シャドーイング練習: Why do people smoke? - 動画で英語スピーキングを学ぶ

Thanks.

I was given an answer to the question just a few moments ago, which is because it's great.

Which isn't the punchline to the talk.

As a biological psychologist, I'm interested in behaviour and how people think that's the psychologist part.

But I'm particularly interested in the biology of that, so how our biology drives our behaviour.

And one of the reasons I'm interested in smoking is

because it's a really good model of understanding how biology drives behaviour

and that's going to be the focus of what I talk about.

What is it about cigarettes, what's in it in those cigarettes that drives our behavior and how can we tell, how can we understand that?

So we've come a long way over the last 50 years since the link between smoking

and a range of different health outcomes like lung cancer and coronary heart disease was discovered.

These are some adverts in the top left from the 1950s

and 60s that look incredibly anachronistic now given how invisible smoking has become.

We don't see tobacco advertisements in this country anymore, we don't see point of sale displays anymore, tobacco branding has been removed from cigarette packs so they're all sold in standardised packs for example.

You don't see the machines that you used to have in pubs, the vending machines for cigarettes.

So gradually through a series of tobacco control policies implemented over a period of decades

We've moved to a point where smoking has gone from being 60% prevalent in the population to something like 15%, with a particularly rapid decrease in the last few years,

which is something I'll talk about towards the end.

You still have some countries which have weaker tobacco control policies, so in the top right you see an advert from Malaysia,

I think it is, which is basically encouraging people not only to smoke that brand of cigarette, but also not to quit.

leveraging the fact that a quitter is something that people would not want to be described as and taking advantage of that.

And you also see changes that have come about in other areas.

So, for example, the association of tobacco products with Formula One racing has been

diluted over the last few years through bans on advertising on those racing cars.

So there are lots of reasons why people smoke.

People start smoking for social reasons because of the marketing of tobacco products

but I'm going to focus particularly on the biology and the effects

that the constituents of tobacco have on us and how we can tell that that's driving our behaviour.

So the key thing to bear in mind is that the principal reason why people smoke is for the nicotine.

And this has been known for a long time.

Mike Russell said this in the 1970s.

Smokers smoke for the nicotine but die from the tar.

It's not the nicotine that's particularly harmful, but it's the thing that gets you addicted.

it's the other things that are in burned tobacco products in particular that are harmful when you spend 20 years inhaling those.

There's nothing particularly magical about tobacco in that respect.

If you spent 20 years inhaling burned lettuce it would be pretty bad for you.

But it's the nicotine that keeps you doing it.

And the cigarette has been designed to be as addictive as possible

by delivering a dose of nicotine as rapidly as possible to the brain.

The dose of nicotine

that you get from puffing on a cigarette reaches your brain within about 10 to 15 seconds of inhaling it.

That's faster than if you inject heroin, for example.

And the reasons for that are complex, but are largely down to the way in which tobacco is cured.

The curing process for cigarette tobacco is different from the curing process for, say, cigar tobacco, which means

that you have to inhale the cigarette smoke into your lungs to extract the nicotine from it

because it has a different level of acidity to cigar smoke.

Cigar smoke allows you to absorb the nicotine through the lining of your mouth, so you only need to inhale the cigar smoke into your mouth,

but you have to inhale the cigarette smoke into your lungs to get the nicotine from it.

And by inhaling it into your lungs, you deliver the nicotine very rapidly.

So what you see here in the top left is a

depiction of the arterial levels of nicotine after smoking a cigarette compared to the venous levels of nicotine

so the nicotine in your arteries compared to the nicotine in your veins

and the levels in your arteries give you a better indication of the delivery of

that drug to the brain and you can see

that immediately after smoking you get this very rapid spike in nicotine levels in the brain

and that's part of the reason why the cigarette is

so addictive it's not just been chemically engineered to be addicting it's also been mechanically engineered to be addicting

the paper that's used, the filters that are used, are all designed very specifically to deliver a high dose of nicotine to the brain as rapidly as possible.

