Trust Me I'm A Doctor (2013) s07e06 Episode Script
Series 7, Episode 6
1 When it comes to our health, it seems everyone has an opinion.
But what's the health advice you can really trust? We're here to weigh up the evidence and use our expertise to guide you .
.
through the contradictions and the confusions.
We do research no-one else has done, and put your health at the heart of what we do.
We listen to the questions you want answered.
And ensure you get the information you need.
We're here when you want to know the latest findings and not the latest fads.
I'm Michael Mosley and, 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.
Hello, and welcome to Trust Me.
Today, we're in Leeds where we're carrying out an Olympic-grade test to see which forms of exercise are best for bones.
Also in the programme, could a germ-free home make you ill? Is it healthier to be a night owl or a morning lark? I was up early, I've had my coffee.
What have you been doing? Nothing! And health advice on the internet, can you trust any of it? But first .
.
we all know that exercise is good for your heart, your lungs and your brain.
But there is one system that's often overlooked - your bones.
As we get older, our bones become less dense which can, ultimately, lead to them becoming weak and porous.
And much more prone to fractures.
Studies have shown that exercise can slow, even reverse, this decline, but what is the best type of exercise you can do in order to get maximum bone strength? We've all heard that calcium and vitamin D are essential for healthy bones.
But exercise also keeps our bones strong by putting them under stress, subjecting them to jolts and shocks.
Surprisingly enough, this is essential for bone health because each jolt sends signals to bone cells, telling them to grow back stronger.
To find out which kind of exercise does this best, we've teamed up with Leeds Beckett University.
Dr Karen Hind, an expert in bone health, is helping us carry out the unique study.
So, from the age of 35, we lose approximately 0.
5% of bone mass per year.
That's very depressing! That is actually accelerated once ladies hit the menopause and once men hit around the age of 50.
Exercise will make a massive difference to your ability to maintain your bone density.
We and the Leeds team have recruited elite male and female athletes, including Olympic medallists from three very different sports.
We want to see exactly how each sport has affected their bones, so we can learn what type of exercise might be of benefit to all of us.
We've recruited cyclists from two different racing teams .
.
cricketers .
.
and gymnasts.
Each of the sports have different movement and physiological demands.
And by looking at those different movements and then looking at bone density, we can actually get an idea of what specific exercises might be beneficial.
Each of our athletes get a type of X-ray called a DEXA scan to measure the bone density in their hips and spine, two common areas for fractures, as we age.
We'll compare their results to the average bone density for people of their age and gender.
Studying elite athletes will allow us to identify any changes in bone density that may be caused by the particular movements involved in these different types of exercise.
So, we've got tumbling and somersaults, so that's, like, quite a lot of impact on our landings.
We talk about muscle content, fat content but we've never, ever looked at bone density.
I wouldn't be able to say what the results are going to end up like.
We shall see! We shall see, indeed.
Karen has now scanned all our elite athletes and the results are in.
Time to find out which exercise best bolsters bones and what you can do to minimise your risk of developing fractures later in life.
We've brought back one male and one female representative from each of our sports.
OK, so, results time.
First, the gymnasts.
We're pleased to say that your bone density did come out at 17% higher than the reference range for your age.
- Fantastic.
- Whoo! That's for the women.
And the same story with men.
So, 14% above average at the spine.
Really, really very good, actually.
For our gymnasts, the results for both the spine and the hips were significantly better than average.
Next, what about our cyclists? We expect the cyclists to be very fit but are they bone fit? With the ladies, we did find a 6% lower bone density overall than average, in terms of bone strength at the spine.
And, for the men, 9% lower than average.
So, lower than average, which is kind of surprising.
Strangely enough, spending a lot of time cycling can actually lead to weaker bones than average in the spine for both men and women, and weaker hips for men, too.
And the reason is to do with the type of activity.
Cyclists are very much weight-assisted, particularly this region here, so, the lumbar spine.
And this is where we saw the more prominent differences between the athlete groups.
Because a cyclist's weight is supported by their bike, they're not putting the kind of pressure on their bones that would strengthen them.
So, while cycling is a great way to improve your fitness and your cardiovascular health, it's not so good for your bones.
Finally, what about our cricketers? - I have low expectations for the cricketers.
- Oh, OK! So, cricketers are the surprising group here.
Cricketers, at the spine, even better.
So, for the women, 22% above average for your age, and, for the men, 18% above average for your age.
That's surprising because you think of cricketers as standing around an awful lot.
You do, and you see cricketers on the field for a long time, but, actually, the movements employed in that sport, even though they're not constant and continuous all the way through the game, those explosive sessions might actually be having quite a beneficial effect for your bone density.
So, cricket was the most favourable of the three sports for bone density, both in the spine and hips.
It seems the combination of running, jumping and twisting has a particularly beneficial effect.
And this indicates the kind of exercise we could all do to improve our bone health.
Taking what we've found from this study, a bit from the gymnastics, from the cricketers, there was exercises that involve a bit of jumping, a bit of twisting.
