Understanding Autophagy and Health

Two people can live nearly the same life and age completely

differently, and a lot of it comes down to a single

switch inside your

cells that you can turn on today. That switch controls a process

called autophagy, and it almost always comes up alongside

fasting. But fasting is just one way to activate it.

In fact, some of the most powerful triggers of

autophagy don't

involve skipping meals at all. And the word autophagy means

self-eating. Think of it like a cleanup crew

that patrols your body around

the clock, and if it finds cells that are broken or

pre-cancerous, it clears them before they can turn into

cancer.

It's one of the most powerful ways your body protects itself, and the

discoveries that explain how autophagy works earned the Nobel

Prize back in 2016. And there are a surprising number of ways to

activate this process. Most of us are just shutting them off without

realizing it. Flip them back on, and your body gets back to doing what it's

built

to do, repairing itself and aging slower and catching

diseases and cancer long before they even have a name.

So in this video, I'm gonna walk you through these switches

one at a time,

and we'll start with the one that almost everyone gets backwards.

And then we'll talk about a few everyday things that turn it on.

Many of them are much easier than fasting and don't take a long time.

And then at the end, I'll go over the nutrients

and supplements that your cleanup

crew needs just to run, including one that about half of adults in the

US don't get enough of without realizing it. And if you're new here, I'm Dr.

Leonard Kim. I'm a double board-certified physician,

and on this channel, my

mission is to give you the science and the practical tools to not only live

longer, but to feel better today. And as always,

even though I'm a physician, I'm

not your physician, so please talk to your doctor before

making any changes to

your health regimen as this video is educational only and not

medical advice. All right, let's get into it.

So switch number one is the one that almost everyone gets backwards.

There's a master control in your cells called mTOR, and it does one of

two things. It basically decides whether your cells

spend their energy

building or cleaning house. And as soon as building materials show

up, it switches into build mode, and then the cleanup crew shuts off.

And this mTOR pathway is one of the most commonly overactive

pathways across human cancers. So dialing mTOR

down and flipping on the cleanup crew brings it back on.

It pushes against the very signaling that fuels a lot of cancer

growth. So what does your cell actually see as

building

materials? Well, surprisingly, it's less about calories in general

and more about amino acids, uh, the building blocks of protein.

And one of these amino acids, leucine, is the main activator switch,

while the other amino acids prime the process, but they're not as

dominant. So when leucine shows up, mTOR kicks into build

mode, and the cleanup crew shuts off.

And leucine is most concentrated and most usable in

animal protein, things like whey and meat and eggs.

And it's not just how much leucine is in each protein.

Uh, the key word here is usable. Because many plant proteins

still pack quite a bit of leucine, but it's more difficult to

digest, so less of it gets absorbed to flip

that mTOR

switch. So a whey protein shake dials your cleanup

down faster

and more completely than a bowl of beans.

Now, this begs the question, is protein bad? Well, no.

Protein is one of the most important nutrients that you can eat,

especially as you get older, and you need it to grow and protect your

muscles, which will protect your bones.

And there's also nothing wrong with animal protein.

Gram for gram, it's one of the most nutrient-dense foods

that you can eat

that's chock-full of useful vitamins.

How you wanna approach this is cycling, so keeping protein high

most of the time but easing off every once in a while.

So one day a week, make it a lower animal protein day, so

you'll lean on plant protein like beans and lentils.

Uh, you're still getting plenty of protein to

protect your muscle.

It's just lower in that usable leucine that flips mTOR on.

And then the other six days, you just get back to your usual protein.

Now, the next switch flips on the same system

but through a completely different

pathway. And whether it works for you, it all depends on the

bacteria in your gut. It starts with a compound called urolithin

A. It's one of the strongest triggers that we know for a kind of cleanup called

mitophagy, which is autophagy aimed at your

mitochondria,

um, the power plants inside your cells.

And this is a very important process because old and damaged

mitochondria, they can stop working well, and they leak harmful

molecules, which can damage the cells around them.

And on top of that, pre-cancerous cells also rely on unhealthy

mitochondria to survive, and mitophagy helps clear those out.

