0:00:07 > 0:00:09I love life,
0:00:09 > 0:00:13so I want to remain young, energetic, enjoy it for as long as I can.
0:00:13 > 0:00:15I'm medically trained.
0:00:15 > 0:00:19I know all the standard advice for staying healthy.
0:00:19 > 0:00:23But in my case, it doesn't seem to be working.
0:00:24 > 0:00:29I've discovered that my body is not the lean, long-lived machine
0:00:29 > 0:00:31I would like it to be.
0:00:31 > 0:00:37- A third of your body is fat. - Thank you...for making that point so emphatically.
0:00:37 > 0:00:42I wanted to see if science can offer a different way to stop the rot,
0:00:42 > 0:00:44slow the clock,
0:00:44 > 0:00:48so I set off to find experts
0:00:48 > 0:00:51who are trying to combat the ravages of ageing.
0:00:51 > 0:00:54- We are rewriting human physiology here.- Ooh...yay!
0:00:56 > 0:01:00If you can find something else that you can do that it doesn't hurt you, that benefits you
0:01:00 > 0:01:03and that causes these changes, I'd like to know.
0:01:05 > 0:01:08What I discovered was truly surprising.
0:01:09 > 0:01:14It involves no pills, no injections and no hidden cost.
0:01:14 > 0:01:17It's all a question of what you eat.
0:01:17 > 0:01:19Or rather, what you don't eat.
0:01:20 > 0:01:25Last night, I dreamt I ate a sandwich and then I felt fantastically guilty.
0:01:25 > 0:01:26It's about fasting.
0:01:26 > 0:01:30But fasting made easier.
0:01:30 > 0:01:32If I were to go onto Joe's lifestyle...?
0:01:32 > 0:01:36In a year, you are going to be cured.
0:01:42 > 0:01:48The big thing is that this is the beginning of something which I think could be huge.
0:01:48 > 0:01:51If it takes off and if it heads off in the direction I imagine it will,
0:01:51 > 0:01:54then this...this could be genuinely revolutionary.
0:02:10 > 0:02:12KLAXON
0:02:18 > 0:02:23There are plenty of people who stay young and fit
0:02:23 > 0:02:25well beyond retirement age.
0:02:33 > 0:02:36They mainly do it the traditional way -
0:02:36 > 0:02:39through lots and lots of exercise.
0:02:39 > 0:02:42Today, I've come to the London Marathon.
0:02:42 > 0:02:47Nearly 36,000 bodies of all shapes and sizes
0:02:47 > 0:02:49are tackling the 26-mile course.
0:02:49 > 0:02:51Some are young,
0:02:51 > 0:02:53many not so young.
0:03:00 > 0:03:03There's an absolutely fantastic atmosphere here.
0:03:03 > 0:03:05Now, I have never run the marathon
0:03:05 > 0:03:08and I have no plans to ever run the marathon,
0:03:08 > 0:03:12but there are plenty of people running today
0:03:12 > 0:03:15who are far older than me.
0:03:15 > 0:03:18There are 7,000 people in their 50s
0:03:18 > 0:03:21and, incredibly enough,
0:03:21 > 0:03:25there are seven people who are in their 80s or older.
0:03:31 > 0:03:35I'm going to trying and flag a few of them down
0:03:35 > 0:03:37to ask how they do it.
0:03:37 > 0:03:39Hello! How are you? Hello!
0:03:40 > 0:03:42- How old are you?- 78.
0:03:42 > 0:03:44- And how old are you?- 81.
0:03:50 > 0:03:54- What's the secret, then, running? - Magic wand!
0:03:54 > 0:03:57- Just eating well. - Hard work son, that's all!
0:03:59 > 0:04:04Anyone who can run a marathon in their 70s deserves my respect,
0:04:04 > 0:04:10but I'm waiting for a man who makes septuagenarians look youthful.
0:04:13 > 0:04:16Fauja Singh is amazing.
0:04:16 > 0:04:19He has been active all his life,
0:04:19 > 0:04:22but he only took up serious running in his 80s.
0:04:22 > 0:04:27So what is it that keeps him so remarkably fit and energetic?
0:04:27 > 0:04:31Hi, there. Nice to see you.
0:04:31 > 0:04:34- How old is Fauja?- 101.
0:04:34 > 0:04:37Born on 1st April 1911.
0:04:37 > 0:04:41Unfortunately he hasn't quite mastered the English language yet.
0:04:41 > 0:04:44Do you mind asking him how he's feeling?
0:04:44 > 0:04:46THEY SPEAK IN PUNJABI
0:04:49 > 0:04:51- He goes, "It's not easy..."- Yeah?
0:04:51 > 0:04:56But the job's got to be done, cos he's not finished yet. You're not going to give up, are you?
0:05:02 > 0:05:05Although he's 101,
0:05:05 > 0:05:09Fauja has never had surgery,
0:05:09 > 0:05:13he shows no signs of heart disease...
0:05:13 > 0:05:16and he takes no medication.
0:05:20 > 0:05:23He believes that his long life
0:05:23 > 0:05:26and his incredible health is down to his diet.
0:05:28 > 0:05:30So, any particular diet?
0:05:30 > 0:05:33He has no particular diet.
0:05:33 > 0:05:39It's a simple Punjabi farmer's diet, so just fresh food,
0:05:39 > 0:05:42- but his secret is that he has smaller portions.- Right.
0:05:42 > 0:05:45In poor countries, people die of starvation.
0:05:45 > 0:05:48In rich countries, people die of over-eating.
0:05:48 > 0:05:52So, how much does he eat, compared to you or I?
0:05:52 > 0:05:55He would eat what would be considered half a portion,
0:05:55 > 0:05:57almost a child's portion.
0:05:57 > 0:06:02So a child portion is probably about half the amount of calories you or I would eat?
0:06:04 > 0:06:08By restricting his food intake so dramatically,
0:06:08 > 0:06:12Fauja has unknowingly been testing a theory that has been around
0:06:12 > 0:06:15nearly as long as he has.
0:06:17 > 0:06:21A scientific theory which is only now really coming into its own.
0:06:26 > 0:06:30I've taken the Tube to the finish line.
0:06:30 > 0:06:33I want to catch Fauja become, hopefully,
0:06:33 > 0:06:36the world's oldest marathon runner.
0:06:44 > 0:06:49And after seven hours and 49 minutes, he succeeds.
0:06:49 > 0:06:52CHEERING AND APPLAUSE
0:06:55 > 0:06:58Can I congratulate you?
0:07:12 > 0:07:15That is absolutely unbelievable - he's 101 years old
0:07:15 > 0:07:19and he has just covered 26 miles.
0:07:19 > 0:07:22Now, I can't imagine that, in 50 years' time,
0:07:22 > 0:07:24I'm going to be running down The Mall,
0:07:24 > 0:07:27but I want to be like him.
0:07:27 > 0:07:32I want to be mentally active and physically active, I want to stay younger for longer.
0:07:42 > 0:07:45For decades, teams of scientists around the world
0:07:45 > 0:07:49have been intensely studying ageing.
0:07:49 > 0:07:55Now, clearly, genes play a significant part in how quickly and well we age,
0:07:55 > 0:07:58but there's nothing much you can do about your genes.
0:07:58 > 0:08:03There is, however, something you can do about what you eat.
0:08:06 > 0:08:11And here in America, they are starting to turn out some truly remarkable research
0:08:11 > 0:08:14linking food with longevity.
0:08:14 > 0:08:20It seems it's not just about WHAT we eat, but how and when we eat it.
0:08:22 > 0:08:27Our story begins in the dust bowls of America during the 1930s.
0:08:27 > 0:08:30There was a terrible drought, food was scarce,
0:08:30 > 0:08:34and the whole country was in the grips of the Great Depression.
0:08:34 > 0:08:37Now, you would imagine, in such difficult times,
0:08:37 > 0:08:42that life expectancy would fall, but in fact it rose.
