The team see whether coconut oil can cut cholesterol, discover how much fruit is too much and investigate a sleep disorder that causes up to 40,000 road accidents a year.
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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 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 am Michael Moseley, 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.
This time, we're coming from Cambridge
where we're carrying out the largest study ever done in the UK
looking at the impact of coconut oil on cholesterol levels.
Could it really be healthier than butter
and even cut our risk of heart disease?
Also, what can genetic testing kits really tell you?
What can you do about losing your hearing?
It's not just learning a skill, it is brain training.
And, how much fruit is too much?
Sales of coconut oil are absolutely rocketing because of health claims.
We're spending £16 million a year on it,
an astonishing 70 times more than just six years ago.
Coconut oil is a so-called superfood.
Its enthusiasts claim it will cure everything
from bad breath to digestive disorders.
You can even use it as a moisturiser.
But perhaps the most surprising claim is that eating this stuff can
cut your risk of heart disease by reducing your cholesterol levels.
If true, could coconut oil be a healthier
yet equally tasty substitute for butter?
Some people claim the reason coconut oil is good for your heart
is because it reduces levels of harmful cholesterol.
Others say that's nonsense, it RAISES cholesterol.
Claims based on the fact it's more than 80% saturated fat -
more even than butter.
So is coconut oil a cholesterol-busting wonder food?
Or is this all simply dangerous hype?
To find out, we've teamed up with the University of Cambridge
to run a ground-breaking experiment.
We've recruited nearly 100 volunteers, who are all over 50,
to test what effect eating coconut oil compared to other fats
will have on their cholesterol.
We're splitting our volunteers into three groups.
Every day for four weeks, group one will eat 50g of coconut oil.
That's about two tablespoons.
Group two will have 50g of olive oil,
a fat that is known to lower harmful cholesterol.
Group three will eat 50g of butter a day which,
like coconut oil, is high in saturated fat.
Helping us run the study are Professor Katie Koor and Professor Nita Forouhi.
They're going to be looking closely at two different types of cholesterol.
LDL cholesterol is the bad cholesterol
and it's linked with increased risk of heart disease and stroke.
So hold on to that, LDL is bad.
There's also another type of cholesterol, HDL cholesterol.
And that is supposed to be good
because it takes away the bad LDL cholesterol.
OK, so I was always taught saturated fat raises LDL levels.
We know that coconut oil is rich in saturated fat,
so presumably it's bad for your heart.
Yes, that's why it's so surprising that there are so many health claims
that coconut oil is good for your heart.
Also, it's now marketed on a large scale and so we really need to know
what the health effects are in the British population.
Before our volunteers start their oily regime,
we're taking baseline levels of both types of cholesterol -
the bad LDL and the good HDL.
We'll repeat these measurements at the end of our trial.
Every day for four weeks,
our volunteers have to incorporate their 50g of oil or butter
into their diet in whatever way they choose.
Jacket potato, it's got some butter on it.
A month later, and our volunteers are back.
So, what happened?
-Hello, thank you very much for coming along.
Want to knock back a pint of fat before we get going?
OK, results time.
Well for LDL cholesterol, which is the cholesterol
that's associated with increased risk of heart disease,
the people who were taking butter on average increased their
LDL cholesterol by 0.3 millimoles per litre which is about 10%.
Right, so the poor old butter group, their heart disease risk went up,
but in a way that was kind of completely predictable, correct?
-And when you stop having that butter, it reverts again.
On the olive oil,
there was a very small average reduction, not significant,
so essentially, no difference in LDL cholesterol on the olive oil diet.
OK, so now for the big one, coconut oil.
Well, LDL cholesterol for coconut oil went down by .09 millimoles
per litre, so no overall increase in LDL cholesterol...
..which was really a big surprise for us, and not in line
with what we've come to believe from previous studies.
So butter raised LDL and olive oil did not.
Both as expected.
But, surprisingly, neither did coconut oil,
which is high in saturated fat.
The fact that it didn't is really, really surprising.
We also measured HDL cholesterol, which is the good cholesterol.
And we found that coconut oil increased your good cholesterol,
HDL cholesterol, more than olive oil and butter.
