Episode 4 Food: Truth or Scare

Are you getting enough of some essential foods?

Because countless reports claim

you're either having too much or too little.

But how much is enough?

Don't worry, we've been finding out.

Every day, we're bombarded with conflicting information

about our favourite foods.

One minute, we're told something's good for us, the next it's not.

And we're left feeling guilty about what we're eating.

Well, we've been wading through the confusion

to separate the scare stories from the truth

so you can choose your food with confidence.

Hello and welcome to Food: Truth Or Scare.

Now, this is the series that helps you fathom the facts about our food

so that you know which of all those confusing claims

about the things we eat are actually true.

Whether it's a health website, a TV show,

or indeed a newspaper headline,

there often seems to be no end of reports

telling us we should have more of this or less of that

if we want to guarantee good health

and steer clear of some serious conditions.

But trying to find how much is enough,

or indeed too much isn't always easy.

You're absolutely right. And hopefully that's where we come in.

Because, as we find out in today's programme,

get it right and the food we eat can have some really impressive,

and, I have to tell you, some really remarkable powers.

Coming up:

We're bombarded with claims of how much water we should drink,

but could you be dangerously dehydrated?

Headaches, tiredness, fatigue,

irritability, lack of concentration -

all of those can be brought on by dehydration.

And if you've never given a passing thought to the bacteria in your gut,

we investigate the claims that might change your mind.

Your gut and the lining of your gut is really, really important.

Is there any good bacteria in a full English breakfast?

Not really, cos most of it's been fried,

so all the bacteria's been destroyed.

Well, now to something that I can guarantee affects all of us - water.

Or, more importantly, how much we should be drinking every day.

Now, while in the face of it this should be a simple question,

there are a lot of very confusing messages about how much is right

and a whole host of claims about how bad it can be for us

if we don't have enough.

So I wanted to find out how much water

we really need to drink every day.

So cheers.

There are some things in life that should be simple and, let's face it,

the amount of water we need to drink every day

really should be on that list.

But look for the answer online

and in the papers,

and the whole subject

becomes surprisingly complicated.

Some sites say we should

sip it all day long,

while others claim

there's no need to do that

because we get all the water

we need from our food.

And while plenty say they've got the answer, they don't always agree.

So I've asked dietician Alison Clark

to help me navigate these choppy waters.

But I can't help but think

this is all a bit of a storm in a teacup.

So is it not enough just to drink when you're thirsty?

Well, it's a common myth

that people say, "Just drink when you're thirsty."

In fact, when you're thirsty, you're already dehydrated.

So we shouldn't really go on our thirst mechanism.

And also, as we get older, we're not very good

at distinguishing between thirst and hunger,

so we'll often reach for a snack,

when it's actually just fluid that we need.

There you go, drink the right amount

and you'll avoid getting thirsty in the first place.

But how much is enough can be a surprisingly thorny issue.

For decades, the Government has said we should all drink

six to eight glasses of water every day,

but do the customers in this pub

know what size those glasses should be?

Oh, I'm probably more this kind of size.

-This size?

-Yep.

Say about that size.

That one? OK.

My container is probably six to eight of these.

-So I think it's probably nearer the quantity I drink.

-Right, right.

-Probably...that one.

-This one here?

-Yeah.

And how much do you drink a day?

Um, probably about four glasses, I'd say.

But most days I probably just forget.

-Two pints?

-Yes.

VOICEOVER: The official guidelines say we should be drinking

between six and eight of these every day. That's about 1.2 litres.

Anything less and we risk dehydration.

Often we get headaches, we have tiredness, fatigue, irritability,

lack of concentration - all of those can be brought on by dehydration.

I suppose the big question is, how can we tell if we are dehydrated?

Well, there's one easy way,

that's very individual to your own circumstances,

and that is looking at the colour of your own urine.

Yes, you heard right - too much information,

but I'm sure we've all heard that the stronger the colour,

the more dehydrated we are.

But Alison says we should all be aiming

for a number one, two, or three on this chart.

If I'm number one, for example, does that mean that's good?

You're adequately hydrated, and well hydrated.

So that would be a good indicator.

Four, five, and six,

that would indicate that you need to start hydrating more.

Remember, these colours don't count

for your first trip to the loo after waking up.

But, the rest of the time, anything darker than a four

means you're dehydrated.

And a seven or eight could lead to something more serious,

like decreased kidney function.

But how many of us hit the top of the charts?