0:08:44 > 0:08:49During the darkest years of Great Depression - 1929 to 1933 -
0:08:49 > 0:08:53life expectancy increased by a remarkable six years.
0:08:59 > 0:09:03Now, on the face of it, that is really surprising,
0:09:03 > 0:09:08and yet, clues as to why could also be found from research done back in the 1930s.
0:09:09 > 0:09:13Nutritionists at Cornell University working with animals
0:09:13 > 0:09:15discovered that if you severely restrict
0:09:15 > 0:09:20the amount they eat, they live longer.
0:09:20 > 0:09:22Much, much longer.
0:09:25 > 0:09:30So the next obvious question - if you do the same with humans,
0:09:30 > 0:09:33will it have the same effects?
0:09:35 > 0:09:39Well, it's been eight decades since that observation,
0:09:39 > 0:09:43and only now are scientists really beginning to understand
0:09:43 > 0:09:47the link between calorie restriction and longevity in humans.
0:09:47 > 0:09:51At long last, it seems, we are starting to get answers.
0:10:00 > 0:10:06Washington University is at the heart of this new science.
0:10:06 > 0:10:09We are rewriting human physiology here!
0:10:09 > 0:10:11It's astonishing, you know,
0:10:11 > 0:10:14how simple dietary intervention can really change
0:10:14 > 0:10:17how the human body works, basically.
0:10:19 > 0:10:24'Professor Luigi Fontana has spent the last ten years studying a group of people
0:10:24 > 0:10:28'who severely calorie restrict every single day.
0:10:30 > 0:10:33'And he is astonished by what he's found.'
0:10:34 > 0:10:37These people, they look like a different species.
0:10:37 > 0:10:40- That's quite a big statement, isn't it?- Yes!
0:10:40 > 0:10:45We are finding that they are going to live longer than their parents and brothers
0:10:45 > 0:10:48on the typical American diet, or Western diets.
0:10:53 > 0:10:56'Luigi is clearly impressed,
0:10:56 > 0:11:00'so I wanted to meet one of this new species of human for myself.'
0:11:00 > 0:11:04- A lovely, lovely house. - Were the directions good? - Very good, thank you.
0:11:04 > 0:11:07Joe Cordell is a CRonie -
0:11:07 > 0:11:10a calorie restrictor on optimal nutrition.
0:11:10 > 0:11:14And that means a lot of fruit and veg.
0:11:16 > 0:11:18I went ahead and kind of put everything out
0:11:18 > 0:11:22- because I thought you might want to have some breakfast. - That would be delicious, thank you.
0:11:22 > 0:11:25When I imagine a calorie restrictor,
0:11:25 > 0:11:30I imagine someone who lives basically on a couple of carrots, or something like that.
0:11:30 > 0:11:34I didn't think you'd go in for breakfast.
0:11:34 > 0:11:37'Joe kicks off his day with a mountain of fruit,
0:11:37 > 0:11:40'some of which he then throws away.'
0:11:41 > 0:11:45Then what I like to do is add some apple to it, but when you're in my position,
0:11:45 > 0:11:50I want to get as much nutritional value as I can for the calorie,
0:11:50 > 0:11:53and virtually all the nutritional value is in the peel.
0:11:53 > 0:11:56So you're going to slip the peel in and throw away the rest of it?
0:11:56 > 0:11:59You're going to do the reverse of what most people do.
0:11:59 > 0:12:04It's great, because literally 95% of the nutritional value here...
0:12:04 > 0:12:07- Is in the skin?- Yeah. The rest is sugar and calories.
0:12:07 > 0:12:11- This is generally what I'll have each morning- The whole thing?
0:12:11 > 0:12:13- Yeah.- That's a big bowl.
0:12:13 > 0:12:17Do you ever think, "What if I'm wrong? What if it's all wrong?
0:12:17 > 0:12:22"I've done this for 10, 20 years, and then a new bit of science comes out
0:12:22 > 0:12:25"which says it's actually all nonsense."
0:12:25 > 0:12:28I tell you, my brother, who weighs 100 lb more than I do,
0:12:28 > 0:12:33he's about my age. He's all the time making the joke to me
0:12:33 > 0:12:36that he's going to end up out-living me
0:12:36 > 0:12:39and, in his opinion, I will have suffered for nothing.
0:12:39 > 0:12:41But the point is, I enjoy doing it.
0:12:41 > 0:12:44Living a healthy lifestyle is fun.
0:12:44 > 0:12:49'There are an estimated 100,000 CRonies worldwide -
0:12:49 > 0:12:53'people living on a diet which is rich in nutrients
0:12:53 > 0:12:55'but low in calories.
0:12:55 > 0:12:59'Joe looks fit, but not impressively young.
0:12:59 > 0:13:02'Perhaps Luigi has been exaggerating.'
0:13:02 > 0:13:05What I'd love to do is take you off and do a number of tests
0:13:05 > 0:13:07and see just how we compare.
0:13:07 > 0:13:11OK, I'm game. So, is this a challenge?
0:13:11 > 0:13:16This is a challenge indeed, a challenge I suspect I may well lose!
0:13:20 > 0:13:25For a decade, Joe's been eating 1,900 calories a day.
0:13:25 > 0:13:28I've averaged around 2,300,
0:13:28 > 0:13:31quite a few of them donuts and burgers.
0:13:31 > 0:13:33How much do you think you weigh?
0:13:33 > 0:13:37Probably about 180. Ooh, more than 180!
0:13:37 > 0:13:39Breathe in!
0:13:39 > 0:13:44I should be around 134, 135, 136.
0:13:44 > 0:13:46We just have to move it down one notch.
0:13:46 > 0:13:49- 134.- Oh, right on.
0:13:51 > 0:13:55We're both in our 50s, and I really don't think
0:13:55 > 0:13:58we look like different generations, let alone species.
0:13:58 > 0:14:01So how different are we?
0:14:01 > 0:14:05I just need for you to relax. Sit still, no talking.
0:14:08 > 0:14:12Some of the simplest ways of assessing ageing don't need specialist equipment.
0:14:12 > 0:14:14Oh, this is good.
0:14:14 > 0:14:17Balance is controlled by your inner ear.
0:14:21 > 0:14:24'As you age, ear structures deteriorate
0:14:24 > 0:14:27'and your balance gets worse.
0:14:27 > 0:14:30- One more.- 'You can test it by standing on your weaker leg
0:14:30 > 0:14:32'with your eyes closed.'
0:14:32 > 0:14:36- How long did I make?- 6.59 seconds. - Not very good.
0:14:36 > 0:14:38'Not good at all.
0:14:38 > 0:14:41'The average 55-year-old should manage 8 seconds.'
0:14:41 > 0:14:43You're down to...
0:14:43 > 0:14:47Yeah, you're doing well for the average 20-year-old.
0:14:47 > 0:14:50Over 30 seconds is what most 20-year-olds can manage,
0:14:50 > 0:14:52but it's one of those skills that drops off dramatically.
0:14:52 > 0:14:56- I think you've proved a point. - Stop.- You can stop, yes.
0:14:58 > 0:15:03'Another good test is reaction time, which drops off with age.'
0:15:03 > 0:15:04Not good. Eight.
0:15:04 > 0:15:07'This one only needs a ruler.
0:15:07 > 0:15:11'At our age, you should be able to catch it around the five-inch mark.'
0:15:13 > 0:15:16Very good. That was 4. You're doing pretty well, I must admit.
0:15:21 > 0:15:25Luigi's methods are rather more scientific.
0:15:25 > 0:15:28We did a range of other medical tests,
0:15:28 > 0:15:30including blood tests.
0:15:30 > 0:15:34Now he's about to give us our results.
0:15:34 > 0:15:37Feels like being in the headmaster's office, doesn't it?
0:15:37 > 0:15:39Waiting for the results.
0:15:39 > 0:15:43Will you get an A-star? Will I get a B-minus?
0:15:43 > 0:15:45'Luigi's face tells me
0:15:45 > 0:15:48'that what I'm about to hear is not good news.'
