Health lies in healthy circadian habits | Satchin Panda | TEDxBeaconStreet

Summary

This talk delves into the critical role of circadian rhythms in our health, explaining how these near-24-hour cycles, influenced by light and food intake, govern our sleep, metabolism, and overall well-being. The speaker discusses the disruptive effects of modern lifestyle on these rhythms, leading to chronic diseases. Innovative solutions like circadian lighting and timed eating patterns are presented as ways to realign our bodies with natural cycles, offering promising insights for disease prevention and treatment.

Takeaways

• 🌡️ Pathogens historically caused infectious diseases, but modern society faces more chronic diseases with no cure in sight.
• 🌞 Circadian rhythms, near-24-hour cycles, are crucial for adapting to Earth's day-night cycle and are encoded in our DNA.
• 🏆 The 2023 Nobel Prize recognized the importance of circadian clocks for health, influencing the speaker's research.
• 🧠 Our internal circadian clocks govern sleep, hormone levels, and performance throughout the day, even in isolation from external time cues.
• 🌙 Disruptions to these rhythms, such as late-night work or caregiving, can lead to poor health and chronic diseases.
• 👀 Light, particularly blue light, resets our circadian clocks, with melanopsin being a key protein in this process.
• 🏠 Spending most of our time indoors and exposure to screens at night can confuse our circadian system, affecting sleep and health.
• 🍽 The timing of food intake is critical for metabolic health; eating within an optimal window can improve circadian rhythm and prevent disease.
• 🧪 Research with mice demonstrated that time-restricted feeding can reverse obesity and disease, emphasizing the importance of when we eat.
• 💊 The circadian clock influences the effectiveness of medications and the timing of medical treatments, suggesting personalized healthcare based on body rhythms.

Q & A

What are circadian rhythms and why are they important for human health?

Circadian rhythms are near-24-hour cycles that organisms, including humans, use to adapt to the 24-hour light-dark cycle on Earth. They are controlled by circadian clocks encoded in our DNA and are crucial for regulating sleep, metabolism, mood, and other bodily functions. Disruptions to these rhythms can lead to various chronic diseases.

How do circadian clocks affect our daily routines and health?

Circadian clocks regulate our sleep-wake cycle, hormone release, and peak performance times. For instance, melatonin levels rise for sleep and cortisol levels rise for alertness. Disruptions, such as staying awake late, can lead to poor health and chronic diseases.

What role does light play in synchronizing our circadian rhythms?

Light is a key factor in resetting and synchronizing our circadian clocks. Bright light in the morning, rich in blue light, activates a protein called melanopsin, which helps to align our internal clocks with the day-night cycle.

How does the timing of food intake affect our circadian rhythms and health?

The timing of food intake is crucial for maintaining metabolic balance. Eating at the right times allows for efficient digestion and energy use, while irregular eating patterns can lead to weight gain and diseases. Eating within a restricted time window, such as 8 to 12 hours, can improve circadian rhythm and health.

What is the significance of the Nobel Prize mentioned in the script for circadian rhythm research?

The Nobel Prize awarded to three scientific leaders in the field of circadian rhythms highlights the fundamental importance of circadian clocks for health. It recognizes the groundbreaking work in understanding how these biological clocks influence our physiology and well-being.

How does the script suggest that our modern lifestyle, particularly indoor lighting, affects our circadian rhythms?

The script suggests that spending most of our time indoors and exposure to bright screens at night can disrupt our circadian rhythms. This is because the blue light from screens can confuse our internal clocks, leading to poor sleep and other health issues.

What is the impact of circadian disruption on children's health and development?

Circadian disruption during early childhood can make children more susceptible to developmental disorders such as ADHD and autism. Proper circadian rhythm maintenance is crucial for children's brain development and overall health.

How can circadian lighting in different environments like schools, offices, and hospitals benefit health?

Circadian lighting can promote alertness, improve productivity, and support healing in various settings. For example, in schools, it can enhance learning and brain development; in offices, it can boost productivity; and in hospitals, it can aid in patient recovery.