Well, to find out, Alison is running a test

with a group of people who should know their fair share about water.

It's the staff at Essex & Suffolk Water.

Every time they head to the loo,

she's asking them to record the colour by spending a penny.

And, while the coins start to stack up,

Alison quizzes the team about their drinking habits.

Try to do a litre every, sort of, couple of hours.

Probably four or five cups of tea a day, as well.

Two or three glasses throughout the day.

-A litre, just if I'm on a non-active day.

-OK.

On a proactive day, I would probably say a couple.

We know that dehydration impairs performance at work,

things like concentration,

and also makes you irritable, being dehydrated.

-Oh, does it?

-Yeah.

-I didn't know that.

In eight hours' time,

Alison will count the number of pennies in each jar

and evaluate just how hydrated the staff here are.

What about those headlines that say

the amount of water we need

is entirely individual?

Well, Alison says those

are true and depends on

our lifestyle.

Whilst these office workers are not doing anything very physical,

it's a different story for fitness coach

and spinning instructor Phil Flood.

Keep our speed at 100+ RPM.

Good.

He's putting a class through an intense spinning session,

where they'll all sweat a lot.

If they don't replace the water their bodies lose,

they'll become dehydrated.

When I do exercise, yes, I like to sip some, a little bit of water.

But although they're all doing the same exercise class,

his students won't all lose the same amount of water,

nor will they be as good at replacing it by drinking.

We can see the differences

by weighing them before and after class.

Let's go, speed up!

If they're lighter at the end, they've lost more than they drank,

increasing the risk of dehydration.

45 seconds above 120. Let's go!

If they weigh more afterwards, they've drunk enough

to replace what they lost through sweat.

Small sips.

Well done.

Excellent, guys. Top class.

The after-class weigh-in revealed some surprising results.

72.2.

Dalen, Dot, and Marco were very nearly the same

as they had been before the class,

so they drank enough water to replace what they lost.

Nacho increased his hydration,

taking on 700ml more water than he lost.

But things are very different for trainer Phil,

who was 600g lighter after the class,

and Shai, who lost a whole kilogram of water

from just half an hour spinning.

Now, if he didn't replace that very quickly,

he'd start to see the side effects of being dehydrated.

Good.

Good.

Which is why the official advice is that we should drink

more than 1.2 litres of water a day when we exercise.

So reports that say we all need a different amount each day are right.

But if you're not a regular down at your local spinning class,

you might look at headlines

like this, which says

we get all the water we need

from our food

and think eight glasses is too much,

especially if you eat

lots of fruit and veg.

So does that mean that

we don't need to worry

about sipping water

all day long?

Well, Alison and I are getting to the bottom

of just how much water really is inside some of the food we eat.

We've brought three meals to a company of centrifuge specialists,

where Jeremy Barker's going to spin them so fast,

it will separate the liquid from the solids.

Have you seen this being done before, Alison?

No, I haven't, it's fascinating.

-Fascinating, isn't it?

-Yeah.

-Really good.

First up, breakfast -

a fruit salad and a bowl of cornflakes.

Now, I'd normally have a decent serving of milk with my cereal,

which of course would count towards my eight glasses of water a day.

But, without that,

the fruit that those reports

say could account for a lot

of my daily water needs

isn't really going to

quench my thirst.

The majority of this water is actually coming from the fruit.

So, really, from, you know, a dish of cornflakes

and a bit of fruit, that's the amount of water.

Up next, it's lunch and it's a high street meal deal,

with a bacon, lettuce, and tomato sandwich, a packet of crisps,

and a bar of chocolate.

Once again, the fruit and veg is doing very little

for the meal's water content.

Oh, nothing in there.

Nothing? Oh, let me see.

You might have to tip it to one side.

-Nothing in there. No, OK.

-No.

-No.

-I thought there'd be a lot more water in there.

Now, the meal deal you might buy those in

will probably come with a drink as well,

and you certainly need it because there's no water in here.

But, Gloria, that doesn't surprise me

-because most processed food is low in water.

-Right.

Which actually brings us, then, to dinner.

Which is a cottage pie.

While that might be ready-made,

the carrots and green beans that go with it are fresh.

But, once again, it's surprisingly dry.

I just have a bit of oil in this one.

-Yeah, small amounts.

-Same for me.

Normally in a cottage pie, you would expect a lot more water to come out.

When you make it at home, you'd hopefully put more vegetables in,

and that can increase all the fluid content.

