로딩 중...
영어학습소
영어학습소
홈
테디잉글리시
수능
Shadowing
재생 속도
0.5x
0.75x
1x
1.25x
1.5x
시작 지점을 클릭하세요
0:00
Hi, I'm Dr. Morgan Levine.
0:00
I'm a professor who specializes in biology of aging.
0:04
Today, I'll be answering your questions from Twitter.
0:06
This is Aging Support.
0:12
First up, Bamabrat74, why does the aging process have to be so dang painful?
0:17
Over our lifespans, we have a lot of biological molecular changes that accumulate in our bodies, and ultimately this makes our bodies function less ideally and causes a lot of these manifestations we see with aging, the aches, the pains, the chronic diseases.
0:33
However, in aging science, we actually think that we can disentangle chronological time from biological aging.
0:40
So chronological age is what it says on your driver's license, however, this is different from what we call biological age, which is really measuring the state of the organism.
0:48
We might say that even though you're chronologically 50 years old, you have a biological state that actually resembles someone who's more like a 60-year-old.
1:00
And what that means is we can actually slow the rate at which these changes accumulate or maybe even reverse them and go back to a better functioning state.
1:00
And with that, we would actually give people more years of life without the painful parts of aging.
1:00
All right, next up from Wild Child, my head hurts so bad.
1:00
Why are hangovers getting worse as we age?
1:00
Science doesn't have an answer for this, and actually a lot of scientists think that it's just that you have poor recall of what your hangovers used to be.
1:00
And actually, there is no evidence that hangovers get worse necessarily as we age, and you might just be forgetting how bad they were when you were younger.
1:39
This could also be in terms of childbirth, why women might actually be more willing to have a kid again because they don't remember how shitty it was to give birth the first time.
1:49
Next up, Jehan asks, why do we age?
1:53
Why do we grow old and die?
1:53
And how does the world really work?
1:56
This is a fundamental question in biology.
1:58
I think of it as up there with what is life.
2:01
It's actually why I got really interested in this field as a whole.
2:06
So an aging system is what we call a very complex system.
2:10
You have to have all your molecules and cells in a very particular pattern to support aging.
2:15
So almost, I like to use the analogy of the sand art.
2:17
You can lay out these different things in a very specific manner, and when it comes to life, if you don't have that exact pattern, you don't have life.
2:26
The problem is that it's hard to maintain this.
2:28
So with any biochemical reaction that your body undergoes, you can get a slight shift, and over time these accumulate in your system.
2:39
And we think that these are why you're manifesting as aging because you develop a state that is less compatible with life than you originally had.
2:48
Next up, Eleanor Shiki asked, how much of aging is genetic?
2:52
Is longevity heritable?
2:55
The good news is, it isn't that heritable.
2:57
We actually think that only about 10 to maybe 20% of your lifespan is dictated by your genes.
3:02
And this is good news because it actually means we have a lot more control over how fast we're aging.
3:09
All right, next up, a question from Meg Shigap, can the aging process stop?
3:14
The science doesn't say that it can't happen, but we're not close to doing this.
3:20
We are close to showing that we can slow the aging process.
3:23
There is even some evidence that we can reverse aging in some degree, especially in cells.
3:31
You can take cells from someone who is, let's say, 65 years old and convert them back to a cell that actually looks like an embryonic stem cell.
3:39
So we do think we have some power to change aging, but to take an entire person, stop the aging process altogether, and hold them frozen at that age forever, I think is probably a little farfetched.
3:52
Katrina Dr. Selick asks, tell me then without saying anything misogynistic, how do men and women age differently?
3:59
Even though we might not be doing quite as well in terms of the pay gap, we're actually doing better than men in terms of the longevity gap.
4:08
Women tend to live about four and a half years longer than men when you look at the world population.
4:14
And even more than that if we look at centenarians, so these are people who live to at least age 100, women make up 83% of that population.
4:20
But unfortunately, it's actually not all good news.
4:25
So there are definitely sex differences in terms of kind of how we age.
4:29
So women tend to be much more at risk for things like frailty and for diseases like Alzheimer's disease and osteoporosis.
4:36
So even though we might live longer, we do tend to suffer more for some of these debilitating conditions.
4:47
So next up from JHNS3, I've been plant-based for a minute, but last week I ate meat and I feel my absolute best right now.
4:50
Like how and why, LOL.
4:54
What is the secret to longevity, laughing my ass off?
4:56
Actually, longevity science says plant-based diet is probably the best diet.
5:01
There's a lot of evidence from both epidemiological, which is the science when you actually look at populations, as well as some more emerging clinical trials that suggest that a diet rich in mostly plant-based foods can actually extend your lifespan and prevent disease.
5:16
Next up from Sabaita Ramen, what are the barriers to figuring out biomarkers or hallmarks to aging?
5:21
Is it that no one else has focused in on it too much or lack of funding and people believing in it?
5:29
I feel a little hurt by this question because this is what I work on and I work really hard on it.
5:33
So I don't think this is just for lack of effort, but this is actually a really complex, difficult thing to figure out.
