Episode 3 Trust Me, I'm a Doctor

We are constantly being told how to improve our lives.

Every day, we are bombarded by health claims -

how to get fit, slim down, look young.

But all too often, that advice can be confusing...

..contradictory.

So, how do you know what's best for you?

I'm Michael Mosley. In this series, I'm joined by a team of doctors.

Together, we'll use our expertise to cut through the confusing adverts,

headlines and health claims.

This is Trust Me I'm A Doctor.

We're in Lancaster, to do a fascinating experiment

to see if planting trees can make us healthier.

Could there be a new and unlikely-sounding way to treat migraines?

Can I have a glass of your house red, please?

What is the truth about the risks of hormone replacement therapy?

That's what he said! It doubles it!

-He did, he said it.

-I can tell you, it is not true.

Are smoothies really good for you?

And is coffee really bad for you?

But first, probiotics, those yoghurty health drinks...

Now, it's claimed they will improve your gut,

your immune system, all sorts of things,

but do they?

Dr Chris van Tulleken is in search of the truth.

Every year in the UK,

we spend three-quarters of a billion pounds on probiotic products,

full of live bacteria which we hope will do us some good.

-What have you bought that has got probiotics in it?

-The Activia.

-Did you buy the Activia because it's got probiotics in it?

-That was one of the reasons, yes.

I mean, they're not for me.

-How long have you been taking them?

-Six or seven years maybe.

What do you think they do for you?

It puts healthy bugs in, instead of all the horrible stuff going around here.

-So, for you, it's about a healthy gut?

-Yes.

The idea of probiotics

is that they add specially cultured live bacteria to your gut.

Every one of these products contains a different magic ingredient.

Yakult has Lactobacillus casei Shirota,

named after the man who developed it.

Actimel has another Lactobacillus in it.

The Activia contains Bifidus Regularis.

The choice is overwhelming. But do they really work?

Is a simple dose of daily bacteria all we need to keep our gut healthy?

You probably remember the old adverts

claiming science is on their side.

It's scientifically proven to support your body's defences.

Now, here comes the science - the real science.

Your gut is full of all sorts of bugs,

including 100 trillion bacteria.

And you have your own, personal, complex mix.

They help you absorb nutrients from food, metabolise drugs,

and they are also in constant contact with your immune system,

teaching it what is and isn't a threat.

Probiotics are supposed to add more of these useful bacteria.

But do they? And what effect do they have?

Gut specialist James Kinross at Imperial College London has been studying the evidence.

Probiotics, whilst you take them, will remain within the system.

But when you stop taking them, they get flushed out.

So, er, if you can get it to work,

it will only work for the duration that you take it,

and there's no guarantee that it will work in the same way between two different people,

because we have different species of bacteria.

Is there any evidence that probiotics just generally make you healthier, even if you're not ill?

There's very little evidence that it's going to make you live longer or generically be healthier.

-Do you ever take them?

-I don't, actually, no,

but I would if I had diarrhoea or irritable bowel syndrome,

and I'd tell my patients to take them in specific circumstances.

But I don't take them every day, because I don't believe

it'll make a difference to my long-term health.

In fact, the European Food Safety Authority agrees

that there's simply not enough evidence

to allow commercial probiotic companies to make the health claims they used to.

These companies have now changed their advertising.

Danone, who make Activia and Actimel, and Yakult,

say they stand by their health claims but comply with the law in EU.

They say their claims are backed by years of research

and are approved in many other countries.

But I've heard of a new line of research in this area.

What if I said there was an alternative to probiotics,

that something as simple as eating a bag of oats

could have a really beneficial effect on the health of your gut?

A bag like this costs less than a pound,

it'll last me all week,

I think it's worth putting to the test.

This is a new, and considerably cheaper, approach.

The concept is simple.

Instead of trying to add more bacteria to our guts,

just give the ones we all already have a bit more food.

It seems like some of the bacteria that are really good for us

thrive on oats.

So that's what I'm going to feed them -

100g a day, every day, for four weeks.

Runny oats, thick oats,

oats with sugar, oats with salt...

I just hope my gut bacteria are appreciating all of this.

To find out, I've also been sending samples of my faeces

to some lucky researchers at the Rowett Institute in Aberdeen.

They've been carrying out DNA analysis on my poo samples

to see what effect the oats have had on the bacteria in my gut.

Dr Karen Scott has the final results.

So, this looks like a DNA fingerprint from a crime TV show, doesn't it?

That's effectively what it is. It's a fingerprint of your poo sample.

So every column is a different poo sample.

-So these are the weeks - one, two, three, four, five, six, seven.

-Yes.

This is your first week, when you were on your normal diet,

and then the four weeks on the oat diet.

Each row of white blobs corresponds to a particular kind of bacterium found in my gut.

The brighter the blob, the more of that bacterium there are.

And it's clear that some of them have been having a field day on the oat diet.

What this might represent, then,

-is one of these bacteria that really likes oats.

-That's right.

How exactly are they good for me?

We know that different gut bacteria produce different by-products

as they ferment the food that you ingest,

and oats seem to be particularly good at stimulating the growth of bacteria

that produce some of the very beneficial by-products.

Some of these are good for the health of your gut lining,

some of them are more important in terms of heart health.

It seems the fibre in the oats

has been feeding up some of my own personal gut bacteria

and, in return, they have been producing chemicals that have been good for me.