What is the significance of the study where mice were fed within specific time windows?

The study demonstrated that the timing of food intake is as important as the quantity and quality for maintaining health. Mice that ate within an 8 to 12-hour window were healthier than those that ate randomly, even when consuming the same diet and calories.

How does the script propose that technology can be used to improve our circadian rhythms and health?

The script suggests that technology, such as smart devices, sensors, and programmed drug pumps, can be utilized to create optimal circadian lighting environments, monitor individual circadian rhythms, and deliver medications at the most effective times, thus improving health outcomes.

Outlines

00:00

🌡️ The Impact of Circadian Rhythms on Health

The speaker, Rhonda Jacobs, introduces the concept of circadian rhythms, which are near-24-hour cycles that organisms adapt to the Earth's 24-hour day-night cycle. These rhythms, controlled by circadian clocks encoded in our DNA, are fundamental to life and are recognized for their importance to health, as evidenced by the Nobel Prize awarded to scientists in this field. The speaker explains that our bodies have an internal clock that regulates sleep, hormone levels, and peak performance times, and that disruptions to these rhythms can lead to chronic diseases. The importance of aligning our daily routines with these natural cycles is emphasized for maintaining health.

05:01

🌞 The Role of Light in Regulating Circadian Clocks

This paragraph delves into how light, particularly blue light, resets our circadian clocks. The discovery of melanopsin, a blue-light-sensing protein in the eye, is highlighted. It is less sensitive to orange light, which allows for proper melatonin production and sleep in dim or orange-lit environments. However, the speaker points out that our modern lifestyle, with extensive indoor time and exposure to bright screens at night, confuses the circadian system, leading to poor sleep and potential health issues. The speaker also discusses the importance of circadian lighting in various settings, such as schools, hospitals, and homes, to promote health and productivity.

10:01

🍽️ The Influence of Eating Patterns on Health and Circadian Rhythms

The speaker explores the relationship between eating patterns and circadian rhythms, emphasizing that the timing of food intake is crucial for metabolic health. The body is prepared to digest food and absorb nutrients in the morning, and the circadian clock helps regulate this process throughout the day. Eating late into the night disrupts this cycle, leading to weight gain and diseases. An experiment with mice demonstrates that restricting eating to an 8- to 12-hour window can prevent obesity and disease, even on a Western diet. The speaker suggests that humans can benefit from similar eating patterns, and early studies show promising results in weight loss and improved health.

15:03

🛠️ Revolutionizing Healthcare with Circadian Rhythm Insights

The final paragraph discusses the broader implications of circadian rhythm research for healthcare. The speaker notes that the timing of drug administration, vaccinations, and surgical procedures can significantly affect their efficacy and side effects. The potential for technology to help monitor and regulate circadian rhythms is highlighted, with the possibility of smart devices, sensors, and drug delivery systems that work in sync with our natural rhythms. The speaker concludes by advocating for a new approach to health that considers circadian rhythms, moving beyond traditional methods like calorie counting and step tracking.

Keywords

💡Circadian rhythm

Circadian rhythm refers to the near-24-hour cycle in the physiological processes of living beings, including humans, that respond to light and darkness in an environment. In the video, this concept is central to understanding how our bodies function and the importance of aligning with these natural cycles for health. The speaker explains that disruptions to circadian rhythms can lead to various chronic diseases, emphasizing the need to respect these rhythms for overall well-being.

💡Sanitation

Sanitation in the context of the video refers to the practices of maintaining cleanliness and hygiene to prevent the spread of diseases. It is mentioned as one of the factors that, along with vaccination and antibiotics, have helped to control infectious diseases and contributed to longer, healthier human lives.

💡Chronic diseases

Chronic diseases are long-lasting conditions that are not resolved by quick medical interventions and are typically managed rather than cured. The video discusses the shift from infectious diseases to chronic diseases as a major health concern, highlighting the need for new approaches to prevent and manage these conditions through understanding circadian rhythms.