5:40
In terms of actually developing biomarkers of aging or hallmarks of aging, we have to first be able to actually measure these changes, which is hard in and of itself.
5:50
But even after we can measure it, we have tons and tons of data.
5:52
Imagine millions or billions of variables that we can actually have to put together to identify patterns.
6:00
So this isn't just some easy feat that, oh, you just need to look in a cell and figure out what happens with age because the aging process is so multifactorial.
6:08
So many things happen.
6:11
We actually have to use a lot of computer science and machine learning coupled with molecular biology to really figure out not just what's going on, but what things are actually causing or driving the aging process.
6:25
From Pretty Matty, does the aging process slow down in space?
6:30
Asking for a friend.
6:32
There was a twin study, uh, with actually the Kelly twins who actually looked when one stayed on Earth and one went to space, what happened to them in comparison to their aging.
6:41
And unfortunately, they actually found that going into space seemed to accelerate a lot of these hallmarks of aging are things that we associate with the aging process.
6:51
So we know that there's gravitational time dilation, so actually it would slow down the closer you are to Earth, but there's also time dilation in terms of the speed at which you're traveling, so if you're traveling faster, time slows down.
7:10
It's kind of counterbalanced, so it's hard to say.
7:10
It depends on what you're doing in space.
7:11
Kennick Edge asked, is healthspan like lifespan?
7:15
Most of us know what lifespan is, it's basically how long you're alive, but a lot of people haven't heard this term healthspan.
7:25
And really what we use the term healthspan to mean is the amount of time you're alive without disease or without some age-related functional impairment.
7:25
So even though healthspan and lifespan are linked, we think if you can extend your healthspan, you'll probably also live longer.
7:38
There are actually two different things and healthspan is more the part we care about.
7:42
We don't all want to just have more and more years in a kind of more debilitated disease state, we want to have more healthy years.
7:53
So this is the part that aging research is trying to target.
7:53
Next up we have a question from Amy Harman, sciency people have there been some definitive debunking and or validation of blue zones?
7:53
Do centenarians in fact cluster there or no?
7:53
So for those of you who don't know, blue zones are these places throughout the world where they tend to have an enrichment of people who survive to age 100.
7:53
They tend to be like longevity hot spots.
7:53
There have not been debunking of blue zones.
7:53
Statistics don't lie.
7:53
Longer-lived people do live in these places, but the reason that they're longer lived is still debatable.
7:53
So a lot of people speculate that they have really good healthy lifestyles.
7:53
They tend to be people who eat more plant-based diet, have really active lifestyles and less stress.
8:36
But again, this is from looking at populations.
8:41
These aren't randomized controlled trials where we pick a set of people, we make them live in these places and we see how long they live.
8:47
Next up from Carly Solstice, does the aging process just go to warp speed as you approach 40?
8:55
I feel like my gray hairs have quadrupled and my wrinkles madly increase in just the last few months.
9:02
What we see in the aging process does seem to increase exponentially later in life.
9:07
Things like graying of hair, wrinkles, the onset of different diseases.
9:12
But actually what's underlying that in the biological aging process, all these molecular and cellular changes that we think are actually the root causes of those manifestations happen much earlier in life.
9:23
However, it takes time for those to accumulate before we actually see them on our skin, in our hair, or feel them in our bodies.
9:30
And that's why it actually feels like the aging process is really accelerating towards the end of life, but actually a lot of the changes happen much earlier.
9:39
Next up, we have a question from Cyrira, is aging a disease?
9:45
My view on it is that I don't like the definition of disease.
9:47
When we think of chronic disease, things like diabetes or heart disease, these are not binary states, you have it or you don't.
9:54
These are continuous processes.
9:57
They're things that lie on a continuum, you can be more sick or less sick.
10:02
And actually rather than saying aging is disease, I would argue that most of these chronic diseases are just manifestations of aging.
10:11
So I would actually flip it around.
10:13
So next up from Kaiser9798, I'm getting old, why do all my joints hurt now?
10:18
I didn't do nothing to warrant the pain.
10:21
So unfortunately Kaiser, this is something that's gonna happen to all of us.
10:24
We are all constantly getting older, we're all aging.
10:28
There are various reasons why your joints might start hurting with age.
10:31
So you can actually lose some of the lubrication between joints.
10:36
People can also develop things called osteoarthritis where you actually lose cartilage and you have more kind of bone on bone.
10:45
We also lose strength in terms of our ligaments and tendons and muscles that just make everything kind of not work as well and start aching over time.
10:54
So next up we have a question from Natalie Marmion, is 45 the new 35 when it comes to pregnancy?
11:02
How safe is it to have a baby later in life?
11:05
People alive today basically look like people from the past who are only two and a half years younger.
11:11
So we're looking better, but maybe not a whole decade better.
11:14
So you could say 45 is the new 42 and a half.
11:20
For the second question, when it comes to pregnancy, how safe is it to have a baby later in life?
11:24
The answer is it probably depends on you.