While the reports aren't wrong

about fruit and veg having the highest water content,

they are wrong to say that we can all get what we need from our food.

I mean, what I draw from this experiment, personally,

is the fact that you cannot depend on food in order to get water.

No, indeed, that's right.

We only get about 20% of our fluid requirements from food alone.

So we need to really make sure that we are drinking enough water

throughout the day.

That's why the official recommendation we should all have

six to eight glasses a day stays the same,

however much you eat.

So have the staff at the water company been keeping up?

Alison is back to check their results.

All day, every time they've spent a penny,

they've been keeping track of its colour.

The higher the number and the darker the colour,

the more dehydrated they are.

They should all be aiming for one to three.

So 60% of you are well hydrated,

putting your pennies in jars one to three.

But it does mean that 40% of you were dehydrated.

So you can see that there were quite a few pennies

in the jar at number four and five,

and we even had a penny in the jar at number eight.

Well over a third of the samples were from staff who were dehydrated.

And that could lead to things like headaches, tiredness,

but also more serious things like lack of concentration,

and problems with short-term memory.

So are the results that we're seeing here today

comparable to the rest of the UK?

We do know that, in workplaces, you are generally dehydrated

because you're very busy,

people tend to have a bottle of water on their desk,

but forget to drink it.

How many glasses of water should you drink in a day?

So NHS Choices recommend that we drink six to eight glasses a day,

and that should equate to about 1.2 litres a day.

Now that can include things like water, no-added-sugar squashes,

and also things like fruit juice.

If you have fruit juice or smoothies during the day,

that only counts up to 150 ml because of all the sugars present.

Alcohol doesn't count

but, despite claims about caffeine having a dehydrating affect,

the guidelines say up to eight cups of tea

and four cups of coffee a day to count towards your total.

And anything over this could have a dehydrating affect.

But, whatever you drink, there is a way

you can help your body make the most of it.

Sip your fluid throughout the day.

Because what tends to happen if you take too much water

and kind of glug it back all in one go,

effectively your kidneys think they're drowning.

So, actually, the kidneys

just get rid of that water very, very quickly.

And, ironically, that might make you dehydrated.

The answer is pretty simple - we're all different

and, as long as we're sipping water throughout the day,

we'll stay at the top of Alison's chart.

And, although we can't rely on food for the water our bodies need,

I, for one, am delighted to hear that tea and coffee

do count towards that daily target.

If you want to stay hydrated but need a change from tap water,

head off to bbc.co.uk/food for soft drink recipes,

along with ideas for some of the other foods

that we're talking about all week.

Now, Gloria, how happy is your gut?

Here we go. Apart from being too big, it's all right, thank you.

Well, I wouldn't say it was too big at all.

And you know how many types of bacteria might be in there?

Frankly, no. But I'll tell you, when I have antibiotics,

the doctor always says to put good bacteria back in.

That's all I know.

Do you know, I hadn't given it much consideration either,

but it turns out that the bacteria in our guts

might be a lot more powerful than you realise.

Depending on which report you read,

it's claimed that it can influence anxiety,

make it harder to lose weight, and even affect arthritis.

But those reports don't always see eye to eye

on the best way to keep your gut healthy,

especially when it comes to those little drinks,

or those yogurts that say they're packed with gut-friendly bacteria.

So, to find out whether the way to good health and happiness

really is through the stomach,

and, if so, what I need to do to keep mine content,

I started out with a group of people

whose diets aren't always considered the healthiest.

Day in, day out, roadside caffs like this...

..serve a steady stream of fry-ups, easy-to-grab snacks, and sandwiches.

-What can I get you?

-Um, sausage and egg.

-Two, yeah?

-Yeah. With brown sauce.

One sausage and a egg, please.

It's filling, tasty food.

But do the customers ever think about what it might be doing

to their gut health?

-Do you ever think about how happy your gut is?

-Um, sometimes.

Do you think it's healthy?

-Mine? No.

-No?

-No.

So, sir, do you think about how healthy your gut might be?

Um, no.

Do you ever think about how happy your gut is?

No. Should I?

Well, all manner of reports say, yes, we should.

Because a gut full of lots of healthy bacteria

is not only essential for keeping our bodies running smoothly,

it can boost memory and keep us healthier in our old age.

Meanwhile, an unhealthy gut

could worsen anxiety,

keep us dependent on fast food,

and even ruin our attempts to lose weight.