Butter and olive oil both raised good cholesterol by about 5%,
but coconut oil raised it by an impressive 14%.
And because it helps remove the bad stuff,
the more good cholesterol you have, compared to bad,
broadly, the better.
So in our study coconut oil did not raise bad cholesterol,
despite being high in saturated fat,
and it also seemed to increase good cholesterol.
So I must admit, I found that surprising,
the idea that you can eat something that's rich in saturated fat
and your LDL levels don't go up. Why?
One explanation is that coconut oil is rich in lauric acid,
which may be processed in the body differently from
other saturated fatty acids.
So I guess the message from it is not all saturated fats are the same
and it is possible that some saturated fats are actually beneficial.
Within saturated fats there are actually probably good
-and bad saturated fats.
-And the art is identifying the good ones.
-That's the challenge.
-So, watch this space.
Further studies are needed to find out the long-term effects
of coconut oil on health,
but our results were unexpectedly good.
So I'm not going to be glugging it by the litre,
but I'm certainly going to be using it more in my cooking.
A staggering 40,000 road accidents a year are thought to be caused
by people falling asleep at the wheel
due to a medical condition they don't even know they have.
GP Dr Zoe Williams has been finding out how to recognise it
and what you can do about it.
Around 1.5 million people in the UK
are thought to have sleep apnoea, a condition that can seriously
deprive you of sleep, sometimes without you even knowing.
Sleep apnoea causes its sufferers to temporarily stop breathing whilst asleep.
So people will fall asleep, stop breathing, wake up,
and start breathing again.
Over and over, sometimes hundreds of times each night.
Surprisingly, all this can happen without the person being aware of it.
But it can lead to you falling asleep during the day,
sometimes with devastating consequences.
Nearly 12 years ago, lorry driver Colin Wrighton had a tragic accident.
I just looked out my window and saw this pile-up.
Said to myself, "Oh, what happened here?"
Not realising that it was, it was me that had caused it.
Colin had fallen asleep at the wheel
and his lorry ploughed into a line of stationary traffic.
25-year-old Toby Tweddell lost his life in the collision.
Initially they obviously thought, oh, had I been drinking?
Had I been on drugs? Had I been using my telephone?
You know, all these went through their mind,
and that's what they were thinking.
Going back three months before this accident happened,
I'd gone to my doctor and asked him why do I keep feeling tired
more than normal. It was, it was hard to explain cos
I didn't feel tired, but I was sort of tired.
And he said, "Oh, you might be diabetic,
"we'll send you for blood tests or your cholesterol might be out."
And they all came back, nothing wrong with me.
If the doctor had known about sleep apnoea,
if they had sent me to a sleep clinic,
then that accident would never have happened.
The condition is often missed or misdiagnosed.
Sleep expert Dr David Jones
began to suspect this might be what was wrong with Colin.
First, Colin completed a simple questionnaire
to assess his likelihood of nodding off during the day
in certain situations, like reading a book,
watching TV, or in a meeting.
This gave Colin a score of 20 out of 24
on what's known as the Epworth sleepiness scale.
So David did a sleep study overnight at the hospital to observe Colin.
David's repeating that test to demonstrate Colin's problem.
Here we can see that Colin has stopped breathing.
There's no air flow.
We can see that he has started to try and get some air flow here,
and here he's woken up and is recovering
and this is the thing which causes him to be
waking up during the night and coming through and being
very, very tired when he wakes up in the morning.
Colin has obstructive sleep apnoea.
When he's sleeping, he can stop breathing up to 70 times an hour.
When Colin's awake, his airways open and he can breathe normally.
But when he goes to sleep, like many of the muscles in his body,
those in his neck relax,
and that means the weight of his neck can push down
on the airway and obstruct it. That means he can breathe any more.
Once the brain detects that he's not breathing,
it forces him awake so that he starts breathing again.
You're more likely to have sleep apnoea
if you're overweight, male, and over 40.
A large neck or recessed jaw also increases your risk.
As well as constant tiredness,
the telltale symptoms include waking up with a dry mouth,
or headache, and snoring.
Losing weight may reduce the severity of your sleep apnoea,
but what else can you do?
