What happens in diabetes

that ultimately can lead to changes in the brain?

So when we think about diabetes,

we're thinking about a peripheral disorder

where you have high levels of glucose

and your body just can't clear it

to use it for energy and fuel

and get it into the tissues,

and so you have high levels of insulin

so you end up with insulin resistance.

But what we are interested in

is how insulin and glucose,

they're also important in the brain

and they have different functions.

Unlike your muscles,

you don't need insulin to necessarily get glucose

into the cells in the brain,

but insulin plays a huge part

in learning and memory.

It has synaptic roles,

it plays roles in inflammation,

and insulin actually has to be transported

from the bloodstream into the brain.

And what happens in metabolic disorders

such as obesity and diabetes

is that you actually have a decrease

in the transport of insulin

so you have a deficiency of insulin in your brain.

And so our research is really focused on

trying to understand if this deficiency

is ultimately what connects diabetes

to having memory disorders,

and if we can increase insulin in the brain

to ultimately improve memory function.

The mechanism for diabetes and insulin

both in the brain and in the body

is fairly well researched.

So what you're looking at

is how do we take that knowledge even further

to understand how it impacts the brain

or how it impacts memory

and how to improve memory moving forward.

Correct.

We know a lot about insulin

in the bloodstream and the periphery,

but what we don't know

is how insulin actually is transported

from the periphery to the brain.

And there's not a lot of studies really trying to focus on

is insulin perhaps a target for us

where we can actually improve memory function

or brain function in general

by targeting insulin and increasing insulin levels.

As we look at metabolic disorders,

diabetes in particular,

are there any groups that are more impacted than others

when we look at this from a population health perspective?

Absolutely. There's a disparity

when it comes to metabolic disorders.

Diabetes, for instance.

African Americans are more affected by diabetes,

as well as other populations

including Hispanics.

They also are more disproportionately affected

by diabetes as well.

So thinking about here in South Carolina,

there is a disparity when it comes to

looking at some of these metabolic disorders

and it definitely needs to be an area

that we should focus on to try to improve

because ultimately, having diabetes

can lead to dementia later in life,

it can also be associated with increased risk for stroke.

And so if we could target disorders

early on in the pathway--

So if we could target diabetes before it's a problem,

then we can ultimately perhaps decrease the risk

of some of these other disorders later in life.

Do we see a connection in the impact between--

you mentioned the African American community

being impacted--

do we see a connection between increased diabetes rates

and then it also impacting disproportionately

African Americans in Alzheimer's

and other memory disorders?

Yes, that is also the case as well.

African Americans are more disproportionately affected

by Alzheimer's disease as well as stroke.

One of the issues we also see with stroke

is that when you look at the African American population,

after stroke, they tend to have more impairment

or longer term impairments related to stroke.

And that seems like, particularly,

a complex issue

because there are lots of reasons

why outcomes might not be what you would expect

or outcomes would be a bit disproportionate

in a particular community, correct?

Correct.

It's actually a really great thought

because we don't really know why that's the case.

Actually, I was a part of a study

that was funded by the American Heart Association

and this was an interdisciplinary project

where we were really trying to understand

why are African Americans more likely

to have long term impairments after stroke?

And this is when all things are considered equal.

So if you have equal socioeconomic status,

equal education,

equal access to care in terms of rehab,

they still are disproportionately affected.

And so, as part of this study,

we were really trying to understand why--

and my role in this study was to understand

the biomarker side of things

and if there is something on the biomedical side

that could explain this discrepancy

or is it a social construct

where perhaps if we were to give patients

a health worker that could sit with them and say,

"These are the questions you should ask,"

or, "Do you have questions that you didn't understand

from your provider?"

Just trying to help coach them.

So a personalized coach is what we like to think of it.

And trying to understand if there are changes

in the brain that are different,

is it possible that African Americans--

we know that they have diabetes

and all these other metabolic disorders--

is it possible that they have them longer

before they're actually treated for it

and that could be the reason why they seem to be impacted.

So these are some of the things that we're curious about

and looking into.