0:15:48 > 0:15:53Total body fat in Joseph is 11.5%.
0:15:53 > 0:15:57This is typical of a super athlete.
0:15:57 > 0:16:0111% body fat is very low
0:16:01 > 0:16:04for a 54-, 55-year-old man.
0:16:04 > 0:16:07Yours is 27.1% fat.
0:16:07 > 0:16:09A third of your body is fat.
0:16:09 > 0:16:13Thank you...for making that point so emphatically!
0:16:13 > 0:16:17'And he's still not done talking about my fat.'
0:16:17 > 0:16:19Abdominal fat is around 30%.
0:16:19 > 0:16:23Abdominal fat is really the bad guy.
0:16:23 > 0:16:26The higher the abdominal fat, the higher the risk
0:16:26 > 0:16:29of developing type 2 diabetes, cardiovascular disease.
0:16:29 > 0:16:32No doubt about it. It's also a risk factor for cancer.
0:16:33 > 0:16:37So, basically, your cardiometabolic profile,
0:16:37 > 0:16:39it's not good. For your age.
0:16:39 > 0:16:42I think you should do something to improve it.
0:16:42 > 0:16:44What we can say is that Joseph
0:16:44 > 0:16:48is not going to develop cardiovascular disease.
0:16:48 > 0:16:50It's impossible to develop stroke,
0:16:50 > 0:16:53myocardial infarction or heart failure.
0:16:53 > 0:16:56These three diseases are responsible
0:16:56 > 0:16:58for 40% of the deaths now in US and UK.
0:16:58 > 0:17:02- No chance he'll die of that? - I mean, one in a million.
0:17:02 > 0:17:06And if I were to go onto Joe's lifestyle...?
0:17:06 > 0:17:08In a year, you are going to be cured.
0:17:12 > 0:17:16I now understand what Luigi means.
0:17:16 > 0:17:20It is as if we are two different species.
0:17:20 > 0:17:24Joe's diet seems to be keeping his organs in pristine condition.
0:17:24 > 0:17:28My diet is undermining my health, and fast.
0:17:30 > 0:17:34Well, that was very sobering. Luigi does not mince his words.
0:17:34 > 0:17:36He talked a bit about abdominal fat.
0:17:36 > 0:17:39In fact, he talked quite a lot about my abdominal fat.
0:17:39 > 0:17:42I've never thought of myself as particularly fat.
0:17:42 > 0:17:45But it was the sort of two visions he held out to me.
0:17:45 > 0:17:48One, where, if I continue as I am at the moment,
0:17:48 > 0:17:53I'm heading almost certainly for heart disease and possibly worse.
0:17:53 > 0:17:57The other is, if I embrace the calorie restriction way,
0:17:57 > 0:18:01he said I could be effectively cured in less than a year.
0:18:01 > 0:18:06My risk factors would move from being almost certainly
0:18:06 > 0:18:08a cardiac victim at some point
0:18:08 > 0:18:10to one in a million.
0:18:10 > 0:18:15When you put it as starkly as that, it's given me a lot to think about.
0:18:31 > 0:18:35Even though the evidence supporting the benefits of calorie restriction
0:18:35 > 0:18:38is getting stronger all the time,
0:18:38 > 0:18:42I cannot in all honesty imagine myself doing what Joe does.
0:18:45 > 0:18:48Which creates something of a dilemma.
0:18:50 > 0:18:53So, what I really want to do is try
0:18:53 > 0:18:57to understand the ways in which calorie restriction works,
0:18:57 > 0:19:01then hopefully I can get all the delicious benefits
0:19:01 > 0:19:03without actually having to do it.
0:19:03 > 0:19:05I'm in Los Angeles,
0:19:05 > 0:19:09a city that is notoriously addicted to youth.
0:19:09 > 0:19:12In fact, many people here seem to think
0:19:12 > 0:19:15that growing old and wrinkled is optional.
0:19:15 > 0:19:19I'm not going to see anyone as superficial as a plastic surgeon.
0:19:19 > 0:19:23I'm here to meet one of the world's foremost experts on ageing.
0:19:31 > 0:19:34- Hi, there.- Hey.
0:19:34 > 0:19:39Professor Valter Longo studies the complex mechanisms which control ageing.
0:19:41 > 0:19:47He's honed in on a critical pathway that links what we eat with how we age.
0:19:49 > 0:19:52He's taking me to see two mice.
0:19:52 > 0:19:58They are both the same age, same species, same sex.
0:19:58 > 0:20:02But there's one significant difference between them.
0:20:02 > 0:20:06The little one is going to be living an awful lot longer
0:20:06 > 0:20:08than the big one.
0:20:11 > 0:20:13This little mouse right here
0:20:13 > 0:20:17holds the world record for longevity extension in a mammal.
0:20:17 > 0:20:19Oh, right. That is remarkable.
0:20:19 > 0:20:22So, how long would these subspecies of mice last?
0:20:22 > 0:20:25The big mouse here, about two years,
0:20:25 > 0:20:28and the little mouse, about a 40% longer lifespan.
0:20:28 > 0:20:30Right. They're very different, aren't they?
0:20:30 > 0:20:33Whoa! He is trying to bite me.
0:20:33 > 0:20:35HE LAUGHS
0:20:35 > 0:20:40- I could feel that one going through. - Should've had the double glove.
0:20:40 > 0:20:43I learned the hard way!
0:20:43 > 0:20:46The big mouse already has a 50% chance of being dead.
0:20:46 > 0:20:48OK, so he's doing well to be alive?
0:20:48 > 0:20:51He's lucky to be alive, that's right.
0:20:51 > 0:20:54- The small one probably has another year to go.- Oh, right.
0:20:54 > 0:20:57The little guy will live on to the equivalent of what, 120 in human?
0:20:57 > 0:21:02Exactly, yeah. Another 30 to 40 years in human years.
0:21:02 > 0:21:06- Can I pick it up?- Go ahead. By the tail.- OK.
0:21:10 > 0:21:11The little mouse I'm holding
0:21:11 > 0:21:15is actually a man-made creation.
0:21:15 > 0:21:18The reason he's so small and so long lived
0:21:18 > 0:21:21is because he's been genetically engineered.
0:21:21 > 0:21:26He has incredibly low levels of a growth hormone
0:21:26 > 0:21:29called Insulin-like Growth Factor 1.
0:21:29 > 0:21:32And it seems IGF-1 is a key factor
0:21:32 > 0:21:35linking calorie restriction and longevity.
0:21:42 > 0:21:46Clues to the link come from this group of people
0:21:46 > 0:21:48who live in a remote region of Ecuador.
0:21:50 > 0:21:54They have a very rare condition called Laron syndrome,
0:21:54 > 0:21:58which affects less than 350 people worldwide.
0:22:03 > 0:22:05That's you, is it? It makes you look like a giant, doesn't it?
0:22:05 > 0:22:08I'm the tall guy there.
0:22:08 > 0:22:13The shortest one is just over three-and-a-half feet tall.
0:22:13 > 0:22:15- Up to my belly button. Is that right?- Yeah.
0:22:15 > 0:22:20'What interests researchers like Valter is not their size,
0:22:20 > 0:22:25'but the fact that they seem to be virtually immune to two of the West's biggest killers.'
0:22:25 > 0:22:27The big findings, of course,
0:22:27 > 0:22:31were, they don't seem to get either diabetes or cancer.
0:22:31 > 0:22:33Do they do all the normal, sensible things we all do,
0:22:33 > 0:22:37- like drink, smoke and all that? - Yes, they do the normal, and more,
0:22:37 > 0:22:39so they a very unhealthy lifestyle.
0:22:39 > 0:22:43Most of them are to some extent at least overweight.
0:22:43 > 0:22:46They seem to really not watch anything they do.
0:22:46 > 0:22:49They smoke or eat very high calorie diets,
0:22:49 > 0:22:53and then they look at me and they say,
0:22:53 > 0:22:55"Oh, it doesn't matter. I'm immune."
