Translator: Rhonda JacobsReviewer: Peter van de Ven So pathogens like thisused to cause infectious diseases that killed humans for centuries.
Until sanitation, vaccinationand antibiotics took care of pathogens and gave us long, healthy lives.
But now, we spend nearly half of our life fighting with these kindsof chronic diseases, and for which there is no cure in sight.
So today, I'll share with yousome really revolutionary ideas of how to prevent, manageand cure these diseases.
And the idea is basedon the concepts of circadian rhythm, our near-24-hour rhythms.
To adapt to the 24-hour light-dark cycle, or day-night cycle, on our planet, almost every plant and animalhas circadian rhythms that are controlled bywhat we call circadian clocks.
These are actually encoded in our DNA.
And this is so fundamentalto life forms on our planet that if we move any animal or humanfrom this planet to another planet that has identical conditionsas the planet Earth but has a day-night cycleother than 24 hours, then we cannot easily survive.
In recognitionof this fundamental property of circadian clocks and health, this year's Nobel Prizewas actually awarded to three scientific leaders in this field.
And I'm really honoredthat all three of them have directly inspiredand influenced my research.
So how do we knowthat these clocks are in-built? For example, if you lock meinside an apartment with no clue about outside time, then my circadian clockwill make me go to sleep around 10:00 at night.
I'll go into deep sleep around 2:00, and anticipating waking up, my body will warm uparound 4:00 in the morning.
As soon as I wake up and open my eyes, my sleep hormone melatonin will plummet, and my stress hormonecortisol level will rise.
My peak performance time for brainwill be around noon.
And my peak athletic performancewill happen around late afternoon.
As evening rolls in, the circadian clockwill crank up melatonin to make me go to sleep again, and my body will cool downto support my sleep.
So this will continue every 24 hours, even if I'm locked inside an apartment.
And these rhythms happen becausealmost every single gene in our genome turns on and offat different times of the day.
Every single hormone and brain chemical also rises and fallsat different times of the day.
So to have these rhythmsis actually to have health.
And when these rhythms break down, when we stay awake late into the nightfinishing an assignment or taking care of a loved one, then we feel horrible the next day.
And if we continue abusing our clockfor weeks or months, then all thesechronic diseases can happen.
So it's very important, then, to know how are these clocks organized so that we can nurture them much better.
So as you can imagine, just like in our brain we have a clockthat makes us go to sleep and wake up every day, the same brain clock sendschemical signals to the rest of the body.
But what is really surprisingis that almost every organ in our body, and even every single cell in our bodyhas its own clock.
What does that mean? It means that just like your brain clockmakes us more efficient at solving complex problemsin the middle of the day, and also the brainneeds to sleep at night, every organ has its ownpeak performance time at certain times of the day.
And every organ needs to sleep, or rest and rejuvenate, at another time.
So all these clocks work togetherto give us daily rhythms in sleep, metabolism, moodand even gut microbiome.
But how are these clocksconnected to the outside world? In fact, every morning as we wake upand open our eyes, bright light goes through our eyesand resets or synchronizes this clock, so that when daylightsavings time changes, or when we move fromone time zone to another time zone, light synchronizes all of our clocksto the new season or the new time zone.
But the property of lightthat resets our clock is very different.
Almost 15 years ago, we discovereda new blue-light-sensing protein called melanopsin.
It's present only in 5, 000 squigglyneurons in our eye.
And these light-sensing neurons are literally hard wiredto our brain clock, to the master circadian clock.
But they have a very interesting property.
They're less sensitive to light, and especially to orange colored light.
So that means, in the evening, as we move around and find our wayunder candle light or dim orange light, the melanopsin is not activated.
It sends a signal to the brainas if it's dark outside so that the brain clockmakes a lot of melatonin and we get a good night's sleep.
And in the daytime as we wake up, go outsidefor at least an hour or so.
The daylight is very rich in blue light.
