Trust Me I'm A Doctor (2013) s03e03 Episode Script

Series 3, Episode 3

1 We're constantly being told how to live our lives.
But what's the health advice you can really trust? In this series, we use our expertise to guide you .
through the contradictions and the confusions.
We'll get to the heart of the debate .
and ensure you get the information you need.
We're here for when you don't know where to turn.
I'm Michael Mosley.
In this series, I'm joined by a team of doctors.
Together we'll cut through the hype, the headlines and the health claims.
This is Trust Me I'm A Doctor.
This time we're in York, surrounded by chocolate, to test a counterintuitive way to stop cravings.
We're making a new discovery -- which cooking oils are safest? - It's a world first.
- It's a world first! I'm very, very pleased about it.
Revealing a whole new branch of medicine.
It could change the face of cancer therapy.
Asking is organic food really better for us? And could duct tape cure verrucas? - No! - Through what? How does it do it, like? Welcome to York, the chocolate capital of the UK.
Now, the main problem I have with chocolate is once I start, I just can't stop, and we're here to test a new approach to curbing cravings.
We've put the call out all over Yorkshire for volunteers to come and help us with an experiment.
We want to put to the test some cutting-edge research into quitting bad habits, and in this case, they all share my problem.
I like chocolate a lot, I'm ashamed to say, but I do.
I eat chocolate every day.
I'll sit there and I'll start eating chocolate without even realising it.
Pretty much every day I would have some chocolate, and some days quite a lot.
Over the next few days, more than 200 people are going to take part in this experiment.
It's the brainchild of Professor Carey Morewedge from Boston University.
And because I can't be trusted near chocolate, Dr Chris van Tulleken is going to be running it.
Now, this is one of the biggest experiments we've ever done on Trust Me I'm A Doctor, and behind me we have the volunteers, all of whom say that they eat more chocolate than they should.
'We're going to try to break their chocolate cravings 'with a really strange-sounding technique.
' Now, I can't tell you the exact details of the experiment because that might alter your behaviour and that will spoil the results, but I can tell you that this is going to involve eating chocolate.
ALL CHEER HE LAUGHS Right, let's go.
We've divided the volunteers into two groups and Carey is going to talk them through the rather strange craving-busting technique that he's devised.
Come around.
Now, group one is going to imagine eating 30 chocolate sweets one at a time.
They're not going to be eating the chocolate sweets, they're going to be imagining eating them in their minds.
Weird, I know.
So first imagine eating a first piece He's going to take them through it piece by piece.
Imagine eating a 22nd piece of chocolate.
Group two is going to do the same thing but they're just going to do it for three chocolate sweets, just three.
Then what we want to know is how much chocolate they eat from the bowls of chocolate that are on the table.
The volunteers have no idea that we're monitoring how much they eat.
Carey has a theory that the more they imagine eating, the less they will actually scoff.
So, Carey, we've got people in a room with the bowls of chocolate, asking them to think about chocolate.
This seems like a bizarre way of trying to get them to eat less chocolate.
It does seem bizarre, but it's really based on some good science about how cravings are formed.
Since I was a kid, what we get told is, just avoid it, avoid it physically, avoid thinking about it, avoid it mentally.
Why can't we just do that? That intuitively seems to make sense but it's problematic because of memory as well, so when we try to avoid thinking about something, like right now, try not to think of a white bear.
- Right.
- Immediately, right, you think about a white bear.
- Yeah.
And so what we find is that when people try to suppress thoughts of something, it tends to actually activate those thoughts and they are more likely to have them.
And that's certainly true with in my own experience, with foods, with anything pleasurable, trying to avoid it makes it more desirable.
To try to iron out all the other factors that might influence how much chocolate people eat, we are testing as many people as possible over seven days, on their own and in groups.
How did you find the experiment, Lucy? Erm, brilliant, obviously, because it involved eating chocolate.
A little bit baffled, I'm not too sure what it's all about.
I'd rather hoped that you were going to ask me to check out the difference between truffles and pralines and ganache.
And finally, when everyone is ready to leave, we have treats for them all -- but with a catch.
So thank you, everyone, very much for taking part.
Now, it isn't quite over yet because the good news is you are all going to go home today with an enormous bag of free chocolate.
ALL: Ooh! But there is a catch -- of course there's a catch to a bag of free chocolate! And I'm going to let our psychologist explain what the catch is.
OK, so every time you think about eating chocolate or you want to eat some of the chocolate, what we ask you to do beforehand is to engage in the same imagination task that you did today, so just as you imagined eating the chocolates today, we'd like you to do so before you start eating the chocolate that you go home with, and then afterwards write down how much chocolate you eat after you're finished eating it.
For the first time ever, we want to put Carey's theories to the test, not just in the lab but also in the real world.
Can simply imagining eating things make us stop wanting them? If so, this could help us all break our bad habits and revolutionise our health.
We'll find out later in the programme.
With us on the streets of York is our trusty Trust Me video booth and people have been flooding in to ask the health-related questions that they are dying to know the answers to.
How do I get rid of a wart? One for A & E doctor Saleyha Ahsan.
Warts are unsightly.
They can make us feel self-conscious and they're often a pain to get rid of.