0:22:55 > 0:22:59But the incredible thing is that there's no evidence
0:22:59 > 0:23:02of a single one of them ever dying of cancer,
0:23:02 > 0:23:06yet their normal-height relatives get cancer like everybody else.
0:23:08 > 0:23:13People with Laron syndrome have a mutation which makes them small,
0:23:13 > 0:23:17but which also seems to protect them against all these diseases.
0:23:19 > 0:23:21It's incredible working with them.
0:23:23 > 0:23:29It's a great group, and of course for us is a group that in one mutation,
0:23:29 > 0:23:33can tell us about diabetes, cancer, cardiovascular diseases and ageing.
0:23:37 > 0:23:40The Ecuadorian villagers and the long-lived mice
0:23:40 > 0:23:42have something in common.
0:23:42 > 0:23:46Their bodies produce exceptionally low levels
0:23:46 > 0:23:48of the growth hormone IGF-1.
0:23:50 > 0:23:56This discovery helped Valter piece together role that IGF-1 plays
0:23:56 > 0:23:59in the complicated business of ageing.
0:23:59 > 0:24:02Our bodies are normally in go-go mode -
0:24:02 > 0:24:07cells constantly driven to divide by IGF-1.
0:24:07 > 0:24:10But when IGF-1 levels drop,
0:24:10 > 0:24:14our cells shift into a completely different mode.
0:24:14 > 0:24:17The body slows production of new cells
0:24:17 > 0:24:20and starts repairing existing ones instead.
0:24:20 > 0:24:25DNA damage is more likely to get fixed.
0:24:25 > 0:24:29And that's why the mice AND the villagers are protected
0:24:29 > 0:24:31from age-related diseases.
0:24:40 > 0:24:44But what's the link to calorie restriction in humans?
0:24:44 > 0:24:49Valter has lined up a very simple, very Californian analogy.
0:24:51 > 0:24:55It turns out there is something in the food we eat
0:24:55 > 0:24:59that affects how much IGF-1 our bodies produce.
0:24:59 > 0:25:01That something is protein.
0:25:02 > 0:25:07When we eat a lot of protein, our cells get locked in go-go mode.
0:25:07 > 0:25:10So it's basically like slamming your foot on the accelerator,
0:25:10 > 0:25:13- saying, "Go! Go! Go!" Is that right? - Exactly.
0:25:13 > 0:25:17It's pushing the cell to burn fuel.
0:25:17 > 0:25:19In go-go mode,
0:25:19 > 0:25:22the body is more susceptible to some cancers and diabetes,
0:25:22 > 0:25:25because your cells are growing too fast
0:25:25 > 0:25:27for damage to be efficiently repaired.
0:25:27 > 0:25:30So it's like driving your car all the time
0:25:30 > 0:25:32and never taking it to the mechanic.
0:25:32 > 0:25:36Right, so that's the key, basically, is to somehow find a way
0:25:36 > 0:25:39to switch your body from going, "Broom, broom, broom,"
0:25:39 > 0:25:44- into a sort of repair mode, "Look after me, make my DNA better." - Exactly.
0:25:46 > 0:25:49So, how do you reduce your IGF-1?
0:25:50 > 0:25:54Well, studies on calorie restrictors suggests that eating less helps,
0:25:54 > 0:25:55but it's not enough.
0:25:57 > 0:26:01As well as cutting calories, you have to cut your protein intake.
0:26:01 > 0:26:05Not entirely - that would be a very bad idea.
0:26:05 > 0:26:08It's about sticking to recommended guidelines,
0:26:08 > 0:26:11something most of us fail to do.
0:26:11 > 0:26:15And you don't have to be a CRonie to lower IGF-1.
0:26:15 > 0:26:18There is another way - fasting.
0:26:18 > 0:26:25In fasting, there is a much more dramatic and much quicker response,
0:26:25 > 0:26:30and so, within 24 hours, you decrease your glucose level
0:26:30 > 0:26:35and you decrease your main growth factor, which is IGF-1.
0:26:38 > 0:26:42I do find it hard to believe that just a few days of fasting
0:26:42 > 0:26:47is going to be enough to jolt my body into a more healthy state.
0:26:49 > 0:26:53But I'm certainly intrigued, and I want to find out more.
0:26:53 > 0:26:56So I've had my IGF measured back in London,
0:26:56 > 0:26:59and they tell me that it's 28.
0:26:59 > 0:27:01Is that good? Bad?
0:27:01 > 0:27:05That's not very bad, but that's high enough
0:27:05 > 0:27:09that, based on a number of studies, including our own,
0:27:09 > 0:27:14it puts you in a higher risk category for several different cancers,
0:27:14 > 0:27:16including prostate cancer.
0:27:16 > 0:27:21Valter believes I should start to see some pretty impressive results
0:27:21 > 0:27:25after just three days and four nights of fasting.
0:27:25 > 0:27:27But it's a daunting prospect.
0:27:29 > 0:27:32I think fasting's quite tough, isn't it? Have you done it yourself?
0:27:32 > 0:27:34I've done it myself, yes,
0:27:34 > 0:27:38I've fasted for four days several times
0:27:38 > 0:27:39and to me it was very tough, yeah.
0:27:39 > 0:27:43And still, if I look ahead at doing fasting,
0:27:43 > 0:27:46I see it as a tough four days, I'm not looking forward.
0:27:46 > 0:27:48Some people do, but I don't.
0:27:48 > 0:27:52I'm Italian, so I look forward to eating well, you know.
0:27:52 > 0:27:55- I'll bear that image in mind.- Yeah.
0:27:55 > 0:27:58The greedy Italian stopping eating when I'm feeling weak about it.
0:27:58 > 0:27:59- There you go.- Thank you.
0:28:08 > 0:28:11Prolonged fasting can be dangerous
0:28:11 > 0:28:15and Valter thinks it should only be undertaken by people in good health
0:28:15 > 0:28:18and preferably, under close supervision.
0:28:18 > 0:28:20So he will be keeping an eye on me.
0:28:21 > 0:28:26OK, I've decided I'm going to try this fast,
0:28:26 > 0:28:29which is going to be a three-and-a-half-day fast
0:28:29 > 0:28:35and all I'm going to have is lots of water, black tea
0:28:35 > 0:28:39and one 50-calorie Cup-a-Soup a day.
0:28:39 > 0:28:44Now... Oh, God, I have never done anything quite like this before,
0:28:44 > 0:28:46so I imagine it's going to be really tough.
0:28:46 > 0:28:49But I'm interested.
0:28:49 > 0:28:52I'm also, I must admit, quite concerned about some of
0:28:52 > 0:28:55the rather bad news, health news I've been getting recently,
0:28:55 > 0:29:01so, um...it'll be a challenge, but I'm sure I'll manage it.
0:29:03 > 0:29:05Reasonably sure.
0:29:08 > 0:29:10And so, my fast begins.
0:29:17 > 0:29:22Right. It is now 10.30 at night and I am hungry.
0:29:22 > 0:29:29It has been, oh, just about 25 hours since I last ate a meal
0:29:29 > 0:29:35and the prospect of going to bed while hungry is not a great one.
0:29:36 > 0:29:39I think it's getting to me, because last night I had a dream
0:29:39 > 0:29:44and I dreamt I ate a sandwich and then I felt fantastically guilty.
0:29:44 > 0:29:47So vivid, I had a look round to see if there were any crumbs in the bed, but there weren't.
0:29:47 > 0:29:50I guess time to go to work.
0:29:53 > 0:29:56Simple dietary intervention
0:29:56 > 0:29:59can really change how the human body works.
0:29:59 > 0:30:01It puts you in a higher risk category.
0:30:04 > 0:30:08Just as Valter warned me, the first day was tough.
0:30:08 > 0:30:11Not really because I was that hungry,
0:30:11 > 0:30:15but simply because I had never done anything like this before.
0:30:15 > 0:30:18It was fear of the unknown.