I don't have the answer yet

but it's still ongoing.

But really important work

in terms of improving lives,

both for individuals and for families long term.

Yes, definitely.

And I guess if there was something

that I could say could help

is to really just think about your diet

and just your lifestyle.

Are there things that you can do now

that can actually improve your health overall

and decrease your likelihood

of developing some of these disorders?

And there are. We could eat healthier.

My lab and I sometimes go out into the community

to talk about our research

and we like to go to the senior home

and I remember going to a senior home

and talking about diet

and how it impacts the brain and your brain health

and how there's little things you can make,

you don't have to try one of these fat diets

and completely cut out everything that you enjoy.

It's okay to have things in moderation

but are there small changes that you can make

that you can actually sustain?

And one thing we talked about was the sugar

versus the artificial sweetener.

And the seniors hated it.

They didn't like the artificial sweeteners.

Some of them do have an aftertaste.

But if you can just commit to one thing,

what's the one thing you can do

to just try to improve your diet?

That's great.

As a Southerner,

someone who grew up in Alabama

and now lives in South Carolina,

what does it mean to you to be a researcher

working on this health issue in this part of the country?

I mean, we know that South Carolina

has high prevalence rates of metabolic disorder,

we know that the African American community,

as we've already discussed, has a higher incidence

of these types of health concerns,

what does it mean to you to be working

on this issue here

really in a space where it's so prevalent?

So there are a couple of things.

One is I'm a basic scientist

and so as I think about my research,

I always want to make sure that it has a translational impact.

Something that we can actually bring to the patient

to ultimately improve health all around to patients.

And South Carolina has the highest levels of diabetes,

Alzheimer's disease, stroke,

all of these disorders

that ultimately I'm interested in.

So this was a great place in the South--

the heart of the Stroke Belt as we know it--

a great place to do my research

and really be informed

based on the clinical population

and make sure that I'm making those same implications

in the laboratory to do my studies.

Also, being from the South,

my family is impacted.

I've had several members of my family

that were diabetic, had a stroke,

impacted by Alzheimer's disease.

So there's also a personal reason

as to why I want to make life better for my children

so that this is something--

and ultimately they don't have to take care of me

when I get older.

So just trying to make lifestyle changes even for myself

because I'm from the South, I love the food,

I grew up with it.

So having to like dial back now as an adult

and try to make healthier choices.

It's not always easy

but it's possible to make small changes.

-And it's worth it. -It's worth it.

It definitely is worth it.

So we've talked a lot generally about this issue

but let's talk about your research

and your current research.

What is it that you're working on?

How are you working to study the impact

of diet and obesity on memory function?

Yeah, so again, we use animal models in the laboratory

and we try to make it

as translationally relevant as possible

so we use high-fat diet in our models.

And what we're doing is really trying to understand

one, if an animal is exposed

to a high-fat diet early on in life--

so thinking about how our children

like chicken nuggets and hot dogs

and french fries growing up--

does that lead to memory impairment?

And if we make changes later on in their life,

can we ultimately improve or reverse

some of those memory impairments?

So that's kind of what my research is focused on

and trying to understand the mechanism.

So what is driving it, ultimately?

And as I discussed before,

one of the things we're looking into is insulin

and the impact that insulin has in the brain.

So we're trying to use various drugs

that can ultimately increase insulin levels in the brain.

So whether it's targeting the actual mechanism

to help get insulin across

or whether it's a direct approach

with using, for example, intranasal insulin

that bypasses the blood-brain barrier

and it doesn't cause

a peripheral drop in glucose levels

to deliver it that way,

to increase insulin levels in the brain

and how does that impact memory

and actually how does it impact recovery

from injuries such as stroke?

So there is a process of moving basic science work

towards the clinic

so that we have that bench-to-bedside model

that moves it towards patient care.

You mentioned particular types of things

like the intranasal insulin.

What does the pathway look like

for you as you're looking at your research

which is on the bench side

for how it could possibly move towards bedside

and really be available to patients

to help improve their care and their lives?