It's like having a trillion tiny pets inside me

that I have to monitor what they eat.

-You have to look after them!

-I've got to look after them.

This new research on oats is only in its early stages,

but there's a lot of interest now in foods containing fibre that could act like this,

boosting our existing gut bacteria.

We already know that people who eat a lot of fibre

have a reduced risk of heart disease.

So whilst we wait for detailed research trials,

I'm happy to carry on my new routine of porridge breakfasts...

..and the occasional flapjack.

You know, what's amazed me here is that...

..a simple change in my diet for a few weeks

has had a dramatic effect

on the health of the bacteria in my gut.

And while there are certain specific medical conditions that do benefit from probiotics,

for most of us who are healthy,

eating oats is much cheaper alternative.

As we all become more environmentally aware,

you'd imagine our towns and cities must be getting cleaner and greener.

Yet headlines like these claim that air pollution is still taking years off our lives.

This is the sort of issue we like to investigate.

So, how do you measure your exposure to air pollution, and what can you do about it?

I've come to Lancaster to find out.

CAR HORN BEEPS

Researchers at the university have been testing some unusual solutions.

But first, the Hunter family have kindly volunteered

to help us measure the effects of air pollution -

Mark, an electrician, Emma, a hairdresser,

their daughters Olivia and Eva,

and Arthur the dog,

all living on the busy A6.

For them, like so many others,

there's a constant stream of traffic going past their house.

I worry about the traffic going past all the time, the amount of cars and the pollution.

I find it very dusty in this house, compared to where we lived before

just because of, I think because of the pollution.

-I don't know what pollution is.

-EMMA LAUGHS

We want to see how much air pollution they're exposed to,

so we have given them individual pollution monitors.

Put it on, ready for school.

The little tubes that they pin up near their heads

will suck in the same air as they do throughout the day,

and a laser inside will constantly monitor

how many soot particles that includes,

as they enjoy a perfectly normal day...

..driving to work,

walking and play...

So, which are the activities that expose us to the most air pollution

and what could we all do to reduce exposure?

We'll find out later in the programme.

But first, we've asked the residents of Lancaster

what questions they'd really like our team of doctors to answer.

I like the taste of smoothies, but are they good for me?

One for Dr Saleyha Ahsan...

Smoothies are marketed as healthy snacks, full of fruity goodness,

but their strong flavours hide their true nature.

I've hit the streets to demonstrate.

Just based on taste, which one tastes sweeter?

-That one tastes sweeter, the coca-cola one.

-OK.

I would say this one, then, has the most.

Actually, it's the smoothie,

and it's got seven percent more sugar.

And we've not been cheating.

A survey published in 2013

found that out of 52 smoothies, 41 had more sugar than coca-cola

and all had more calories.

They're not as healthy as their marketing would have you believe.

One of the reasons why fruit tastes so good

is because it's got a high sugar content.

If you eat fruit sensibly,

it's fantastic for you.

Like many plant products, fruit contains fibre

and compounds that are good for you.

But smoothies are very concentrated,

and that packs in a lot of sugar, along with the good stuff.

If you love smoothies, keep them as a treat

and don't use them as a cornerstone for a healthy diet.

Throughout the series, Gabriel Weston is scouring the world

for radical new treatments for common health problems,

things that could change the future for thousands of us

if trials are successful.

This time, I've heard of a new way to treat a condition

that affects about eight million people in the UK,

a condition that turns this from being the perfect meal...

Can I have a glass of your house red, please?

..into a nightmare.

And I have a particular interest as I'm a sufferer myself...

..of migraines.

Something as simple as wine or cheese, seafood or chocolate

can trigger an attack.

Far from being just bad headaches,

people who have migraines can experience very dramatic symptoms.

So, is there a way to get rid of them?

Andy Bloor is a university lecturer,

but he is also a sufferer of extreme migraines.

So, Andy, I can see there's no reason to be wearing sunglasses,

-do you have a migraine now?

-I'm having a migraine attack, yes.

-I'm having to focus and concentrate on just walking in a straight line.

-Right.

And when you couple that with having to form sentences,

which, again, I'm really having to focus on,

it's a bit of a struggle.

People often think that a migraine is just a bad headache,

but what you're describing is proper neurological symptoms from your headache.

Yes. Somebody once described it as a full-on body assault. That's a good way to describe it.

HORNS BEEP LOUDLY

Migraines are still little understood,

but seem to happen because of the way sensory information is processed by the brain.

People who have a predisposition to them have sensitive periods

when strong flavours, like cheese or chocolate,

or bright lights and loud noises can overload their sensory system.

If too many of these triggers build up at once,

they can reach a threshold and cause a migraine attack,

when all the senses become heightened.

Andy had his first attack in his early 20s.

You're a senior lecturer here in Canterbury, at the university,

how do you manage your condition alongside those responsibilities?

There I am, lecturing in front of a group of students,

and I might start losing my balance,

I might start slurring my words, struggling to find my words,

and, yes, quite frankly, it's very embarrassing.

If there was a treatment out there

that might offer you some significant improvement in your symptoms,

-what would that mean to you?

-It would revolutionise it.

It's been almost 20 years I've had migraines,

I can't remember a time when these things didn't blight my life.

It stops you doing the things you want to do,

it stops you being the person you want to be.

Because migraines are so poorly understood,

new treatments to deal with them are rare.

