Horizon (1964) s54e10 Episode Script

Are Health Tests Really A Good Idea?

100 years ago, if doctors wanted to know what was going on inside you, well, they'd probably have to wait till you'd died, cut out your organs and have a look.
These days, of course, we have much better technology.
We have scans, we have blood tests, and the promise is if we can detect a disease early enough, then we can do something about it.
Ah Thousands of people who are perfectly well have health tests every day, with the hope they'll pick up the very first signs of illness before any symptoms occur.
PA: 'Michael Mosley to room number two, please.
' 'Now, I'm pretty healthy but to see if they're worth having, 'I put myself through a battery of tests.
' They have got a little opening at the back.
'It's been embarrassing.
' It feels like it's going to come out through my mouth! I could keep going that way but I don't think you want me to.
No, I don't think so.
'Experimental.
' Basically, it's a lovely little tube.
You go HE HAWKS 'And worrying.
' These soft plaques, they try to kill you.
'I want to find out which screening tests are truly useful.
' COMPUTER: 'Injection in progress.
' OK 'If any are worth paying for.
' Whoa, that is weird.
'And if some could do more harm than good.
' Open nice and wide.
Ah Looking for the diseases that may lurk inside us before we have any symptoms has become big business.
Here in the UK, we spend about ã135 million a year on private health tests.
Excellent! And about ã750 million on NHS screening programmes.
And we are not alone.
33 other countries have national screening programmes.
In Japan, annual health tests are compulsory for employees and in America, an astonishing half of all visits to the doctor are for routine check-ups.
But, if you're healthy on the outside, is it really worth probing inside? I'm going to start with tests for heart disease because it is the number one cause of premature death in the UK.
In fact, someone dies every six minutes of a heart attack.
I also have an intensely personal interest because my grandfather and my father both died of heart disease.
This is a picture of my father about the same age as I am now and he died when he was in his early 70s and I would rather last a little bit longer.
RECEPTIONIST: The Simpson Centre? I'm starting with a basic health check that here in the UK is available to anyone free on the NHS.
So, I'm here at my GPs to have a cardiac assessment, really to see what are the odds that I'm going to have a heart attack in the next ten years or so.
It's a series of relatively simple tests but because I have this rather dodgy family history, I'm feeling a bit anxious.
PA: 'Michael Mosley to Dr Jenkins in room number two, please.
' 'My GP Sally measures my blood pressure.
' 132/83, that's perfect.
'My Body Mass Index or BMI, based on my weight, 'height and waist measurement.
' That's 84.
'And my levels of total cholesterol, measured from a blood sample.
' 6.
34, and so, from that, we can put it into our little magic calculator.
'These are all risk factors for heart disease.
'The biggest one is something 'you can do absolutely nothing about - your age.
'The idea is to work out their impact when they're put together.
' So The moment of truth.
That gives you an overall risk, which is the ten-year risk, so it's a heart attack, it's angina, cardiac death and that's 11%.
So, 11%, OK.
One-in-ten chance.
Hm.
'That score puts me just within the low-risk group, 'but the latest UK guidelines recommend 'that if you get a score over 10% - mine - 'then you should be offered medication.
' You're actually in that group now where we would consider a statin.
OK.
And the idea of having a statin is trying to reduce your cholesterol, which reduces your risk.
But of course, we haven't taken into account your family history so we can add in that and put that into the calculator and see if that makes a difference.
Right.
Family history is heart attacks at less than 50, really, so you're kind of borderline for that, but that immediately Oh, blimey! .
.
increases your risk to 15.
9.
Wow! 'Other risk factors you may have 'will have an even more dramatic impact on your score.
' We could say you were diabetic.
I am at risk.
See what happens there.
My dad was diabetic - again, wow! That nearly doubled.
It's phenomenal.
And the next thing, of course, we could add in smoking.
I know you're not, but we could add that in and see the effect that has.
Blimey, nearly a 50% chance that I would, if I was That I would have a heart attack.
Yeah, that shows how bad smoking is for you.
Right, OK.
And how good it is to continue not to smoke, really.
Right, OK, that's given me lots to think about, thank you.
That simple test took just a few minutes and cost me nothing, but behind this kind of magic calculator is six decades of research carried out in a small American town called Framingham.
Much of what we now know about heart disease is thanks to people like Eva and Gina .
.
Joe and Eileen, and their four sons .
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Phyllis, Richard and their daughters.
They're all part of a group of scientific guinea pigs.
About every four years, we go in for a battery of tests that takes three or four hours to complete.
All the way up, two.
Every time you come, they've done extensive cardiac testing, blood pressure, cholesterol monitoring.
Eyes, ears, brain.
Data gathered from the people of Framingham has transformed our knowledge of heart disease.
We've been tested from head to toe, mentally and physically.
