Yeah, one mL JUUL pod

contains 56 milligrams.

You can extract about 20 milligrams

from a pack of cigarettes.

Probably more than that...

Hi, my name is Taylor Hayes, I'm a

professor of medicine and in

the general internal medicine

division at Mayo Clinic.

I'm also the director of the

Nicotine Dependence Center at Mayo

Clinic in Rochester, Minnesota.

So today we're gonna talk about

electronic cigarettes, a topic

that a lot of clinicians have some

confusion about.

What we're going to do today is look

at some of the trends in the use

of e-cigarettes and look

at some of the concerns that

have come from the use of

e-cigarettes, especially recently in

the news.

And finally, look at some

of the evidence for and against the

use of e-cigarettes to help people

stop smoking traditional tobacco

cigarettes.

So the use of tobacco

cigarettes and the declining

prevalence in the United States is

really probably one of the greatest

public health victories in the last

century.

We've seen a steady decline in the

use of traditional tobacco

cigarettes in adults from somewhere

around 15% of men

in 1965.

And now among all

adults, the prevalence is more like

14-15% in the United

States.

The bad news is that we still have

about 15% of adults smoking,

and that represents about

35-40 million people because

of the growth in the population

of the US. So we still have a lot of

work to do.

We've also seen an

uptake of electronic cigarettes

in adults.

Certainly not to the degree that

we've seen in youth, which I'll talk

about in a moment.

In adults, most of the electronic

cigarette use has been in people

under age 50 and in fact, most of

it's been under age 35.

And for most

adult smokers who

use e-cigarettes, it's dual use.

Although they may be trying to quit

smoking, they continue to use

tobacco cigarettes and have reduced

their use of tobacco and are

at the same time using electronic

cigarettes.

That's not what we've seen in

kids. However, what we've seen in

youth, especially in middle school

and high school students, is

a really worrisome increase

in the use of electronic cigarettes.

Now, this came at the time that we

were seeing another good news story.

Tobacco use among high school and

middle aged students had declined,

remarkably over the last decade.

In

2016-2017, we saw a decline in

e-cigarette use as well.

And we thought maybe we breathed a

sigh of relief. You know, that the

uptake of electronic cigarettes that

we'd been seeing in youth seems

to be waning. But then in 2018,

we saw almost an

80% increase in the prevalence

of cigarette use in high school

students.

And in 2019, we now have

1:4 12th graders currently

using e-cigarettes and 1:10

middle schoolers.

And those numbers seem to be rising

all the time.

What fueled this increase?

Well, probably a number of things.

But one was the marketing

done by this unregulated industry,

the marketing of electronic

cigarettes to kids that took the

form of a lot of common consumer

products that kids like:

candy, gum,

whipped cream, apple juice.

And some of the

pictures you've probably seen in the

news have shown some of the labeling

that these companies have used

to make their labels for the

electronic cigarette liquids

look like candy and whipped

cream and other consumer products.

The other thing that has fueled

this has been the

marketing of a product called JUUL,

in particular, this

is a company

that marketed an electronic

cigarette product that looks like a

an external drive from a computer.

So it didn't look at all

like a cigarette.

And so parents and students and

adults didn't know what these were

and kids took them up in remarkable

numbers.

So with that in mind

as background, we are going to talk

now a little bit about the products

themselves, the electronic cigarette

devices.

The thing to remember about all of

the devices, no matter what kind it

is, is that they have some common

features.

The common features are

you need a heating element that

usually is a metal coil,

and that heating element needs a

power source.

So there's a battery.

And then the other component is

electronic liquids.

These liquids contain typically

nicotine. But as you know from the

news, that they can contain other

drugs as well, particularly

marijuana extracts, or THC.

But those are the common

components.

A heating element.

A coil.

A power source or battery.

And electronic cigarette

juice or e-liquid,

which usually contains nicotine and

other chemicals, which I'll describe

in a minute. And these products have

changed remarkably over the last

10 years.

The initial products

looked like cigarettes and we call

them cigalikes.

They were typically disposable.

They were closed systems.

You use them a few times and threw

them away once the liquid was used

up.

The newest models of electronic

cigarettes look nothing like

cigarettes.

They look like boxes or

vape pens.

Sometimes they're called and they

contain components that are

interchangeable

amongst the different

brands. So they all

still contain a power source

and a coil and e-liquid.

But now they've been modified to the

point that you can use different

liquids. They have refillable models

and the vessel that contains the

liquid can be refilled with

different liquids.

You can also interchange all

of the parts.

You can interchange the power

source.

You can use different coils

in these and you can

use different mouthpieces.

They've become very sophisticated as

well. You can actually modify

the voltage and amperage with which

they deliver the e-liquid.

Now, the key

to all of these

products, the key to all of these

devices are two things.