Now, I can't imagine dietician Dimple Thakrar

comes to many diners like this,

but today she's meeting me here with some key facts about our insides.

How important is it to have a healthy gut?

It's a barrier.

-So, if your gut isn't healthy, that barrier becomes weak.

-Right.

So therefore you're going to get toxins going into your system

that shouldn't be there,

causing inflammation and, in effect, causing disease.

So your gut, and the lining of your gut, is really, really important.

Right, so it's like a filter system?

It's your filter system, absolutely.

It's a huge organ,

and it's the only organ, apart from your skin,

that's exposed to the exterior.

While there's no doubt how important a healthy gut can be,

there's plenty of debate on the best way to get one.

And one of the most popular ways

is by using a probiotic product containing live bacteria or yeast.

Some reports say these products

will vastly improve your existing

intestinal bacteria, and therefore

your overall gut health.

Others say they are

a complete waste of money,

and that you can get

all the bacteria you need

from eating healthily.

The customers here weren't sure what to believe.

What about the gut bacteria, do you ever think about that?

Sometimes, but that's only when I'm eating the yogurts.

-Do you have those?

-Yes.

Brilliant, do you think they work?

I'm not sure, I'm not a medical expert.

What do you think you could do to make it happy or healthy?

I've never tried any of those bacteria drinks

or yogurts or anything.

But one thing is clear -

the customers won't be getting the greatest start

from this caff's bestsellers.

So, is there any good bacteria in a full English breakfast?

Not really, cos most of it's been fried,

so all of the bacteria's been destroyed.

However I did notice there was some yogurt over there,

so if that yogurt is a live yogurt,

then there'll definitely be some great bacteria in there.

So that doesn't bode well for the gut health of the diner's regulars,

like trucker Nick Rollinson.

-Hey up, Chris.

-Hello, mate. This is a nice big cab, innit?

Nick's been driving lorries for two years,

and says he's never given a thought to how healthy or unhealthy

his gut bacteria might be.

So, what about your diet when you're out on the road?

I'll probably stop at services and have a bacon sandwich and a coffee.

That sort of sets me up for the day.

I just probably have junk food.

-Chocolate...

-Right.

..maybe some biscuits, crisps, pop.

So, do you think, would you say you have a bad diet?

I've got a bad diet, yeah.

Do you ever consider what this diet is doing to your health?

Well, I'm 47, so you're coming to a milestone,

so, yeah, I do worry about it, of course I do.

But, erm...

But obviously, the job what I'm doing, you can't always eat healthy.

It's no surprise that all that high-fat, processed food

puts Nick at a greater risk of heart disease, amongst other things,

but it's not giving his gut bacteria much to thrive on either.

And judging by what many reports,

and indeed Dimple have told me

so far, looking after his gut

could be just as important.

Morning.

So, as Nick stops to pick up a typical lunch,

I'm catching up with Dimple to see if it's any better than breakfast.

And she's not holding her breath.

I bet it's going to be chocolate. It's going to be crisps.

Quite possibly, quite possibly.

It's difficult, I think, for these guys on the road all the time.

Their options are limited.

I think it isn't always that easy to make healthy choices,

even if they want to.

Well, I would actually say that they've got used to

making the choices they make.

Cos even in the diner, there was fruit available,

but how many chose that?

Nick's choice of a chicken sandwich, crisps,

chocolate and a fizzy drink doesn't go down too well with Dimple.

So, in terms of Nick's gut health, how does this lunch stack up?

Not great. There's not much fibre in this whatsoever.

So in terms of your large intestine

and getting some really good roughage,

-there's very little in here.

-Right.

So if I went back in the shop, what would you suggest?

Swapping the chocolate bars for some fruit...

-..perhaps, would be a great idea.

-Yeah.

-Swapping the fizzy drink for some water.

-OK.

And swapping the bread for

a wholemeal or a granary kind of sandwich

with a little bit more salad in there would be amazing.

-Put some fruit in.

-Some fruit in, yeah, and water.

-OK.

Those alternatives will be less processed,

less fatty and contain more fibre,

all of which encourage healthy gut bacteria.

But even though Dimple's confident that Nick could easily pick up

a gut-friendly lunch, even in at a small corner shop like this,

he'd be forgiven for reaching for something that looks much easier -

a probiotic yogurt.

Not only are they convenient,

the health claims made about them

in some reports are impressive.

But Dimple has news for Nick.

If he was to do that, would that put this right?

No, it wouldn't cancel this out.