SHE CHUCKLES Did you enjoy it? Of course not! ALL LAUGH What's made the Framingham heart study so influential is that three generations of families have taken part since it began shortly after the Second World War.
My father and my mother were original participants in the study back in 1948.
My parents were both in the heart study.
My parents were both in the heart study.
This is my mother, she's 107 years old.
She was one of the first.
She looks pretty good, doesn't she, for 107? One of the heart study's current directors is cardiologist Professor Daniel Levy.
Today, we know about a number of modifiable risk factors associated with heart disease risk, things like high blood pressure and high cholesterol levels, diabetes, cigarette-smoking to name just a few.
But back when the study began, those risk factors weren't even known.
In fact, the very term "risk factor" was coined right here in Framingham.
Do you see me in this photo? Now, I think that measuring blood pressure and cholesterol, the sort of risk factors identified by Framingham, is a good thing to do and you can get it done easily enough by your GP, but you have to do more elaborate tests if you actually want to identify whether you HAVE heart disease.
These promise to detect the main culprit behind heart attacks .
.
fatty deposits, rich in cholesterol, that can clog up our arteries as we age, called plaques.
If these rupture, they cause blood clots which can starve the heart of oxygen and be fatal.
Behind these discreet doors is a wonderland of advanced and very expensive technology.
Now, I've come along to have a heart scan which should reveal, not just my risk of having a heart attack, but the actual plaques themselves which may be growing inside my arteries.
For those who can afford them, a range of cardiac CT scans are available in private clinics.
They cost between ã600 and ã1,000.
I want to find out if they're worth the cash.
Medical director Dr Paul Jenkins is, not surprisingly, a great fan of these tests.
Your build is not that of a typical somebody who might suffer a heart attack but let's remember, about up to half of people who've had a heart attack have very few, if any, risk factors.
OK, so, how reliable are these tests I'm about to have? Extremely reliable.
The CT scanners are exquisitely sensitive coupled with expert radiologists to interpret the images, and if they say that your heart arteries are clear, I can be virtually 100% certain that you are clear.
Do come straight through.
OK, right.
Lying on your back, head this end.
'Originally developed as a diagnostic tool 'for people with symptoms of heart disease, like angina, 'this scanner will give the best images of my heart 'that money can buy.
' OK, so the first thing I'm after is a vein in your arm.
OK.
Needle coming in now.
'A contrast dye will show how well blood is flowing 'through my coronary arteries and if it is being obstructed by plaques.
' That's grand.
No discomfort? No.
Splendid.
When we run it in, it makes you feel warm all over.
It may give you It may make you think you've wet yourself.
You haven't.
It's just a warm feeling, OK? That's splendid.
OK, Michael, I'm just programming the computer for the first set of scans.
OK.
COMPUTER: 'Injection in progress.
' Whoa, the contrast medium is going in and that is weird! 'Take a breath in - and hold it.
' 'The scanner uses X-rays to generate images 'so I'm getting a small dose of radiation.
'It's one reason you might think twice about having 'a scan like this if you don't have any symptoms.
' 'You may breathe normally.
' 'That's the easy bit over.
' OK moment of truth.
Hello.
Hello.
Michael Mosley.
Duncan Diamond, nice to meet you.
Right, OK, so, that's my heart, is it? Yes, so, this here in red is the left anterior descending artery which runs down the front of the heart which we as cardiologists know is the single most important coronary artery, the one that is most commonly the culprit for heart attacks and, unfortunately, fatalities.
So, what you see here in white is the actual passage of the contrast medium and you can see there, that little wedge? That little wedge-shaped You can see it on both sides of the artery, just there and there, and that's dark, and the reason it's dark is because that is a deposit of soft cholesterol-rich plaque on the wall of the artery.
Right, that's bad? Yes.
These soft plaques, they try to kill you and I don't want to sound overdramatic, but those are the ones which are dangerous because of their propensity, unpredictably, to cause heart attacks in someone who's been completely well, free of symptoms, living a normal life.
You know, the person who, 45-, 50-year-old, goes out in the morning to work and doesn't come home.
Right.
Presumably, you can't tell me what the chance IS? If we could do that, we'd be a quantum leap ahead.
If we could say to you, we know that you're going to have a heart attack in four years and ten months, we'd be, you know, Star Trek medicine, quite honestly.
But all we know is that this is probably the most powerful thing we can do to say that Michael Mosley needs to take a statin.
I'd have no hesitation, because soft plaques with statins metaphorically have the cholesterol sucked out of them.
I'm looking at it and wishing it wasn't there.
That's exactly what I did.
I wished it wasn't there, but you know what? It is there, and all the hand-wringing in the world isn't going to undo it.
OK, so, that was actually worse than I had been expecting or hoping or fearing, and my first reaction when I looked at it, I thought, "Bugger, this is bad!" And I'm still kind of reeling a bit at the shock of it, but I guess the thing I need to do is go back home and talk to my wife Claire about it, and probably start on statins, but it has been a nasty shock.