11:26
The oldest woman to ever give birth, I believe, was just shy of 66 years old.
11:30
So for her, she was able to give birth to a healthy baby and there's no issues.
11:36
However, we don't all age at the same rate and some of us are able to reproduce much later in life and some of us are gonna age faster and it's not healthy.
11:47
So ultimately, it's probably up to you and your doctor to figure out what's best for you.
11:47
So next up we have a question from Dennis Wurtz, cellular hallmarks of aging, what are the most predictive determinants of aging, the biochemical properties of cells or biophysical ones?
11:47
For that, I would argue that actually the hallmark that I study, epigenetic modifications, is probably the most predictive as of right now.
12:54
So what I mean by that is these are biochemical modifications to your genome.
13:04
So one might say, okay, they're biochemical properties, but actually they change the biophysical structure of your DNA.
13:04
So I don't actually think we can group things into either biochemical or biophysical because in biology we learn form equals functions.
13:04
So the physical structure will affect the biochemical functioning of a lot of these molecules.
13:04
Next up a question from 57th Snowflake, are you aware of any studies on epigenetics and the impact on longevity and if so, what impacts have been seen?
13:04
Yes, I'm aware of these, these are actually what my lab focuses on day in and day out.
13:04
We study the epigenetics of aging.
13:04
So what I mean by that is the epigenetics are changes, so these are chemical modifications to the DNA without changing the sequence.
13:04
And the exciting thing about epigenetics is even though every cell in your body has essentially the same DNA, your epigenetics is what gives cells their identity.
13:04
It's what makes a skin cell different from a brain cell.
13:14
The interesting thing is it also is what makes a young cell different from an old cell.
13:20
So we actually see specific epigenetic changes, so these chemical changes that occur as a function of age, we can measure them and we can actually use that information to infer something about how quickly someone's aging.
13:31
And this tells us something about the probability that they're going to die in the next 10 or 20 years and also the probability that they're going to develop various chronic diseases of aging.
13:42
So next up from Stormy Leather New York, are there any anti-aging remedies for hands because that's what's aging on me the fastest?
13:52
My hands look 80.
13:55
Probably not.
13:55
I would recommend sunscreen.
13:57
Next up a question from Hike Shannon, what is senescence?
14:00
This is actually the term people used to use instead of aging, so we called it senescence.
14:04
More recently, people have actually started to study something called cellular senescence, and what cellular senescence is is when a cell undergoes some stress or has reached the end of its lifespan, it'll actually transition to what we call a senescent cell, which means it's no longer dividing but you can't kill it.
14:22
So it doesn't have this what we call apoptosis or this selective cell suicide.
14:30
But the issue is that these cells accumulate in our bodies as we age and they actually have a really damaging profile.
14:36
So they're excreting all of these pro-inflammatory factors that can damage the nearby cells and cause a lot of tissue inflammation.
14:43
And so people in the aging field have actually been trying to target senescent cells to try and remove them from aging tissues thinking that this will restore some anti-aging benefits.
14:53
So next up from Ethan J. Weiss, is it true that calorie restriction does well, exercise does not increase lifespan in mice?
15:02
If so, why and is that interesting?
15:06
Actually, there's evidence now looking at different mouse strains, so these are mice with different genetic backgrounds, but actually showing calorie restriction doesn't work quite as well in all of them and some of them they actually live shorter when they restrict their calories.
15:19
In terms of exercise, I actually don't think that there's good evidence that exercise is not beneficial.
15:26
There was a study that showed that there was a very limited increase in lifespan for the exercise mice for sedentary mice, but the important thing in that study is they showed there was an increase in healthspan, which ultimately to me is the more important thing.
15:42
All right, next up, B. Dolan SFR asked, what are the neurological effects of excessive consumption of the modern American diet over the lifespan of an adult male?
15:42
How many 60s and 70s babies are experiencing pre-diabetic irritability and accelerated brain aging due to a lifetime of eating garbage?
15:42
The American diet is, and it's not good for the aging process, and we actually need to change our dietary habits if we want to live longer, healthier lives.
15:42
And this can be even more problematic for people who have genetic predispositions to some of these diseases of aging.
15:42
So you can imagine the average American diet, which is basically the McDonald's diet, could be really problematic to someone whose body is actually not doing quite so well in this area.
15:42
And finally from Dr. Roy P. S. medical science has made great strides and thus longevity and life expectancy has increased significantly.
15:42
Major pitfalls has been the exponential rise in dementia, cognitive impairment and Alzheimer's.
15:42
Is there anything to rejoice?
15:42
These conditions are worse than death.
15:42
So ideally what we would want is not for people to spend 60 years disease free, then develop a disease and then you keep them alive for another 40 years.
15:42
We actually want them to stay disease free for let's say 95 years, maybe develop a disease and then you only have five years with that disease.
15:42
So this is what we call healthspan extension rather than just lifespan extension, and is really what we need to work towards.
17:19
All right, so that's it for now.
17:21
Thank you so much for your questions.
17:24
I think they were great ones and I hope you guys learned something.