And you can see the result of that in the bottom right hand corner,

which is a stylized representation of nicotine levels over the course of the day in a heavy regular smoker.

You smoke your first cigarette of the day, you get this arterial spike, this very rapid delivery of nicotine to the brain when you smoke that first cigarette.

But because nicotine has quite a short half-life, it's cleared very quickly from the body, after an hour or two you start to go into withdrawal.

So you need to have another cigarette.

So you step outside, you have your second cigarette, you deliver that second rapid burst of nicotine to the brain

and over the course of the day what you're trying to do is stave off the withdrawal symptoms

that you experience when nicotine is cleared from your body.

But every time you do

that by having a cigarette you're delivering this very rapid dose

of nicotine to the brain in the context of the smell

and the taste and all of the other cues that come with a cigarette.

And that's the cycle that gets you addicted.

When you go to sleep at night, the nicotine clears very rapidly to the point where in the morning you're almost entirely nicotine free and the cycle starts again.

Very dependent smokers have sleep that's disrupted by the nicotine withdrawal

that they go into in the middle of the night

and have to have a cigarette at two o'clock in the morning before they can go back to sleep again

because the nicotine withdrawal has woken them up and they need to smoke before they can go back to sleep again.

And the best way of telling how addicted someone is to a cigarette

or to nicotine generally is just to ask them how soon after waking they smoke their first cigarette of the day.

If they smoke their first cigarette of the day within 15-30 minutes they're probably pretty nicotine dependent.

And people will titrate their smoking behaviour, they will change their smoking behaviour unconsciously to extract the nicotine

that they need having become accustomed to a particular level of consumption.

And you can see that here by looking on the right hand side.

Cigarettes

will come in packs that tell you how much nicotine is in those cigarettes and how much tar is in those cigarettes.

Those readings are generated by machines that smoke cigarettes in a way that's almost completely unlike how real human beings smoke cigarettes.

These machines were designed by the tobacco industry to create readings

that give a false sense of the health benefits of low-tar cigarettes compared to high-tar cigarettes.

Because a low-tar cigarette doesn't differ in terms of the tobacco that's in the cigarette.

What's different about a low-tar cigarette compared to a high-tar cigarette is the filter, not the tobacco.

And the filter in a low-tar cigarette has holes drilled into it, so that when you put that cigarette into a machine

that gives the reading that you see on the side of the pack, the filters draw in air that dilute the smoke that go into the machine and give a lower reading.

When you give that low-tar cigarette to a person, they can put the filter into their mouth and close those holes

and it literally becomes a high-tar cigarette or they can close with their fingers

or they can inhale more deeply and change their behavior

and response so when people switch from high tar brands to low tar brands there are no health benefits

because they simply change their behavior to extract the level of nicotine

that they need from the cigarette and therefore all of the other constituents

that are actually harmful from that cigarette and you can see

that here at the top you have a measure of tobacco

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specific nitrosamines the cancer causing chemicals in tobacco smoke across a range of different nicotine content brands

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and the line is completely flat.

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Whatever your tar content, you're extracting the same level of harmful constituents from that tobacco.

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But in those same people, the volume of smoke that's being inhaled is different.

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You can see that the lines slope so

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that in the high tar brands they're inhaling less smoke compared to in the low tar brands

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and as a result you get that figure at the top which is the

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flat level of exposure irrespective of the tar content of the brand

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so if you're a smoker don't worry about whether it's a high tar brand

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or a low tar brand it makes no difference in terms of your level of exposure

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and you can see similar data here on the on the

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left hand side irrespective of the nicotine content of the product you get a very flat line

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when it comes to the actual levels of exposure in this case of cotinine

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which is the the primary metabolite the main byproduct of nicotine

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that we can measure more easily than nicotine because it hangs around longer.

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So the biology is clearly driving the behaviour.