Dancing would be perfect.
OK, so a bit of squat, ideally a bit of star jumping.
Anything that involves a bit of leaping.
That's even better because you're working that muscle but you're also, through the jumping, you're also getting that gravitational loading.
That wasn't quite what I was expecting.
I already do quite a lot of cycling but it seems that isn't enough for maximum bone strength so I'm going to have to throw in some star jumps, perhaps a bit of weight training.
Maybe even a little bit of Zumba dancing.
When it comes to sleep, some of us are larks, we enjoy an early morning.
Others are owls.
They prefer a late night.
But what happens when your biological clock is out of sync with your alarm clock? Dr Giles Yeo investigates.
For many of us, the time of day we're expected to be at work doesn't fit in with our body's natural rhythm of sleeping and waking.
This can result in us getting fewer hours' sleep than we really need.
And scientific evidence suggests that's not good for our health.
Long-term sleep deprivation is linked to a whole host of different health problems, including increased risk of cancer and heart disease.
For every hour's difference between your body's natural rhythm and your actual daily routine, you increase your risk of obesity by up to 30%.
So, why do these differences occur, and what can we do about it? Well, research suggests some of it is down to your age and could explain the biggest mystery for any parent of a teenager.
Why can't teenagers get up in the morning? Are they just being lazy? My teenage son Harry and I are going to do an experiment to compare which time of day our brains are most alert - morning or evening.
7am, and it's time for the morning test.
Threetwo .
.
one, go! Under time pressure, we have to respond to the direction of arrows on the screen.
- Are you feeling bright eyed and bushy tailed, Harry? - No, not really.
The test is designed to reveal our levels of attention.
See, I was up early, I've had my coffee.
What have you been doing? Nothing! 8:30 PM, and time for the evening rematch.
- Are you ready? - Yeah! - OK.
You may be good at stuff like being famous but, yeah, I'm good at Arrow Beam and stuff like that.
Oh! Got that wrong.
I'm amazing at this.
I might as well be a pro gamer.
So, how did Harry and I compare? For reaction time, both of us were faster in the evening.
And for our ability to ignore distractions, both of us were better in the morning.
But, for one important measure - our ability to shift focus quickly in response to the arrow, we're complete opposites.
I did much better in the morning while Harry did better in the evening.
So, his brain really does seem to work on a different daily rhythm from mine.
In fact, everybody has what is known as a "chronotype" which determines what time of day you're at your best.
It's set by a part of our brain that acts as our master body clock and sets our daily rhythm.
Recent research suggests that as timing is shifted by age-related hormones, such as testosterone, which rises sharply in teenage boys and falls off as they grow older.
Now, if hormones radically alter our body clock, then our chronotype is going to change as we age.
There's nothing we can do about it.
And, for most of us, the timing of our working day stays roughly the same throughout our entire lives.
If you could change it, though, how much difference would that really make? One school in London is finding out.
It's 1.
00 PM and these students are just arriving at school, but they're not late.
Their lessons start now.
At Hampton Court House Sixth Form, classes run from 1.
30 PM to 7.
00 PM to fit around a teenager's naturally late chronotype.
This new school day is the brainchild of headmaster, Guy Holloway.
You clearly have buy-in with the staff.
What do they think about this? In-house, we talk about the "golden period".
That period between five o'clock and seven o'clock where the quality of work far outperforms what might happen first thing in the morning.
Really? 5-7? We have teachers who specifically want to teach at that time because they can get the most out of their students and their students work happiest and most productively at that time.
It's a radical approach for a school to take, one that's being watched with interest by schools in other countries and it's certainly popular with the pupils.
We're still putting in the same amount of work, the only difference is we're doing it a bit later and, as a direct result of that, we're more productive and we get more out of it.
How has this new schedule made you feel? I don't have to fall asleep when I get home any more.
Just more energy and things like that.
So, for the students here, fitting the school day around their body clock seems to be working.
Now, for most of us shifting our work day like that is just simply not possible.
But there's plenty that we can do in order to bring our body clocks in line with our daily routine and avoid tiredness and sleep problems.
One of the most useful things to reset your body clock is light.
Get some natural daylight as soon as you can in the morning.
Keep getting up at the same time every day, even on the weekends.
And in the hour before bed, avoid screens, like phones, laptops and tablets.
But my advice is, depending on what your work routine will allow, try not to fight your body clock.
And maybe cut your teenage son some slack when it's midday and he still hasn't got up.
Coming up - is wiping out germs in your home bad for your health? And when health headlines contradict each other, how do you know what to believe? But, first .
.
when we're not feeling well, a surprising number of us, these days, over 50%, would rather turn to the internet for a diagnosis than visit their GP.
But is that wise? Dr Zoe Williams investigates.
Let's say you've gorged yourself on a huge meal and an hour later you're having some weird cramping pains in your chest.
Type in the symptom "chest pains" into a search engine and the first result that usually pops up is a heart attack.