So, unsurprisingly, they're not something any of us want, but we will pretty much all get them at least once in our lives, despite most of us feeling grossed out by them.
What do you think of warts? Warts? Well They don't look very attractive.
I think it's quite natural.
Like, fairy tales, there's a frog or a toad, you're going to get warts from them! Strange growth growing on your finger or nose? We might laugh about warts but around 12% of us have them at any given time.
The good news is that they are pretty harmless in most cases.
We can get them anywhere on our bodies but they are most common on our hands and on our feet.
Here they come in the form of a verruca, which is just another name for a wart.
So how do you get rid of them? Well, you might be surprised to hear that if you leave them alone, about three out of ten clear by themselves in ten weeks.
If they don't, though, you have a number of options.
Firstly, you could go to the doctor's or a wart clinic to get them frozen with liquid nitrogen.
Or at home you can try the less effective treatments like home freezing or salicylic acid, which takes about three months to eat away the wart.
But we've heard of an easier and potentially quicker remedy.
Duct tape -- the king of quick fixes.
It was one small study that showed that 85% of warts treated with duct tape disappeared compared to only 60% with freezing, and most warts disappeared within 28 days of using duct tape.
That's way faster than what's usually projected for both freezing and salicylic acid.
So if you fancy giving it a try, cut the duct tape close to the size of your wart, place it on top and keep it on for six days.
Then take it off, soak the wart in warm water and scrape off the dead skin.
The next day, put the tape back on and repeat until the wart falls off completely.
There's plenty of anecdotal evidence that it works, but to be absolutely sure, we want to create the biggest study yet.
This is where you come in.
We'd really like to record your experiences of this treatment, so if you fancy being part of our very own Trust Me experiment, go to our website 'Now, could your fry-up be more dangerous than you think?' When it comes to fats and oils, we are spoilt for choice.
You might already choose ones that you think are healthier, but what few of us realise is that when you heat fats, they can change radically and some of those changes can be very bad for you.
So which should we be cooking with? Some people swear by butter for frying or goose fat for roast potatoes.
You're probably thinking to yourself, "But surely the vegetable fats are much healthier.
" But are they? The problem is when some fats and oils are heated, they can break down and produce chemicals that have been linked with heart disease and cancer, so which do people think are healthier to cook with? I do like cooking with butter still, mainly because of the taste, not really for the health benefits.
Anything with grape seed oil, vegetable oil, anything like that would smack of healthiness to me.
I know olive oil is really good for health, but the rest of them are not that good for health.
Sunflower oil.
I don't know, man.
Sunflower oil.
It's got the word "sun" in.
And "flower".
That's good.
The health messages we've all heard about apply only to fats and oils at room temperature, but which become harmful when heated? To try and get to the truth, we're about to do our very own Trust Me experiment.
We want to test a whole range of oils and fats to see which produce harmful chemicals when used in cooking.
To help us, a team at De Montfort University in Leicester are getting ready to analyse them in their labs .
while a range of Leicester residents kindly agreed to do some cooking and give us samples of the oils and fats that they've used.
'First up, local firemen Sam and Raj.
' - Hello, Michael.
- Got some presents? We've got sunflower oil there for you and vegetable and rapeseed oil.
- Great.
- Hello, Michael.
There's corn oil and there's goose fat.
- Thank you.
- There you go.
- See you later.
- Bye-bye, now.
'Round the corner to James.
' Howdy, you have something for me? Yep.
Some lard, some butter and some cold pressed rapeseed oil.
- Fantastic.
I'll see you later, then.
- No problem.
- Thanks.
'Finally, Sandra.
' - Lovely.
- Groundnut oil and refined olive oil.
And the extra virgin.
Thank you.
- See you later.
- OK, bye.
These oils and fats fall into three different types -- there's lard, butter and goose fat, which are high in saturated fats, usually said to be unhealthy.
Then there's vegetable oils and sunflower oil, high in polyunsaturated fats, said to be good for us.
Lastly we have those high in monounsaturates -- olive oils, rapeseed oil and groundnut oil, also thought to be healthy.
But when used for cooking does the same apply? Which are healthy and which are harmful? All our samples were analysed in the lab where they also heated the same oils without food.
They were looking for chemicals such as aldehydes, formed when heat breaks fat down.
These aldehydes have been linked with cancer and heart disease.
'Professor Martin Grootveld is about to give me the results, 'starting with the oils rich in polyunsaturates.
' There's quite a few surprises there when you look at it.
The striking thing there is how high the peak is on sunflower oil, but also on vegetable oil, isn't it? The oils which were actually polyunsaturate-rich, for example corn oil and sunflower seed oil, generated very, very high levels of aldehydes.
So some of the oils we've been told are good for us actually turn out to be potentially dangerous when used for cooking.
I'm kind of really gobsmacked.
I'd assumed the sunflower oils were probably a good thing.
So Martin thinks that polyunsaturates, like sunflower oil, probably shouldn't be used for cooking.
The other oils we think of as healthy -- like olive oil, rich in monounsaturates -- fared better in our test.
I would recommend olive oil for a frying or a cooking process, largely because a lot lower levels of these toxic compounds are actually generated, and secondly the compounds which are generated, they are actually less threatening towards the human body.