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People are smoking for the nicotine.

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And the tobacco industry knew this back in the 1950s and 1960s.

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In the 1990s there were a series of tobacco industry documents released under legal action in the United States

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and they revealed all sorts of things like the fact

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that Sylvester Sloan was paid half a million dollars to smoke a particular brand of tobacco product in his movies,

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his movies but they also revealed that the tobacco industry executives knew in the 1960s that they were selling nicotine.

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There's a great quote from those documents which says, we are in the business then of selling nicotine, an addictive product.

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The rest of it is just packaging and delivery devices

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but what they're selling you is nicotine and the unfortunate consequence of

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that is that many of their customers die so half of regular smokers will die as a result of They're smoking prematurely,

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and it's pretty much the only product that you can buy legally that does that to you.

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And the relationship between the nicotine in cigarettes and our biology

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and our behaviour as a downstream result of

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that is complicated by the fact that you have these two levels to the effects of nicotine.

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The first cigarette of the day, and anyone who's a smoker might recognise this, is typically the one that smokers would least like to give up.

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It's the best cigarette of the day.

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And the reason for that is because it's the only one that's smoked against a background of no nicotine.

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If you think back to that stylised representation I showed you earlier, most cigarettes are smoked against a background of nicotine where you're just trying to stave off withdrawal as you go into it.

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But the one cigarette that is smoked against a background of no nicotine is the first cigarette of the day.

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And so that's the one that leads to a much more profound release of dopamine,

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the chemical in the brain that is linked to the reward processes that underlie addiction.

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The other cigarettes that you smoke later on in the day have quite different effects

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and are mostly driven by the cues that are associated with

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that initial release of dopamine that you get from the first cigarette, so the smell and the taste and the context, but but also the fact that you want to stave off withdrawal.

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So Maddy was talking earlier about positive reinforcement and negative reinforcement.

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The first cigarette of the day is the positively reinforcing one, the one that feels really good, that you really enjoy.

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The subsequent cigarettes are the ones that you smoke to stave off withdrawal.

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So those are the ones that are negatively reinforcing.

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So it's a really interesting model for the role that biology plays in driving our behaviour, often unconsciously.

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But most of our attempts to help people to stop smoking have been relatively unsuccessful.

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So we've gone from a prevalence of smoking of about 60% to a prevalence of about 15%.

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That masks a much more complicated picture.

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Smoking is very socially patterned now, very strongly socially patterned.

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So that smoking rates in the most disadvantaged sections of society are still at about 50%.

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You go to some parts of Bristol and you can see that.

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In fact, Bristol is an interesting natural experiment because south of the river where we used to have a tobacco industry

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you get higher rates of smoking even when you match on social deprivation for example.

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Because in the old days people would get free tobacco products

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as part of their employment with the tobacco industry industry

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and there's still an echo of

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that down several generations where you see higher levels of smoking

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because people pick up smoking from their parents and from the context that they live in.

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So it's not just a biological issue but that's one of the factors that I particularly focus on.

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But if you look at these figures they show you why we've cut down on rates of smoking overall notwithstanding

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that complexity around the social patterning.

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These are rates of smoking by age across different birth cohorts, so people who were born in the 1920s, 1930s, 1940s and so on.

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So these are the ones who were born in the 1920s and then going backwards to being born more recently.

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And what this tells us, slightly busy as a figure, is that what has changed principally is not the rate of people quitting,

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not the slope of this line.

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As people get older you get more people quitting and more people dying as a result of their smoking.

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And so rates of smoking go down as people get older because of the compound effect of those two things.

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You see that in the slope, and that slope hasn't really changed that much over time.

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We haven't got much better at helping people to stop smoking.

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What has changed is that fewer people are taking up the habit.

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Fewer younger people are starting smoking.

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So we've been very successful at helping to reduce rates of smoking amongst young people,

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or the rates of uptake of smoking amongst young people would be much less successful at helping people to quit.