Tests like these are never black or white.
They depend crucially on the skill of the operator and of the interpreter.
So, how worried should I be? It's been two weeks since my scan and it's been preying on my mind.
So, I have been brooding a bit about what Dr Diamond told me and what I've got here.
I'm looking at that particular area of the artery.
The scanner found a plaque but is that knowledge really useful? Frankly, the advice I got from Dr Diamond was pretty much the advice I got from Sally, my GP, without having to do the enormous expensive test and that was start on a statin.
So, has the test given me a warning in time, or has it just created unnecessary anxiety? I'm in the fortunate position - I can get a second opinion.
I've come to Edinburgh to see Dr Marc Dweck.
Marc is an expert in cardiovascular imaging and his team has scanned thousands of patients with severe heart disease.
I want to know what Marc thinks of my results.
Dr Diamond identified this particular part of my heart scan as troublesome, so what's the news - good, bad? It's very superficial.
It's on the outside of the artery.
It's not really blocking the artery, blocking the flow of the artery, so the flow of blood down that will be fine.
It's non-obstructive.
OK.
But I think, overall, we're not too worried and that's partly because, if you looked at people of your age in the population, and we HAVE, we see a lot of these plaques and a lot of people have these plaques and the vast majority of them are not going to do anything.
That's reassuring, I must admit.
'Well, a little reassuring.
'But how useful does he think these scans are in people at low risk?' I don't think it moves things on a great deal from knowing your risk factor scores.
You know, the advice is still the same - lifestyle, and potentially, a statin.
OK, and do you think that if you show people these sort of images of their own heart, it's likely to make them change their behaviour in a sort of better way, or perhaps begin taking statins and stick to taking it? Well, I think, anecdotally I think, yes.
We do see that patients look at their own heart and they're struck by the images, and certainly, in the short term, they sign up to lots of healthy activity.
How long that lasts is a different matter.
'And Marc's got a gruesome specimen 'that I think is meant to make me feel better - 'a plaque removed from an artery in someone's neck.
' So, these are taken from patients who've had a stroke.
It's the same processes that lead to heart attack.
Blimey, that's dire, isn't it? Well, yeah, and what's happened is that the plaque in this region has ruptured and it causes the blood to clot and then bits of that blood clot can fire up off the circulation.
This is the artery going up to the brain and lodge in the brain and cause a stroke.
It is quite something, isn't it, when you think there are people walking around with that sort of thing and indeed, all of us to some degree, are kind of walking around with some of that going on.
So, at least mine doesn't look anything like this.
That's right.
It's a very different stage of disease to the plaque that was seen on your scan.
I'm actually feeling very reassured now.
There's nothing quite like looking at somebody else's really dodgy arteries to make you feel good about your own, but above all, I kind of got the message which I've received from three doctors now, so I'd basically better do it.
Take the statins, don't worry too much.
There isn't yet enough evidence about whether having heart scans is effective in the long run.
I can see how they might be useful in people with existing disease or who are at high risk, but for those without symptoms, I'm not convinced.
Before you pay for a fancy new test, ask your doctor if it's really going to give you more useful information than a simpler test would, and is it worth the anxiety it might cause? If heart disease doesn't see you off, it's likely that the big C, cancer, will.
There are over 200 different types of cancer and it is incredibly common.
I'm sure everyone knows someone who's had it.
The thing about cancer is it is a disease of uncontrolled growth and therefore, it makes sense to detect it and get rid of it as quickly as possible or does it? If you're worried about cancer, there are plenty of tests but how useful are they? Hold your breath there very still.
I lost my sister with breast cancer, so this was really the one that I was sort of a little bit apprehensive about.
Just keep your chin up for me.
The UK Government green-lit the world's first national breast cancer screening programme in 1987.
You all right there? Yes.
Women between 50 and 70 are invited for mammograms to try and detect cancers which are too small to see or feel.
It's good that we get it on the NHS and it's just nice to have it done every three years and make sure that you're clear of any lumps.
Lovely, breathe away, well done.
Dr Robin Wilson is chair of the UK's Breast Screening Advisory Committee.
Breast cancer is the highest cause of cancer death amongst women in this country and detecting the disease early does result in a reduction in mortality, and the calculation is that 1,200 women will not die of breast cancer that would have done if the screening programme hadn't been in place.
It's something that needs to be done.
It's reassuring.
OK, all done.
Breast cancer screening is one of three national cancer screening programmes, the others being cervical and bowel cancer.
They're evaluated using a set of guidelines first set out by the World Health Organisation.
With all screening programmes, there's a risk that some cancers will be missed, but this isn't the only problem.
When a suspected cancer is discovered by screening, it will be confirmed by studying a biopsy, a sample of tissue taken from the patient.