As for the saturated fats like lard and butter, usually demonised, Martin's lab test showed them to be the least likely to produce nasties when heated.
Remarkably, though, in our Trust Me experiment, Martin discovered something he'd never seen before.
It seems that when hot fats come into contact with food, two new aldehydes are produced.
- We've done some new science here.
- It's a world first.
I'm very, very pleased about it.
Do we know if the new products you've found are dangerous? If they are aldehydes, they are toxic anyway.
Simple as that.
Martin plans to investigate this further.
So, in the meantime, what's his advice? If I had a choice between using lard and polyunsaturates for cooking, I would use lard every time.
I don't want to cook with something which I know possibly might give me cancer.
I found Martin's results very surprising.
'So I wondered what our volunteers in Leicester would make of them.
' Right, so now we actually have the results, the worst were sunflower oil and corn oil.
They are rich in polyunsaturated fats, and we've been told for a long time now that polyunsaturated fats are jolly good for you.
Turns out, when it comes to cooking, they are not.
Sunflower oil you generally think is healthier, because sunflower seeds are seen as very healthy.
Yeah, those results do surprise me.
Yeah, they surprised me.
Polyunsaturated fats are fine at room temperature, used perhaps in salad dressing.
But when heated, the most stable fats of all are actually the saturated ones, like butter, although you should still use them sparingly.
Does that surprise you? Yeah, very much so.
Like you say, I think the saturated fats there have been demonised for a long time now.
So, yeah, that does surprise me.
Now it is, I must admit, very confusing.
The message I take from this is that the best overall oils, and probably the ones that taste best as well, are the ones which are rich in monounsaturates.
These include rapeseed oils and olive oil amongst others, but if you're planning to cook with an oil, look on the back of the bottle to check there are more monounsaturates than polyunsaturates in it.
'Try to keep your oils in cupboards as sunlight can cause them 'to break down into the dangerous aldehydes as well.
' Try not to re-use oils, because constant heating makes the problem worse.
There's more information on our website.
I'm going to give lard a go.
I can't even believe I'm saying that! Still to come, could a new technique help us beat our bad habits? And how to spot a stroke before it happens.
But, first we have more questions from the residents of York.
Does manuka honey do any good? Answering the question this time, surgeon Gabriel Weston.
You can go into a shop and pick up honey for a couple of quid, but if you go into a health food shop and buy this manuka honey, it's bound to be much more expensive, up to £60 for a 500g jar.
Now it looks science-y and people buy it because they think it's going to do them some good.
But is it? I've been finding out.
Have you ever bought manuka honey? I have bought it, yes.
What did you buy it for? I bought it because I'd heard that it had good health components.
It's got healing qualities, apparently.
- But do you believe that it has healing qualities? - I do, yeah, I do.
Would you believe if a friend of yours said, "I tried manuka honey for my allergies", and so on and so forth Yes, because I know people who have.
I like to believe things if they sound like fun -- a bee eating special food on a special bush, producing a special honey, it's special.
So it's fun to believe that.
- You'll pay 60 quid for it.
- I don't do it a lot.
I'm not an addict, you know.
Manuka honey comes from New Zealand and is just honey from hives near bushes of the native wild manuka plant.
Honey tainted with manuka blossom used to be thrown away because of its medicinal taste.
But in the early 1990s a discovery was made that changed its fate.
The hype surrounding manuka honey in recent decades stems in part from research funded by New Zealand beekeepers who showed that it was particularly good at killing bacteria.
Now most honey contains a compound that produces hydrogen peroxide, which is a bleach that dyes hair and kills bugs, but manuka honey appeared also to have an ingredient that was an antibiotic.
The New Zealand scientists called it "unique manuka factor" and started labelling jars with a UMF number based on how many bacteria the honey killed over and above normal honey.
But this led to some manufacturers just labelling jars of honey with essentially random numbers with no justification at all, just implying they were better for you and so worth more money.
The active ingredient in manuka honey has now been identified.
It is an antibiotic called methylglyoxal, or MGO.
But although it is good at killing bacteria in a Petri dish, should we really be throwing large amounts of money at buying this expensive honey in the hope that it'll do us some good? There have been very few independently funded trials of manuka honey, or studies in people.
One study in children showed that any honey can soothe a cough but there's little evidence that manuka honey is any better, or that the antibiotic in it survives stomach acid and does anything for infections or gut problems.
A positive piece of research has come from Cardiff, showing the wound-healing properties of all honeys.
And because of manuka honey's antibacterial properties, it may be best for this.
But you shouldn't go slathering it on your wounds at home.
My overall advice is if you're feeling rotten and you like honey, have a spoonful of it or dissolve it in a hot drink.
But don't waste your money on manuka honey for its medicinal qualities.
There's no evidence that it's worth it.
There are plenty of things which we know we shouldn't consume in large amounts, like nicotine, alcohol, certain foods.
But just knowing they are bad for us doesn't mean we're going to be able to give them up.
So what can we do about it? Here in York, we've got 200 volunteers trying a DIY method to beat their food cravings.
Meanwhile, I want to investigate some brand-new experimental research being carried out at University College London.
