A public health approach to an aging world

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Coming up on Harvard Chan: This Week in Health…A public health approach to an aging world.

{***Lisa Berkman Soundbite***}

(So everything that we’ve planned, every way we’ve thought about how the world should look isn’t going to look that way anymore.)

People are living longer than ever before—and that is raising new questions and challenges.

Coming up in this week’s episode: We explore how public health researchers are grappling with issues surrounding aging and longevity—from rethinking work to preventing Alzheimer’s disease.



Hello and welcome to Harvard Chan: This Week in Health. It’s Thursday, February 8, 2018. I’m Amie Montemurro.


And I’m Noah Leavitt.


Noah—people around the world are living longer than ever before.

In fact, there are now more people older than 65—than there are young than five.


And that demographic shift comes with major implications for societies around the world.

How should we re-think work and retirement as people live into their 90s?

How will we care for aging populations?

And what will longer life expectancies mean for the development and treatment of chronic diseases?


Those big questions were the focus of a recent Harvard Chan School event in San Francisco.


The event, Living Longer, Living Better: Public Health Perspectives on Aging and Longevity, brought together two of the School’s leading researchers on aging—Lisa Berkman and Albert Hofman—for a fascinating discussion with Dean Michelle Williams.


Lisa Berkman is Thomas D. Cabot Professor of Public Policy, Epidemiology, and Global Health and Population and Director of the Harvard Center for Population and Development Studies.

And Albert Hofman is Chair of the Department of Epidemiology and Stephen B. Kay Family Professor of Public Health and Clinical Epidemiology.


We’ll get to that discussion between Berkman, Hofman, and Dean Williams in a few moments, but first we wanted to share some excerpts from presentations made by Berkman and Hofman to set the stage for what will come later.


Lisa Berkman told the audience about the implications of our aging society—making the important point that different countries will be affected in different ways.

{***Lisa Berkman Soundbite***}

(So everything that we’ve planned, every way we’ve thought about how the world should look isn’t going to look that way anymore, because there are going to be lots and lots of older people.  And thank goodness they’re aging successfully.  People are living longer – because if they weren’t, then there’d be lots of trouble.  But everything depends on older people living better, not just longer.  Otherwise this is really a catastrophe.  But if everybody’s in good shape, then it becomes a different situation.

Some societies have had a lot of time to think about this.  When you look at France, Sweden, the UK – Germany is way out here – there are some countries that have had almost 100 years to become aging societies – that is to have a percent of – to rise from 7% to 14% of the population over 65.  So some countries have actually been reasonably well prepared and knew this was coming and changed and adjusted retirement ages – although very few countries have actually adjusted retirement policies long enough.  And other countries, mostly the Asian tiger countries, have had no time to think about this – have no pensions, have no way of thinking about it.  It has happened so rapidly for them that they can’t even contemplate the meaning of this kind of a transition.  The United States is just about in the middle.

So what does it mean for how we work?  What does it mean for how families are going to take care of people?  What does it mean for how we think about education and retooling for different jobs?  It becomes a completely dramatic situation.  So again I think, in our heads, we knew this – kind of – but knowing it deeply and understanding the repercussions for how we have to kind of redesign societies is a really major undertaking.)


As Berkman said at the beginning—if people age in a healthy way—then this demographic shift may go smoothly.


But what if those added years are not healthy?

That’s where Albert Hofman’s work comes in.


Hofman has studied dementia and Alzheimer’s disease for decades—and he says that the longer someone lives—the greater their chance of developing Alzheimer’s

{***Albert Hofman***}

(Lifetime risk of dementia and Alzheimer’s disease is about 40%.  That is to say, if you live long enough, then you have a nearly half chance – one in two chance – to have dementia.  Now this of course has enormous consequences also worldwide, because these changes that I just saw – this triumph of increase in life expectancy—this is taken in millions of people suffering from dementia.)


But this is not necessarily a doom and gloom scenario.

Hofman’s research has shown that while the total cases of Alzheimer’s rise—because people are living longer—rates of the disease are going down.

His research has also shed important light on key strategies for preventing the disease.


That will be coming up a bit later in the podcast.

But now we’re going to jump into that panel discussion moderated by Dean Michelle Williams.

And just a quick note that because this was recorded on location, there are a few points where there’s some extra noise. We’ve done our best to clean up the audio in those instances.

And Dean Williams started the conversation by asking Lisa Berkman to expand on the larger implications of our aging world.

{***Panel Discussion***}

Michelle Williams: Taking it down to the community and the family, what are the implications?  What is your research telling us about the implications of this unprecedented demographic transition?  What does it have?  What are the implications for society, for families, for work, for communities?

Lisa Berkman:  Sure.  So maybe the best way to think about it is take two examples.  One is about work – how we’re going to have to rethink about what we do for work.  And the other is what are the repercussions for families and what are the risk factors for life expectancy that are related to both work and family?  So I would say, for starters, most of the evidence we have suggests that work is good for your health, that people who live longer have benefitted from working for a long time.  This is true for most professions.  The times when it’s not good have to do probably with very physically demanding jobs, where people really have early disability and shouldn’t be working – they should really stop.  But for many of us, the trajectory of working longer is likely to lead to good health.

And the same thing goes for families and social engagement – that being socially engaged and having lots of support and living with a tightly knit family and in a tightly knit community is good for your health.  So these things are things that we want to encourage on the whole.