But, of course, it's most likely not a heart attack at all, probably just a nasty bout of indigestion and you're simply causing yourself unnecessary worry.
So, can we ever trust the internet to give reliable medical information? If you're one of the two thirds of the British population that asks "Dr Google" that type of thing often, you may be experiencing cybercondria.
That's medical anxiety caused by researching your own symptoms online.
For me, as a GP, the internet is a fantastic tool, but most of the sites I use are designed for doctors.
The online equivalent to medical textbooks.
And if you're just using a regular browser to find information, the internet tends to offer the very worst-case scenario.
So, why is that? One of the main reasons for this is the way that search engines hunt.
So, if I was to put in "chest pain causes", the first thing that comes up is heart disease.
So, we might think that they would list them with the most likely first but they don't.
In fact, they use algorithms that rank pages according to how many times a key word is mentioned or how many clicks a page gets.
We tend to focus on the first couple of results, rather than looking through the list.
These are the ones that get clicked on again, and again, and that means they remain at the top, even if the diseases they're looking at are rare.
Another common way to search for information is to use an online symptom checker.
But, according to a recent study, they only make the correct diagnosis 34% of the time.
To get the best out of these sites, be as specific as you can about your symptoms.
For example, talk about the intensity of your pain or the duration of your vomiting.
This can help to narrow down the results.
But these sites still seem to struggle with differentiating between life-threatening illness and a simple tummy ache.
Most of us probably know we shouldn't fully trust the medical content of something we've looked up online.
And, yet, the temptation seems irresistible.
So, why do we do it? Well, for a start, it's easy.
For some people difficulty in getting a GP appointment or getting the time off work.
But, I think there's also another reason, something that I call FOFO.
And that's the Fear Of Finding Out.
For me, the danger in using the internet to self-diagnose is that it can delay a visit to the doctor that could give you a correct diagnosis and treatment.
But if you do want to use the internet, then my best advice is to stick with the NHS websites.
The information there has been rigorously checked by clinicians, and there are also sections to help guide you through popular myths and misconceptions.
You can find good information on the internet, and it's especially useful if you share it with your doctor, but in most cases, it's not a substitute for a visit to your GP.
When it comes to health, the media often seem to perform spectacular U-turns.
One day, coffee's good for you, the next, it's bad.
Eating cheese makes you fat.
No, here's a study which says it makes you thin.
So what is going on? Are scientists changing their mind all the time? Are journalists getting it wrong? And how do you know what to trust? I've lined up two experts to help me get to the bottom of it.
First, I'm meeting Sir David Spiegelhalter from the University of Cambridge.
He's a professor of statistics, and regularly criticises the press for the way health news is reported.
So, I think most people believe that the reason we get these confusing headlines is because the journalists are making stuff up.
- Is that true? - There's a whole pipeline, from an original scientific study, that then goes through, it's published in a journal, the press officers then summarise the story and often tend to add in exaggerations.
They want to get it covered.
And so then it goes to the journalist, and my feeling is that the journalists often do quite a good job, but then, the sub-editor sticks a headline on it in order to get the clicks or to get attention, and that's again when serious distortions can occur.
Right.
I've got here some headlines.
So the first one here is, "why Marmite could prevent miscarriages and birth defects.
" - What's wrong with that? - This does annoy me, because it makes it sound like this is a proven benefit on human beings, whereas in fact, the experiments were just done on mice.
It's not proven to have any benefit to humans at all yet.
But the press release never used the word "mice".
So ideally, this headline should "Why Marmite in mice could prevent miscarriages" Yes, but not many people might click on that one! OK.
Moving on, we have, "Why going to university increases risk of getting a brain tumour.
" Ah, this is a wonderful one.
This was again a rather dull Swedish study that showed that richer men tended to have slightly more diagnoses of brain tumours.
By the time it got to the newspaper, it was, "Why going to university increases the risk of a brain tumour.
" But this is implying a causation? A causation, that going to university increases the risk of a brain tumour, which I hope it doesn't! How would you go about getting more responsible headlines? More people just hammering on the doors of the newspaper through social media.
I think this is one of the power of social media.
The journalists see this, and they don't like it, actually, when their articles are being criticised.
Thank you.
Next up is Chris Smyth, Health Editor for The Times newspaper.
He specialises in covering medical news.
David Spiegelhalter would say that his biggest beef is frankly with the headline writers.
Well, headline writing is incredibly difficult.
You've got five usually pretty short words to summarise something which is, you know, particularly when we're talking about complex medical statistics, going to be very complicated, so there's just no practical way that it is going to tell you everything you need to know about the story while also making sense to that person flicking through their paper on the train.
So the role of the headline is basically to advertise, "The story's about this topic," and you can't really judge a headline unless you read the story.
Do you see it as part of your job, holding science to account? Scientists get an enormous amount of public money, and they do wonderful things with it.
But as with everything else, you don't want people to be marking their own homework and saying, "This is what we think.