The thing about addictions and cravings is they are strongly associated with positive memories -- the last time you did that thing and you got a buzz.
So one way to reduce your cravings might be to change your memories.
Changing memories sounds like science fiction.
But doctors Ravi Das and Sanjeev Kamboj are going to try to do it to me.
- OK, Michael, so how are you today? - I'm very well, thanks.
Slightly bemused.
I haven't really got a clue what is going on! 'Now, I enjoy the odd beer but the team here 'are going to see if they can change that 'by changing the memories I associate with drinking.
'What's crucial is I don't know exactly what their methods will be.
'Otherwise it might change my behaviour.
'So the scientists are telling me absolutely nothing.
' 'Before Ravi tries to alter my perception of alcohol, 'he first needs a baseline score 'that measures how much beer appeals to me before the experiment.
'He does this by showing me pictures of alcoholic drinks 'scattered amongst other images.
'A device will measure my subconscious eye movements, 'to see how much my eyes linger on the shots of booze.
'When that is done, it's on to part two.
' I wonder what he's up to! 'Here, they make me think of pleasant emotions 'I normally associate with beer.
' It does make me want to drink.
What we're doing at the moment is getting Michael to recall a positive experience with alcohol.
When that memory is recalled, under certain circumstances, it can become unstable, where you can modify the memory.
You can potentially even erase a memory.
'It's an unsettling thought, 'that our memories are not actually permanent.
'And to demonstrate, they are now going to try 'and change my own pleasant beery memories.
'I wonder how.
' Oh, God! 'The next thing we are doing 'is pairing the pictures of alcohol with disgusting images.
' We're trying to reverse the positive associations that Michael has with beer.
Oh, God! Oh, God, that's horrible! We've also paired alcohol pictures with a disgusting taste, getting him to drink, basically, the most bitter compound known to man.
"Drink now!" OK.
Oh That's horrible! Having that association is going to make beer less appetising.
Michael is going to want to drink it less than he did before.
HE GROANS Oh, God! HE RETCHES 'It's a particularly nasty end to an interesting day.
' God! Horrible! 'Two days later, I'm back at UCL 'to find out if the experiment has worked -- 'if my positive memories of alcohol have been changed.
'But I already have a clue that something might have happened.
' Well, after that experiment the other day, knocking back the nasty liquids, I went off to a party and I drank a few glasses of wine.
And I must admit, I felt really quite bad afterwards, unexpectedly bad.
And then that continued yesterday, so I decided not to have a drink last night.
In fact, I didn't miss it at all.
Whether it has anything to do with the experiment I do not know.
'But it's an intriguing possibility.
'To discover whether the experiment has worked, 'back to the eye-tracking device.
' OK, that's all the trials.
Thanks very much, Michael.
'The big question is 'have they succeeded in changing my positive memories 'and making alcohol less appealing than before?' I'm dying to know the results, I must admit.
I think I've worked out what was going on but I'm not entirely sure.
OK, so to start with, looking at beer pictures compared to neutral pictures.
These are my baseline scores.
They show that I had a pretty neutral response to alcohol.
My eyes were neither more nor less drawn to it than the other images on the screen.
But what about after the experiment? Ooh, blimey! The blue bars are your responses now.
So you've had a massive reduction in how much you are looking at the alcohol pictures of around 300% compared to your baseline.
Which is a huge effect considering - that they're only on screen for a couple of seconds.
- Yeah.
No, wow.
That is something.
In fact, that's a staggering result.
My eyes are clearly now much less drawn to the booze, suggesting it's not as tempting as it was before.
My pleasant memories of alcoholic drinks do appear to have been altered, which is a surprise to me.
I always kind of assumed that memories were fixed.
That's been the overriding kind of theme of a lot of psychology and neuroscience research.
But over the last ten years it's really kicked off -- this idea that memories become unstable once they're recalled under certain circumstances.
Right, so when I actually have a memory, which you activated by showing me the pictures, I'm thinking of the beer -- a long, hot summer, there's a moment of opportunity there where you can shake that memory up and remove some of the pleasant associations? - Is that the idea? - Exactly.
It is a really new area of research but all the evidence suggests that memory altering may in future help tackle the very root of drug or alcohol addiction, rather than just treating the symptoms.
And I for one can attest to its power.
Right, it's a hot day out there and this is a nice, cold beer but actually, frankly, at this moment in time, I can take it or leave it.
It would be quite nice but I feel no compulsion to do so.
Now, whether that is something to do with the therapy I've just been through or not, I couldn't tell you.
But it was certainly absolutely fascinating to do and you can see the potential for people who do have serious addictions to things.
In fact, just for somebody like me who sometimes finds it harder to resist alcohol than I would like, it could prove very helpful.
In this series, I want to investigate the products on our shelves that are sold on the promise of improving our health.
How do we know we are not just wasting our money? In the UK, we have some of the tightest regulation in the world about the health claims that products can make.
And that's a good thing, cos it stops us all wasting our money on useless or even harmful things.
But the marketeers are still trying to persuade us that all kinds of products are good for our health.
And it's not always easy to see through their smokescreen of confusion to the real truth.
Today, I am looking at an area where there's loads of confusion.
Organic food.