It fully activates melanopsin.
That synchronizesthe brain clock nicely with the day.
It reduces sleepiness and depression, and increases alertness.
But the problem is, we spendmore than 90 percent of our time indoors.
And at nighttime, bright screensand bright light activates melanopsin; it sends a confusing signal to the brain, and the brain thinks it's not night yet, so it produces less melatonin, and we sleep poorly.
The next day when we wake up, as we spend most of our time indoors, this indoor lightis not rich in blue light, so it again sends anotherconfusing signal to the brain, and the brain thinks it's not day yet.
So all the chemicalsthat should boost our mood are actually not produced enough.
So we kind of go back and forthbetween insomnia and fogginess, and if it continues for weeks or months, then a lot of diseases can happen.
And what is interesting is, this is particularlyimportant for children because their brain is still developing.
And when children go throughearly childhood circadian disruption, they are more proneto diseases like ADHD and autism.
So this new simple idea, that we needmore bright blue light during the daytime and less light, or darkness, at nighttime, is starting a new lighting revolution.
And you are just getting a glimpseof this new light revolution when your smart screen and computer screendim down and turn orange at nighttime.
But there is more to it.
Just think about it: Circadian lightingat daycare and schools will promote healthy brain developmentand promote learning.
Circadian lighting at home, factories, offices, will promote alertnessand improve productivity.
Circadian lighting at hospitalsor retirement homes will promote healthand accelerate healing.
And in fact, right now, there is new circadian lighting in our International Space Stationto promote productivity of our astronauts and make them have better nights' sleep.
So light is not the only factorthat affects our clock.
In fact, just like lightin the middle of the night disturbs the brain clock and breaksthe chemical balance in our brain, food at the wrong timecan disturb the peripheral clock and break the metabolicbalance in our body, and that will push us towards disease.
Now, let's figure out how.
So in the morning, our stomach is actually ready with the right amount of hormonesand digestive enzymes, and even good gut microbiometo digest food.
So after we eat our first breakfast, a body absorbs enough carbohydratesand uses it to fuel our body.
At the same time, it savesa little bit of nutrient as fat.
As we continue at lunch and dinner, the same process continues.
And after the last dinner, last bite, a body slowly goes low on carb.
At the same time, the circadian clockcranks up morning fat.
And after a few hours, the clock turns into a resetand repair rejuvenation mode.
That means that it turns on enzymes that will break downcholesterol and toxins.
It also turns on mechanismsto repair the DNA that we have damaged during the daytime.
And a lot of cells that are damagedon our stomach lining or our skin lining are also replaced with healthy new cells so that allergy-causing chemicalsor bacteria cannot get into our body.
So after 12 to 16 hours of fasting, when we eat our next breakfast, the cycle of nurture, rejuvenation continues.
But imagine if we delaythat last bite late into the night.
So in this case, this daily rhythmin metabolism becomes shallow.
There is not enough time to burn fat, and there is not enough time to break down the toxins, cholesterol, etc.
So, you can imagine that somebodywho eats within ten hours might have a much better circadian rhythm, whereas somebody who eatswithin 15 hours may not.
To test this idea, we went back to the old lab and brought two identical groups of mice born to the same parents, raised in the same room, same age.
And one group of micegot the standard Western diet to eat whenever they wanted.
And then the second group was trained to eat the same number of caloriesfrom the same food, but they had to eat everything within eight to 12 hours at nighttimewhen they're supposed to eat.
And we measured the foodand weighed the mice carefully every week for almost 18 weeks.
At the end of 18 weeks, the first group of mice, who ate randomly, were obese, where at the same time, they had a host of different diseases – they were really morbidly sick – where the second groupthat ate within eight to 12 hours were completely healthy.
But what is more surprising is this: If we take those morbidly sick mice and give them the same diet, same number of calories, and they have to eatonly within eight to ten hours, they become healthy.