Surely the yogurt would compensate, or...

No, because the yogurt, the bacteria in that yogurt,

needs fibre, particularly soluble fibre from fruit and vegetables,

in order for it to work for your gut.

If you want great results and you want to be healthier and have

a healthier gut, you need to be looking at the bigger picture -

the overall diet.

Dimple's clear - if you eat a bad diet,

you can't just expect one of these products to sort your insides out.

Not that they claim that, of course,

but their advertising campaigns do make good gut health look very easy.

That's why I eat Activia Fibre.

-To help towards my digestive wellbeing.

-Hey!

So, if Nick did eat the fibre those bacteria need to thrive,

probiotic yogurts and drinks could give his gut health a helping hand.

We've come to the University of Salford,

where Dr Chloe James quickly puts that into context.

She says few bacteria ever make it to where it's needed.

OK, so, take this person.

He has a probiotic yogurt drink

that we know has good bacteria in it.

How does it get into the gut?

So, first of all, it will come down into the stomach.

The stomach has a low pH - that means it's really highly acidic -

so a lot of bacteria will be destroyed in the stomach.

So if it survives the stomach acid,

the next step is to come down into the small intestines.

So this is the small intestine here,

which has a very big surface area.

So there are trillions of bacteria in the small,

and particularly in the large intestine.

So the bacteria that survives into the intestines

is really just a drop in the ocean.

And Chloe says there is another limitation of these products.

A healthy gut has hundreds of different strains of bacteria,

but in many cases, yogurt and drinks contain just one.

One organism is not really good enough, because we rely on

consortia of bacteria that all have different jobs to make sure that

we absorb all of the different nutrients that we need.

So just one probiotic, even if it survives the stomach acid,

once they get to the gut,

if we already have a perfect consortium of bacteria there,

they're kind of just going to be lost.

So unless your body's deficient in the exact strain of bacteria

in those bottles, there's not much point.

And in 2016, one study concluded just that,

saying that for healthy adults,

there was little evidence of a consistent effect of probiotics.

And Chloe's not convinced that even Nick's unhealthy diet

would benefit from a probiotic yogurt.

I'm eating a lot of fatty food

and the diet's not the best in the world,

so would I benefit from eating one of these yoghurts?

It's really hard to give a definitive answer and say that

drinking these products will definitely be of benefit to you.

What I would advise is a balanced, healthy diet

and a healthy lifestyle.

Exercise and diet are all interlinked,

and they do, I believe, have an effect on your microbiota.

While the bottles of bacteria you might pick up in the supermarket

may not be the secret to good gut health,

there is more evidence that supplements,

which often contain many more strains of bacteria,

may have positive effects,

especially for people with gut problems already.

Studies have been done with trials where people, for example,

with irritable bowel, will take a more sophisticated probiotic,

and there has been evidence that their symptoms are relieved.

But we're still in the infancy of understanding

exactly what's causative and what's effect.

While that's encouraging, it's not exactly the type of superpower

that many reports seem to credit gut bacteria with.

They say it can boost your mental health and even control weight loss.

Chloe, however, is much more cautious than some of those reports.

This headline here about gut bacteria

that might be to blame for anxiety,

I know that studies have been done in mice where they've shown that

the bacteria that are more associated

with a healthy microbiota,

those mice were less stressed.

-So there's an element of truth to all of these.

-Yeah, absolutely.

These things are true.

There's been a strong association found between the types of bacteria

in your gut and obesity,

but we're just still at the early stages of understanding

exactly what the bacteria are doing.

Are the bacteria having all of these effects,

or are these conditions affecting the balance of our bacteria?

So we're not ready to solidly make these claims,

and we're certainly not ready to use probiotic drinks

to fix any of these problems.

Chloe might be cautious about some of the boldest claims,

but as Dimple told me earlier,

a healthy gut can be really beneficial for our overall health.

So is Nick going to swap those fry-ups

for something a bit more gut friendly?

So, knowing what you know now, are you going to give more

consideration to your gut and its health?

Salads, fruit and veg, etc, yes.

Yogurts, I'm not so sure about,

but it's certainly going to change my eating ways, yeah.

Nick might sound unsure, but he's no need to worry.

Back at the caff, Dimple says it doesn't need to take too much effort

to help your gut bacteria.

It's about having a good range,

being sensible with what you're eating.

On the whole, if we eat a lot of healthy foods,

occasionally having the odd treat, it's not going to do us any harm.