Is it better for us or is it just a waste of money? There are a lot of reasons why people choose to buy organic food.
For some people, it is an ethical and environmental choice.
Organic food uses fewer pesticides and less intensive farming methods.
But there's a whole other set of reasons for buying organic that we on Trust Me I'm A Doctor can actually test.
First, does the way organic food is produced actually make it more flavoursome? We're inviting the local shoppers of Chester market to do a blind tasting.
Right, taste test! We've selected organic and non-organic equivalents of carrots, apples and tomatoes from a single supplier and chosen them by how closely they match in terms of variety and appearance.
Ladies and gentlemen, free fruit and veg.
Roll up! One side of our table has organic produce, the other has non-organic.
But the shoppers don't know which is which.
Do you want to try a tomato from my left, your right? Put the whole thing in your mouth, I say! - Just pick a nice, large one.
- Yeah, yeah, exactly.
Have a big bite of that.
I feel like a rabbit.
So which tastes better to our people from Chester? Organic or non-organic? McKenzie, which apple do you prefer? Them carrots are lovely.
That one's slightly tastier.
I prefer this one, the first one.
- Cheers! - Thanks a lot.
So the results are in and more people preferred the organic tomatoes and apples, but interestingly, most people preferred the non-organic carrots.
So, it is not the most robust scientific test I have ever done but at least today, in Chester, with the people who took part, we can say that the non-organic food is not a million miles behind the organic food in terms of taste.
But how do organic and non-organic food compare in the levels of harmful chemicals they contain? We sent a sample of each away for pesticide analysis.
Professor Graham Bonwick from the University of Chester is here with the results.
Graham, we sent the food to you for testing.
Tell me about the levels of pesticides in the organic food.
OK, in the organic food there was none detectable.
- None detectable? - Yeah.
- OK.
- So that is obviously a good thing.
- It is.
It is perhaps no surprise that pesticides were not detected in the organic produce.
It is after all one of organic food's major selling points.
But what about the non-organic food? Graham found it did contain some -- around 50 parts per billion, usually described as trace amounts.
So "traces.
" I don't really know what that means, is that bad? - It doesn't sound like that much.
- No, these are considered to be levels that are safe for human consumption.
So really you shouldn't be worried at all.
If you wash your fruit and veg, presumably that is going to get rid of most of it anyway? No, most likely the pesticides, if there are any, will have been fairly uniformly incorporated into the fruit or vegetable material.
So actually washing will have very limited effect.
It may remove some soil from the outside and if that soil itself is contaminated, certainly that helps.
But to all intents and purposes, washing fruit and vegetables has no effect.
Of course, pesticides can harm the environment.
So that is one reason for buying organic.
But as far as your health is concerned, current scientific research suggests that no fruit or veg sold in the UK contains levels that could be harmful, whether organic or not.
Finally, Graham tested something I have always wondered about, is organic food more nutritious? We tested for vitamins C and also total polyphenols, and essentially we found no difference between conventional and organic produce.
Really, no difference in the potatoes, tomatoes, carrots, - the apples? - None at all.
- None at all.
- Statistically, no difference.
- Amazing.
OK, to all intents and purposes, these are equal.
- Correct.
So in terms of nutritional content, Graham's tests show no appreciable difference and this is backed up by published research done in other labs.
So when you're out buying fruit and veg, is it true that it doesn't matter what you buy in terms of your health? Well, Graham thinks there is something we should all know and I've come to find out.
'This looks a bit like my lab! 'Only with more carrots.
' OK, so first thing -- gloves on, please.
Obviously, I would never dream of cutting carrots - without wearing safety gloves.
- Absolutely.
Graham's got three different kinds of carrot and he's keen to show me how different they are in nutritional content.
OK, Chris, would you like to do the honours? We are looking at vitamin C levels and we are comparing fresh organic carrots, the same carrots kept in the cupboard for four days and frozen carrots.
First up, the fresh carrots, and a healthy vitamin C level just above 730 milligrams per kilo.
Then the four-day-old carrots.
A startling drop, down to 630 milligrams per kilo.
That seems quite a lot.
I mean, I wouldn't think anything about keeping a carrot for four days.
Well, vitamin C does degrade with storage time and in this case, we've got exactly that.
We have a drop in the vitamin C concentration and so we are seeing a decrease in the freshness of those carrots with time.
Finally, then, the frozen carrots.
A whopping 740 milligrams per kilo.
For me, this is a really surprisingly result.
The frozen carrots kept all their vitamin C.
See, this is remarkable, isn't it? Because when you say frozen, I basically think of the opposite of fresh.
I mean, food is either fresh or it's frozen.
Well, this is a common misconception.
Frozen food is usually as good as, maybe better than, fresh - in some cases.
- Really? Why? Well, frequently the frozen food is frozen - within literally an hour or so of being harvested.
- Really? And so it is locking those nutrients in right from the start.
And that loss of nutritional content because of storage affects organic food just as much as any other.
Personally, I think there are lots of good environmental reasons to eat organic food.
But there isn't much evidence of an increased benefit to your health.
And if it's maximum nutrition you're after, your best bet might be to reach into the freezer compartment.
As an Accident & Emergency medicine doctor, I see people coming in through the hospital doors with all sorts of medical conditions.