The standard advice for treating migraine hasn't changed for years

avoid triggers, try and maintain regular patterns of sleep and diet,

and when attacks do occur,

hit them hard with safe, high-dose painkillers.

Usually, ground-breaking medical advances

are made in the world's leading hospitals,

but this one came out of the blue

from, of all places, the beauty clinic.

Supposedly the elixir of youth in a tiny bottle,

it's known as Botox.

Some clients, though, found it did more than smooth their brows,

it soothed their migraines, too.

This gave researchers a new insight into the condition.

So, what is Botox actually doing?

Andy has volunteered to go under the needle of Dr Mark Weatherall,

here at Charing Cross Hospital in London.

-Hi, Andy. Nice to see you.

-Hi, Mark.

-Hi. Nice to see you. Do come in.

Mark is going to give Andy a total of 31 injections of Botox

in his face, head, neck and shoulders,

aiming not for specific muscles, but for regions carrying sensory nerves.

OK, so just give me a frown.

OK, and just relax.

-So we're going to start here. Are you ready to go?

-Mm-hm.

So...

-How are you feeling, Andy?

-I'm OK.

-Yes.

I'm not the happiest person with needles.

Some of the areas are similar to those targeted in cosmetic wrinkle treatments,

but the aim is different.

So we think that Botox, when it's treating migraine,

is affecting sensory information, not the muscles themselves.

Botox stops nerves carrying their signals.

These include the signals from the brain to contract muscles,

causing smooth, expressionless Botoxed faces.

But it seems also to stop nerves carrying sensory signals TO the brain

and it came as a surprise that this helps many migraine sufferers.

It's given researchers an unexpected insight

into what's causing migraines.

When you finish a treatment like this, Mark, how long do you expect to wait?

Interestingly, some people notice a benefit very quickly

within a few days.

Typically, most people will start to notice an improvement within a couple of weeks.

So, Andy, when we met last,

you were wearing dark glasses and you looked white as a sheet.

Today, you look like a different man. How have you been feeling since we last met?

I'm a lot better than when I saw you last!

Some people describe having Botox as being like a light switch, that it switches them off.

For me, it's better to say it's a dimmer switch,

it's brought down the intensity for me.

I know that your attacks were having a very significant impact on all aspects of your life.

Can you tell me how that's changed?

It has given me more freedom to be confident about doing things,

not thinking, "What happens if...?" or "Can I...?"

When I met friends at the weekend, I was able to enjoy myself

and not worry about having a migraine that was going to debilitate me so badly.

So this is a story of true serendipity

a treatment being discovered by chance

that actually sheds light

on the causes of the condition itself.

It's also reminded me that so often in medicine,

the best solutions, the breakthroughs even,

arise in the places that we least expect them.

Still to come...

What is our national coffee addiction doing to us?

And would you know how to save someone who had drowned?

But first...

It's coming on now. Ah, yes!

Every year, I suffer from attacks like this one...

There's a bit of leaking going on in the eyes.

..and so do a quarter of the UK population.

It's hay fever.

It's beginning to produce some quite unpleasant symptoms.

Symptoms that are familiar to millions of us.

At-choo!

My throat and my ears kind of itch inside, if that's possible!

Itchy eyes, erm, runny nose, congestion...

It feels like you've got a very, very bad cold.

So, if hay fever is such a problem for so many people,

what's being done about it?

The hay fever season starts around February,

when trees like birch start to release pollen,

which, for some people, is their main trigger.

But for most of us, though, the peak is mid-summer,

when the grasses really get going with their pollen.

Hay fever happens because your body treats pollen

as if it were some dangerous, invading parasite.

Amongst other things, it releases chemicals called histamines.

Unfortunately, histamines have some annoying side effects,

as I'm going to demonstrate with these lovely stinging nettles.

We all know that stinging nettles sting,

but they also inject you with histamines.

Right, let's give it a go.

Agh! Ooh, yes, nice!

Agh! That's painful.

Very quickly, you see this area's going red

and some nice big blobs are appearing.

The histamines injected by the nettle cause inflammation and itching.

But your body also produces its own histamines

as part of its defence mechanism.

When you have an allergic reaction to something like pollen,

you are releasing them in the eyes and nose.

It's as if there's been an attack by parasites,

and one of their effects is annoying itchiness and runniness.

The way to combat to the effects of histamine

is, naturally enough, to take antihistamines.

The antihistamine market is huge.

We spend £72 million in the UK on antihistamine pills.

Now, severe hay fever is really unpleasant,

but antihistamines can also have side effects

so it's vital to get the right treatment.

Professor Angela Simpson has seen the dramatic effects of hay fever on children,

especially noticeable when their performance is measured in exams.

There's a very interesting study in children,

because we've got natural experiments with public exams in June,

right in the middle of the hay fever season,

but the mocks are done in January, before the grass pollen season,

and so you can look to see what factors predict children dropping a grade

between their mock exam and their actual exam in June.

Besides being a boy, which is a predictor,

-the biggest predictor is having hay fever.

-Right.

But perhaps, more importantly,

another important predictor is being treated with a sedating antihistamine for your hay fever.

Your whole life can be transformed. You get a lower grade, you don't go to university...

-Because you had hay fever that wasn't properly treated.

-OK.