It's about a balance, isn't it?

Because I think if we told everybody in here

that they had to only eat quinoa and rocket salad,

I think we'd get shown the door, wouldn't we?

Over the next six weeks, Nick cut down the number of fry-ups,

limited himself to just a few bacon sandwiches a week,

and more importantly, started to eat more fruit, veg and fibre,

and he's seen a transformation.

Afternoon, love.

Since I've changed my diet, I feel that bit more energetic.

My gut health, it's been better, actually.

It's made me realise that I need to be eating more healthy

and it's opened me eyes to a lot of different products.

I'm certainly eating more veg, and I'm also eating a lot of fruit.

So I am trying to cut down the fat more,

and hence, I've lost a little bit of weight.

Still to come, could what we eat boost our brainpower?

-Oh!

-I feel myself getting smarter.

LAUGHTER

Cheers.

All this series, we're asking whether

some of the latest fashionable and apparently healthy foods

really live up to the hype,

or whether they're little more than a fad.

And I have to say that the one we're looking at today

is a very odd choice for me, because I'm much more used to seeing it

as something that food is cooked on, rather than an ingredient itself,

and I'm talking about charcoal.

You may well have seen the charcoal breads, pizza bases,

and even drinks are all the rage.

But I don't get it. It just looks unappetising, doesn't it?

It does. I would never, ever have a black biscuit over an ordinary one.

But if the health claims stack up,

you might be tempted to forget about how it actually looks.

So is it true that there are all sorts of benefits to your health?

Like almost every fashionable food fad, this one started Stateside.

We're using food-safe activated charcoal.

Food-grade charcoal is being mixed into everything,

from ice cream to pizza dough.

What, activated charcoal?

That's something you have on the fire, isn't it?

I know they give you charcoal if you drink too much alcohol,

in the hospital. Or get poisoned.

I've heard of charcoal for wind.

Activated charcoal?

I think someone's just taking us for a ride. Sorry.

Well, it might sound far-fetched,

but it's allegedly great for clearing toxins from your system

and can now be found in restaurants, coffee shops,

and even on supermarket shelves over here as well.

Something that's not been missed by our resident fad watcher,

dietician Linia Patel.

Activated charcoal has many bold claims.

It claims to...

..because it absorbs everything and anything it gets its hands on.

So in terms of a hangover,

it binds all the sulphites that might be causing a hangover.

In terms of the cholesterol, it's thought it binds

the bad cholesterol, excreting it out.

And very similarly, in terms of toxins like heavy metals,

it's thought that activated charcoal absorbs all of these

and just excretes them out.

For just that reason,

it's long been used by medics to treat cases of poisoning.

But the charcoal fad relies on all of us being tempted by black foods

on a daily basis, and that might be a bit much for some.

I thought it was chocolate-looking at first.

-You can't taste it.

-They're all right.

I don't taste any charcoal.

But don't let the taste tempt you just yet.

Linia says there's a dark side to charcoal as well.

It can also absorb the good stuff as well.

For example, if you're on medication,

or if you're taking vitamins and minerals,

and you consume a drink containing activated charcoal,

then the activated charcoal will render those medications inactive.

Linia is sceptical that eating activated charcoal

has any health benefits.

In fact, in certain cases, it might even damage your health.

So even though its super-absorbent properties are used medically,

there's still little evidence that activated charcoal

has any benefits as a food additive.

In fact, Linia says our bodies are already perfectly designed

to remove any toxins.

We don't have to put activated charcoal

in our juices and our breads, in our soups,

for our body to actually detox.

If you want to actively detox,

the way to do that is just by eating a healthy, balanced diet.

Make sure you're drinking enough water,

and make sure you're getting a lot of colourful fruit and vegetables

as part of that five-a-day.

Now, I'm sure you've all heard the term "brain food"

and I expect the first thing that springs to mind is fish.

But there are countless more foods that it's claimed

have an effect on our little grey cells,

sometimes, in fact, giving us a pretty instant brain boost.

And while that might sound far-fetched,

it's hard not to be tempted by the idea that a bowl of blueberries

might give you the edge before doing the crossword

or that ice cream for every member of the quiz team

might lead you to victory.

So we asked Danny Crates to investigate

whether foods really can be that powerful, that fast.

Whether it's getting the edge on your bitter rivals

at a local pub quiz,

solving that punishing Sunday broadsheet Sudoku,

or simply wanting to show off when watching Mastermind,

it's fair to say we'd all quite like to be a little bit smarter.