But it's often not possible to tell an aggressive and fast-growing cancer from one which is slow-growing and which would never go on to cause the patient any problems.
This leads to one of the greatest drawbacks of screening programmes - over-diagnosis.
Over-diagnosis is one of the reasons that Dr Iona Heath, former president of the Royal College of GPs, thinks screening does more harm than good.
Breast cancer screening undoubtedly harms more people than the number of lives it prolongs.
In 2012, the Government reviewed the extent of the problem.
The Marmot Report said that we can prolong the life of this woman .
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but that would be at the expense of harming three other completely healthy women who had been labelled as having breast cancer.
Most of those will receive treatment, some of which is dangerous in itself - mastectomy, radiotherapy, chemotherapy, those sorts of treatments - when they actually have a cancer that is never going to harm them in their lives.
They're going to die of something else.
The report concluded that this balance of harm to benefit was acceptable.
Marmot agreed that screening does probably reduce mortality from breast cancer by 20% and that, in the opinion of most people, including women who come for screening, outweighs the risks of treatment for a breast cancer that doesn't matter.
But what has made the issue so controversial is that other studies have found that the number of women who will be over-treated to benefit one woman is as many as ten.
Ten women.
This is now called the mammography war.
And so, my personal decision is to wait until I get a breast lump, and get the best treatment I can get, and there's a population screening thing to say to women, "You should do this because it will benefit you," that I don't think that's defensible any more.
I am absolutely not talking about if they find a lump.
If they find anything wrong, go to see the doctor.
I think women need to be aware of what the risks are and how they balance out against the benefits in order to make an informed choice about whether they participate or not, and what we, the medical profession, need to do is get better at finding out which of the cancers we don't need to treat.
The wars that rage around over-diagnosis are even fiercer when it comes to cancer of the prostate, a gland that, in men, sits beneath the bladder.
There's no national screening programme for prostate cancer, but there is a blood test, the PSA, which you can request from your GP.
The PSA test is based on research carried out in the 1970s by this chap, American urologist Professor Richard Ablin.
The test was originally intended to be used simply to track existing cancer, but in the 1990s, they started using it as a screening test.
Millions of American men were urged to have the test but doctors like Professor Gilbert Welch based at Dartmouth Medical College in New Hampshire quickly realised it was detecting thousands of cases of prostate cancer that we now know would never go on to cause any harm.
Studies have shown that once a man's over age 60, at least half of men have some pathologic evidence of prostate cancer.
The reality for older males is most of us will live with prostate cancer.
We will die with prostate cancer, not FROM prostate cancer.
Many men receive surgery that is not only unnecessary, but has devastating side effects.
One of the effects of PSA-testing was to leave a lot of men impotent and incontinent.
Professor Ablin was horrified that the work he'd done had been hijacked with such disastrous consequences.
'The science was pushed too far.
'People were too fast to biopsy and too fast to treat.
'We've spent $60 billion, over-diagnosed 'and over-treated millions of men.
'This is why I call it a public health disaster.
' Now, my dad had a PSA test done as part of a routine medical.
They told him it was elevated, he had his prostate examined, discovered he'd got prostate cancer, so he decided to have a radical prostatectomy which left him incontinent and impotent, and then he died a couple of years later of heart failure so I think he would have been better off not to have the test at all, and I am extremely sceptical about its benefits.
I've come to Addenbrooke's Hospital to meet a group of men who might just change my mind.
They're taking what seems like a very cavalier approach to their cancer.
They've had the PSA test, been diagnosed with prostate cancer and then, amazingly enough, decided to simply monitor it.
So, when you said you weren't going to have surgery, did your children, did your family, did anyone say, "No, you're going to have the operation, "you really should rid of it"? Yeah, both my daughters said, "Get rid of it straightaway.
" For lots of people, the word somebody's got prostate cancer, they immediately think you're at death's door or you've got to have a serious operation.
In our case, it's something you know that is there but with this monitoring, if it does develop, you know that you're in a good position, that it's going to be caught quickly and they can do something.
I don't know, I genuinely don't know what I would do, whether I would be like my dad and I would feel that it's there, I'm thinking about it, I must get rid of it, or whether I would be capable of sitting there and waiting.
It was an easy choice for me just to have this active monitoring rather than surgery.
My life has not changed one iota.
I'm doing everything that I used to do, I don't think about it, don't worry about it.
We're quite happy and it's not affected our lives at all.
So, given your time again, would you all still have a PSA test? MURMURS OF AGREEMEN Most certainly.
Yes.
'The active monitoring programme here 'is run by Dr Vincent Gnanapragasam.
' Are there any you've missed? A metastatic cancer, you told the person that they were absolutely fine and before you saw them again, it had spread? In my experience, it hasn't actually happened as yet, but certainly it can happen.
It is not a zero-risk method of management.