So we're keen to make sure people are properly treated,

and for us, that would be starting a nasal steroid,

probably a couple of weeks before the onset of your symptoms.

For you, being grass pollen allergic, May would be a good time to start your nasal steroid,

to try and calm down inflammation in the nasal passages

so you don't get the attacks of sneezing and the nasal stuffiness

and the itchy eyes that impair your concentration.

It could be the reason I failed that exam way back then was because of this!

-Definitely.

-Thank you. I have a perfect excuse!

It's clearly important to ensure that if you do have hay fever,

you treat it and treat it right.

So nasal steroids get the thumbs-up.

If you are taking antihistamines, do check on the back of the packet

that they are the sort that won't make you feel drowsy.

And don't forget to start taking the nasal sprays

two weeks before your normal sneezing season to get full effect.

But even with the best drugs and steroid sprays,

many people still struggle to find a way

to deal with their hay fever symptoms.

I take pills and I've got a nasal spray. Eye drops...

-And do those work?

-Yes, er, usually kind of short-term

and then they tend not to work after long-term use.

I don't find that any antihistamines or nasal sprays actually make an awful lot of difference.

My son has some prescription drugs, I don't know the names of them, but he gets them from the doctor.

-And do they work?

-Er, not wholly, no.

Clearly, there's a need for better treatments for hay fever.

I've come to find out about a new approach

which could even get rid of the allergy for good.

-Please, sit down.

-Thank you.

Professor Stephen Durham has been working on these rather unusual pills.

Can I have a go?

They're weird, aren't they? It's not like any pill I've ever encountered before.

Is this essentially grass pollen mixed with sort of...

It's a freeze-dried grass pollen.

-Just pop it under your tongue.

-OK.

OK, is it -

You shouldn't speak. Just hold down your tongue

and just keep it there for two minutes.

This pollen pill works a bit like a vaccine.

By exposing yourself to pollen in regular small doses,

your body learns not to react to it.

It's a technique called immunotherapy.

-Any sensation at all?

-There was a sort of slight tingling, I thought.

-Well, that's it. OK.

-That was it?

-Yes.

So if I wanted to get rid of my hay fever forever,

-it would just be a matter of taking one of those?

-One of those a day for three years.

Some 15 million people suffer from hay fever

and approximately 80-85 percent of patients will benefit,

so that's, I think, a very exciting development.

It's quite a commitment, taking daily pills for three years.

So, what do people think?

-If you could take a pill, and there's a new one out there, which will get rid of it...

-Yes.

-..but you have to take it every day for three years...

-I'd take it.

Three years? That's quite a... No, I'm willing to give it a go.

I don't think I would, no. I don't think I would be prepared to take that,

because every day for three years seems an awful long time

for one month of discomfort.

Yes, I would, actually, because, erm,

if it solves the problem permanently, it's worth doing.

These pollen pills are only available on prescription,

but long-term clinical trials suggest they can be very effective

and immunotherapy is also being trialled for other allergies.

I think immunotherapy is an fascinating approach,

which has wider uses than simply hay fever.

I also think that when these pills come down in price,

they will be more routinely prescribed.

Visit our website at bbc.co.uk/trustme

for more information about identifying the pollens you might be allergic to

and about treatments for your hay fever.

MUSIC: "Coffee & TV" by Blur

Can I get a big filter coffee?

If you're a fan of reading the health headlines,

you'll probably be pretty confused about coffee.

No-one seems to agree whether the 70 million cups of it that we drink every single day

are doing us harm...

..or good?

There's a whole raft of health benefits proposed about caffeine and coffee,

but for every health benefit, there often seems to be a contradictory risk.

So, what's the real truth?

Caffeine is found in a whole range of plants,

from tea leaves in China to the cocoa beans of Mexico,

and we've found many ways to get it into our diets.

I've got seven things on this table and they all contain caffeine.

I'm going to put them out in order, because I think it isn't obvious which one has the most.

The least amount of caffeine is in this large glass of cola.

With a little bit more, we've got a cup of normal tea.

A bit more than the tea, a large bar of dark chocolate. That's 50 grams.

More than the chocolate, a single espresso.

Then we've got a standard energy drink.

That's got quite a lot.

And of the food and drink items,

the one with the most amount of caffeine

is a mug of filter coffee.

But with more caffeine than all of them...

..is a single dose of painkillers.

These are Paracetamol Extra with caffeine in it.

They've got more than four times the amount of caffeine than you find in a cola drink.

# Coffee and TV... #

Plants use caffeine as an insecticide,

which doesn't sound like something we should be taking.

In humans, caffeine's a powerful stimulant,

used by millions of us every day to wake us up,

help keep us alert and generally boost our concentration.

# Coffee and TV... #

The way caffeine works is, it increases the flow of adrenalin.

Adrenalin is the hormone used for fight or flight,

so it boosts your heart rate, your blood pressure and increases blood flow to your muscles.

All these things combine to give you that much-needed kick.

So, is that good or bad for us?

Most studies show there's no harm in drinking caffeinated coffee,

but new research does come out all the time,

and if you've got high blood pressure or you're pregnant, you should be cautious.

But caffeine isn't the whole story.

Coffee's packed full of other ingredients

and research into these often hits the headlines, too.

If you go for the lighter roasts grades 1-2 -

then coffee is fantastically rich in compounds called polyphenols.