The gold standard treatment is a CPAP machine.
This is a little machine, this one.
And this sits on the bedside and it blows air through a tube,
through a mask, which fits on the patient's face...
-..and enables them to keep breathing,
nice and evenly and steadily throughout the whole night.
People find huge positive benefits, completely life-changing.
Being prescribed a CPAP machine transformed Colin's sleep patterns.
And in the years since the accident, he's been campaigning
to raise awareness of the condition that caused it.
I want to make people realise it's a silent killer.
It's all in memory of Toby
and that's why I'm doing the campaigning.
I think, I think what you do, Colin, from such a tragedy,
if we make ten diagnoses for making this programme,
-that will save lives.
-Yeah, it will.
The DVLA recognises that with the proper treatment,
sleep apnoea doesn't affect your ability to drive.
So a diagnosis won't cost you your licence
if you get the right medical care.
GPs are improving at spotting the subtle signs of sleep apnoea,
but we need to get even better at diagnosing this condition.
The Epworth sleepiness scale is a simple questionnaire that you can do
on your own or with your GP.
So if you have any concerns about yours or your partner's
daytime sleepiness, please, do go and see your GP.
Still to come, what can genetic testing kits really tell you?
And what can you do if you're losing your hearing?
Thousands of you have been sending in questions to the Trust Me website,
and we've been finding answers to some of the more popular ones.
Can eating a lot of fruit be bad for you?
One for geneticist Giles Yeo.
From an apple-a-day to the government's mantra of five-a-day,
if there is one health message that's been drummed into us
since we were kids, it's that eating fruit is good for us.
But recently, the health headlines have been full of claims
that challenge this long-held idea.
That's because fruit has a high sugar content
and, as we all know, too much sugar is bad for us.
So is fruit nature's superfood or a sugary health hazard?
A useful clue can be found at the zoo.
In order to survive, animals, including us,
have a rather pretty good sense about what is safe to eat.
If it tastes bad, it generally means it's poisonous - avoid.
If it tastes nice, however, like the fruit over here,
it generally means it's good for you - eat loads.
In fact, given the chance,
most of the animal kingdom will happily gorge on fruit.
That's because animals in the wild have to work hard for their food,
and fruit packs a nutritional punch,
giving them both sugar for energy and a dose of crucial vitamins.
The trouble for us humans is,
these days it's easy to get our hands on fruit,
far more of it than our bodies need.
But can it really do us any harm?
Well, when it comes to overdosing on vitamins and minerals in fruit,
the answer is generally "no".
Our bodies can't store a lot of these nutrients from one day
to the next, so if you have more than you need,
you don't get any nutritional benefit from it,
you simply wee it out.
But what your body will hold on to is this stuff.
Eat more of it than you need and you risk becoming overweight,
which can lead to serious health problems.
And fruit contains more than you might think.
Let's compare an apple to a can of full-sugar fizzy drink.
Typically, a regular-sized soft drink contains about
seven to eight teaspoons of sugar.
This apple contains four teaspoons of sugar.
So have two apples,
and you've taken in as much sugar as you've had in this can.
That sugar comes mainly in two forms.
One is glucose, your body's preferred source of energy,
which goes straight into your bloodstream.
The other is fructose, which is taken to your liver
and if not needed, it's turned into fat.
These are chemically identical to the sugars you get in junk food,
so if you're not careful, they can cause you the same problems.
Sugar is sugar and you're going to gain weight
if you eat too much of it wherever it comes from.
So how can you get all the health benefits of fruit
without overdosing on sugar?
Well, the first thing is to choose your fruits carefully.
Gramme-for-gramme, bananas, cherries, pomegranates,
mangoes, grapes, and figs all contain more than
watermelon, raspberries, kiwi fruit, and fresh cranberries.
The riper the fruit, the more sugar it contains,
so try not to leave it lying around for too long.
You should eat most of your fruit whole
and no more than one glass of juice or smoothie,
as digesting the fruit releases the sugar more slowly
and avoids overloading your system with one big hit.
Finally, don't neglect veg.
There is no vitamin or mineral in fruit that you can't get from veg,
in return for only a fraction of the sugar.