But there was a study published a few years ago in America which took men with all kinds of prostate cancer and randomised them to either having nothing done or radical surgery, and at the end of ten years, there was actually no difference in the overall survival.
Most importantly, the men with low-risk cancer had absolutely no evidence of a benefit from radical treatment.
That's the problem with science in general and medicine in particular.
I went in that room utterly convinced that I was not going to have a PSA test and now I probably am! In fact, soon afterwards, I did have the test.
My score was normal.
Snare open for me, please.
And close for me, please.
Thank you.
Now, as you'll have gathered by now, many screening tests are controversial.
There is however one test which most experts agree is a really good idea.
There is, however, a significant drawback.
It is embarrassing.
In the name of science, however, I'm about to give it a go.
This team is preparing to insert a tiny camera into me.
Unfortunately, the camera is at the end of a metre-long tube.
The plan is to explore my colon and look for signs of bowel cancer.
So, what we're looking for is polyps.
These are the types of polyp we get.
The majority of them may be small, but you can get larger polyps such as these ones down here.
Bowel cancer is the second biggest cancer killer in the UK and this is a new screening test, that over the next year the NHS will offer to everyone when they turn 55.
Consultant nurse Maggie Vance will be at the helm of this procedure, called a bowel scope.
I'm familiar with colonoscopy and endoscopy and you kind of feed a tube with a camera down.
How is this different? Well, it's the same mechanism.
We're going to look inside the lower bowel with a tube with a camera on the end of it, but we're just not going as far as we would do with a colonoscopy.
The bowel is about a metre in length and we want to look at the first third, about the first 40 centimetres today.
If we find a polyp, we remove it.
We send it to the lab and, depending on the type of polyp, we'll either say that's OK, you can go away or you would be offered a colonoscopy.
And how often are polyps either sort of pre-cancerous or frankly cancerous? It's about 10% of them.
So, if you find a polyp today? I'll remove it for you.
You'll remove it and there's a one in ten chance it might be a bit dodgy? Exactly.
It sounds perverse, but it is actually the best cancer to have in terms of survival rates if you pick it up early.
And we've found that by removing a polyp in the lower bowel, you can reduce the risk of getting bowel cancer in the lower bowel by 45%.
OK, you've done this a few times, have you? I've done this about 15,000 times, so yes.
15,000 times? OK, well, I've got my enema pack here which was sent to me through the post and it seems to be very clear, so I'd better get on with it.
Thank you very much.
You're welcome.
See you soon.
So, here I have some top-of-the-range dignity shorts.
They're very nice.
They have got a little opening at the back, so please, put the opening to the back, not to the front, OK? OK! Any questions? No, that's fine! See you in about an hour's time.
If you experience any discomfort, let us know straightaway.
We have some entonox which is what ladies use in labour.
Hopefully, this will not be as painful as that, but if you get any discomfort, you can have the entonox or we'll just stop, because it's about going as far as is comfortable for you.
So, if we could ask you to roll over onto your left? OK.
I'm just going to open these very glamorous shorts for you.
Now, what you're going to feel is the instrument coming inside now and I'd like you to take a big deep breath in for me, please, and breathe out.
OK? That's it.
How are you feeling, Michael? Fine.
OK, so, that's the tube just inside you.
And here is your beautiful rectum.
Indeed, lovely! That's where you can feel the gas.
I admire your enthusiasm(!) What we're going to do is just pull back a little bit and blow a little bit of gas.
It's a bit like a Dyson, this tube.
We've got suction, air, water, everything.
Doing very well.
It's a fairly weird sensation, I have to say.
Yes, it feels like you want to go to a toilet.
It does.
And it looks beautiful so far.
Are you all right for me to continue? I am fine.
OK, so we're just going very slowly and gently for you now.
Heading up into the bowel, and you can see May I have a wash just here please? .
.
these beautiful blood vessels.
And that's how the bowel should look, so it looks all normal.
Nice and pink and healthy.
Thank you.
Blimey, that enema did the business, didn't it? It did.
So, we've already gone far enough so if I can go a little further, but only if it's comfortable for you.
That's fine.
As you say, it's quite a weird sensation in the gut now, isn't it? It is, but you're doing exceptionally well.
This is where it can feel a bit crampy though, so to warn you.
Oh, weird.
That is weird! Is that relieving? Oh, God, that's weird.
Still feels windy there? Yeah.
OK, you've done very well.
So, Nicky, we are at 55 centimetres.
55? Yeah, we're in there.
55 centimetres, so you're about that far in, are you? We are.
It feels like it's going to come out from my mouth at some point.
I could keep going that way, but I don't think you want me to, so we're going to come back now.
Descending colon, so we're coming back now.
So, you've seen nothing so far? Nothing so far.
Actually, going in is what people focus on but coming back is the most important bit because we're looking carefully.
You have more control, don't you? And I'm going to remove that gas.