These are the beneficial chemicals found in what the media like to call "superfoods",

and they have been shown to help blood flow in the heart and brain,

protecting against strokes and dementia.

Research is in its early stages,

but a lightly-roasted coffee could eventually turn out to be good for you.

At the moment, the only guidelines in the UK

are that pregnant women should limit their daily intake to a maximum of 200mg of caffeine,

that's the equivalent of two cups of filter coffee.

For the rest of us, there's no clear-cut evidence

that it's either overall good for us or overall bad for us.

Until there is, I'm going to keep enjoying coffee whenever I feel like it.

Earlier in the programme, we met the Hunter family, who are wearing pollution monitors

to see how much pollution each one of them is exposed to

during a typical day.

Once soot and tiny particles get into our lungs,

what happens to it there

and what can be done to reduce exposure?

I'm cycling through London, as I do most days, getting my lungs full of traffic fumes.

And then it's time to cough it all up,

with help from Dr Rossa Brugha.

Go for it, big wet coughs. HE COUGHS & SPLUTTERS

I can assure, you this is as unpleasant for me

as it is for you!

What we need is these nice big chunky bits,

there and there.

Rossa's making me cough up everything I can

so I can see what's going on inside my lungs.

He's got some misty salt solution to make my sputum more liquid.

-I think we're done.

-I think I'm beginning to feel a little faint!

-Fair enough!

-OK.

So, what am I looking at here?

You are now looking at cells that come from inside your lungs.

You coughed up your sputum for us.

This cell, you can see it's speckled with these black little... little particles here,

probably soot from diesel engines.

Despite legal controls,

cars and trucks, particularly those with diesel engines,

still produce large amounts of tiny bits of particulate matter,

or PM.

Too small to see and too small for our noses to filter out,

they go deep inside our lungs.

Fortunately, our lungs have defences,

cells called macrophages, that can eat up these particles.

The problem is that macrophages are slow workers -

we speeded up this footage -

so we have to be careful not to overload them.

If you're at the traffic lights and a lorry starts off in a low gear

and gives a big pile of cloud coming from the engine,

your macrophages aren't going to be able to deal with all the particles you breathe in in one go.

That stuff is going to sit on the lining of your lung,

causing damage by stressing the lining of your lung fluid

-and being generally bad for you.

-OK. How bad?

A report came out a couple of years ago, commissioned by the government,

that said that 29,000 people a year die

because of breathing in this stuff, this PM or soot.

Or they equated it to losing about six months of your life

-simply because of the quality of the air.

-That's significant.

We worry so much about clean water and clean food,

but we're all breathing dirty air all the time.

29,000 deaths a year is an astonishing figure.

New research has shown that the tiny PM particles from diesel fumes

can get into our blood stream from the lungs,

and there they increase our risk of heart disease.

But if we keep our pollution exposure low enough

we give the macrophages in our lungs a chance to deal with a lot of it.

Personal pollution monitors have been giving researchers real insights,

so back in Lancaster, Rossa's hoping the Hunter family's results will help.

It turns out that the person with the most dramatic pollution exposure was little Olivia.

As Olivia arrives at school, she gets this huge spike in pollution exposure.

-That's big?

-That's big. It's bigger than anything we see from Mum or Dad during the day.

Back indoors, not very much. And then she goes on a car journey, I think she goes to Brownies,

and you see these spikes again when she's in the car with her mother.

Rossa's research group have, again and again,

found this same pattern of exposure in children.

Getting through the school gates quickly is the key.

At school, she has to go outside and run around, and we absolutely want her to do that,

but there's things that expose children to air pollution that adults don't get,

such as people letting their engines idle at the beginning and end of the day.

That's the big spike, when she arrives,

and there's presumably a load of cars outside with their engines idling.

Olivia was exposed to twice as much pollution as her mother.

Mum gets lower levels,

but it's interesting to see what drives her exposure to pollution.

In the morning, she walks the dog. She takes the car out three times in the day.

Every time she takes the car out one, two, three

she gets big spikes in exposure.

ENGINES REV

This is another common finding in Rossa's research.

When you're driving, you are most at risk

because you're directly in line with the exhaust from the car in front.

If you close your air vents and windows

and keep a little way behind the car in front,

and you can dramatically reduce your pollution exposure.

But most telling of all was Mark's data.

Although he also gets a spike when given a lift to work in the car,

he manages to avoid it in the evening.

He walks home,

so he doesn't get the pollution spike that you'd expect from being in a car or being in traffic.

So, he actually gets less pollution walking home

than he did being driven to work in the morning?

It looks about half.

Mark managed to reduce his pollution exposure walking home,

because on the pavement you are not directly in line with the exhaust from another car.

Being just a few metres away from the road, on the far side of the pavement,

goes a long way to protecting you from airborne soot.

People, I think, are often quite fatalistic about air pollution.

They know it's there, they know it's affecting them,

but they don't feel there's a huge amount they can do.

I think it's quite obvious from Mark's trace

that you can decrease your exposure to air pollution by changing the way that you behave.

But what about all those hours we spend at home?

Is there anything we can do to protect ourselves there?

A team at the University of Lancaster claim

that you can improve the quality of the air in your house simply by planting a tree outside.

Can that really make a difference?

It's the sort of claim that would need pretty good evidence to convince us,

so surgeon Gabriel Weston has been setting up an experiment,

along with the researcher responsible for the original idea,

Professor Barbara Maher.