0:30:18 > 0:30:22My nightfall, I'm beginning to think this is a very bad idea...
0:30:25 > 0:30:28..particularly when I had dinner with the crew.
0:30:33 > 0:30:36Or rather, when they had dinner.
0:30:38 > 0:30:41So, yeah, here I am in a nice old Korean restaurant
0:30:41 > 0:30:45with the rest of the crew.
0:30:45 > 0:30:48And they are currently digging in...
0:30:48 > 0:30:50Enjoying it, guys?
0:30:50 > 0:30:51- Beautiful.- Yes.
0:30:51 > 0:30:56It's a good smell. I really, really wouldn't mind a little bite.
0:30:59 > 0:31:02I do feel very hungry.
0:31:03 > 0:31:08Fortunately, my dinner is waiting for me in my hotel room.
0:31:13 > 0:31:15I had to leave, I couldn't bear it any longer.
0:31:22 > 0:31:26- HE SIGHS - My delicious miso soup here.
0:31:26 > 0:31:29Give a bit of a stir with the hotel pen,
0:31:29 > 0:31:31because there's no other cutlery around.
0:31:33 > 0:31:34Mmm!
0:31:36 > 0:31:38Health. 25 calories' worth.
0:31:38 > 0:31:40And I'm looking forward to it.
0:31:44 > 0:31:46Ah!
0:31:48 > 0:31:52OK, final full day of fasting.
0:31:52 > 0:31:54Delicious breakfast here, black tea.
0:31:54 > 0:31:58I'm feeling a bit light-headed but otherwise actually all right.
0:31:58 > 0:32:00So, just 24 hours to go
0:32:00 > 0:32:03and now I'm pretty confident I'll be able to do it.
0:32:11 > 0:32:15I've learnt that hunger does not build and build,
0:32:15 > 0:32:16but comes in waves that pass.
0:32:18 > 0:32:21By now, I have depleted my body's store of glucose
0:32:21 > 0:32:26and will have switched to burning fat for fuel instead.
0:32:26 > 0:32:27And if Valter is right,
0:32:27 > 0:32:33my liver should also have stopped producing so much IGF-1,
0:32:33 > 0:32:36putting my cells into repair mode.
0:32:39 > 0:32:44Finally, it's 7am, day four, I'm getting my blood test done.
0:32:45 > 0:32:49- So, after this, I can go and have breakfast?- Absolutely.
0:32:49 > 0:32:51The first food for three-and-a-half days,
0:32:51 > 0:32:55the first food for 86 hours. Well, who's counting(?)
0:32:55 > 0:32:58I'm just hoping that this is going to show some change,
0:32:58 > 0:33:02particularly in my IGF, cos if I have spent the last three-and-a-half
0:33:02 > 0:33:05to four days not eating and the results have been absolutely zero,
0:33:05 > 0:33:07that would be very, very depressing.
0:33:09 > 0:33:13The fast is over.
0:33:13 > 0:33:16Mmm. Ah! That is very...
0:33:16 > 0:33:19I can just sort of begin to feel the empty spaces.
0:33:19 > 0:33:23I wasn't actually terrible hungry when I woke up this morning, but...
0:33:25 > 0:33:28..when I start eating this, I realise what it is I was missing.
0:33:33 > 0:33:37Later that afternoon, I meet up with Valter to find out
0:33:37 > 0:33:39if it's all been worthwhile.
0:33:41 > 0:33:44I broke my fast this morning, I had some porridge and some bacon
0:33:44 > 0:33:47- and I feel better.- Oh, good, good.
0:33:47 > 0:33:50I'll feel even more terrific if these results are any good.
0:33:50 > 0:33:53Yeah, let's take a look at them.
0:33:53 > 0:33:58So, your insulin-like growth factor one, IGF-1, this is the normal value.
0:33:58 > 0:34:01- Wow.- The bad news, you're almost at the top of the normal range.
0:34:01 > 0:34:03For American standards, you're doing good.
0:34:03 > 0:34:07But not good full-stop, but not bad. I'm an average American, am I?
0:34:07 > 0:34:10That's right, yeah. And the good news is,
0:34:10 > 0:34:13- with your fasting diet, you dropped to almost half.- Wow.
0:34:13 > 0:34:16- That's big, isn't it?- Yeah. - That's a big drop.
0:34:16 > 0:34:18It's a very dramatic drop, so you respond very well.
0:34:18 > 0:34:20I have to say, it was fascinating.
0:34:20 > 0:34:25Seeing that is very, very... um, surprising.
0:34:25 > 0:34:28'Surprising - and a huge relief.
0:34:28 > 0:34:32'Halving my IGF-1 should cut my risk of certain cancers,
0:34:32 > 0:34:34'like prostate cancer, which my father had.
0:34:34 > 0:34:37'My blood sugar has also dropped to healthy levels,
0:34:37 > 0:34:39'which I'm really pleased about.'
0:34:40 > 0:34:47I challenge you in four days to get more extreme metabolic changes
0:34:47 > 0:34:50than these with anything you want.
0:34:50 > 0:34:52I think this is quite extreme enough! Yeah.
0:34:52 > 0:34:55Yeah, but, you know, if you can find something else that you can do,
0:34:55 > 0:34:58that it doesn't hurt you, that benefits you
0:34:58 > 0:35:01- and that causes these changes, I'd like to know.- OK.
0:35:05 > 0:35:08But Valter says, unless I switch
0:35:08 > 0:35:11to a lower protein, more plant-based diet,
0:35:11 > 0:35:14the effects won't last.
0:35:16 > 0:35:18I'll also need to fast once every couple of months,
0:35:18 > 0:35:21to maintain the benefits.
0:35:21 > 0:35:25Can I really see myself doing that?
0:35:25 > 0:35:27You have to make a decision now, in your case,
0:35:27 > 0:35:29what do you want to do, you know?
0:35:29 > 0:35:32And there is a lot of drugs that you could be taking,
0:35:32 > 0:35:34and is that what you want to do?
0:35:34 > 0:35:39And if you do so, in a few years, or in a number of years,
0:35:39 > 0:35:43you're going to be the typical 65-year-old in Europe
0:35:43 > 0:35:47that takes eight drugs a day, and so that's the option.
0:35:47 > 0:35:50MICHAEL LAUGHS And that's your call.
0:35:50 > 0:35:54Thank you, OK! That's quite an interesting choice!
0:36:01 > 0:36:04That is really, really impressive,
0:36:04 > 0:36:06that in just three-and-a-half days,
0:36:06 > 0:36:09if this data is right, and the animal data is right,
0:36:09 > 0:36:12I have massively decreased my risk
0:36:12 > 0:36:16of a whole range of age-related diseases.
0:36:16 > 0:36:19The big question in my mind at the moment is,
0:36:19 > 0:36:22can I do fasting once a month,
0:36:22 > 0:36:25for however long it takes?
0:36:25 > 0:36:28Or is there a better way, a different way,
0:36:28 > 0:36:30a more manageable way out there,
0:36:30 > 0:36:33that can do much of what this does,
0:36:33 > 0:36:37but perhaps with a little less pain?
0:36:37 > 0:36:40What I've discovered about myself is that
0:36:40 > 0:36:46the biggest problem with prolonged fasting is me.
0:36:48 > 0:36:51VALTER: 'You have to make a decision now.
0:36:51 > 0:36:52'Fasting is tough.'
0:36:55 > 0:36:58Despite knowing all the wonderful benefits...
0:37:00 > 0:37:03..I just can't bring myself to do it.
0:37:15 > 0:37:18But the great thing about science
0:37:18 > 0:37:22is there is always someone doing further work,
0:37:22 > 0:37:25building on what others have achieved,
0:37:25 > 0:37:28which is why I'm here in Chicago.
0:37:28 > 0:37:33Here, they are doing studies not just on mice, but also on humans.
0:37:37 > 0:37:39And they seem to have found a way
0:37:39 > 0:37:43of making fasting a lot more palatable.