" You want to have people scrutinising what they're doing, what they're finding.
We all do.
I mean, you're doing it to me now.
You're scrutinising my journalism.
Scrutiny is always helpful.
One thing that sometimes comes up is, is this a drug company funding a trial to show that their drug is amazing? And this is quite a difficult issue, because you could not really test drugs if drug companies were not paying for trials, and some fantastic medicines have been discovered in that way.
How you account for that is a difficult judgment, and I don't think it's one that's so much a journalistic problem.
I think doctors also struggle with this.
Thank you.
As we've just seen, the medical stories you read in the newspapers are the product of a long chain of events which begin with the scientists and end with the headline writers, and at any point, someone can put their spin on it.
Not just journalists, but medical companies, and their press officers too.
It's rare that someone gets it wrong, or worse, deliberately sets out to mislead.
But the same evidence can be slanted in different ways.
So, when you do read a story, ask yourself, "Does this sound plausible?" Because extraordinary claims require extraordinary amounts of evidence.
Over the last century, there has been a dramatic rise in asthma and other allergic diseases.
Now, this is often blamed on excessive cleanliness.
But is that true? Are there some bugs you should have in your life? Surgeon Gabriel Weston has been investigating.
Last year, we spent a staggering £74 million on antibacterial surface wipes, and there's no doubt that some germs are harmful.
You do need to be scrupulously clean, for instance, after handling raw meat or using the toilet, to avoid bugs that can make you ill.
But all around us are countless other microbes - bacteria, moulds and yeasts that do us no harm and give our immune system a workout.
And there are worries that wiping them out with antibacterial products is actually harming our health.
The theory goes, we spray and wipe away so many natural microbes in our homes these days that our immune system, without the usual things to fight, turns instead against our own bodies, causing asthma, eczema and hay fever.
But can using antibacterial products in our homes really be the problem? To help us find out, we've recruited three families and given each a removable kitchen worktop.
To begin the experiment, they'll clean this board using antibacterial wipes.
This will get rid of all bugs, good and bad.
Over the next 36 hours, they'll use their kitchen as normal, and take regular samples from the board, so that we can measure how long the service remained germ free.
And how quickly any microbes return.
Analysing the data is microbial physiologist Dr Lynn Dover at Northumbria University in Newcastle, and it's time for the results.
The first sample we took was after one hour, and in all cases, there was bacterial and fungal growth after one hour.
So pretty much immediately after someone has disinfected their surface, these things are now beginning to regrow again.
Yeah, and that progressed over the next 36 hours.
So, as you can see, after six hours, eight hours and 12 hours, there's progressively more.
This 12-hour sample is quite dramatic.
As you can see, there were lots of different types of fungi.
They have totally covered the plate.
I imagine if I did it after two minutes, we'd probably find something.
Where do all these bacteria and fungi that end up on these plates come from? The whole environment is absolutely teeming with microorganisms and life.
They're from our bodies, they're from the air around us, little bits of skin that come off that form household dust, just land on the surface and they carry bacteria and fungus with them.
So, no matter how well an antibacterial product has cleaned a surface, the bacteria, yeasts and moulds that are everywhere in the environment begin to reappear almost immediately.
It means that using antibacterial products is not affecting our exposure to microbes as much as we thought.
They're all around us all the time, so it's just not realistic to blame the rise of allergies on these products alone.
But if our cleaning habits aren't to blame, what is? To find out, I'm having a picnic with Dr Claire Lanyon, a microbiologist from Northumbria University.
She believes the problem is that we're not exposing ourselves to enough of the bugs found in nature, and one way to do that is to spend more time in places like this.
Exposure to microorganisms is actually what reduces the incident of you developing allergies in certain situations.
I think the key point is diversity.
We should be exposing ourselves to lots of different varieties of them.
Bacteria don't live as single entities, they live as a community, and the community is constantly responding with each other and with us.
As the microbes interact with our bodies and with each other, they make by-products that can help strengthen our immune system.
And they produce something called secondary metabolites.
Now, some of these are antibiotics, such as what we've utilised and used to fight infections.
So these little defence mechanisms that the bacteria have are constantly shaping our immune response.
In an average ten square metres of parkland, there are hundreds of varieties of generally harmless microbes.
And encountering some of them could be a key way to help your immune system.
So your advice, then, would be to increase our exposure to lots of different kinds of organism? Absolutely.
Being exposed to microorganisms is a good thing.
- I will say cheers to that.
- Cheers! So, it seems that for a healthy immune system, you need more germs in your life, not fewer, and the wider the variety you encounter, the better.
So my advice is, vary your diet, get out in the outdoors, keep a pet, if you like, get your hands dirty, and whatever you do, don't waste another minute of your life trying to keep your house spotless.
That's it for this series.
Visit our website to find out more about the stories in this and all the other series of Trust Me, I'm A Doctor.