We're installing a line of trees in the Hunter family's street.

But they're not just any trees,

they're specially-chosen silver birch trees.

Barbara, we've got a busy, polluted road here.

You're hoping that these trees

might do a job of dusting the air or cleaning up the air in some way?

We're here to see if these silver birch trees, specially chosen for the job,

if they can make a big difference to the PM,

the amount of PM in the atmosphere,

and indeed inside the houses adjacent to this area, as well.

We've chosen this tree particularly, we've chosen it for two reasons.

The first reason is that the structure of the leaf

makes it very, very good at removing particulates.

It has ridges on it, it has hairs on it,

so when the particles that are floating in the atmosphere, when the PM hits the leaf,

the PM lodges on the leaf, it sticks to the leaf,

and it's removed from the atmosphere. So that's one reason.

The second reason, the tree itself is a very tolerant tree,

so when it receives all this pollution,

it doesn't get too stressed itself.

There are hardly any leaves on our tiny little trees,

but over two weeks, we're going to see if they afford any protection

by monitoring the air inside eight houses on the Hunters' street.

Four will be supposedly protected by our trees

and the four neighbouring ones won't be.

And we'll be measuring the levels of PM pollution in the air indoors

by using the dust-attracting static of the residents' TV screens.

We can come in, we clean off the TV screens

so it's totally free of any PM before the start of the experiment.

We come back after two weeks, we wipe another bit of the screen with the wet wipe

and we measure the magnetic content,

and that tells us about these iron-bearing particles

that have come specifically from the vehicle outside.

-Great, so this one's done.

-This one's done. Let's go to the next house.

Leaving the residents of the street with sparkling-clean screens

and a new view from their windows,

our work here is done for now.

In two weeks' time, we'll be back to see how much PM has built up on the screens

of the four houses with trees and the four without.

We'll find out the results later in the programme.

I work in a busy A&E, where I see patients who could be saved

if more people had the confidence or knowledge to try first aid.

You don't need to have a full medical training

to be able to help someone who's in trouble.

I want to share my skills with regular people up and down the country

so that as many of us as possible know what to do in an emergency,

before the paramedics arrive.

I want to show you how to save a life.

This time, I'm dealing with drowning.

Over 400 people drown each year,

most not in the sea, but in a lake, river or swimming pool.

Would you know what do if you came across someone in trouble?

Many people who drown are found by walkers,

so I've come to Blackthorn in Oxfordshire to meet a rambling group,

to teach them the skills to save a life.

Dealing with a drowning casualty is a rescue of two parts.

The first part is - don't become a casualty yourself.

Don't get in the water.

Do your best to get them out,

use whatever is around you to try and hoick them out,

but don't jump in yourself.

The last thing anyone needs is another casualty,

so stay calm and stay safe yourself.

If you have managed to get them out of the water safely, shout for help,

and then you can try the second part of the rescue -

a few simple steps which could help them survive.

The first thing you do is to try and rouse them,

wake them up.

Hello? Can you hear me? Can you hear me.

Give their... Grab hold of their shoulders and give them a shake.

ALL: Hello? Hello?

If they're not waking up, the other thing you can do,

a little pinch to the earlobe, OK?

That sometimes does it.

If they're still not responding, make sure their airway is clear.

Lift their chins up and tilt their head back.

That in itself could be enough.

Next, check if they are breathing.

We use the words, "Look, feel, listen," OK?

Cheek down close to the mouth...

..and look down the chest.

Can you see it falling and rising?

Can you feel any warm breath, or any kind of breath on your cheek?

If not, call the emergency services

and try mouth-to-mouth resuscitation.

It's not as scary as it sounds.

We need to give them five rescue breaths.

Pinch the nose.

Each breath... lasting for a second.

When you do that, make sure you've taken a breath in,

otherwise you'll be fainting over the patient!

Then start CPR.

Use both hands together, right in the middle of the chest,

and with straight arms start pushing down twice a second,

about five centimetres each time.

These two things could get life-saving oxygen to the person's brain.

If you are alone and without a mobile phone

then don't leave the casualty before doing this.

It's really important that you do these steps first

before taking the time, a few minutes, to call 999.

You know what to do, you can swap in.

Once help is on its way,

continue giving 30 chest compressions, followed by two rescue breaths,

until they arrive.

If the casualty starts breathing,

the best thing to do is to put them into the recovery position.

Move the arm closest to you to one side.

Grab their other arm and place it by their cheek.

Then, by pulling on the knee that's furthest away from you, roll them onto their side.

The recovery position will keep the airway open.

-Comfortable?

-Of course!

# Come on, baby, and rescue me... #

If there is going to be any vomit or anything coming out of the mouth,

it will come out this way and they won't choke on anything.

This is a stable position to leave someone in whilst you go off to get help.

Remember, if they are not breathing

you have to initiate those five rescue breaths

and start that one minute of CPR.

Make sure that 999 has been dialled.

And then continue CPR until help arrives.

If you follow those steps you could ultimately save a life.

Still to come...

Does cracking your knuckles give you arthritis?

And what happens in our tree experiment in Lancaster?

Whoo! Whoa!

I am utterly astonished.

Throughout the series, I'm trying to get expert advice on the risks and benefits

of some of the pills that we are all encouraged to take in our lifetime.

After all, we take an estimated 40,000 of them,

enough to fill a wheelbarrow.