0:37:43 > 0:37:48I'm here to meet Dr Krista Varady,
0:37:48 > 0:37:52who has been researching something that sounds easier.
0:37:52 > 0:37:54Alternate day fasting.
0:37:54 > 0:37:57- Hello! Hello there!- Hi!
0:37:57 > 0:38:00- Very nice to meet you.- Nice to meet you! My name's Krista Varady.
0:38:00 > 0:38:02Hello! So what have you got here, then?
0:38:02 > 0:38:04So this is some of the components that we'd use
0:38:04 > 0:38:08in an alternate day fasting diet.
0:38:08 > 0:38:11It basically involves a day of pretty heavy calorie restriction.
0:38:11 > 0:38:13For women, about 400 to 500 calories a day,
0:38:13 > 0:38:16and for men, about 500 to 600 calories a day,
0:38:16 > 0:38:18and that's actually just as one meal, around lunchtime.
0:38:18 > 0:38:22We call that the fast day.
0:38:22 > 0:38:24So the fast day isn't about total abstinence.
0:38:24 > 0:38:27It's about meals that look like this.
0:38:27 > 0:38:31What's great about alternate day fasting
0:38:31 > 0:38:33is what happens on the alternate days.
0:38:33 > 0:38:36And then that's alternated with something we call the feed day,
0:38:36 > 0:38:40which is where you can eat whatever you want. Absolutely whatever you want.
0:38:40 > 0:38:44So here's the pattern of alternate day fasting.
0:38:44 > 0:38:46Fast day.
0:38:46 > 0:38:47Feed day.
0:38:47 > 0:38:49Fast day.
0:38:49 > 0:38:51Feed day.
0:38:51 > 0:38:56It certainly sounds easier than either prolonged fasting
0:38:56 > 0:38:59or the daily calorie restriction I looked at earlier.
0:38:59 > 0:39:00But is it as effective?
0:39:00 > 0:39:04Well, Krista's currently doing a trial with overweight subjects
0:39:04 > 0:39:08which suggests it might be.
0:39:08 > 0:39:10What we saw was that the alternate day fasting group
0:39:10 > 0:39:12actually lost a bit more weight,
0:39:12 > 0:39:16so about 5lb more after the 6-month period.
0:39:16 > 0:39:21And they actually saw some pretty nice decreases in LDL cholesterol,
0:39:21 > 0:39:23as well as triglycerides.
0:39:23 > 0:39:26So LDL cholesterol is the bad cholesterol,
0:39:26 > 0:39:29and triglycerides - basically higher amounts of that
0:39:29 > 0:39:32can lead to heart disease and age-related disease.
0:39:32 > 0:39:36We also see really nice decreases in blood pressure
0:39:36 > 0:39:37over the course of the trials.
0:39:37 > 0:39:42So, again, another key heart disease risk factor.
0:39:49 > 0:39:51'In addition to so far rather limited human trials,
0:39:51 > 0:39:55'there's lots of good evidence from animal studies
0:39:55 > 0:39:58'that alternate day fasting, ADF, is safe and effective.
0:40:00 > 0:40:02'I'm convinced enough to try it.
0:40:02 > 0:40:05'Yesterday I fasted.
0:40:05 > 0:40:07'Today I feed.'
0:40:07 > 0:40:11So hopefully, we will make it back...easily enough.
0:40:11 > 0:40:15- Ooh, magical mystery tour! I like that!- Yeah, yeah!
0:40:15 > 0:40:18MUSIC: 'Johnny B Goode' by Chuck Berry
0:40:27 > 0:40:29- BUZZER - Hi, thanks for stopping.
0:40:29 > 0:40:31May I take your order, please?
0:40:31 > 0:40:35# Deep down in Louisiana Close to New Orleans
0:40:35 > 0:40:37# Way back up in the woods among the evergreens
0:40:37 > 0:40:40# There stood a log cabin made of earth and wood
0:40:40 > 0:40:42# Where lived a country boy named Johnny B Goode. #
0:40:42 > 0:40:44A very good choice!
0:40:44 > 0:40:47I particularly like the green stuff that's oozing out of it.
0:40:47 > 0:40:48So, I must admit,
0:40:48 > 0:40:52I am surprised to be here.
0:40:52 > 0:40:55I kind of imagined you'd be sticking on a sort of, um,
0:40:55 > 0:40:58you know, a veggie diet or something like that.
0:40:58 > 0:41:00Or, yeah, a lot of salads or something on the feed day?
0:41:00 > 0:41:04No, actually as long as you stick to the calorie goals on the fast day,
0:41:04 > 0:41:09you can literally eat whatever you like on the feed day.
0:41:09 > 0:41:13'One of Krista's most recent studies compared two groups on ADF,
0:41:13 > 0:41:16'one eating high fat, the other low fat,
0:41:16 > 0:41:18'on their feed days.'
0:41:18 > 0:41:21I'm concerned about my blood glucose,
0:41:21 > 0:41:23I'm concerned about my cholesterol,
0:41:23 > 0:41:25- I'm concerned about a load of stuff. - Yeah, yeah.
0:41:25 > 0:41:29Are those not, sort of, made worse by eating high fat?
0:41:29 > 0:41:31That's actually what we thought would happen.
0:41:31 > 0:41:32And then, surprisingly,
0:41:32 > 0:41:35we saw the same decreases in LDL cholesterol,
0:41:35 > 0:41:36so that's the bad cholesterol,
0:41:36 > 0:41:38and in triglycerides,
0:41:38 > 0:41:40and also in blood pressure.
0:41:40 > 0:41:43So in terms of cardiovascular disease risk,
0:41:43 > 0:41:45it didn't matter if you were eating a high-fat or low-fat diet.
0:41:45 > 0:41:50Another big surprise was that, after a day of fasting,
0:41:50 > 0:41:54people rarely gorge themselves on their feed days.
0:41:57 > 0:42:01So when we ask someone to consume 25% of their energy needs on the fast day,
0:42:01 > 0:42:03I just thought that when I started running these trials,
0:42:03 > 0:42:05that people would eat 175% the next day.
0:42:05 > 0:42:09But right from the get-go, no matter what,
0:42:09 > 0:42:13people just can't eat that 175% the next day.
0:42:13 > 0:42:16Most people eat around the 110%.
0:42:16 > 0:42:18So just slightly over what they usually eat, actually.
0:42:18 > 0:42:21You appear to be slowing down the ageing process,
0:42:21 > 0:42:23or the diseases associated with it.
0:42:23 > 0:42:25You're cutting the risks of the diseases associated,
0:42:25 > 0:42:28- which is quite a profound thing to do.- Yeah, absolutely.
0:42:33 > 0:42:37Krista's research is still in the early stages.
0:42:37 > 0:42:40But from what I've seen and experienced,
0:42:40 > 0:42:42I am now starting to be won over
0:42:42 > 0:42:45by the idea that a simple pattern
0:42:45 > 0:42:49of feast and fast can be powerful.
0:42:49 > 0:42:54It seems to have an impact which goes beyond simply eating less.
0:42:54 > 0:42:57And I think it could work for someone like me.
0:43:03 > 0:43:05My final stop is Baltimore.
0:43:05 > 0:43:09I'm here because I need a final bit of motivation.
0:43:12 > 0:43:17There's one aspect of ageing I find more terrifying than any other.
0:43:17 > 0:43:21The effects of ageing on my brain.
0:43:24 > 0:43:27I'm trying to catch up with Professor Mark Mattson.
0:43:27 > 0:43:31Mark is a leading expert on the ageing brain.
0:43:31 > 0:43:34His research suggests that fasting
0:43:34 > 0:43:37may help delay the onset of diseases
0:43:37 > 0:43:40like Alzheimer's, dementia, and memory loss.
0:43:40 > 0:43:41- Very good!- How you doing?
0:43:41 > 0:43:44- Hi there! Michael Mosley. - Mark Mattson.
0:43:44 > 0:43:47- You work here?!- Work here? No!