So that's a really great question

and something that I'm always thinking about.

And to do this,

I collaborate with clinical scientists

who actually can do some of the clinical trials.

So I have partnerships ongoing right now

and my stroke research

was part of the Stroke COBRE here at MUSC

which is mainly involved in clinical trials for patients,

or mainly sees stroke patients for rehab.

It's a rehab facility for stroke.

And I partner with some of the scientists there

and we are constantly thinking about

how we can take the intranasal insulin that we see

because we've seen tremendous impact

at least on the pre-clinical side in the animals

where it improves survival,

it improves some of the deficits after stroke,

and it also improves recovery

in terms of motor and cognitive impairment.

So we're interested in how we can actually

bring this to patients

and it's something that we're working on

and we're working towards,

so hopefully we'll get there soon.

But one thing about the intranasal insulin

is that it's already been in clinical trials.

So there's been trials with intranasal insulin

for Alzheimer's disease, for example.

And the initial trials were promising

but I think the current trials

are probably on hold at the moment.

So this is something that is translationally relevant

that we can bring to the bedside.

There's just a few more steps that we have to overcome.

Right, right.

I want to ask you about mentorship,

which is something we've talked about before

on the podcast, and I think it's so important

and it's clear to me,

looking at your lab page, your lab webpage,

that you have lots of folks who come in

who are hoping to learn

not only about the specific issues that you're studying,

but also about that process of becoming a basic researcher

and how important the basic research is

to the whole multitude of discoveries

that we can make to improve health.

Can you talk a little bit about the importance

of mentorship to you

and sort of what you're doing in your lab

to seed that next generation of researchers?

Yes, mentorship is the most rewarding part

of my work that I do

and it's something that I hold

really near and dear to my heart.

It's more about, to me,

the transference of the knowledge that I have

and trying to impart in my students

that same not only just rigor in terms of science

but also having that enthusiasm for science

and some of the results

and being inquisitive and asking questions.

So I love mentoring

and I think that good mentorship is important

and something that we should all strive for.

Because ultimately, it helps to move science forward,

bringing individuals together from various walks of life,

having a diverse lab group

which you probably notice from my webpage,

I do all levels from high school

all the way through as a post-doc.

It's important to have that diverse environment

and to get various perspectives

in order to move science forward.

I really want to leave our listeners today

with some ideas and some thoughts

about what they can do to live healthier

as it pertains to brain health.

And you already mentioned earlier diet,

which of course we all know can be challenging

especially when you live somewhere like Charleston, too,

where the food is really incredible.

But there are also other things that we can do as well

that can help decrease our risk

for maybe metabolic disorders

and therefore decrease our risk for memory loss later.

What are some of those things?

Yeah, so in addition to diet,

another thing is exercise.

Exercise is very important.

I struggle with that myself.

But if you can just commit to doing just a little bit,

like perhaps instead of taking the elevator

take the stairs for a flight.

But just little things to do.

Take a class that's fun

and not just having to walk on a treadmill.

But think of activities that you enjoy doing

and that you can do no matter what your age is.

Swimming is a really great way to get exercise.

But just thinking of exercises that you can do.

Ultimately, that also improves your brain health.

Anything that you do to keep your body active

and make your body healthier even peripherally

ultimately has a positive impact on your brain as well.

So we're going to take small steps

towards eating better and moving more

and we're going to keep researching

how those things and other things

can help us live longer, live healthier,

and keep our brains intact as we age.

-Absolutely. -Great.

Well, thanks so much for being with us

on Science Never Sleeps.

Thank you. It was a pleasure.

We've been talking to Dr. Catrina Robinson

about her research to understand the connection

between metabolic disorders and brain health.

You can find out more about the research happening at MUSC

by visiting research.musc.edu.

Have an idea for a future episode?

Send us an email at ScienceNeverSleeps@musc.edu.

Science Never Sleeps is produced

by the Office of the Vice President for Research

at the Medical University of South Carolina.

Special thanks to the Office of Instructional Technology

and Faculty Resources

for production support on this episode.