We take pills for allsorts of reasons.

Sometimes it's just to treat a headache or perhaps an infection.

But there are also treatments given on a long-term basis,

and one of the most controversial of these is HRT -

Hormone Replacement Therapy.

HRT is taken by women who suffer symptoms around the menopause.

It boosts their levels of the hormones oestrogen and progesterone, which fall at this time,

and it can give a lot of benefits.

But if you read the health pages of magazines,

you'll have seen a lot of confusing information about its risks.

-Are you thinking of HRT?

-Not at this moment in time, no.

I think my symptoms are mild and I'd rather wait until I was really desperate.

If I read a bit more about it

and I felt it would be of benefit to me in the future, I would take it, yes.

-How long were you on HRT for?

-For ten years.

Would you have liked to have continued on it

-or were you happy off it?

-I was fine on it.

For many years, women were sold the idea

that taking HRT was the equivalent of the elixir of youth,

and for decades sales absolutely soared.

And then, about ten years ago, came a couple of studies

which suggested that, far from being safe,

long-term use of HRT was associated with increased risk of stroke,

heart disease and breast cancer.

Sales collapsed.

So, were the fears about HRT justified?

I'm going to hear the case from two experts, with very different views.

Professor Klim McPherson of Oxford University

studies the long-term effects of HRT.

He was an author of one of the studies 10 years ago

which revealed unexpected risks.

So, should women take HRT?

If women have symptoms which they want to get rid of,

then they should probably think about taking HRT,

but only as low a dose as possible and only as short a time as possible.

-What about things like osteoporosis, then?

-Magic! HRT is magic.

It stops bone loss, you know, overnight basically,

and continues to prevent bone loss, bone-density loss while you're taking it.

But women at 50 don't really have much in the way of bone loss and fractures

compared to women of 60, 70 and 80,

and therefore, to get that benefit, you've got to take HRT for a long time,

10, 15 years, which, given the risks, is out of the question.

-What are the risks?

-You get breast cancer more commonly, twice as commonly.

The risk is 2 per thousand, per year. You go up to 4 per thousand, per year.

You get an increased risk of ovarian cancer, clots of various kinds,

strokes, DVTs and so on.

What about things like heart disease?

Well, we dug out all the trials that were submitted by manufacturers to the regulators,

of which there were something like two or 300,

and among those trials, there were several which had a massive increase in coronary heart disease,

which presumably weren't published for that reason.

-It is slightly shocking when you hear that, isn't it?

-People thought we were bonkers.

-Do you feel vindicated now?

-Of course. Completely vindicated by the WHI trial in America,

with 8,000 women given HRT and 8,000 women given placebo in a double blind trial,

which showed the same results.

Do you think that if you're currently on HRT,

-you've been on HRT for five years, would you suggest coming off it?

-Yes.

If you haven't tried coming off it, it's very well worthwhile trying it.

-Because?

-Because your symptoms might not be there any more and you will no longer need it,

and therefore, the risks will be ameliorated.

Professor John Studd is a consultant gynaecologist,

awarded the Royal Society of Medicine's Gold Medal for lifetime services.

He has a very different opinion on the risks of HRT.

There are about a million women in the UK on HRT at the moment.

Do you think that figure is too low or too high?

Well, it has fallen in the last ten years,

therefore, I would like it to go back to normal levels.

I would certainly like it higher, for the sake of women's health and women's future health.

What about the argument that

there is an increased risk of breast cancer from taking HRT,

do you accept that?

There may be a very small increase in breast cancer,

but even that's disputed, and I certainly dispute it.

Some experts are saying combined HRT increases the risk of breast cancer, doubles it.

-Nobody said that.

-Somebody said it just this morning to me!

-Not even the Oxford people say that.

-That's what he said.

-It isn't true.

-Klim McPherson said to me, it doubles it.

-Not true.

-He said it.

-Well, I can tell you it's not true.

-You absolutely deny that, do you?

-Absolutely.

There've been these two very controversial studies

showing more heart attacks and more breast cancer

and they've mostly been retracted,

even, you know, by the investigators.

I followed one of the investigators at a meeting last month,

and he publicly apologised

for the...

the failure to analyse these data correctly.

And he particularly made the point that you have in America

these ten million or so women, 50 to 60,

who, because of this scare, this false scare,

have been denied the preventative aspect

as regards osteoporosis,

heart attacks, Alzheimer's, etcetera,

because of this study.

One third of all women get a fracture.

You can prevent almost all of those,

you can reduce the risk of heart attacks,

you can prevent a lot of Alzheimer's.

Why aren't you winning the argument, then?

Because women are continuing, presumably, to not take the pills,

they've decided HRT is too dangerous, they've given up.

I have no doubt that once the facts become quite clear,

that people will take up HRT again

for removal of their symptoms and preventative medicine.

Thank you.

I'm not sure I've ever met two experts

who disagree so profoundly on a subject.

They are disputing the results of the same studies.

It's impossible for the rest of us to know who is right

and who is wrong.

From the conversations I've had, this is what I've concluded...

if you have severe menopausal symptoms,

then the benefits of HRT in the short term are clear.

The risks are small in absolute terms -

an increased risk of breast cancer -

but in the longer term those risks mount.

But so do the benefits,

including the reduced risk of osteoporotic fracture.

In the end, it has to be an intensely personal choice,

one that you have to make with your GP.