This was a really earth-shattering, eureka moment for us, because for the first timein the history of nutrition science, we found that when we eat is as importantas what or how much we eat.
Well then, how do wetranslate [that] to humans? The first thing we wanted to know is, when do people eat? To do that, we started a new study – and people usually sign up for the studyat mycircadianclock.
org – and then, since peoplelove to take pictures, we asked them to take pictures ofevery single thing that they eat or drink, and we'd do the rest.
So when the pictures come to our server, we add them on a timeline so that it's easy for usto figure out when they eat.
And they continue taking picturesfor almost two to three weeks.
So that we can take a nice snapshotof their food life during the weekdays and weekends.
And you can see, for this particular person, he or she eats very randomlythroughout the day.
And if you look at the weekdayand weekend pattern, those are also very random.
And if you combinethe weekday and weekend, there is another interestingthing that comes up.
It appears as if the personis on the East coast during the weekday and comes to the West coaston the weekend, which is also very badfor our circadian clock.
Now, if we combine all of this data and plot it as ifwe are looking at a clock, then you can see that this personwas eating almost around the clock.
He's not an outlier, actually.
If we look at the first150 people who had signed up, nearly 50 percent of adultswho actually have regular 8 to 5 jobs, eat for 15 hours or longer.
So that means if they have their first biteat 7:00 in the morning, the last bite or last sip of winehappens at 9:00 or later.
What is interesting is, if we feed mice even a healthy diet, and they eat for 15 hours or longer, then slowly they become overweightand they get all these diseases.
So that's why we wanted to aska very simple question.
We brought back peoplewho were eating for 15 hours and were a little overweight, and asked them to eat whatever they wantwithin ten hours of their own choosing, and we wanted to see what happens to them.
So within three to four months, these people actually boosted uptheir circadian rhythm and they lost the excessivebody weight that they had.
And over the last one year, we've had thousands of peoplefrom all over the world who are signing upeither through our study or doing this by themselves.
They try to eat all of their foodsomewhere between 8, 10 or 11 hours.
And when they do that, after a few weeks, they're truly amazedby the untapped potential of the healing power of circadian rhythm.
Almost all of themlose a little bit of weight, but as they continue, they actually feel much better, more energetic throughout the day.
They sleep much better at night, and their mood is much better;they feel very sharp.
And slowly, over months, they suffer less from different diseasesof the gut, heart, immune system, diabetes and evensome of the mental diseases.
So we're truly excited about this study, but at the same time, we learned another very important insight, and let me share that with you.
That is, circadian clock tunes the potencyof almost every drug that we take for almost every disease.
So that means, at certain times of the day, the drug is more potent and can cure you, but at the wrong time of the dayit can have a more severe adverse effect, as if it's a poison.
So this is really important.
And the effect isnot even [only] to drugs, at what time of the daywe take our flu shots, at what time we scheduleour surgery for liver or heart, does matter.
Even cancer patients who are going through chemotherapyor radiation therapy, it really matters whetherthey schedule the chemo or radiation in the morning or late in the afternoon.
So this new knowledgeabout circadian rhythm is poised to start a new revolutionin healthcare and healthy habits.
Because the current ideaof taking care of your health by counting calories and counting stepsis just prehistoric.
And the same software and tools that our tech companies are usingto make us watch more arts, sleep less and eat around the clockcan be used for something better.
We can have devices and sensors that can create a nice circadianlighting environment around us.
Sensors can go on us to monitorour own circadian rhythm every day and how it interactswith the real outside world.
Devices can prompt uswhat to eat and when to eat to boost our circadian rhythm.
And even there will be smart pillsand programmed drug pumps that can deliver the right medicine, at the right dose, at the right time, even in the middle of our sleep, so that we can get cured much faster.
So I truly believe that circadian rhythmhas untapped potential to prevent, manage and cure many of the chronic diseasesthat affect billions of people.
(Applause) (Cheers) Thank you.