💡Circadian clocks

Circadian clocks are the internal timekeeping mechanisms present in almost all living organisms, including humans. They regulate physiological processes in a 24-hour cycle. The video explains that these clocks are encoded in our DNA and are crucial for health, as disruptions can lead to various health issues.

💡Melatonin

Melatonin is a hormone that regulates sleep-wake cycles. In the video, it is mentioned as a hormone that plummets when we wake up and increases as we prepare for sleep, regulated by our circadian clocks. The speaker discusses how exposure to light and darkness affects melatonin production, impacting sleep quality.

💡Cortisol

Cortisol is a hormone associated with stress and is part of the body's response to various stimuli. The video describes how cortisol levels rise in the morning, coinciding with waking up, as part of the circadian rhythm. It plays a role in regulating metabolism, immune response, and inflammation.

💡Melanopsin

Melanopsin is a light-sensitive protein found in specific neurons in the eye. The video explains that melanopsin is involved in the regulation of circadian rhythms through its sensitivity to blue light. It helps to synchronize our internal clocks with the external light-dark cycle, affecting sleep, alertness, and overall health.

💡Daylight savings time

Daylight savings time is the practice of setting the clocks forward one hour from standard time during the longer days of summer, and back again in the fall, to make better use of natural daylight. The video mentions how changes in daylight savings time can affect our circadian rhythms, emphasizing the importance of light in regulating our internal clocks.

💡Gut microbiome

The gut microbiome consists of the collection of microorganisms living in the digestive tract, which play a crucial role in health. In the video, it is mentioned that our circadian rhythms influence the gut microbiome, which in turn affects digestion, metabolism, and overall health. Disruptions to these rhythms can lead to imbalances in the gut microbiome and contribute to disease.

💡Circadian lighting

Circadian lighting refers to the use of light in indoor environments that mimics natural daylight patterns to support human circadian rhythms. The video discusses the potential benefits of circadian lighting in various settings, such as homes, schools, hospitals, and workplaces, for promoting alertness, productivity, and health.

💡Time-restricted eating

Time-restricted eating is a dietary approach where food intake is limited to specific hours of the day, aligning with the body's natural circadian rhythms. The video presents research suggesting that eating within a restricted time window, such as 8 to 12 hours, can improve metabolic health, reduce weight, and decrease the risk of chronic diseases.

Highlights

Pathogens were the cause of infectious diseases that killed humans for centuries.

Sanitation, vaccination, and antibiotics have controlled pathogens, leading to longer, healthier lives.

Chronic diseases are now a significant health challenge with no cure in sight.

Circadian rhythm, our near-24-hour body clock, plays a crucial role in health.

Circadian rhythms are controlled by circadian clocks encoded in our DNA.

The 2023 Nobel Prize recognized the importance of circadian clocks for health.

Circadian clocks are in-built and can be observed even in isolation from external time cues.

Every gene in our genome has a daily rhythm, influencing health and disease.

Disruptions to circadian rhythms can lead to chronic diseases.

The brain and every organ in the body have their own circadian clock.

Light is the primary synchronizer of our circadian clocks.

Melanopsin, a blue-light-sensing protein, plays a key role in resetting our circadian clock.

Indoor lighting and screen time disrupt circadian rhythms, affecting sleep and health.

Circadian lighting in various environments can promote health and productivity.

Food timing is crucial; eating at the wrong time can disrupt metabolic balance and lead to disease.

Eating within an 8 to 12-hour window can improve health and prevent obesity.

When we eat is as important as what and how much we eat for our health.

Circadian rhythms influence the effectiveness of drugs and the timing of medical treatments.

Circadian rhythm has the potential to revolutionize healthcare and treatment strategies.

Technological advancements can help monitor and enhance circadian rhythms for better health.

Transcripts

Translator: Rhonda Jacobs Reviewer: Peter van de Ven

So pathogens like this used to cause infectious diseases

that killed humans for centuries.

Until sanitation, vaccination and antibiotics took care of pathogens

and gave us long, healthy lives.

But now, we spend nearly half of our life

fighting with these kinds of chronic diseases,

and for which there is no cure in sight.