Meanwhile, Lancastrians have been throwing more questions in our direction...

Is it true that cracking your knuckles gives you arthritis?

One for Chris

One of my favourite pieces of research ever was done by Dr Donald Unger.

For 50 years, he cracked the knuckles in his left hand

and he didn't crack the knuckles in his right hand.

Do you know what he found? No arthritis in either hand.

And other, more rigorous studies

have confirmed that the link to arthritis

is just an old wives' tale.

We've all heard joints crack

and you might've wondered what exactly causes that sound.

Well...?

Doctors think that cracking sound is bubbles,

forming and then disappearing in the fluid in our joints when we move them.

For two weeks, this small stretch of the A6 in Lancaster

has been home to an unusual experiment -

to see if trees, even ones as small and flimsy as these,

can help shield us from the harmful effects of PM pollution

produced by traffic.

In her lab at the University of Lancaster,

Professor Barbara Maher is showing Gabriel some promising signs.

Scanning electron microscope images of some leaves taken from the trees

show that - lodged between the ridges and grooves -

there are lots of particles.

So this leaf that we're looking at, this dark leaf,

would have been completely clean a couple of weeks ago,

and this is after just two weeks on that heavy road,

with all of that traffic exhaust being churned out?

That's right. We chose the silver birch deliberately

because our previous work has shown how efficient it is

because of its roughness and its hairiness.

We can actually see just how well the surface of the leaf

provides all of this opportunity

for the particles to be intercepted and to lodge

and to be kept on the leaf surface.

It's clear the pollution particles are sticking to the trees.

When it rains, this will get washed away,

leaving the leaves clean to collect more.

But have the leaves on our trees actually made any difference at all

to the amount of pollution that reached the houses and the residents inside?

Barbara returns to collect the final measurements from inside the houses.

The static TV screens and computer monitors

that we left nice and clean a fortnight ago

now get another wipe.

The pollution from traffic tends to be rich in magnetic iron,

so Barbara can simply measure the magnetic properties of each wet wipe

and estimate how many particles there are on each

so we can compare the pollution levels

in the four houses with trees outside

against those in the houses without.

Barbara, when I first heard about this, I was extraordinarily sceptical.

-You weren't expecting much?

-Not at all.

-OK.

-So I'm dying to see the results!

-The best thing to do, then, is to show you some data.

-OK.

You recall we did this interesting thing

where we wiped the TV screens in the front room of all the houses along our street,

our experimental street.

These are the TV wipe data for the houses with no trees.

So, will the levels behind our trees be lowered at all?

These are the same data for...

-Whoa!

-..the tree-lined streets.

Well done! Wow!

I am genuinely astonished.

That is very, very, very impressive. I am utterly astonished.

I was expecting no shift, or possibly a tiny shift, because they are little trees!

-It's about a 50 or 60 percent reduction.

-That is good!

They have done a good job. Wow.

Wow, good old silver birch!

-That's it -

-Who would've believed it?

The trees are special. We knew birch would do a good job because of their leaves,

-because of the nature of the leaves.

-Right.

An incredible 60 percent reduction in harmful particulates

inside the houses, behind the little trees,

more than halving the amount of pollution

the people living inside were breathing in.

..the fact it does something as impressive as that,

with that few trees, that small...

The line of trees is what's important. You don't need a forest or a continuous canopy.

It's that edge that provides the interception of those particulates

before they get into people's houses.

That means the people inside hopefully are breathing

half the amount they were breathing just because of the little trees.

Just because that little row of green trees,

that looked a bit like an art installation

-but were doing a fantastic job of cutting the dust.

-Wow!

For the Hunters, and many of us who live on busy roads,

these results are incredibly good news.

I'm amazed that such a small thing makes such a big difference, really.

Everybody that spotted the trees said, "What difference could they possibly make?"

It is incredibly early days

and they need to do lots more research,

but I am very impressed.

I think that, especially for the girls,

it would be a good idea to clean the house pollution up a bit

by getting some trees out.

Good idea.

Research continues into the best way to tackle traffic pollution.

But it seems silver birch trees may have their place.

I was really surprised by how much impact

the silver birch trees had on the air pollution in the house,

and since air pollution is clearly exacerbating heart disease -

and heart disease is Britain's biggest killer -

you can see that this is potentially a hugely important area of research.

Certainly, if I lived on a busy street, I would want to see trees outside,

and if I had a front garden, I would be out planting my own.

That's it from us. I hope you have found it useful.

We have certainly found it eye-opening.

That's quite a shock. That is quite a shock.

Standing badly like you are, it's dreadful!

That's what you're not supposed to do!

That's astonishing.

# I just made an appointment For a special rendezvous

# To see a man of miracles And all that he can do

# I checked in at reception Put my hat into my lap...

I feel really rude taking your strawberries. Go on.

Whoo! Whoa! That is good!

# Come over here And give me some medicine

# Move a little closer So my head can spin

# A little bit of potion Makes my fever go

# Get it out of me like a volcano

# Da-ba-da-be-di-be-da-be-du-doh-doh

# Doc-tor, I want you

# Mmm, my Doctor Wanna Do

# I can't get over you

# Doctor do anything That you wanna do

# Doc-tor, I want you

# Mmm, my Doctor Wanna Do

# I can't get over you

# Doctor do anything That you wanna do #

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