# 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 onto my lap # And when he walked in dressed in white # I had a heart attack # Doctor, I want you # Ooh, my Doctor Wanna Do I can't get over you
But what's the health advice you can really trust? We're here to weigh up the evidence and use our expertise to guide you .
.
through the contradictions and the confusions.
We do research no-one else has done, and put your health at the heart of what we do.
We listen to the questions you want answered.
And ensure you get the information you need.
We're here when you want to know the latest findings and not the latest fads.
I'm Michael Mosley and, 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.
Hello, and welcome to Trust Me.
Today, we're in Leeds where we're carrying out an Olympic-grade test to see which forms of exercise are best for bones.
Also in the programme, could a germ-free home make you ill? Is it healthier to be a night owl or a morning lark? I was up early, I've had my coffee.
What have you been doing? Nothing! And health advice on the internet, can you trust any of it? But first .
.
we all know that exercise is good for your heart, your lungs and your brain.
But there is one system that's often overlooked - your bones.
As we get older, our bones become less dense which can, ultimately, lead to them becoming weak and porous.
And much more prone to fractures.
Studies have shown that exercise can slow, even reverse, this decline, but what is the best type of exercise you can do in order to get maximum bone strength? We've all heard that calcium and vitamin D are essential for healthy bones.
But exercise also keeps our bones strong by putting them under stress, subjecting them to jolts and shocks.
Surprisingly enough, this is essential for bone health because each jolt sends signals to bone cells, telling them to grow back stronger.
To find out which kind of exercise does this best, we've teamed up with Leeds Beckett University.
Dr Karen Hind, an expert in bone health, is helping us carry out the unique study.
So, from the age of 35, we lose approximately 0.
5% of bone mass per year.
That's very depressing! That is actually accelerated once ladies hit the menopause and once men hit around the age of 50.
Exercise will make a massive difference to your ability to maintain your bone density.
We and the Leeds team have recruited elite male and female athletes, including Olympic medallists from three very different sports.
We want to see exactly how each sport has affected their bones, so we can learn what type of exercise might be of benefit to all of us.
We've recruited cyclists from two different racing teams .
.
cricketers .
.
and gymnasts.
Each of the sports have different movement and physiological demands.
And by looking at those different movements and then looking at bone density, we can actually get an idea of what specific exercises might be beneficial.
Each of our athletes get a type of X-ray called a DEXA scan to measure the bone density in their hips and spine, two common areas for fractures, as we age.
We'll compare their results to the average bone density for people of their age and gender.
Studying elite athletes will allow us to identify any changes in bone density that may be caused by the particular movements involved in these different types of exercise.
So, we've got tumbling and somersaults, so that's, like, quite a lot of impact on our landings.
We talk about muscle content, fat content but we've never, ever looked at bone density.
I wouldn't be able to say what the results are going to end up like.
We shall see! We shall see, indeed.
Karen has now scanned all our elite athletes and the results are in.
Time to find out which exercise best bolsters bones and what you can do to minimise your risk of developing fractures later in life.
We've brought back one male and one female representative from each of our sports.
OK, so, results time.
First, the gymnasts.
We're pleased to say that your bone density did come out at 17% higher than the reference range for your age.
- Fantastic.
- Whoo! That's for the women.
And the same story with men.
So, 14% above average at the spine.
Really, really very good, actually.
For our gymnasts, the results for both the spine and the hips were significantly better than average.
Next, what about our cyclists? We expect the cyclists to be very fit but are they bone fit? With the ladies, we did find a 6% lower bone density overall than average, in terms of bone strength at the spine.
And, for the men, 9% lower than average.
So, lower than average, which is kind of surprising.
Strangely enough, spending a lot of time cycling can actually lead to weaker bones than average in the spine for both men and women, and weaker hips for men, too.
And the reason is to do with the type of activity.
Cyclists are very much weight-assisted, particularly this region here, so, the lumbar spine.
And this is where we saw the more prominent differences between the athlete groups.
Because a cyclist's weight is supported by their bike, they're not putting the kind of pressure on their bones that would strengthen them.
So, while cycling is a great way to improve your fitness and your cardiovascular health, it's not so good for your bones.
Finally, what about our cricketers? - I have low expectations for the cricketers.
- Oh, OK! So, cricketers are the surprising group here.
Cricketers, at the spine, even better.
So, for the women, 22% above average for your age, and, for the men, 18% above average for your age.
That's surprising because you think of cricketers as standing around an awful lot.
You do, and you see cricketers on the field for a long time, but, actually, the movements employed in that sport, even though they're not constant and continuous all the way through the game, those explosive sessions might actually be having quite a beneficial effect for your bone density.
So, cricket was the most favourable of the three sports for bone density, both in the spine and hips.
It seems the combination of running, jumping and twisting has a particularly beneficial effect.
And this indicates the kind of exercise we could all do to improve our bone health.
Taking what we've found from this study, a bit from the gymnastics, from the cricketers, there was exercises that involve a bit of jumping, a bit of twisting.
Dancing would be perfect.