So today, I'll share with you some really revolutionary ideas

of how to prevent, manage and cure these diseases.

And the idea is based on 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 animal has circadian rhythms

that are controlled by what we call circadian clocks.

These are actually encoded in our DNA.

And this is so fundamental to life forms on our planet

that if we move any animal or human from this planet to another planet

that has identical conditions as the planet Earth

but has a day-night cycle other than 24 hours,

then we cannot easily survive.

In recognition of this fundamental property

of circadian clocks and health,

this year's Nobel Prize was actually awarded

to three scientific leaders in this field.

And I'm really honored that all three of them

have directly inspired and influenced my research.

So how do we know that these clocks are in-built?

For example, if you lock me inside an apartment

with no clue about outside time,

then my circadian clock will 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 up around 4:00 in the morning.

As soon as I wake up and open my eyes, my sleep hormone melatonin will plummet,

and my stress hormone cortisol level will rise.

My peak performance time for brain will be around noon.

And my peak athletic performance will happen around late afternoon.

As evening rolls in, the circadian clock will crank up melatonin

to make me go to sleep again,

and my body will cool down to support my sleep.

So this will continue every 24 hours, even if I'm locked inside an apartment.

And these rhythms happen because almost every single gene in our genome

turns on and off at different times of the day.

Every single hormone and brain chemical

also rises and falls at different times of the day.

So to have these rhythms is actually to have health.

And when these rhythms break down,

when we stay awake late into the night finishing an assignment

or taking care of a loved one, then we feel horrible the next day.

And if we continue abusing our clock for weeks or months,

then all these chronic 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 clock that makes us go to sleep and wake up

every day,

the same brain clock sends chemical signals to the rest of the body.

But what is really surprising is that almost every organ in our body,

and even every single cell in our body has its own clock.

What does that mean?

It means that just like your brain clock makes us more efficient

at solving complex problems in the middle of the day,

and also the brain needs to sleep at night,

every organ has its own peak 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 together to give us daily rhythms in sleep,

metabolism, mood and even gut microbiome.

But how are these clocks connected to the outside world?

In fact, every morning as we wake up and open our eyes,

bright light goes through our eyes and resets or synchronizes this clock,

so that when daylight savings time changes,

or when we move from one time zone to another time zone,

light synchronizes all of our clocks to the new season or the new time zone.

But the property of light that resets our clock is very different.

Almost 15 years ago, we discovered a new blue-light-sensing protein

called melanopsin.

It's present only in 5,000 squiggly neurons in our eye.

And these light-sensing neurons

are literally hard wired to 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 way under candle light or dim orange light,

the melanopsin is not activated.

It sends a signal to the brain as if it's dark outside

so that the brain clock makes a lot of melatonin

and we get a good night's sleep.

And in the daytime as we wake up,

go outside for at least an hour or so.

The daylight is very rich in blue light.

It fully activates melanopsin.

That synchronizes the brain clock nicely with the day.

It reduces sleepiness and depression, and increases alertness.

But the problem is, we spend more than 90 percent of our time indoors.

And at nighttime, bright screens and 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 light is not rich in blue light,

so it again sends another confusing signal to the brain,

and the brain thinks it's not day yet.

So all the chemicals that should boost our mood

are actually not produced enough.

So we kind of go back and forth between 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 particularly important for children

because their brain is still developing.

And when children go through early childhood circadian disruption,

they are more prone to diseases like ADHD and autism.

So this new simple idea, that we need more 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 glimpse of this new light revolution

when your smart screen and computer screen dim down and turn orange at nighttime.

But there is more to it.

Just think about it: Circadian lighting at daycare and schools

will promote healthy brain development and promote learning.

Circadian lighting at home, factories, offices,

will promote alertness and improve productivity.

Circadian lighting at hospitals or retirement homes

will promote health and accelerate healing.

And in fact, right now, there is new circadian lighting

in our International Space Station to promote productivity of our astronauts

and make them have better nights' sleep.

So light is not the only factor that affects our clock.