Is that starting to feel easier for you now? It is, yeah.
Good.
'Just when I thought it was all going to be OK, 'Maggie spots something.
' So, this here, can you see this little nodule here? This little polyp here, can you see this little area here? So, you have found something? I'm going to remove it with a cold forceps for you and send it off to the lab.
I'm sure it's benign, but could I have a cold forcep, please? You're going to see a little orange instrument come out now.
Can you see that there, like a little forcep? I'm just going to get it in the right position.
Open the forcep for me, please.
Close the forcep for me, please.
Close, and I'm going to remove that for you.
Thank you.
That's it gone, thank you.
You don't feel anything.
No, you don't feel anything.
There's no nerve endings in the mucosa.
And may I have some wash, please? Then that's it gone.
That's gone, right.
It was quite subtle, wasn't it? Very subtle, and they often are.
That would bleed about less than a teaspoon.
It looks a lot more because it's magnified.
Almost over.
You've done really well.
I'm just coming back, and I'm now, a few deep breaths for me and I'm going to take the tube out.
And that's it.
I have seen a fair few of them and from my experience, I would say that that polyp is nothing to worry about but we send it to the lab anyway.
You can never tell whether a polyp's going to turn into a cancer or not which is why we do this test and remove them all, so if you remove all of them, then it lessens your risks.
Right, OK.
Surprisingly all right, and I can see that compared to quite a lot of other tests, the great advantage is that you can do something about it.
Absolutely.
That's good.
OK.
Thank you.
So, I'm now your 15,000th And one! And one! Thank you.
That was good.
You're very welcome.
No screening procedure is entirely risk-free, even the bowel scope, and it's clear there's a lot of uncertainty around screening healthy people for breast and prostate cancer.
Which of these tests to have can only be a personal decision.
And there's a group of even more controversial health tests emerging which I want to give a try.
In 2003, the entire human genome was mapped for the first time.
Amongst other things, this breakthrough has given rise to a brave new world of tests which divide opinion.
They promise to unlock the secrets of our future health by peering into our genes.
But should we really be dabbling in our DNA? Now, this is just one of a number of tests you can get.
It's from a company called 23andme.
It costs 125 quid and you send off for it and they send you this.
Basically, it's a lovely little tube which you spit into, then you put the top on, and then it's ready to be sent off.
This is the latest of a range of DIY genetic tests and promises to give you some insight into your ancestry and to screen your DNA for genes associated with conditions like Alzheimer's and Parkinson's.
But is giving us the power to look into our own DNA a good idea? To find out a bit more about how these tests work, I'm meeting geneticist Dr Ewan Birney at the Wellcome Collection.
Behind him is a set of books listing the three-billion-letter code of the human genome.
'If you were to print out my genome, it would look very similar, 'just a few letters' difference here and there.
' And your genome has about three million differences so it's like three million different spellings, alternative spellings of the genome compared to this book.
It means that, imagine we're on a particular page here and at this point here, rather than a T, you're a G.
Yeah.
And there would be another point here, about a thousand places down, where you'll be a C rather than a T here.
Yeah.
'These variants determine different traits we each have, 'like the colour of our eyes.
'Many DIY genetic tests work by comparing the letters you have 'at some of these points.
' Now sometimes it really is that that one single change, just one very specific thing, and it ends up changing one very specific thing for you so one of them is whether you can smell asparagus or grass or these things.
That's a smell receptor.
Either you have that receptor or you don't.
So, it could literally be one letter? It is one, it is one letter, it is one letter in one of these books and it's all very clear-cut at that point.
Now, there are some diseases which are also a bit like that.
Sometimes not now just one letter, but maybe a couple of pages, and it would be a number of different variants that could happen.
That would be, for example, cystic fibrosis would be in a similar situation.
But many diseases aren't that simple.
Instead, they are the product of a complex interplay of environmental, lifestyle and many different genetic factors.
Things like type 2 diabetes, or heart attacks or strokes, well, it's thousands and thousands, maybe tens of thousands of variants, that are scattered all over these books so it's very complicated to take this information and turn it into anything that's really changing your odds of getting the disease by much.
So, this sort of freelance, send off 125 quid, get something in the post, you're not a fan of? No, just for fun, just for your ancestry.
I recommend it for that.
But not for your health? Not for my health, no.
Not for my health and not for your health, because there's dangers about people getting worried inappropriately.
There's dangers of people perhaps being slightly obsessed about a particular diagnosis that may or may not be right, so this is best handled when you're meeting a clinician who has experience of all these scenarios, to give you good advice.
'The thing is' Hello Terry! '.
.
I've already paid for the test, I've got an e-mail with the results 'and I simply can't help looking.
' Terry! Come here.
You're going to come and share this moment with me? "Earwax, wet" and they are very confident about that.
Eye colour, they're very confident about that, four stars and it tells me that I likely have blue eye colour.