In randomized trials, urolithin A improved muscle strength and

endurance and markers of healthy mitochondria.

And in your trial, also found improvements in aging immune

cells.

Now, no one's tested whether it slows down

chronic disease or it

actually lowers cancer risk in people, but the cleanup it drives is real, and

we can measure it. Now, there's a catch to this.

Urolithin A isn't actually in any of the foods that we eat.

Foods that we associate w- with urolithin A, um,

things like pomegranates

and walnuts and berries, well, they give you the raw

ingredients, but your gut bacteria have to turn this

into urolithin

A. And only about 40% of people carry the

bacteria that can

do this. So two people can eat the exact same

pomegranate, but

only one of them turns this into this useful compound, but the other one makes

almost none. Same fruit, but completely different

results. So we still wanna eat the right foods

that provide the raw

ingredients, pomegranates and walnuts and berries.

But since not everybody carries the right bacteria, this is one

place where a supplement may make sense.

Taking urolithin A directly can skip the whole gut bacteria lottery.

Now, one important side note is there's not a whole lot of human data

here. Uh, most of the studies are smaller and shortened

duration, and these studies measured biomarkers

and short-term

physical endpoints, like muscle strength and endurance and

aerobic tests, but not long-term disease

or cancer outcomes.

And so the question is, what can you do after those meals

when a walk just isn't

gonna happen? And this is where we get back to the muscle in your

calf, and it

becomes a really useful tool. That muscle is called the soleus,

and it sits in the

back of your lower leg underneath the bigger calf muscle

that you can actually see,

and it's tiny. We're talking about roughly 1% of your

body mass.

So how does one tiny muscle produce a 52% drop in blood

sugar? Well, gram for gram, researchers found

that the soleus could work at

roughly eight times the metabolic rate of your leg muscles during the

moderate walk. And part of the reason is that the soleus is built for a very

different kind of work. It's packed with slow oxidative muscle

fibers,

and these aren't the fibers designed to give you one huge burst of power.

They're designed like that Energizer Bunny

that just keeps going.

In contrast, think about doing squats.

You're using your quads and your glutes, some of the biggest muscles in your

body, and that's great for pulling glucose out

of your blood.

But as we keep doing more squats, our legs will eventually start burning,

and we're gonna have to stop. But the soleus is almost built for the

opposite job,

a small amount of work, but they can keep going for a very

long time. And there's actually another whole

separate reason it can do that.

So normally, when your muscle is working, one of the fuels it uses is glycogen,

which is basically a carbohydrate already stored inside that muscle.

It works like a little fuel tank. Uh, it's right there ready to use,

but there's only so much of it before it gets depleted.

But when researchers had people doing these soleus pushups, this muscle barely

touched that stored glycogen. Across hours of continuous work, glycogen

only supplied about 4% of the energy used.

So instead of burning through its own stored carbohydrate and glucose storage,

the soleus was relying heavily on the outside fuels coming

from the blood. And that mechanism explains how

that little muscle can go for so

long, and it really explains those remarkable

numbers in that study, with

blood sugar being down 52% and insulin down 60%.

Now, these are the numbers that you've probably seen making rounds

online and in

other YouTube videos, but there is one important part that tends to get

left out. In that study, to get those numbers, they were doing

that exercise

for three hours. They kept the soleus working throughout

the entire

three-hour glucose test. And when you look at the other work from this

group, that

duration appears to be pretty important.

They didn't start seeing a significant increase in glucose uptake until about 30

minutes in. And when the contractions stopped

while glucose was still elevated,

blood sugar started moving back toward what they saw was just sitting.

So that 52% number is real, but it came from keeping this muscle

working for hours and not minutes, and that's the

trade-off. A lot of muscle can do the job in three

minutes, but 1% of

your body, like the soleus muscle, well, that needs a lot longer.

But that doesn't mean you need to sit there doing this for three hours straight

to

get anything out of it. So with that framing, the honest take is this

is not

something we do for five minutes and then check it off your list.

There-

Translate.mom