And these drive the delivery of the

chemicals from the aerosol it's

formed, so one is the coil,

the metal coil that's used to heat

e-liquid and aerosolize it is

different in different products.

And now we are able

to get these coils to very

high temperatures with the power

sources that are being used.

The other key is the pharmacology

of the electronic cigarette liquids

that are being used.

We know from chemistry that the

tobacco industry developed going

back into the early 1960s

that the more basic

the aerosol or

the smoke from a cigarette, the

better the delivery of nicotine.

And that's because

as the smoke

or vapor becomes more basic

from a traditional pack tobacco

cigarette, the more unprotonated

nicotine you'll find.

And it is the freebase nicotine

that is absorbed well across

biological membranes.

The tobacco industry actually added

ammonia to tobacco to get a more

basic or alkaline

pH.

But what we know is that at high

concentrations alkaline pH

causes a lot of adverse reactions

and mostly nausea.

People gag when they are exposed

to high alkaline pHs.

And so what the electronic

cigarette industry has come

to learn is that actually

creating more acidic liquids

that are salts or

nicotine salts has become a more

effective way to deliver high

concentrations of nicotine

in the e-liquids.

These are salts that usually

use benzoic acid as the diluent

and the pHs are more acidic.

These can contain high

concentrations of nicotine without

causing nausea when

they're inhaled.

We also see that with

these high concentrations of

nicotine in the e-liquid solutions

and the newer coils, higher power

in the batteries that we are

now seeing the delivery of

nicotine as

monitored by blood levels

comparable to what we see with

tobacco cigarettes.

Also, the profile

of uptake is looking more like

tobacco cigarettes.

So with a tobacco cigarette, you can

get nicotine levels that are 10

to 20 nanograms per mL in the blood

within just a few seconds of

inhaling.

And now with electronic cigarettes,

we're seeing a similar profile

within a minute or so of the

inhalation.

You can see high levels of nicotine

in the blood.

Nicotine salt, delivery systems,

typically in the pod systems, but

also in some of the refillable is

now contain as much nicotine as one

to two or more packs of cigarettes

per day.

I know people have heard that the

JUUL, which I mentioned before, is

fueling the youth uptake of

cigarette use contains

as much as "a pack of cigarettes".

In fact, the JUUL pods contain

about one and a half to two

and a half package

equivalents of nicotine.

So if you smoke a pod a day

of JUUL, a

high school student doing that is

consuming about the same amount of

nicotine as he or she would get from

a pack and a half to two packs of

cigarettes in that day.

That means they're becoming

nicotine dependent very quickly.

The other part of the nicotine

or rather the e-cigarette liquids

that you need to understand is that

although nicotine is the thing

that causes the

addiction, that dependence and

delivering high levels of nicotine

quickly is important to create that

dependence.

There are other components of

electronic cigarette liquids.

These are typically carriers,

vegetable glycerin and propylene

glycol.

Now, these are generally recognized

as safe either for oral consumption

in foods or as a topical

applicant. So they're used in

gels and creams on skin.

They're used as sweeteners

or diluent in food

that we consume.

And they're safe in that way.

They're used also as the vehicles

for electronic cigarette liquid

propylene glycol is used

and usually mixed with vegetable

glycerin because the vegetable

glycerin is a bit thicker and

you need a thickening agent in most

of these e-liquids,

so that they don't leak out of the

vessel.

When these things are heated to very

high levels, they no longer

stay as vegetable glisten or

propylene glycol.

But they are inhaled as carbonyl

compounds among these formaldehyde

and acetaldehyde.

And now at the high temperatures we

see with the coils in the modern

e-cigarettes, you're getting

significant levels of formaldehyde,

acetaldehyde inhaled.

And we know that these compounds,

among other carbonyls, are

carcinogens.

And so we don't know what the long

term impact will be of dail, the

inhalation of high levels of these

chemicals.

Finally, let's

talk a little bit about some of the

health impacts of cigarette use.

Now, frankly, we hadn't seen a lot

of adverse health impacts of

cigarette use up until

this past year.

And this past year, we saw

a remarkable rise in

what has been called EVALI (EVALI),

or the electronic-cigarette

and vapor associated

lung injury.

This epidemic started

in about the second quarter of 2019

and now seems to have peaked

somewhere around the third quarter

of 2019. Early

in 2020, we're seeing

many fewer cases and

that's probably because of the

education that went out through the

news and through other public health

channels, as well as through

magazines and newspapers.

Now, I don't want to leave you with

the idea that EVALI is caused from

nicotine containing e-cigarettes,

although it may be a small portion

of the cause of a EVALI.

We think now that most

of the lung injury was caused from

vaping solutions that contained

THC.

That is the

active ingredient of marijuana that

causes the high and

that it seems that many of the

e-liquids that were being used that

contain THC were being cut with

not propylene glycol or vegetable

glycerin, but with vitamin E

acetate.