Lactose, apparently, I'm tolerant to lactose.
Again no great surprise because I can drink milk and I'm European.
Muscle performance! HE LAUGHS It says I'm a sprinter which is not at all true, not even remotely true, I have to say.
"Asparagus metabolite detection", higher odds and that is true.
So, what have I got out of that? I mean, it hasn't really told me anything I didn't already know.
The report will also tell you if you are carrying genetic mutations you could pass on to your children.
So, if you have it in the family or you have reasons to believe you're at higher risk, this would perhaps be useful.
For example, it tells you whether you had the cystic fibrosis trait which is really of interest if you're going to marry and have children with somebody else who has a cystic fibrosis risk, because then, one in four of your children are likely to have it.
So, that's probably the commonest one on this list.
Most of the others are relatively exotic, but I don't have any of them.
So, now we come to the genetic risk factors which, I guess, is the bit that is the scariest bit for most people.
This part of the test looks at genes which have been shown to affect your chances of getting certain diseases.
And this bit is interesting because it's a locked report.
So it gives you Alzheimer's, risk of breast and ovarian cancer and Parkinson's, and I guess we'd all kind of wonder about those.
So, this is the moment where you might stop and reflect about whether you really want to know whether you have a risk of Alzheimer's.
Right, I'm going to look at it, because I can't bear not looking at it.
OK, right, and then it gives you quite a lot of blurb first.
It really doesn't want you to know.
"Michael Mosley has two copies of the APOE E3 variant.
"This variant is not associated with high risk "of developing Alzheimer's disease.
" Right, I guess that is a considerable relief.
I don't know how I would have responded and I don't know if I would have told you if it had been associated with a higher risk.
I would probably have lied to you, I'd probably have said I was fine.
I don't think I really thought it out, to be completely frank.
It wasn't until the result came up, so I'm hugely relieved.
I'm greatly, greatly relieved.
I do wonder if letting people access this kind of information without someone who can put it into context is really the right thing to do.
I've actually got a print-out of the risk factors which I should have read before I started doing this test, and any responsible person would have, but I, like I imagine 90% of people, just kind of rushed for the results and if I'd really read it properly then it might have scared the hell out of me a great deal more because top of the things is the APOE E4 thing, and if you have that, then that is unbelievably scary, because if you've got two copies of that one, then it says here that you, if you're a man, you have a 50/50 chance of developing Alzheimer's by the age of 85.
If that's true, it's five times the average risk for an 85-year-old man.
It would have sent me off on a really Into a really dark place.
I've decided I don't want to open the other locked reports.
I don't want to know.
I think, with Parkinson's, I'm quite adamant, and having done this test, I'm even more adamant now.
There is absolutely nothing I'm aware of we can do about Parkinson's.
I think it opens a whole can of worms which is completely inappropriate.
But my journey into my DNA isn't over yet.
I've agreed to do a final health test which is potentially even more disturbing.
It's still experimental, and isn't available to the public.
So far, I've done a range of tests which have tried to predict whether I'm likely to develop a particular disease.
I'm off now to get the results of another test, but this is different because it's not about a particular disease, but really about how well I am ageing.
For the past eight years, Professor Jamie Timmons has been carrying out a study looking at the DNA expression of people who are ageing healthily.
Unlike my earlier genetic test, Jamie's not looking at differences in the code but at how active parts of it are.
By way of example, that means essentially how much water is flowing through a tap.
You can turn it on to a greater or lesser extent.
It's really the same with measuring gene expression.
Remarkably, he's discovered a set of 150 genetic markers whose activity is different in those who are ageing well from those who are ageing badly.
By testing blood samples, Jamie can examine the activity of those markers and work out a score.
He has found that those with dementia and certain cancers have a lower score than healthy people of the same age .
.
and that a low score indicates who is likely to die at a younger age.
I sent him a blood sample four months ago and I'm about to get my results.
I'm actually feeling reasonably good about it because I think there's part of me which is insanely optimistic.
I always think they're going to tell me that I'm doing brilliantly well.
There is obviously a tiny bit of fear that he's going to say something very different.
Hello, Michael.
Hello, good to see you.
Nice to see you.
What we have done is we've run 60 samples, all from people born roughly the same time as Michael, all who are living normal lives and we've compared Michael's signature with these other 60 people.
OK, open the envelope, and the Oscar goes to So, there's two graphs here.
The first graph is really just to show you the score of each of the individuals you've been compared with.
So, as you can see here at one end of the scale, and you're surrounded by a number of individuals who are What I'm trying to guess is, am I at the good end of the scale or the bad end of the scale? Well, you have to look at another graph in order to know that, so this is the distribution of scores.
You can see that you're low score.
And is a low score good or bad? Unfortunately, in our clinical analysis, an individual with a low score, that tends to associate with a higher risk of age-related diseases.
OK.