But the cases that really affect me are the ones where we lose someone whose deterioration could have been prevented had we been able to act sooner.
The key is recognising what we call red flags -- the small signs and symptoms that act as a warning of something more serious about to happen.
This time I'm going to tell you about two red flags that could save you from one of the largest killers in Britain.
Every three minutes and 27 seconds, someone in the UK has a stroke.
That's when blood supply to part of the brain is cut off, either by a burst blood vessel or a clot.
And, without blood, brain cells begin to die.
Although a stroke could affect anyone, our chances of having one double every decade after we turn 55.
That's why I've come to this acting workshop in Newcastle to talk to a group of retirees about the signs they should be looking out for to help prevent stroke.
First things first, roll up your sleeves.
First, get to know your pulse.
Find it with your fingers and count the beats over 30 seconds.
Then double that number to find how many beats there are per minute.
What we're checking for is atrial fibrillation.
It's something that up to a million people in the UK have and it increases your risk of a stroke by up to five times.
The warning signs are a pulse that is persistently lower than 60 or higher than 100 beats per minute, or that's irregular.
- OK, that's 30 seconds.
So what have you got? - 74.
- 90.
- 90.
And there are variations from sitting, standing.
Get to know your pulse.
Should you find that it's not what it normally is, come and see us.
And your pulse isn't your only red flag.
So has anyone ever heard of transient ischaemic attacks? Transient what? - What about funny turns? - Loads of.
- Yes.
A transient ischaemic attack, or a TIA, is also known as a mini stroke.
And that's where you've got a temporary obstruction to the blood supply to part of the brain.
They last no more than 24 hours but they can be over within minutes.
Each year in the UK, 46,000 people have their first TIA.
Over these, it's thought almost half dismiss the fleeting symptoms as just a funny turn, yet one in 12 will suffer a major stroke within a week.
The symptoms of a TIA are the same as those that signal a major stroke, and can be remembered with the word FAST.
So F is for your face.
Is there a droop? Is the eye drooping, is the mouth drooping? The A is for the arms.
Is there weakness? Are they having problems lifting up a cup? Speech.
Is it slurred? Are you having difficulty in getting your words out? If any of those symptoms are there then it's time.
The T is for time -- to call 999.
It's estimated that if all mini strokes were recognised and treated urgently we could prevent a whopping 10,000 major strokes a year.
So, whatever you do, don't ignore red flags.
Get to know your pulse.
It should be somewhere between 60 to 100 beats per minute.
And be wary of funny turns.
Don't write off numbness, weakness or slurred speech.
Think about FAST -- F.
When it comes to stroke, a little bit of knowledge can make a huge difference.
Coming up, is paracetamol bad for you? And the results of our big craving-beating experiment.
But first On Trust Me I'm A Doctor we try to tackle issues that most matter to you.
We wanted to find out which questions you particularly wanted answers to, so we commissioned a poll of 2,000 people.
When the results came in, 40% of you wanted to know, "How can I avoid cancer?" Now, if you take all the different types of cancer and put them together then cancer is the leading cause of death in the UK.
Around a half of us will be diagnosed with it and more than one in four will die from it.
So what can you do to reduce your risk? I've got a list of things that have, over the years, been claimed to be risks or benefits for cancer.
So, which do people think are important? Oh, artificial sweeteners are supposed to be benefit, aren't they? - I think caffeine's going to be a risk.
- Oh, it's hard, isn't it? - I mean, that's obviously got to be a very good one.
- Yeah.
Yeah, cos I do lots of that myself.
I've no idea what radon gas is but it sounds dreadful.
I'd put that there, actually.
- OK, so you put it there and you took it away again? - Can I put it back?! Well, they say that wine's good for you.
It's obviously all very confusing.
So I've come to see one of the leading experts on the causes and prevention of cancer, Professor Tim Key of Cancer Research UK.
Now, people tend to think of cancer as kind of A disease but it's actually many different diseases, isn't it? That's right, it's very complicated.
There are up to 200 different types of cancers.
But some of them are much more common than others.
So for example, in this country, in men the commonest cancer is cancer of the prostate, followed by lung cancer and bowel cancer.
In women the commonest is breast cancer, followed again by bowel cancer and lung cancer at about the same level.
If you were to look at the things you can change about your lifestyle that might make a difference, might reduce overall cancer risk in the UK, what would it be? Well, the number one is smoking, without a doubt, that's far more important than other aspects of lifestyle.
So how big an effect is smoking on lung cancer? People who do smoke a lot for many years will be about 50 times at higher risk of developing lung cancer than people who've never smoked.
- Wow.
- Mm.
So, if I'm a smoker and I stop, is that going to make a difference? Yes, it makes really quite a large, important difference.
People who smoke and stop in their 30s eliminate most of that increased risk, but even people in their 50s and 60s, there is real benefit that occurs quite quickly.
It's never too late for people to stop smoking, there'd be a really substantial benefit.
You've been doing a big study here in Oxford, comparing vegetarians with red-meat eaters, and what are you finding? For colorectal cancer, we don't find any clear difference at the moment, so the vegetarians certainly are not immune to colorectal cancer, but the advice that's been put forward by expert bodies is, you know, in the in terms of not eating excessive amounts of meat.