This is a thickening agent

and a diluent that was being used

in these unregulated

e-cigarettes liquids.

And we think that the chemical

changes that occurred with heating

of the vitamin E acetate probably

led to some of the lung injury.

That's a best guess right now.

But what is clear is that

inhalation of many

e-liquids may cause lung

injury, perhaps not

to the degree that we saw with EVALI

where many people got very ill very

quickly and we had many deaths.

But over the long

term, we think that inhalation of

some of these chemicals will cause

lung injury.

What do we do with all this

information?

I mean, the promise of e-cigarettes

really was that perhaps

it would be a way for us to finally

get adults to stop smoking

tobacco cigarettes, where we know

over 60% of people who use

them regularly will die from a

tobacco caused disease.

Maybe we could use e-cigarettes to

get them to switch.

And ultimately, we could have

a society where no one used tobacco

any longer.

That would be an approach called

harm reduction.

Now, we're familiar with harm

reduction in many other forms.

We use seatbelts in cars not

because it eliminates all the harm

of driving. We use

bicycle helmets to prevent head

injuries. But it doesn't prevent all

of them. And we, even in health

care, have

safe needle programs so that

injection drug users

can reduce the harm of serious

infectious diseases from using

their injection drugs.

Now, none of these approaches

eliminates the harm of these

behaviors, but they reduce it.

Similarly, we thought, well, maybe

e-cigarettes would be a way to

reduce harm from tobacco use if we

could get people to switch.

What we don't know is really where

does e-cigarettes fall

on that continuum of risk where we

know cigarettes are most harmful.

And complete cessation

of all tobacco product use,

including e-cigarettes, is the least

harmful.

Where do e-cigarettes fall?

We thought they were probably

ultimately relatively safe.

There had been a publication from

Public Health England in 2018 that

said, "They

were 95% safer

than than regular cigarettes".

It's unclear whether or not that's

true, especially in light of what we

saw with the EVALI that occurred

in the past year.

What is clear is

that they are safer, but

not necessarily safe.

And so when we advise

patients, we try to advise them

based on what we know is supported

by best evidence,

what we know from all of the

evidence so far with electronic

cigarettes is that there is

insufficient evidence to recommend

them as a smoking cessation

approach.

So for clinicians,

our advice and the nicotine

dependence center is to say

if someone is committed to quitting

smoking cigarettes, we advise

the use of what is known to be

effective and safe.

That is the combined approach

of behavioral therapy or

counselling, plus approved

medications.

And there are seven approved

pharmacotherapies for smoking

cessation in the US.

We don't advise the

use of electronic cigarettes.

There is only one randomized trial

that is compared directly

e-cigarettes and nicotine

replacement therapy.

And that was done in England, it was

published in 2019.

It did show that electronic

cigarettes seem to be equivalent

or perhaps even slightly better

than the nicotine

replacement therapy nicotine patch

plus gum.

This is only one study.

It hasn't been replicated by anyone.

And so our advice follows

the U.S. Preventive Services Task

Force in that behavioral therapy

plus pharmacotherapy that's approved

is the best way for people to quit

if you have someone who simply

will not quit in any other way, you

may say to them, well, perhaps

e-cigarettes is the best way to do

that.

If you make that recommendation,

do that knowing that we don't know

the ultimate safety of e-cigarettes

and that the only way that they can

have the health benefits

of stopping smoking is to quit

completely using tobacco cigarettes

and switch completely to

a known brand of electronic

cigarettes that at least we think

complies with some good

manufacturing process.

Most of our professional

societies have

said that they don't recommend

e-cigarettes, although some have

said if you have to

advise a switch, but the switch

needs to be complete for adults

and we'd never advise pregnant women

or children to use e-cigarettes.

The reason

we take this approach is really the

precautionary principle.

And that principle is this.

The introduction of a new product or

process whose ultimate effects are

disputed or unknown

should be resisted.

And we as clinicians,

although we're very interested in

the public health, our

responsibility is to the patient

who's in front of us.

We are a fiduciary to that patient.

So our advice to the patient

is based on best evidence.

And our best evidence today says

behavioral therapy plus nicotine

replacement therapy or other

approved medication is the best

and safest approach.

So to summarize,

we we reviewed some of the

epidemiology and the remarkable

rise of cigarette use in

youth especially.

We looked at some of the pros and

cons of using e-cigarettes for

smoking cessation.

And we talked about

some of the health impacts of these

new devices that now are changing

very quickly.

There's still a promise that

e-cigarettes might help us in the

future, but we're going to have to

work through this current issue of

the diseases and health negative

health impacts that e-cigarettes

have had on lung injury

and come up with new technologies

that are proven to be safe for our

patients before we can recommend

them.