Translator: Zhou Su Reviewer: Maria Pericleous
How is everyone doing?
(Audience) Good.
Good.
I want to start off with a question: how long do you expect to live?
Let's see a show of hands if you plan to live more than 65 years.
Everybody.
What about - keep your hands up - if you want to live more than 80 years.
No change; everybody wants to live past 80.
What about if you want to live more than 100 years.
Ooh, half the hands went down.
Among people who still have their hands up,
how many of you actually believe you will live more than 100?
Ooh, very few.
All right.
Let me ask you a question, another question.
Take a guess.
If you were a person in China in the year 1960,
what is the average life expectancy?
Yes, think of a number in your mind.
The number is 44.
The average life expectancy in 1960 in China is only 44 years old.
So back then, your life would be halfway over, or almost over.
If you knew this, would you behave any differently?
Maybe you'd have different priorities in life.
Now take another guess.
In the same year, 1960, what is the life expectancy in the United States?
(Audience) 70
Ooh, you've been studying.
It was 70 years old, that's right.
So the gap between the United States and China was 26 years.
Now, what about today?
What is the life expectancy in China today?
(Audience) 70
Very close.
The number is 76 years old.
What about the United States?
(Audience) 80
Very close.
The number is 79 years old.
So let's look at the math:
From 1960 to 2016,
China increased its life expectancy by 32 years.
Whereas the United States only increased its life expectancy by 9 years.
The current gap between China and the U.S. is only three years.
That number is going to become smaller and smaller over time,
and I think in our lifetime, that number is going to reach zero.
I guarantee you.
Or you can make a bet with me.
(Laughter)
So we are living longer than ever.
We've lowered infectious disease and famine,
and we've improved our income levels, so that we have more wealth,
so that the life expectancies are increasing.
But what if you want to live longer?
[80+]
Many of you said you want to live more than 80 years old.
What can we do to make this possible?
So let's talk about longevity.
I want to start by telling you a story of a study that was started in 1998
by researchers from Duke University in the United States
and Peking University in China.
It was called the Chinese Longitudinal Healthy Longevity Survey.
So it has a very long name.
But it has a very interesting story.
They interviewed people, a lot of people,
20,000 people above the age of 80, which they called the "oldest old."
They also interviewed over 5,000 people
who were above the age of 100, also known as centenarians.
It was the largest study of its kind in the world
to determine how we can live longer.
So they conducted face-to-face interviews,
meaning that they went into people's homes,
and then they asked them questions regarding their socioeconomic factors:
how much money they were making,
their marriage history,
their living arrangement - who they lived with;
also, their social connectedness,
how many children they had,
what kind of friends they had, and if they had any siblings.
They also collected, most importantly, information on their health,
including their physical function, their cognitive function,
whether they have chronic diseases or not,
and they also took blood samples.
And this went on.
They collected this information roughly every two years.
And they went on until today.
So we have over two decades of data.
There is a lot of information.
So after 20 years of research,
they produced hundreds and hundreds of research publications.
And since I have a lot of time on my hands,
I basically read all of them.
(Laughter)
And I want to summarize for you
the secrets of living to 100 years old.
Are you ready?
(Audience) Yes!
Yes! Good.
Secret number one is not a secret.
It's winning the genetic lottery.
People who lived until they were very old
also had family members who lived until they were very old.
However, recent studies have shown
that genetic contribution to longevity is actually not that big.
Some estimates say it's only 3%.
Some say it's 20%.
Some say it's fewer than 7%.
So what this tells us
is that our environment and behavior
are the major contributors of longevity.
Secret number two: gender.
Women live longer.
On average, women live five to six years longer than men.
In this audience, you probably are more likely
to have a grandfather who passes away before your grandmother.
But if you want to pass away
at the same time as your spouse or partner,
you should do the timing right and think about these life expectancies.
How do you feel about that?
So why do women live longer?
It's a complicated question with complicated answers.
But it may be hormonal and genetic advantages that women have over men.
Yes, there are advantages.