What about alcohol consumption and cancer? Alcohol, the current estimate's around 4% of cancers in this country are caused by alcohol.
Which ones? Which cancers? Well, the main ones caused by alcohol are the cancers of the mouth, the throat and the oesophagus, going down to the stomach.
Alcohol also, importantly, can affect liver cancer, mainly through high intakes causing cirrhosis.
The other cancer that it's important for is breast cancer in women.
Estimates suggest that, you know, maybe up to 10% of breast cancers in this country, alcohol is a contributing factor.
The size of the effect is around a increased risk of about 10%, so, you know, going up by a tenth for women who drink one largish glass of wine a day Will it increase your risk by 10%? By about 10%, so if it was two or three every day it would go up from 10% to 20%, maybe 30%.
So there is a real effect of alcohol.
How much difference, if you change your lifestyle in other ways, is it likely to make to your cancer risk? If you do everything that affects risk about your lifestyle, which includes, erm, obesity, alcohol, some dietary changes, some other factors like not getting sunburnt, possibly up to 40% of cancers might be avoided.
So it turns out there are some clear ways we can all reduce our risk of getting cancer.
And of course, even if you get cancer, there are now effective treatments.
In fact we have many weapons in our arsenal against this set of diseases, and it's an area of medicine that's innovating all the time.
In the war against cancer there have been a number of significant advances.
There was radiotherapy, chemotherapy, and, as surgeon Gabriel Weston has been finding out, there is now a new and very promising approach.
What we're talking about here is a potential cure for skin and other forms of cancer that could give hope to thousands of people a year.
It's an approach called virotherapy and basically involves taking a virus and using it to attack the disease.
One of the main reasons why cancers are so difficult to treat is that they are malfunctions of the body's own cells, so there's nothing foreign present like a virus or bacterium that our immune system would recognise and attack.
This allows the cancer to grow unchecked.
One patient who faced this devastating situation is Sir Michael Lockett.
It must have been 2007.
I was just having lunch and it was just one of those occasions I put my hand up to my neck and I thought, "What's that?" I went to see my doctor, who referred me.
It was a, sort of, almost an instant diagnosis, which was pretty terrifying at the time.
He had said immediately that that was cancer.
And it was like a complete bolt out of the blue.
Michael had cancer of the head and neck, which was already well advanced.
Conventional treatments, like chemotherapy and radiotherapy, would only have offered him around a 30-40% chance of survival, so he joined an early-stage virotherapy trial being run by Professor Kevin Harrington at the Institute for Cancer Research in London.
The technique takes the common herpes virus, which usually causes cold sores, and turns it into an anti-cancer treatment.
The virus has been genetically modified in the laboratory and two specific genes have been removed from the virus.
The first gene is necessary for the virus to cause disease in normal cells.
By taking it out, the virus is able to grow in cancer cells, but not in normal cells.
The second gene that has been removed is a gene that the virus normally uses to cloak it from the immune system.
By taking that away, we make the virus visible to the immune system.
So, it is not just doing damage to the cancer cells? It is actually triggering an immune response? So long as you kill some of the cancer cells in a way that makes those cells visible to the immune system, the immune system is powerful enough to hunt down the cancer cells throughout the rest of the patient's body.
The modified virus is injected directly into the cancer cells, which makes it suitable for cancers like Michael's head and neck tumour.
Patients on the trial received four of these injections over nine weeks, alongside courses of chemotherapy and radiotherapy.
And just open wide for me.
- Good.
Just put your chin up.
- When he started his treatment, Michael's tumour very quickly started to change.
'The third injection, 'Kevin's words were that the tumour was melting away 'and had done so to such an extent 'that, actually, he had a little bit of trouble 'finding where the tumour was.
' In fact, Michael never received his planned fourth injection.
After five years without any recurrence, he was declared officially cured of cancer.
I think it sort of sharpens your enthusiasm for life and, for me, made my appetite for life even greater.
And Michael is not alone.
Five years after receiving the therapy, an astonishing 70% of the patients in the head and neck cancer trial were still cancer free and could be classed as cured.
So, Professor Harrington decided to turn his attention to melanoma -- skin cancer.
And the early results from this phase of the trial are equally exciting.
In melanoma, in fact, this treatment has had its greatest effects, both in terms of the response of the tumour, the duration of response, and in some subgroups, a really very impressive improvement in their ability to survive the disease.
Kevin, if you were looking 10-20 years into the future, what would you fantasise for this therapy? Well, my real dream for virotherapy is that we see a day where we use viruses right up front at the time patients are first diagnosed and we use them as part of a combination strategy with other treatments -- including, perhaps, radiation therapy, chemotherapy, surgery -- to cure more patients the very first time - they are diagnosed with cancer.
- So, it could change the face of cancer therapy? Certainly, that is the plan and that is the desire.
It is too early to say whether the melanoma patients who have gone into remission using this treatment will be completely cured, but I can't wait to find out.
The team here are eager to launch the drug within a year and, in the meantime, they will be continuing their research and launching new trials, to refine and improve the treatment.
Go to .
for more details.