In fact, just like light in the middle of the night

disturbs the brain clock and breaks the chemical balance in our brain,

food at the wrong time can disturb the peripheral clock

and break the metabolic balance 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 hormones and digestive enzymes,

and even good gut microbiome to digest food.

So after we eat our first breakfast,

a body absorbs enough carbohydrates and uses it to fuel our body.

At the same time, it saves a 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 clock cranks up morning fat.

And after a few hours,

the clock turns into a reset and repair rejuvenation mode.

That means that it turns on enzymes

that will break down cholesterol and toxins.

It also turns on mechanisms to repair the DNA

that we have damaged during the daytime.

And a lot of cells that are damaged on our stomach lining or our skin lining

are also replaced with healthy new cells

so that allergy-causing chemicals or 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 delay that last bite late into the night.

So in this case, this daily rhythm in 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 somebody who eats within ten hours

might have a much better circadian rhythm,

whereas somebody who eats within 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 mice got the standard Western diet

to eat whenever they wanted.

And then the second group was trained

to eat the same number of calories from the same food,

but they had to eat everything

within eight to 12 hours at nighttime when they're supposed to eat.

And we measured the food and 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 group that 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 eat only within eight to ten hours,

they become healthy.

This was a really earth-shattering, eureka moment for us,

because for the first time in the history of nutrition science,

we found that when we eat is as important as what or how much we eat.

Well then, how do we translate [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 study at mycircadianclock.org -

and then, since people love to take pictures,

we asked them to take pictures of every 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 us to figure out when they eat.

And they continue taking pictures for almost two to three weeks.

So that we can take a nice snapshot of their food life

during the weekdays and weekends.

And you can see, for this particular person,

he or she eats very randomly throughout the day.

And if you look at the weekday and weekend pattern,

those are also very random.

And if you combine the weekday and weekend,

there is another interesting thing that comes up.

It appears as if the person is on the East coast during the weekday

and comes to the West coast on the weekend,

which is also very bad for our circadian clock.

Now, if we combine all of this data

and plot it as if we are looking at a clock,

then you can see that this person was eating almost around the clock.

He's not an outlier, actually.

If we look at the first 150 people who had signed up,

nearly 50 percent of adults who actually have regular 8 to 5 jobs,

eat for 15 hours or longer.

So that means

if they have their first bite at 7:00 in the morning,

the last bite or last sip of wine happens 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 overweight and they get all these diseases.

So that's why we wanted to ask a very simple question.

We brought back people who were eating for 15 hours

and were a little overweight,

and asked them to eat whatever they want within 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 up their circadian rhythm

and they lost the excessive body weight that they had.

And over the last one year,

we've had thousands of people from all over the world

who are signing up either through our study

or doing this by themselves.

They try to eat all of their food somewhere between 8, 10 or 11 hours.

And when they do that, after a few weeks,

they're truly amazed by the untapped potential

of the healing power of circadian rhythm.

Almost all of them lose 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 diseases of the gut, heart, immune system,

diabetes and even some 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 potency of 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 day it can have a more severe adverse effect,

as if it's a poison.

So this is really important.

And the effect is not even [only] to drugs,

at what time of the day we take our flu shots,

at what time we schedule our surgery for liver or heart,

does matter.

Even cancer patients

who are going through chemotherapy or radiation therapy,

it really matters whether they schedule the chemo or radiation

in the morning or late in the afternoon.

So this new knowledge about circadian rhythm

is poised to start a new revolution in healthcare and healthy habits.

Because the current idea of taking care of your health

by counting calories and counting steps is just prehistoric.

And the same software and tools

that our tech companies are using to make us watch more arts,

sleep less and eat around the clock can be used for something better.

We can have devices and sensors

that can create a nice circadian lighting environment around us.

Sensors can go on us to monitor our own circadian rhythm every day

and how it interacts with the real outside world.

Devices can prompt us what to eat and when to eat

to boost our circadian rhythm.

And even there will be smart pills and 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 rhythm has untapped potential

to prevent, manage and cure

many of the chronic diseases that affect billions of people.

Thank you.

(Applause) (Cheers)

Thank you.