While fruit is clearly healthy and natural,
we need to resist the call of our genes
and actually watch how much fruit, and therefore sugar, we eat.
In this series of Trust Me,
I've been investigating some of the most controversial health questions
that have made the headlines in the decades
that I've been a health journalist.
To get to the bottom of them, I've lined up a series of experts
with opposing views. This time, we're looking at genetic testing.
There are plenty of DNA tests out there,
which look into your genes and then offer you advice on
what you should eat and how you should exercise, as well as
telling you about your risks of developing things like cancer
or Alzheimer's, but how reliable and useful are they?
It's widely agreed that there are two important limitations
to any form of genetic testing.
First, most genetic conditions are not caused by changes
in a single gene, but by several in combination.
Secondly, the environment also has a huge influence on their effect.
Given these constraints, are the testing kits
consumers can buy really able to tell you anything useful?
Craig Pickering is a sports scientist at one of the UK's
biggest companies that sells home testing kits online,
costing £100 to £250.
He believes they can be a powerful tool for improving health.
I've tried one that claims it can tell me all sorts
of interesting things, like whether I'm lactose intolerant.
I have the results of my DNA test here.
So this says that I'm lactose tolerant.
How confident are you in this result?
So when we're talking about lactose intolerance,
it's just one gene that we're looking at,
so really, we're very, very confident, 100% confident,
that that version of that gene tells you
whether you can or can't digest lactose.
That is a single gene change, if you'd like, which you can detect,
but for most of this stuff, it isn't like that.
-It's much more complicated.
-We are certainly very confident
in the impact that we say it has,
but the context for the person will differ from situation to situation.
Why should I believe what's written down here?
Every gene that we test for,
we put that through a really rigorous scientific process, so
we look at all the research on it, it has to have a minimum of three
studies done on it, in humans, with a clear consensus of its effect.
Done on large numbers of people, so we can be as sure
and confident as we possibly can be that that gene has the effect
-that we say it does.
-Don't you think it should be done in proper
-professional hands, your GP for example?
-Yeah, I always agree,
I would love the NHS to offer genetic testing to everybody
to give them the ability to make lifestyle changes which will improve
their overall health, which then will have a knock-on effect of
reducing the burden on the National Health Service
-cos people will be much healthier.
Next, I'm meeting professor Frances Flinter, a clinical geneticist
at Guys & St Thomas Hospital. She's highly sceptical
of the benefits of consumer genetic testing kits.
So what do you think about these commercial DNA tests
you can buy which offer you advice on everything,
from how you should exercise to what you should eat?
I think we all know we should eat more fruit and vegetables
and most of the genetic tests that people have done to look at
what sort of diet they should eat generally come back with
a recommendation that they should eat more broccoli,
and you don't need to pay a lot of money to find out that good advice.
At some level, it seems like harmless fun.
And it's better to have a bit of information than no information,
-so, kind of, what's wrong with it?
the technical sequencing of the DNA is fine.
People are very good at doing that now,
but the commercial companies tend to only look at certain parts
of the DNA, so they will miss some significant mutations
simply because they're not testing for them.
The other concern is that it may reveal information that
once you've got it, you decide you really would rather
not have known about, and it may reveal information that has
implications for other members of your family,
such as your children, which you might not have thought about
-before you had the test done.
-Would you encourage or discourage
someone like me, who's reasonably healthy,
from doing one of these genetic tests?
Yes, I would discourage it because
the chance of it giving you any useful information is very small.
So, are genetic tests useful?
Well, if all you want to get out of it is some advice on
what you should eat and what form of exercise you should do,
then it's entirely up to you how you spend your money.
If however, you really do want an answer to a serious
genetic question, you would clearly be better off going to your GP
and getting a referral to see a geneticist.
10 million people in the UK, one in six of us,
has some degree of hearing loss.
Now, that's seen as an almost inevitable part of ageing,
but there is emerging evidence it's linked to wider health problems.
So, what can we do about it?
Dr Alain Gregoire has been finding out.
I'd like a cappuccino with chocolate on top, please.