SWING MUSIC Despite 30 years as a medical journalist, I'm still occasionally bemused and surprised by the things I read in newspapers.
So, Dr Saleyha Ahsan has been looking at the truth behind some of the more recent headlines.
Paracetamol is the world's most popular painkiller and it is used in a huge range of over-the-counter products.
And you can get it in stronger forms as a prescription.
So, the report that it might have negative side effects was big news.
The press reported figures of dramatically increased risks of sudden death and heart attacks and strokes.
But should we all be worrying? Paracetamol has long been thought of as a relatively safe painkiller because it does not carry the same risk of stomach bleeding that you get with aspirin and ibuprofen.
But this study seemed to show that long-term, frequent use might cause health risks.
The study that caught the headlines brought together data collected by many different researchers in the US, the UK, Sweden and Denmark.
But although the study looked at data for a lot of people, they were all taking paracetamol for different reasons.
Some were patients with kidney problems, while others were prescribed paracetamol with ibuprofen.
So, it is not clear whether the effects seen in this study were caused more specifically by paracetamol or applied more generally.
The study did suggest, though, that higher doses of paracetamol over many years might have side effects.
This is an important finding, which will need to be studied further, but the headlines were way too scary.
There is no need to worry if you are just an occasional user of painkillers.
As long as you stick to the daily limits, paracetamol is still thought to be the safest way to bring down fevers and manage occasional aches and pains.
But if you are taking it regularly for long-term pain relief, I would recommend that you go and speak to your doctor, to find an alternative.
SWING MUSIC Here in York, our lucky volunteers are about to get the results of our chocolate-craving experiment.
And I am assured there is going to be lots of chocolate on hand.
It is over two weeks since our experiment started, in which our chocolate-loving volunteers had to do some very strange things, imagining they were eating chocolate before they were allowed to do so.
Our volunteers thought they were coming here to taste chocolate, but what they didn't know is that we wanted to find out if, by imagining eating chocolate, they could reduce their cravings.
We divided them into two groups.
One group had to imagine eating 30 chocolate sweets.
The other had to imagine eating just three.
We then secretly measured how much chocolate they ate afterwards.
And then, we asked them to try the same technique at home for two weeks, to see whether either of these techniques could reduce their cravings longer-term.
So, how have they been getting on? And was there a difference between the two groups? So, thanks very much for coming back, everyone.
We have the results.
And we found that those of you that had imagined eating 30 chocolates ate almost 40% less than the group who'd imagined eating three.
So, that is a huge amount less chocolate.
So, it seems as if imagining eating something many times before you actually allow yourself to eat it could reduce the amount of it that you actually eat.
How does this work? Over to psychologist Professor Carey Morewedge.
This is very counterintuitive, that people who thought more about the chocolate then ate less of it.
How is this working? So, basically, we have people imagining eating three chocolates or we have people imagining eating 30 chocolates.
So, when people are imagining eating three chocolates, it's increasing how much they want the food.
With people imagining eating 30, though, it's enacting what we call habituation.
We want to eat less of the food or no longer want another thing.
OK, so let's say I've just imagined the 30 chocolates.
Will it then help me resist a plate of chips, of French fries, that is put in front of me? No, the key thing is that it is really only working for the food that you imagined or the foods that are very similar to it.
So, Carey's theory is an interesting one and it certainly seems to work in the short term, like on our testing day with the volunteers.
But can it really be used by all of us as a craving-beating technique long-term? That has never been tested before, so we sent you all home with that deliberately crave-inducing big bag of chocolate and we were interested in how much of the chocolate you ate, but the main thing we were recording was how much your craving went down, and those of you that had imagined every day, several times a day, eating 30 chocolates, you had twice the reduction in craving of the other group -- the three-chocolates group.
So, that is extremely significant, over a long period of time.
Many of the 30 group found the technique interesting.
Once you sit there and you try and imagine, you can taste it, and about halfway through, I thought, "I need a drink.
" LAUGHTER "I need a drink.
" Water, I hasten to add! LAUGHTER So, we have replaced one addiction with another, by the sounds of things! I can't leave an unfinished bag of chocolate, but I can after this.
Michael, what do you think? Michael is well known on the Trust Me team for having a serious chocolate problem.
So, I know that, behind that curtain over there, is a massive collection of chocolate and I obviously haven't been listening to a word Chris has been saying, because I've been thinking about that.
So, I now ought to think about it 30 times.
I am going to seriously try this, because if it is there, I eat it.
So, it seems as if we may have discovered a new technique that anyone can try.
And it may work for other cravings, as well, such as smoking, so the next time you want something you don't think you should have, try just imagining having it instead, 30 times, and see if that helps.
That is it from York and our happy chocoholics.
It is also the end of this series, although we will be back soon.
Meanwhile, do go and visit our website.
You can find more information on all the subjects we have covered in this series and take part in our experiments.
You can let us know about the health questions you'd like to have answered in the next series, when we will be witnessing pioneering bionic eye surgery and discovering the secret to a good night's sleep.
Good night! I just made an appointment For a special rendezvous To see a man of miracles And all that he can do Doctor, I want you Mmm, my Doctor Wanna Do I can't get over you Doctor, do anything that you wanna do.