But also men engage in a riskier lifestyle,
including smoking and drinking, and also higher risk occupations.
Secret number three: marriage can help you.
Because marriage helps with social integration.
You have more friends.
It helps with greater reinforcement of healthy behavior.
You monitor your partner
to make sure they're not eating too much junk food
or watching too much TV.
And it also leads to more economic resources
because people can share and they can make more money.
In this study marriage was shown to lower death rate by 47%,
even more than having children.
Having children lowers death rate by about 4%.
Also interestingly, men benefit more from marriage than women.
And nobody knows why.
But we think it's because in traditional families,
women usually do more work.
Another secret is having social circles.
Social interaction promotes longevity.
However, we found an interesting story.
At age 80, those who engage in a social activity
have a 19% lower risk of mortality.
By age 95, that number goes down to 7%.
And at age 95, that number actually goes to 0.
Above the age of 95, those who are very, very old,
social interaction is actually harmful to people's health.
And we think that's because at very old age,
you should invest your limited resources, your attention,
on those you really care about, the intimate relationships.
The next one is perhaps one that you've heard of, which is staying active.
Staying active helps people live longer.
The investigators of this study
measured activity called "activities of daily living,"
things people do on a daily basis,
such as eating, taking a bath, getting dressed, going to the toilet,
getting into bed or moving around.
We want to help the elderly population with this.
But surprisingly, those who received little or no help
maintained these capabilities longer,
and that allowed them to live a longer life.
So here is the message, do more things yourself, especially basic things.
How many hours of sleep did you get last night?
(Audience) Four. Seven.
Four. Seven.
(Audience) Nine.
Nine. Pretty good.
We all know that sleeping and resting are essential to good health.
Studies found that people who sleep fewer than six hours
have higher mortality rates and worse health.
But surprisingly, those who slept more than 10 hours
have even worse health outcomes.
So don't sleep too much.
The optimum time for sleeping is seven to nine hours.
Eating vegetables is extremely important.
And study after study have demonstrated
the more intake you have of vegetables and fibers
can help you elongate your life.
However, eating vegetables that are salt-preserved
increases your sodium intake.
Your sodium intake causes hypertension and cardiovascular diseases.
They found that those who ate salted vegetables occasionally or daily
have a 10% higher risk of mortality.
We're almost there.
Where you live matters
because the environment has a huge impact on our health.
In this study, they found that the median PM 2.5 concentration
was 50 micrograms per cubic meter.
And for each 1/10 unit increase of PM 2.5,
mortality rate increases 8%.
So air pollution has proven to be bad for health.
However, you may be able to counteract this with greenness,
because greenness promotes exercise
and gives you a better mental well-being,
and that actually allows you to live longer.
Here is the last secret.
And that secret is optimism.
After the age of 65, people's physical function
and their cognitive function declined,
linearly, sometimes exponentially.
However, their satisfaction in life doesn't change, or it may not change.
This study found that even when your physical and cognitive functions decline,
if you have higher optimism, higher sense of personal control
and positive feelings about yourself, you will live longer.
Negative emotions such as loneliness,
anxiety or feeling of incompetence
lowers life expectancy.
They used to say laughter is the best medicine.
In this case, we can see that optimism surely increases longevity.
All right.
So we are living longer than ever.
But are we living better?
If you just look at the headlines of life expectancy,
you might think we have an astonishing achievement
in making the average life expectancy very high.
But these extra years are not necessarily in good health.
This is from the latest Global Burden of Disease study.
On this side, we can see the highest cause of death in 1990,
and on the other side, we see the highest cause of death in 2017.
So we have new challenges,
and the new challenges for the elderly population
are hypertension, heart disease and diabetes.
In younger populations, our new challenges are mental issues
and lower back pain from working in an office
or sitting in a chair for long periods of time.
So we can live longer and better, only if we can tackle these challenges.
Longevity is the greatest achievement in the modern era.
And I believe people in this room can live to the age of 80
because you were born in the right place at the right time.
But if you want to live to 100, you need to make a strategy today.
Thank you.
(Applause)