Some of our marker genes are at places in the genome which you tend to have particular individual cancers five to ten years earlier than average.
Right, so I have a greater risk of developing those cancers earlier, not necessarily a greater risk of getting them, but just they're likely to occur earlier? Yeah, exactly.
Right.
The strongest data we've got is the association with dementia and cognitive dysfunction and perhaps because those diseases are essentially a type of accelerated ageing.
This is not good, is it? This is experimental, but there are only three people out of 60 with a lower score than me.
Now, there are always caveats to data and the way the scientists present data, so we've compared you with 60 people here.
It's plausible that we've compared you with 60 people who have relatively good healthy ageing scores and they're making you look bad.
Statistically, that's not so likely, but it'sbut it is possible.
That's not a particular straw I feel impelled to clutch.
At the simple level, what it suggests is that there are some people who probably need to be more careful about their health and I appear to be one of those.
Yeah.
Right.
Thank Thank you.
Yeah, no, that's been quite sobering.
I must admit, I'm quite shaken, and I suppose at one level, you can say that if you keep on doing tests, inevitably you're going to come across some that give you results you really, really don't want to hear.
I guess, all I can really do is be careful and pay attention to my lifestyle, and in that sense, the test has been motivating.
It hasn't induced panic, but it could have.
I'm still grappling with what it means, and I suspect that it's part of a thing that I think more people are going to have to grapple with.
On both sides of the Atlantic, there are mounting concerns about the impact of more and more health tests.
Whenever we look for early forms of disease, we are getting ahead of symptoms and when we get ahead of symptoms, that means we're telling some people that something's wrong that will actually never bother them, and that's a balance we all need to understand because it is entirely conceivable if we test the population for all sorts of diseases, it's literally a recipe to make all of us sick and to intervene on all of us, and I think that's not good for population health.
This is a helpful metaphor.
This is the clear water of health which is something that just doesn't impinge on you.
You live your life, your body does what you expect it to do, you don't have to think about it, you don't have to obsess about it.
But if you are told that a test has shown something, that seeds fear.
People worry about it.
And once the black ink of fear is in the clear water of health, you can't take that fear out again.
What I am talking about is frightening well people.
It's time to leave the well people alone, concentrate on the sick people, use our resources to help people who are sick and suffering and stop doing this to people who are well.
People like Iona think the money the NHS spends on screening would be better spent elsewhere.
For the last 20 years, we have been systematically taking away resources from people who are sick and devoted them to worrying the well .
.
for pretty marginal benefit.
I think it's important for people to ask themselves what they really most want out of their medical care system.
What I would suggest is a system that excels in the care of the acutely injured and sick.
That's what youthat's when you really want medical care.
When something really goes wrong, you want access to good treatment.
In a way, our problem is to do with seeking technological solutions to existential problems.
We all have to get old, we all have to die, we will all lose people we love.
Technology cannot stop these things happening to us, but we are kind of clinging to the possibility that it might.
Now, personally, I'm not as sceptical about health tests.
While all come with risks, some are more clearly beneficial, if embarrassing.
It's only by weighing up the evidence for and against the particular test that you can make the personal decision whether to have it or not.
I do think people need to be informed and they need to do something with the information.
For example, it may seem obvious, but there are lifestyle changes you can make, and the best evidence that they work comes from a study done in Wales.
In 1979, researchers began tracking the lifestyle choices of 2,500 men in the town of Caerphilly.
At the beginning of the study, the men were assessed to see, out of five, how many healthy behaviours they followed.
Did they smoke? Take regular exercise? You're a walker, OK.
Yeah, yeah Did they eat healthily, keep their weight down and drink in moderation? I don't overdo it.
Half a pint of Guinness a month.
Professor Peter Elwood from Cardiff University set up the study.
Can I introduce Mr Mosley? Hello.
He's one of the top men in the BBC, he does nothing but talk! Have a seat.
One of the men is a skydiver.
Still? And he is due to do his 30th dive later this year.
Wow! Be a good way to go! ALL LAUGH In many ways, it seems blindingly obvious that eating more fruit and veg, doing a bit more exercise, not smoking, they're all good things to do.
I mean, why do you need to do a study? To give quantitative evidence.
Simply saying, "If you lose weight, "you will reduce your risk of diabetes" By how much? Now, our study, over 35 years, can put very exact quantities on the answer.
Now, that is so much more encouraging than just telling people blandly, "Oh, you should take more exercise.
" They all know that.
We are very confident on the results that we've produced and the results are remarkable.
They certainly are.
Do some exercise, eat healthily, and keep your weight down, don't smoke, drink in moderation.
It turns out that following at least four of these rules delays dementia by seven years, reduces the chance of having a heart attack or stroke by nearly 70%, and could give you six extra years of life.
The Caerphilly study is a stark reminder there are better ways to ensure a healthy life than testing to see what you might come down with.

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