OK, so a bit of squat, ideally a bit of star jumping.
Anything that involves a bit of leaping.
That's even better because you're working that muscle but you're also, through the jumping, you're also getting that gravitational loading.
That wasn't quite what I was expecting.
I already do quite a lot of cycling but it seems that isn't enough for maximum bone strength so I'm going to have to throw in some star jumps, perhaps a bit of weight training.
Maybe even a little bit of Zumba dancing.
When it comes to sleep, some of us are larks, we enjoy an early morning.
Others are owls.
They prefer a late night.
But what happens when your biological clock is out of sync with your alarm clock? Dr Giles Yeo investigates.
For many of us, the time of day we're expected to be at work doesn't fit in with our body's natural rhythm of sleeping and waking.
This can result in us getting fewer hours' sleep than we really need.
And scientific evidence suggests that's not good for our health.
Long-term sleep deprivation is linked to a whole host of different health problems, including increased risk of cancer and heart disease.
For every hour's difference between your body's natural rhythm and your actual daily routine, you increase your risk of obesity by up to 30%.
So, why do these differences occur, and what can we do about it? Well, research suggests some of it is down to your age and could explain the biggest mystery for any parent of a teenager.
Why can't teenagers get up in the morning? Are they just being lazy? My teenage son Harry and I are going to do an experiment to compare which time of day our brains are most alert - morning or evening.
7am, and it's time for the morning test.
Threetwo .
.
one, go! Under time pressure, we have to respond to the direction of arrows on the screen.
- Are you feeling bright eyed and bushy tailed, Harry? - No, not really.
The test is designed to reveal our levels of attention.
See, I was up early, I've had my coffee.
What have you been doing? Nothing! 8:30 PM, and time for the evening rematch.
- Are you ready? - Yeah! - OK.
You may be good at stuff like being famous but, yeah, I'm good at Arrow Beam and stuff like that.
Oh! Got that wrong.
I'm amazing at this.
I might as well be a pro gamer.
So, how did Harry and I compare? For reaction time, both of us were faster in the evening.
And for our ability to ignore distractions, both of us were better in the morning.
But, for one important measure - our ability to shift focus quickly in response to the arrow, we're complete opposites.
I did much better in the morning while Harry did better in the evening.
So, his brain really does seem to work on a different daily rhythm from mine.
In fact, everybody has what is known as a "chronotype" which determines what time of day you're at your best.
It's set by a part of our brain that acts as our master body clock and sets our daily rhythm.
Recent research suggests that as timing is shifted by age-related hormones, such as testosterone, which rises sharply in teenage boys and falls off as they grow older.
Now, if hormones radically alter our body clock, then our chronotype is going to change as we age.
There's nothing we can do about it.
And, for most of us, the timing of our working day stays roughly the same throughout our entire lives.
If you could change it, though, how much difference would that really make? One school in London is finding out.
It's 1.
00 PM and these students are just arriving at school, but they're not late.
Their lessons start now.
At Hampton Court House Sixth Form, classes run from 1.
30 PM to 7.
00 PM to fit around a teenager's naturally late chronotype.
This new school day is the brainchild of headmaster, Guy Holloway.
You clearly have buy-in with the staff.
What do they think about this? In-house, we talk about the "golden period".
That period between five o'clock and seven o'clock where the quality of work far outperforms what might happen first thing in the morning.
Really? 5-7? We have teachers who specifically want to teach at that time because they can get the most out of their students and their students work happiest and most productively at that time.
It's a radical approach for a school to take, one that's being watched with interest by schools in other countries and it's certainly popular with the pupils.
We're still putting in the same amount of work, the only difference is we're doing it a bit later and, as a direct result of that, we're more productive and we get more out of it.
How has this new schedule made you feel? I don't have to fall asleep when I get home any more.
Just more energy and things like that.
So, for the students here, fitting the school day around their body clock seems to be working.
Now, for most of us shifting our work day like that is just simply not possible.
But there's plenty that we can do in order to bring our body clocks in line with our daily routine and avoid tiredness and sleep problems.
One of the most useful things to reset your body clock is light.
Get some natural daylight as soon as you can in the morning.
Keep getting up at the same time every day, even on the weekends.
And in the hour before bed, avoid screens, like phones, laptops and tablets.
But my advice is, depending on what your work routine will allow, try not to fight your body clock.
And maybe cut your teenage son some slack when it's midday and he still hasn't got up.
Coming up - is wiping out germs in your home bad for your health? And when health headlines contradict each other, how do you know what to believe? But, first .
.
when we're not feeling well, a surprising number of us, these days, over 50%, would rather turn to the internet for a diagnosis than visit their GP.
But is that wise? Dr Zoe Williams investigates.
Let's say you've gorged yourself on a huge meal and an hour later you're having some weird cramping pains in your chest.
Type in the symptom "chest pains" into a search engine and the first result that usually pops up is a heart attack.