Well, if these headlines are true,

what we eat could be the key in boosting our brains.

But what foods can unlock that potential?

-Fish?

-Yeah, fish is good for the brain.

Protein foods.

Bananas, don't know why.

-Green chillies.

-Green veg, really.

Tomato, onions.

Broccoli, spinach.

But some reports say it's not just healthy foods that can increase IQ,

-with pizza...

-Pizza? I think of it as being junk food.

-..egg fried rice...

-Yes, I like rice, yeah.

..and even coffee supposedly offering gains to our grey matter.

That's a stimulant, I know that,

but I wouldn't have thought it would have done a lot for your brain.

Actually, everything here has been said to boost brain power.

Yes, even ice cream.

It might sound far-fetched, but it's joined by green tea,

rosemary, broccoli, dark chocolate, blueberries and much, much more,

on a menu that could apparently work miracles for our minds.

So to put some of those claims to the test,

I've come to King's College London.

It's home to some of the brightest brains in the country.

But can even the sharp synapses of the chess team be boosted by food?

Max, you guys are already a clever bunch. But if there's any truth

in those headlines that there is brain-boosting foods out there,

you'd take that advantage into your next big competition, wouldn't you?

Yeah, we'll take any competitive edge, to be honest,

particularly with our match against UCL on Monday.

Max and the team are going to see if they can reproduce the findings

of three studies widely reported in the press and online.

This one, which found drinking peppermint tea could improve memory...

This is team memory and it's a simple pairs game.

..this one, which found that blueberries can improve concentration...

The buzzing wire, they've got to see

how quickly they can get around without buzzing it.

..and of course, the most unusual-sounding of all,

this one, saying ice cream for breakfast makes you smarter.

And then we've got the ruler reaction test.

All those studies claim brainpower was boosted

just a short time after the food was eaten,

so we're going to start by measuring the team's reactions

before they eat the apparent wonder foods.

On your marks, get set, go.

Home straight.

There you go.

Oh!

26.

Nine, and done with Italian style and flair!

Next, it's time to eat.

I can feel myself getting smarter!

THEY LAUGH

And after we've given the food time to take effect,

I'll be back to rerun those tests and see if it makes any difference.

Cheers.

While many studies into how food affects the brain

are on the impact of a diet over years,

these studies all found that food can boost the brain

in the short term too,

which could mean there's more riding on your last meal before an exam,

a competition or a quiz than you might think.

And Dr Sandrine Thuret,

who is an expert on how food affects our brains,

says the science seems encouraging.

So, Sandrine, there's been plenty of headlines out there,

suggesting that certain food groups can boost brainpower.

-Can it be true?

-Yeah, certainly.

I mean, there are some strong scientific evidence

that diet will have an impact on your cognitive abilities.

So, there is definitely, probably, some truth out there.

Let's look at some of the headlines, and one of the favourites is

blueberries can boost children's brainpower.

Now, surely, these little berries can't be that powerful, can they?

Actually, they could. I mean, blueberries contain flavonoids,

which have been shown already to have an effect,

not only in children, but also in adults

in certain specific memory tasks.

The study was done on primary school children

and it had some impressive results.

Two hours after having a drink

containing a high dose of wild blueberries,

the children showed improvements in memory and concentration.

And while that was a short-term boost,

Sandrine says blueberries contain compounds known as flavonoids

which are proven to improve brainpower in the long term too.

I'm guessing if I eat this pot of blueberries,

-I'm not going to become a genius overnight?

-Not overnight.

Healthy diet is a long-term commitment.

Over time, probably you will see an improvement

in your cognitive abilities, but not from one day to another.

The study that inspired this headline

investigated the powers of herbs

and discovered that after drinking peppermint tea,

subjects were more alert and had an improved short-term memory.

The same happened when they just inhaled the smell of rosemary.

But camomile had the opposite effect,

slowing attention and alertness.

Hmm, that's interesting.

The group has shown that smelling the rosemary

would improve some aspects of memory.

But drinking peppermint tea is not necessarily going to improve our brainpower?

I would like to see, you know, a little bit more work around it.

But Sandrine is much less optimistic about the ice-cream study,

which was never published,

so it's impossible to know what its findings were based on.

Even so, a high-fat diet has been shown

to actually be bad for our brains.

You know, actually,

a high-sugar and high-fat diet will decrease cognitive ability.

So, that's probably not a good long-term solution.