I suspect my hearing isn't as good as it used to be,
so I've been looking into some surprising ways to help us cope
with age-related hearing loss.
Gradual hearing loss is far more than an inconvenience.
It can lead to social isolation which, in turn,
can contribute to mental health problems such as depression.
And there is research suggesting that it may be linked to
your risk of developing dementia,
so it's really important that we don't ignore it.
Yet on average, people suffer for a staggering ten years
before they seek treatment.
Many are worried about being given a large, obtrusive hearing aid.
But these are far more discreet and effective than they used to be.
Another reason many people don't get the treatment they need
is they simply don't notice that their hearing is declining.
One reason that it's tricky to spot gradual hearing loss,
is our brains have a surprising way to compensate,
and we're not even aware of it.
I can demonstrate this effect on myself, with a little help.
My friend Michael has sent me a couple of video clips
and I've got to listen, and watch, and decide what he's saying.
Well it's pretty easy really. He's just saying "bar" repeatedly to me.
Sounds a bit like a sheep really.
Let's see what the next clip shows.
Far, as in over there in the distance.
So what was Michael trying to prove with those two clips?
Alan, you might be surprised to learn that it was exactly
the same sound in each of the clips.
The only thing that changed was the pictures.
That's really amazing.
In the second clip, although the sound is "bar",
Michael is actually mouthing "far"
and that's what my brain tells me I'm hearing.
What's happening here is my brain is prioritising
what I'm seeing over what I'm hearing.
And this is something we can all use to our advantage
to help us cope with hearing loss -
an area that's being researched by auditory neuroscientist
Dr Jennifer Bizley.
We used to think that dedicated bits of the brain did hearing
and a separate bit did vision
and only later was that information put together.
Now we know that actually there's crosstalk between the senses
at a really early stage.
And one of the things that we think the information could be doing
is helping you in situations that are difficult,
like listening in a noisy restaurant.
Being able to see a mouth movement or see gestures might
allow you to pull that person's voice out of a sound mixture,
out of the noise, more effectively.
So the effectiveness of your hearing is dependent on your sight
and your processing as well?
Yes, so we know that as people age, their processing speeds slow down.
-And that can really impact upon not just your ability to listen
to someone in a noisy situation,
but actually how much effort it takes to do that.
So it might be that you CAN hear people, but it's exhausting.
And so any little extra piece of information that you can get,
for example through vision, will really help you to
both communicate more effectively
but also to find that process less effortful.
So to help you hear better in a noisy situation,
it helps if you can see better too.
If you're with other people, place yourself in the middle of the group.
Have the light behind you to help you see the other person clearly.
Ask people to face you when they're talking to you
and not cover their mouths.
And there's something else you can try.
I've got a little exercise for you to do.
Have a look in your mirrors and say the word "fast".
Many of the people in this class suffer from age-related hearing loss.
I find it very difficult at dinner parties and other noisy environments
to hear, because everything is just competing for my attention.
You don't feel like you're with everybody in the same room.
Molly Berry runs the lip-reading class
and is chair of the Association Of Teachers Of Lip-reading To Adults.
It's not just that you are learning a skill that's going to help you,
it is giving you brain training,
training your brain to look and listen at the same time
and get the gist of everything that's happening,
which helps you not to get the cognitive decline
that can be associated with hearing loss.
Now, I feel confident in talking to someone and focusing on their face.
I was in depression for a little while,
but went to a lip-reading class and
just realised there was another way of coping.
So although there's no cure for age-related hearing loss,
there's plenty you can do to help improve things.
The important message here is
if you think you're hearing's deteriorating, don't delay.
Get help from your GP who'll be able to rule out any
temporary causes and refer you for a hearing test if you need it.
That's it from us.
Next time we're in Guildford,
where we will find out which is healthier -
carbs for dinner or carbs for breakfast.
Michael Mosley runs an experiment to test the claim that coconut oil can cut cholesterol. Giles Yeo investigates how much fruit is too much. Zoe Williams investigates a sleep disorder that causes up to 40,000 road accidents a year. Michael quizzes two experts on whether genetic-testing kits are worth the money. And Alain Gregoire finds out how you can use your eyes to help cope with age-related hearing loss.