0:43:47 > 0:43:50- Nor do I work out here! - MICHAEL CHUCKLES.
0:43:50 > 0:43:54OK, Michael. We need to put some booties on!
0:43:56 > 0:43:59We're heading down into the basement
0:43:59 > 0:44:03of the National Institute on Ageing.
0:44:03 > 0:44:04- OK?- Yeah.
0:44:04 > 0:44:06Hidden away down here,
0:44:06 > 0:44:09there's a special mouse he's keen to show me.
0:44:17 > 0:44:20This mouse is exploring a maze.
0:44:22 > 0:44:25It's a memory test, designed to see how well he remembers
0:44:25 > 0:44:28where he has found food before.
0:44:28 > 0:44:32- So the food is actually in there, is it?- The food's in here.
0:44:32 > 0:44:35The mice they study are destined to develop Alzheimer's disease.
0:44:38 > 0:44:41Normally, they succumb within a relatively short time,
0:44:41 > 0:44:44but when these mice are put on a diet
0:44:44 > 0:44:47of feast days and fast days,
0:44:47 > 0:44:50what Mark calls "intermittent energy restriction",
0:44:50 > 0:44:51the results are incredible.
0:44:51 > 0:44:55..So that the animals on intermittent energy restriction,
0:44:55 > 0:44:58they'll live much longer with normal,
0:44:58 > 0:44:59at least, as best we can test,
0:44:59 > 0:45:03normal learning and memory, before they start having problems.
0:45:03 > 0:45:05Significantly longer?
0:45:05 > 0:45:07Yeah, highly significantly.
0:45:07 > 0:45:10We found in one study, six months to a year.
0:45:10 > 0:45:14That's the equivalent in a human of the difference between
0:45:14 > 0:45:17developing signs of Alzheimer's at say, the age of 50,
0:45:17 > 0:45:20- and the age of 80? Something like that? Is that right?- Yeah.
0:45:20 > 0:45:24'On the other hand, when the mice eat a fast-food diet,
0:45:24 > 0:45:27'they go downhill much earlier.'
0:45:27 > 0:45:30- We give them...- Lots of sugary drinks?- A high-fat diet, exactly.
0:45:30 > 0:45:32And we put fructose in their drinking water,
0:45:32 > 0:45:35and that has a dramatic effect.
0:45:35 > 0:45:37The animals will have an earlier onset
0:45:37 > 0:45:40of the learning and memory problems.
0:45:40 > 0:45:41How much sooner?
0:45:41 > 0:45:44- Um, three to four months sooner.- Wow.
0:45:44 > 0:45:48So that is the equivalent of them developing Alzheimer's
0:45:48 > 0:45:51- in their 30s or maybe early 40s? - Right.
0:45:51 > 0:45:55So far, they've only done studies in mice,
0:45:55 > 0:45:58but they're about to carry out human trials.
0:45:58 > 0:46:00How good if the evidence that if someone like me
0:46:00 > 0:46:02were to start on intermittent fasting,
0:46:02 > 0:46:05it would cut my risk of brain disease, broadly?
0:46:07 > 0:46:10I think, from the human standpoint,
0:46:10 > 0:46:16if we go on a scale from poor to good to very good
0:46:16 > 0:46:18to excellent to outstanding,
0:46:18 > 0:46:20it's in the very good to excellent range.
0:46:21 > 0:46:24That's the way I would categorise it.
0:46:29 > 0:46:31So, what's going on?
0:46:33 > 0:46:36Well, when they examined the brains of the fasting mice,
0:46:36 > 0:46:39they found something extraordinary.
0:46:39 > 0:46:44These green objects are newborn brain cells.
0:46:44 > 0:46:47These three here are brand new?
0:46:47 > 0:46:53Sporadic bouts of hunger actually trigger new neurons to grow.
0:46:53 > 0:46:57Why should a brain start to generate
0:46:57 > 0:47:00new nerve cells when you stop feeding it?
0:47:00 > 0:47:03If you think about this in evolutionary terms, it makes sense
0:47:03 > 0:47:09if you're hungry, you'd better increase your cognitive ability.
0:47:09 > 0:47:11That will give you a survival advantage,
0:47:11 > 0:47:15if you can remember where the location of the food is and so on.
0:47:17 > 0:47:22It seems that fasting stresses your grey matter the way that exercise stresses your muscles.
0:47:25 > 0:47:30- So hunger really does make you sharper?- Yes. We think so.
0:47:34 > 0:47:39Mark's research is starting to point towards a simple conclusion.
0:47:39 > 0:47:43Alternate day fasting has better effects on the brain
0:47:43 > 0:47:47than does a lower amount of daily calorie restriction.
0:47:47 > 0:47:53It's true of mice, but he needs to do proper human trials to prove it's true in us.
0:47:57 > 0:48:02I've come to the end of my search to find out how to eat, fast and live longer.
0:48:03 > 0:48:07The official advice is, eat at least 2,000 calories a day,
0:48:07 > 0:48:11and if you really want to fast, even on an intermittent basis,
0:48:11 > 0:48:15see your doctor first, because there are people it could harm,
0:48:15 > 0:48:19such as pregnant women or those who are already underweight.
0:48:21 > 0:48:25I'm going to be cautious, and have decided to go with a pattern that Mark recommended.
0:48:25 > 0:48:31Not alternate day fasting, but a less extreme five/two diet -
0:48:31 > 0:48:37five days' normal eating, followed by two days' fasting, each week.
0:48:38 > 0:48:43It's my last day in the States, and it has been absolutely eye opening.
0:48:43 > 0:48:48I had no idea at all that there was so much research going on
0:48:48 > 0:48:54into fasting, calorie restriction in all its forms, and sort of anti-ageing research.
0:48:55 > 0:48:59I've decided now that I am definitely going to try the five/two diet,
0:48:59 > 0:49:05that's five days' normal eating, then two days of 600 calories a day.
0:49:05 > 0:49:07I really, really hope it makes a difference,
0:49:07 > 0:49:11because I'm conscious now that I am really at the foothills
0:49:11 > 0:49:14of what could be quite a steep advance into age,
0:49:14 > 0:49:19and if there is something that could slow that ageing process down and give me
0:49:19 > 0:49:25more years of healthy living, then I would really embrace that.
0:49:31 > 0:49:35I'm heading home to the UK.
0:49:35 > 0:49:40I've decided to give myself five weeks to get used to my new diet,
0:49:40 > 0:49:43and see if I get results.
0:49:49 > 0:49:52This is going to be one of my fasting days,
0:49:52 > 0:49:55and I've decided I'm going to eat breakfast as my main meal.
0:49:55 > 0:49:59Mark Mattson told me he doesn't think it matters
0:49:59 > 0:50:01when you eat your calories on a fast day.
0:50:01 > 0:50:05I've tried other things, but it is really quite discouraging
0:50:05 > 0:50:07going into work when you're feeling hungry.
0:50:09 > 0:50:12There's another reason I'm determined to try this regime.
0:50:12 > 0:50:16When I arrived home, I had another IGF-1 test.
0:50:17 > 0:50:21Annoyingly, my levels were higher than ever.
0:50:21 > 0:50:27Turns out the hard-won effects of the four-day fast only lasted a short while.
0:50:27 > 0:50:30And she's kind of running with it at the moment, I think.
0:50:30 > 0:50:33'So I hope this is something I can stick to.'
0:50:33 > 0:50:37Good. It's done. It's actually twenty to two,
0:50:37 > 0:50:41and I don't feel remotely hungry, but it is lunchtime,
0:50:41 > 0:50:44so if nothing else, I think I'm going to go and prowl around.
0:50:44 > 0:50:50MUSIC: "Harder, Better, Faster, Stronger" by Daft Punk
0:51:02 > 0:51:06I found that fasting when I'm busy at work was doable,
0:51:06 > 0:51:09but the next big test is my holiday.
0:51:09 > 0:51:11I'm walking with some friends.
0:51:11 > 0:51:17We are doing a walk across the Trans-Pennine Way.