So apart from the ice-cream claim,

there is some truth in the headlines?

Yeah, absolutely, there is some strong scientific evidence

that nutrition will have an impact on cognition, absolutely.

So with that, time to head back to the chess club.

We've given the peppermint, blueberries and ice cream

just over an hour to take effect.

But will there be any difference?

Are you ready to see if it's had any impact?

Yes, yes. Let's have a look.

OK, so we're going to start off with team memory.

With a time of 41.6 seconds to beat,

let's see if peppermint tea has made a difference.

-Oh, come on!

-Second time around,

they're an average of ten seconds quicker.

Next up, it's the concentration test.

Will a bowl of blueberries help our subjects improve their performance?

-Go on.

-There's an air of confidence about him now, isn't there?

He's cruising.

Oh!

This is your last chance to prove that blueberries do help.

-We both did better.

-Both did better.

Last but not least, ice cream.

Seven!

So you both improved quite a lot.

Maybe ice cream does work!

Every team showed an improvement,

but Sandrine isn't sure that was always thanks to the food.

It's probably due to practice and understanding the game better,

than, I would say, the peppermint tea

but let's not dismiss the peppermint tea.

I mean, you know, there's nothing bad with peppermint tea, so why not?

She's also pretty sure about what caused the ice-cream team

to perform better.

Ice cream, high content in sugar, so, you know, possibly,

a boost of glucose in the brain for reaction time

is not something we can dismiss.

But ice cream for breakfast, I would say no.

High fat, as well, content and high glucose content

wouldn't be a long-term, you know, diet I would advise.

So the improvement is likely to be

the result of a short-term sugar rush

rather than increased brainpower long term.

Team concentration, they had the blueberries

-and they both improved as well.

-Yeah, so, that's good.

There are some compounds in blueberries

that could help this type of task

so, you know, again, we need a little bit more information

and a bigger, longer study.

Whether it was the blueberries that swung it for team concentration,

or just good old practice, the science behind the idea

that they're good for our little grey cells

is solid because they contain flavonoids.

And, in fact, many of the foods mentioned in the other reports,

such as broccoli, dark chocolate and spinach,

all contain high levels of flavonoids as well.

The effects we observed are only short-term

and just limited to individual foods,

but Sandrine has been researching

the long-term impact of diet on our brains.

Her team is investigating how it can help stimulate

some parts of the brain to regenerate or develop new neurons,

meaning what we eat could slow down

how our brainpower declines as we get older.

Is this a really exciting breakthrough in scientific terms,

the fact that we now know that we can regenerate neurons in our brain?

Yeah, we think this is,

this is really something that has a lot of potential.

So, very important for learning and memory

but also, for example, for mood and depression.

So if we can enhance and increase that production

of new neurons in our brain through our diet,

does that mean we're going to get more intelligent

or just stave off the decline?

So, I think probably number two.

Any food, for example, with flavonoids

is probably very beneficial.

But if you continue and sustain this diet,

maybe you will not see a cognitive decline

as pronounced as someone that eats no fruit and veg, or fish,

at all during their lifetime.

While that could be great

for slowing down our declining brainpower,

is there anything else I can do to actually boost it in the long term?

What do I need to do to improve my memory?

I would say, healthy diet, throughout life,

high fatty fish, so, like, salmon,

which contains omega three fatty acids,

would for sure be beneficial.

Green vegetables,

and some fruit with high content of flavonoids, dark-skinned fruit.

So it comes down to a healthy lifestyle,

a healthy diet and then I should have a healthy mind.

Absolutely.

But back at Kings College, it's a mixed result

for Max and his chess team,

who drew in their grudge match against UCL.

Although food probably didn't play a part in that result,

it's clear that what we eat could have a huge impact

on our brains and our pub-quiz bragging rights.

So it's definitely a big bowl of blueberries for everybody

next time I'm leading the pub quiz team

because, quite frankly, we could do with all the help we can get.

That's just what I've heard. Now, you know, I think that that film,

and, in fact, all the stories in the programme today,

just go to show how powerful the food we eat can be,

if we get it right.

A lot of the time, well,

we talk about scary stories and daunting claims

about how bad some foods can be for us. So I must say,

it's really encouraging to see the positives as well.

Absolutely. Well, I'm afraid we're out of time for today

but we'll be back very soon

cutting through more confusing messages about our food.

So until then, thank you very much for joining us.

-And you're buying the blueberries. Bye-bye.

-Bye-bye.