But, of course, it's most likely not a heart attack at all, probably just a nasty bout of indigestion and you're simply causing yourself unnecessary worry.
So, can we ever trust the internet to give reliable medical information? If you're one of the two thirds of the British population that asks "Dr Google" that type of thing often, you may be experiencing cybercondria.
That's medical anxiety caused by researching your own symptoms online.
For me, as a GP, the internet is a fantastic tool, but most of the sites I use are designed for doctors.
The online equivalent to medical textbooks.
And if you're just using a regular browser to find information, the internet tends to offer the very worst-case scenario.
So, why is that? One of the main reasons for this is the way that search engines hunt.
So, if I was to put in "chest pain causes", the first thing that comes up is heart disease.
So, we might think that they would list them with the most likely first but they don't.
In fact, they use algorithms that rank pages according to how many times a key word is mentioned or how many clicks a page gets.
We tend to focus on the first couple of results, rather than looking through the list.
These are the ones that get clicked on again, and again, and that means they remain at the top, even if the diseases they're looking at are rare.
Another common way to search for information is to use an online symptom checker.
But, according to a recent study, they only make the correct diagnosis 34% of the time.
To get the best out of these sites, be as specific as you can about your symptoms.
For example, talk about the intensity of your pain or the duration of your vomiting.
This can help to narrow down the results.
But these sites still seem to struggle with differentiating between life-threatening illness and a simple tummy ache.
Most of us probably know we shouldn't fully trust the medical content of something we've looked up online.
And, yet, the temptation seems irresistible.
So, why do we do it? Well, for a start, it's easy.
For some people difficulty in getting a GP appointment or getting the time off work.
But, I think there's also another reason, something that I call FOFO.
And that's the Fear Of Finding Out.
For me, the danger in using the internet to self-diagnose is that it can delay a visit to the doctor that could give you a correct diagnosis and treatment.
But if you do want to use the internet, then my best advice is to stick with the NHS websites.
The information there has been rigorously checked by clinicians, and there are also sections to help guide you through popular myths and misconceptions.
You can find good information on the internet, and it's especially useful if you share it with your doctor, but in most cases, it's not a substitute for a visit to your GP.
When it comes to health, the media often seem to perform spectacular U-turns.
One day, coffee's good for you, the next, it's bad.
Eating cheese makes you fat.
No, here's a study which says it makes you thin.
So what is going on? Are scientists changing their mind all the time? Are journalists getting it wrong? And how do you know what to trust? I've lined up two experts to help me get to the bottom of it.
First, I'm meeting Sir David Spiegelhalter from the University of Cambridge.
He's a professor of statistics, and regularly criticises the press for the way health news is reported.
So, I think most people believe that the reason we get these confusing headlines is because the journalists are making stuff up.
- Is that true? - There's a whole pipeline, from an original scientific study, that then goes through, it's published in a journal, the press officers then summarise the story and often tend to add in exaggerations.
They want to get it covered.
And so then it goes to the journalist, and my feeling is that the journalists often do quite a good job, but then, the sub-editor sticks a headline on it in order to get the clicks or to get attention, and that's again when serious distortions can occur.
Right.
I've got here some headlines.
So the first one here is, "why Marmite could prevent miscarriages and birth defects.
" - What's wrong with that? - This does annoy me, because it makes it sound like this is a proven benefit on human beings, whereas in fact, the experiments were just done on mice.
It's not proven to have any benefit to humans at all yet.
But the press release never used the word "mice".
So ideally, this headline should "Why Marmite in mice could prevent miscarriages" Yes, but not many people might click on that one! OK.
Moving on, we have, "Why going to university increases risk of getting a brain tumour.
" Ah, this is a wonderful one.
This was again a rather dull Swedish study that showed that richer men tended to have slightly more diagnoses of brain tumours.
By the time it got to the newspaper, it was, "Why going to university increases the risk of a brain tumour.
" But this is implying a causation? A causation, that going to university increases the risk of a brain tumour, which I hope it doesn't! How would you go about getting more responsible headlines? More people just hammering on the doors of the newspaper through social media.
I think this is one of the power of social media.
The journalists see this, and they don't like it, actually, when their articles are being criticised.
Thank you.
Next up is Chris Smyth, Health Editor for The Times newspaper.
He specialises in covering medical news.
David Spiegelhalter would say that his biggest beef is frankly with the headline writers.
Well, headline writing is incredibly difficult.
You've got five usually pretty short words to summarise something which is, you know, particularly when we're talking about complex medical statistics, going to be very complicated, so there's just no practical way that it is going to tell you everything you need to know about the story while also making sense to that person flicking through their paper on the train.
So the role of the headline is basically to advertise, "The story's about this topic," and you can't really judge a headline unless you read the story.
Do you see it as part of your job, holding science to account? Scientists get an enormous amount of public money, and they do wonderful things with it.
But as with everything else, you don't want people to be marking their own homework and saying, "This is what we think.
" You want to have people scrutinising what they're doing, what they're finding.