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And the reason for that is that the products that we've had historically, the nicotine patches and gum and lozenges that you can buy in boots,

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for example, do a pretty poor job of imitating a cigarette.

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For a number of reasons, but principally because the dose of nicotine

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that they deliver is lower than the dose that you get from a cigarette and delivered more slowly.

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So the rapid spike that we see with a cigarette here tells you about the speed of delivery,

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and the area under that curve tells you about the dose of nicotine that's delivered.

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And on both of those measures, nicotine gum and patch products do a far, far worse job.

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They deliver nicotine more slowly, and they deliver less of it.

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And even other tobacco products like Swedish Snus, for example, which is the smokeless tobacco that you get in a small tea bag that you put inside your mouth,

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It still gives you a fairly high dose of nicotine if you look at the area under the curve.

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Probably an equivalent dose to smoking a cigarette.

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It still delivers it much more slowly, so it's less addicting.

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And it doesn't give you that same rush, particularly for the first use of the day, compared to a cigarette.

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So that's the main reason why we've not done particularly well at helping people to stop smoking.

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But there is something that's happened recently that has made an impact.

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and that seems to be electronic cigarettes because one of the things

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that we run the risk of losing sight of is the fact that not all tobacco products are equal.

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There are a range of different tobacco products out there.

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Some weird and wonderful tobacco products that you can get in different parts of the world.

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In India there's a tobacco toothpaste for example to give you

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that kind of minty fresh nicotine high at the start of the day.

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So there are some really strange tobacco products out there particularly smokeless tobacco products

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and the Indian subcontinent has a monopoly on the weirdest smokeless tobacco products.

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But they vary in harm.

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And this is a kind of qualitative assessment of the different harms associated with different products.

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You have cigarettes here as the most harmful products

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because you're burning something and the burning process creates far more chemicals than the unburned product.

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You're inhaling it into your lungs, which is not a part of your body that should be inhaling anything other than clean air, ideally.

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All the way through to pharmaceutical nicotine products, patches and gum, which are very clean, contain pretty much only nicotine, you don't have to inhale it into your lungs and so on.

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And so you have a spectrum of harm across these different nicotine containing products.

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From the high harm products, cigarettes, cigars, pipes, water pipes and so on, to the lower harm products,

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and the thing that has emerged over the last five to ten years are are electronic cigarettes

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that deliver nicotine with relatively little else.

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Yes, you're inhaling that into your lungs, but in the absence of the other pyrolyzed, burned byproducts that you get when you smoke a cigarette.

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So the question is, what impact have e-cigarettes had on rates of smoking?

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Have they helped people to stop?

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And there are a range of different devices that are out there now.

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I'm sure you are familiar with e-cigarettes.

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If you don't use them yourself, you'll have seen them.

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They're pretty ubiquitous now.

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And they come in all shapes and sizes, and there's a whole subculture that's grown up around them, people who mix their own liquids, people who go in for cloud chasing,

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where you create these big billowing clouds of vapor from your e-cigarette by ramping up the battery strength, for example. And people like these.

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And the reasons why people like these are quite interesting

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and go back to both the biology and the social reasons for smoking.

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The biological reasons are to do with the dose of nicotine that's delivered.

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If you don't know what an electronic cigarette does, you have, this is one of the old cigar-like types that not many people use anymore.

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But the principles are still the same.

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You have a heating element that heats a mixture of propylene glycol and nicotine to create an aerosol.

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They call it vapor, but technically it's not a vapor.

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And you inhale that into your lungs, and it's carrying the nicotine that's suspended in that aerosol into your lungs, where it can be absorbed.

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And as a result, it delivers a relatively high dose of nicotine relatively quickly in a manner much closer to

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that of a cigarette.

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So it's much more satisfying as a nicotine delivery device than the patches

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and gum that have historically been the main way that people have tried to stop smoking.

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You can see that here.