0:51:17 > 0:51:22Had breakfast this morning about two hours ago,
0:51:22 > 0:51:28and I'm planning on eating next breakfast tomorrow.
0:51:28 > 0:51:32So far I am feeling quite good.
0:51:35 > 0:51:39It's now about seven o'clock. Haven't eaten for about 12 hours.
0:51:39 > 0:51:43The others are behind me in the pub eating,
0:51:43 > 0:51:47so I decided to come outside for a bit, because...
0:51:47 > 0:51:50I'm not as strong-minded as I thought I was.
0:51:50 > 0:51:53My stomach is begin to rumble a bit, but it's all right.
0:51:57 > 0:52:02'It's been five weeks since I started the five/two diet.'
0:52:02 > 0:52:04Heel! Heel!
0:52:04 > 0:52:06Not very good dog!
0:52:06 > 0:52:10'I managed to fit in two 600 calorie fast days each week,
0:52:10 > 0:52:13'though they tended to be a bit scattered around.
0:52:13 > 0:52:16'But has it been enough to make a difference?'
0:52:17 > 0:52:19So, today's results day.
0:52:19 > 0:52:21I have lost, I know, some weight,
0:52:21 > 0:52:25I'll find out in a moment just how much, but I'm mainly interested
0:52:25 > 0:52:29in the bloods, because five or six weeks ago they were pretty terrible.
0:52:29 > 0:52:34I have high blood glucose, high cholesterol, high IGF.
0:52:34 > 0:52:37And I'm really, really keen to see them improve,
0:52:37 > 0:52:41because frankly, if they haven't improved, then I am in trouble,
0:52:41 > 0:52:46and I do want to stay young and healthy for my family, for myself.
0:52:46 > 0:52:51So, I'm quite anxious, because this matters an awful lot to me.
0:52:55 > 0:52:59Just to remind you, this is what I looked like at the start of this film.
0:53:01 > 0:53:04And this is me today.
0:53:04 > 0:53:06I've had to add a few new holes to my belt,
0:53:06 > 0:53:09so I know that something has changed, but by how much?
0:53:09 > 0:53:14Right, the moment of truth, in which I discovered just how much weight I have lost.
0:53:14 > 0:53:18These are a special type of scales which are going to measure my weight accurately,
0:53:18 > 0:53:20but also, apparently, my body fat.
0:53:20 > 0:53:23Hey! That is fantastic!
0:53:23 > 0:53:31That is 173.8lb, which means I have lost well over a stone.
0:53:31 > 0:53:36My body fat when we did it before was 27%,
0:53:36 > 0:53:39and now it's below 20.
0:53:39 > 0:53:42That is really, really pleasing.
0:53:46 > 0:53:50I feel good, and my family say I look slimmer.
0:53:50 > 0:53:54It really hasn't been that difficult,
0:53:54 > 0:53:58and I'm delighted that I'm no longer in the overweight category.
0:53:58 > 0:54:02But what I really want to know is what's changed inside my body.
0:54:06 > 0:54:12Professor Luigi Fontana is about to call with my final results.
0:54:12 > 0:54:15- Hi, Michael! - Hi, Luigi, how are you?
0:54:15 > 0:54:17- I'm fine, and you?- I'm very good.
0:54:17 > 0:54:19So, we've got your results.
0:54:19 > 0:54:23Just by fasting two days a week, you made a great impact
0:54:23 > 0:54:28on your cardiometabolic health, and so I'm very proud of you.
0:54:28 > 0:54:33'But what's happened to my IGF-1? Is my body still in go-go mode?'
0:54:33 > 0:54:38IGF-1 is the major risk factor for cancer.
0:54:38 > 0:54:42Breast cancer, prostate cancer, colon cancer.
0:54:42 > 0:54:45Both the three-and-a-half day fasting
0:54:45 > 0:54:51and the five weeks' intermittent fasting dropped your IGF-1 by 50%.
0:54:53 > 0:54:56'Which is enough to reduce my risk of certain cancers.
0:54:56 > 0:55:00'But what about my blood sugar, which was borderline diabetic?'
0:55:00 > 0:55:05- Your glucose dropped to 90. - Right.- Fantastic.
0:55:05 > 0:55:07So your glucose became normal again.
0:55:07 > 0:55:10'My final result is cholesterol.'
0:55:10 > 0:55:15So, you had a reduction in total cholesterol,
0:55:15 > 0:55:17and in an increase in the good cholesterol.
0:55:17 > 0:55:21This shows how little it takes, you know,
0:55:21 > 0:55:26to improve without drugs, without taking medication.
0:55:26 > 0:55:29'It wasn't THAT little an effort,
0:55:29 > 0:55:34'but I have cut my risk of developing diseases which could shorten my life.'
0:55:34 > 0:55:37Thank you. So, I should live happily ever after, should I?
0:55:37 > 0:55:40I don't know if you're going to live happier,
0:55:40 > 0:55:44but you have a lower risk of developing diseases.
0:55:44 > 0:55:47- Thank you very much, Luigi, really, thank you.- You're welcome.
0:55:47 > 0:55:50I'm very, very pleased. Very pleased indeed.
0:55:50 > 0:55:53That was far better than I was expecting.
0:55:55 > 0:56:00'I wanted my wife Claire, who is a GP, to share my results.'
0:56:00 > 0:56:05So, this is my IGF, which is kind of my cancer/ageing risk.
0:56:05 > 0:56:10- This one's come down to half on the two-day fasting.- Yes.
0:56:10 > 0:56:14All of them have shown the improvement that you, kind of, hoped for.
0:56:14 > 0:56:15Yes.
0:56:15 > 0:56:19That basically means you're not going to have to take tablets at all, at the moment.
0:56:19 > 0:56:20- No.- If you stick to it.
0:56:21 > 0:56:24Well, you're looking good on it.
0:56:24 > 0:56:26Thank you. No, I'm really pleased.
0:56:26 > 0:56:28- I have to say that's really, amazingly good news.- Mmm.
0:56:33 > 0:56:37The results have been absolutely fantastic for me,
0:56:37 > 0:56:42but that doesn't mean that intermittent fasting will work for everyone.
0:56:44 > 0:56:48It's really important that they do more trials on humans,
0:56:48 > 0:56:51to find out if, in the long term, it is safe and effective.
0:56:53 > 0:56:58But having experienced intermittent fasting, I plan to go on doing it.
0:56:59 > 0:57:03It seems to have undone some of the damage
0:57:03 > 0:57:05that I have done to my body down the years.
0:57:08 > 0:57:12It is very poignant looking at the photographs of myself
0:57:12 > 0:57:15and members of my family growing up and growing older,
0:57:15 > 0:57:18but it doesn't make me want to hold back the hands of time.
0:57:18 > 0:57:23I sort of think that we do grow old, we should grow old,
0:57:23 > 0:57:26and there's very little we can do about it.
0:57:26 > 0:57:31But fasting is somehow different. Fasting is not about trying to live to 140,
0:57:31 > 0:57:35it's about staying healthy for as long as you can,
0:57:35 > 0:57:39and with the sort of time bomb we're facing as a nation,
0:57:39 > 0:57:42with obesity going up, diabetes going up,
0:57:42 > 0:57:45we desperately need something which can make a difference.
0:57:45 > 0:57:49Fasting is the first thing I've come across
0:57:49 > 0:57:52that I genuinely believe that if people were to take it up,
0:57:52 > 0:57:56it could radically transform the nation's health.
0:57:56 > 0:58:03So, I hope that we continue to see massive research going into this territory.
0:58:04 > 0:58:08Doing this fasting has been one of the most interesting...
0:58:08 > 0:58:11no, I would say THE most interesting sort of journey, film,
0:58:11 > 0:58:14whatever you want to call it, that I have been on.
0:58:14 > 0:58:16DOG WHIMPERS
0:58:16 > 0:58:18And I've never said that before.
0:58:32 > 0:58:35Subtitles by Red Bee Media Ltd