We all do.
I mean, you're doing it to me now.
You're scrutinising my journalism.
Scrutiny is always helpful.
One thing that sometimes comes up is, is this a drug company funding a trial to show that their drug is amazing? And this is quite a difficult issue, because you could not really test drugs if drug companies were not paying for trials, and some fantastic medicines have been discovered in that way.
How you account for that is a difficult judgment, and I don't think it's one that's so much a journalistic problem.
I think doctors also struggle with this.
Thank you.
As we've just seen, the medical stories you read in the newspapers are the product of a long chain of events which begin with the scientists and end with the headline writers, and at any point, someone can put their spin on it.
Not just journalists, but medical companies, and their press officers too.
It's rare that someone gets it wrong, or worse, deliberately sets out to mislead.
But the same evidence can be slanted in different ways.
So, when you do read a story, ask yourself, "Does this sound plausible?" Because extraordinary claims require extraordinary amounts of evidence.
Over the last century, there has been a dramatic rise in asthma and other allergic diseases.
Now, this is often blamed on excessive cleanliness.
But is that true? Are there some bugs you should have in your life? Surgeon Gabriel Weston has been investigating.
Last year, we spent a staggering £74 million on antibacterial surface wipes, and there's no doubt that some germs are harmful.
You do need to be scrupulously clean, for instance, after handling raw meat or using the toilet, to avoid bugs that can make you ill.
But all around us are countless other microbes - bacteria, moulds and yeasts that do us no harm and give our immune system a workout.
And there are worries that wiping them out with antibacterial products is actually harming our health.
The theory goes, we spray and wipe away so many natural microbes in our homes these days that our immune system, without the usual things to fight, turns instead against our own bodies, causing asthma, eczema and hay fever.
But can using antibacterial products in our homes really be the problem? To help us find out, we've recruited three families and given each a removable kitchen worktop.
To begin the experiment, they'll clean this board using antibacterial wipes.
This will get rid of all bugs, good and bad.
Over the next 36 hours, they'll use their kitchen as normal, and take regular samples from the board, so that we can measure how long the service remained germ free.
And how quickly any microbes return.
Analysing the data is microbial physiologist Dr Lynn Dover at Northumbria University in Newcastle, and it's time for the results.
The first sample we took was after one hour, and in all cases, there was bacterial and fungal growth after one hour.
So pretty much immediately after someone has disinfected their surface, these things are now beginning to regrow again.
Yeah, and that progressed over the next 36 hours.
So, as you can see, after six hours, eight hours and 12 hours, there's progressively more.
This 12-hour sample is quite dramatic.
As you can see, there were lots of different types of fungi.
They have totally covered the plate.
I imagine if I did it after two minutes, we'd probably find something.
Where do all these bacteria and fungi that end up on these plates come from? The whole environment is absolutely teeming with microorganisms and life.
They're from our bodies, they're from the air around us, little bits of skin that come off that form household dust, just land on the surface and they carry bacteria and fungus with them.
So, no matter how well an antibacterial product has cleaned a surface, the bacteria, yeasts and moulds that are everywhere in the environment begin to reappear almost immediately.
It means that using antibacterial products is not affecting our exposure to microbes as much as we thought.
They're all around us all the time, so it's just not realistic to blame the rise of allergies on these products alone.
But if our cleaning habits aren't to blame, what is? To find out, I'm having a picnic with Dr Claire Lanyon, a microbiologist from Northumbria University.
She believes the problem is that we're not exposing ourselves to enough of the bugs found in nature, and one way to do that is to spend more time in places like this.
Exposure to microorganisms is actually what reduces the incident of you developing allergies in certain situations.
I think the key point is diversity.
We should be exposing ourselves to lots of different varieties of them.
Bacteria don't live as single entities, they live as a community, and the community is constantly responding with each other and with us.
As the microbes interact with our bodies and with each other, they make by-products that can help strengthen our immune system.
And they produce something called secondary metabolites.
Now, some of these are antibiotics, such as what we've utilised and used to fight infections.
So these little defence mechanisms that the bacteria have are constantly shaping our immune response.
In an average ten square metres of parkland, there are hundreds of varieties of generally harmless microbes.
And encountering some of them could be a key way to help your immune system.
So your advice, then, would be to increase our exposure to lots of different kinds of organism? Absolutely.
Being exposed to microorganisms is a good thing.
- I will say cheers to that.
- Cheers! So, it seems that for a healthy immune system, you need more germs in your life, not fewer, and the wider the variety you encounter, the better.
So my advice is, vary your diet, get out in the outdoors, keep a pet, if you like, get your hands dirty, and whatever you do, don't waste another minute of your life trying to keep your house spotless.
That's it for this series.
Visit our website to find out more about the stories in this and all the other series of Trust Me, I'm A Doctor.
# 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 onto my lap # And when he walked in dressed in white # I had a heart attack # Doctor, I want you # Ooh, my Doctor Wanna Do I can't get over you