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The circles are a Marlborough Gold King-sized cigarette, and this is delivery of nicotine over time.

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You can see that initial spike, and then when you have your second cigarette you get another burst of nicotine.

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And an electronic cigarette maps much more closely onto that, if you think back to the figure that I showed you previously,

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than nicotine gum, nicotine patches, even high dose nicotine containing products like smokeless tobacco snus.

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So the electronic cigarette is doing a better job of delivering nicotine in a manner similar to a cigarette.

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There are other reasons why people like electronic cigarettes.

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Anecdotally, one of the reasons that they're attracted to people is

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that they allow people to manage their own nicotine use in a way

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that doesn't require it to be life they don't have to

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go to a GP they don't have to go to boots to get some slightly dull looking packs of gum

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and patch to get their nicotine they can do it in a way

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that allows them to still enjoy using nicotine but in a way

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that doesn't require them to be exposed to the other harmful constituents of tobacco smoke

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and ever more developed devices are emerging onto the market over time

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so those first generation cigalike products that looked like cigarettes

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and had a little LED on the end did a reasonable job of delivering nicotine

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but not nearly as good a job as the newer devices

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that are emerging onto the market now we have third

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and fourth generation devices that have tanks attached to them variable battery voltages

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and so on

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that do a yet better job of delivering nicotine in a manner that's similar to what you would get from a cigarette.

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And in terms of the constituents of electronic cigarette aerosol, well it's certainly not something that you would encourage your 15-year-old kids to do because like I say,

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your lungs should really not be exposed to anything other than clean air ideally.

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But the concentration of these harmful constituents of tobacco smoke are far,

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far lower in electronic cigarettes than they are in cigarette smoke.

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surprisingly because there's far less in electronic cigarette liquid than there is in tobacco

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and you're not burning it you're simply heating it

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so you can see the ratios here

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and in some cases they're quite dramatic some of these things are measurable in electronic cigarettes vapor

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or aerosol or liquid but just because something is measurable doesn't necessarily mean

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that it's having a profound biological impact many of these things are at the limits of detection

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and unlikely to be having marked health consequences for the users.

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Now of course there are likely to be health consequences of vaping, like I say it's not something that you would encourage people who never smoked to take up,

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but if you're a smoker and you'd rather not be a smoker

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but you still want to continue using nicotine

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or you feel like the only way to stop smoking is to continue using nicotine, then electronic cigarettes would seem to be a more effective route out.

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And there's now emerging evidence that e-cigarettes do help people to stop smoking

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and interestingly they don't do a dramatically better job than nicotine gum

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and patches they do a slightly better job probably

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because they deliver nicotine in a manner that is more similar to a cigarette

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but the main reason why electronic cigarettes have for the first

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time helped us to improve quitting rates as opposed to drive down initiation rates amongst young people is

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that they're just more popular far more people are using them the biggest problem

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that we had when we were trying to help people to stop smoking 10 years ago was

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that people didn't use the products that were available, the gum and the patches and so on.

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They simply tried to quit cold turkey and that's absolutely the worst way to try and stop smoking and

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very unlikely to be successful.

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Electronic cigarettes are helping by allowing people to continue using nicotine in the absence of the other byproducts of cigarette smoke,

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but they are doing so in a way that is much more popular

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so we're now seeing far more people use those products

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and that's the thing that I think is having the impact on smoking cessation rates.

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And that's one of the reasons why we've seen a particularly

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dramatic drop over the last five years in rates of smoking as people transition out of smoking and into vaping.

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So all of this together, for me, provides a really interesting model for understanding how our behaviour, which feels complex and multifactorial,

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can be influenced in quite direct ways, bio-biology and bio-drug.

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And this is something that the tobacco industry has known for at least 50 years, that they're in the business of selling us nicotine and the rest of it is just packaging.

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Thank you.

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイング練習: Why do people smoke? - 動画で英語スピーキングを学ぶ

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シャドーイングとは？英語上達に効果的な理由