The downside is it’s actually very hard right now to work longer, that many corporations don’t see a value in older workers and would rather have younger workers replace older workers without fully understanding, I think, what the capacity of older workers is.  So I think that’s a huge area that we know very, very little about.  And it’s also true that I don’t think anybody ever meant for us to live 30 years not working – like to retire at 60 and live until 90 – right – for 30 years without being kind of actively engaged in something, whether it’s paid or not.

And the same thing is true for families.  There is a downside, which is there’s a lot of caregiving burden that could potentially happen.  We live in a country that has almost no social protection for work and family so that, if you want to take care of a family member and you’re working, you’re incredibly challenged – and that’s probably putting it really nicely – for this.

So I think figuring out what the right balance is and how to redesign work so it will be engaging for a long period of time and so families, which are the best source of support, are able to do the kind of caregiving means that we have a lot of redesign to do, but the evidence would say this is good for your health – like people should have both of those things in their lives probably in some way or another to live longer.

Michelle Williams:  So you suggest that a redesign is needed.  We need to think about society in a different way.  And I understand a little bit of this really begins with some of the work that you do in understanding the role of social networks.  And when you talk about retiring at 60 and having 30 years of not working, when you’re socialized to either be in school or to be working and you’re facing 30 years where your social network of being a student or being an employee is gone, how do we think about a redesign of how we live so that there is a social network post-retirement – to stave off the risk factor that I know comes from your work around the impact of social isolation as a way to attenuate the healthier aging curve?

Lisa Berkman:  Yeah.  So what we know is that social isolation is harmful for your health, that it’s related to increased risk.  And we also know in a kind of allied way that social engagement looks like it prevents cognitive decline, potentially reducing dementia kinds of risk – although that evidence is much – just thinner in this.  But the solutions I think are really ones that you have to think of as working at multiple levels so that you have to think about really mobilize, I think, private industry, private corporations to think about what are the ways that we could design work that would enable people to balance their lives to both work longer and do it – and value older workers.

So some of the evidence that some colleagues of mine have recently shown is that, in work teams where there is one older person and a bunch of younger people – and in general in diverse workgroups – that the productivity of the team is higher.  Even if the older worker isn’t as skilled technologically in any one thing, the kind of interpersonal skills that they have are huge, and they actually make the team overall more productive.  And they’ve shown it in retail – like selling in clothes stores – that kind of thing – like Bloomingdales does better when they have diverse teams to do it.  Car manufacturers – BMW plants in Germany and Volkswagen plants have tried to engage in workplace redesign, and they both stay more productive – like this kind of mixed team approach turns out to be really good for the bottom line – and it probably is health promoting as well, so I think that’s the answer.

And then in terms of family, I think it’s very hard to recreate families, so the least we could do is support them.  So if we had more leave – medical leave, family leave, parental leave, sickness absence – we would be able to let families maintain what they mostly want to do.  I think families work really hard to take care of each other when they can, and it’s just against incredible odds that they’re challenged in this way.  So I think the solutions are totally out there.  We just have to recognize that they’re out there.

Michelle Williams: You, Lisa, are the author of the book – the social epidemiology book – it didn’t exist until Lisa and Ichiro Kawachi – another professor, who is now chair of the Department of Social and Behavioral Sciences, codified this area of epidemiology – social epidemiology.  And fundamental to the work in social epidemiology is understanding health inequity.  And we’ve been speaking in aggregate here.  And what I’d like to do is ask this last question before I go to Bert – can you speak to a little bit about how social inequality manifests in this area of healthy aging or unhealthy aging and longevity?

Lisa Berkman:  Yeah.  So it’s hugely important, and inequality – health inequalities – are increasing, so things are worse now than they were a while ago.  A while ago, there was a report that came from the Urban Institute on life expectancy overall over the last 40 years looking at two cohorts of people – people who were born in 1920 and people who were born in 1940.  And what happened is that, if you’re in the top half – but really the top two or three deciles – of both income and education, your life expectancy has increased for men something like eight years and for women about six years – so really major gains in basically a generation.  If you’re in the bottom third, never mind the bottom decile, for men they’ve had a 1.8 year increase in life expectancy compared to eight years for men at the top.  And for women, there has been virtually nothing.  It’s zero.  And that applies to about 30% of the population.  It takes 30% of the bottom part of the population to get to an increase of 1.8 years for women.

So there’s been incredible stagnation at the bottom that is a huge, I think, crisis for us to be thinking about, so that inequalities have always been pervasive.  I don’t think we’re ever going to reduce them 100%.  But the fact that they’re growing like this creates an urgency for us to think about what are we doing at the bottom that’s so tough – that so disadvantages people?  And what are the people at the top doing that’s so good?  Like is there something about how they’re living that we can really learn from and help spread it around without actually taking from the top?  We don’t have to decrease the life expectancy of people at the top.  It’d be great to just provide it to people at the bottom.

Michelle Williams: I want to now turn to Bert.  And Bert, I will tell you that, when we completed a 2011 survey at the Harvard Chan School asking participants to tell us, what are the health risks that keep them up at night, dementia, Alzheimer’s and cancer were the top two.  So you’re working in an area – your own personal research – in an area that keeps people awake at night.

And I wanted to share with the audience the first time I heard you talk about this – Alzheimer’s – in an epidemiology conference in Kresge Hall.  And some of you will remember the big lecture room on the fifth floor, 502.  And I was sitting close to the front of the room trying to stay in my chair when Bert said, in trying to give us some good news, that the curve – the incident rate curve – for Alzheimer’s is going down.  And I will tell you I was shocked.  And I kept asking myself, why am I shocked, because the lay press doesn’t tell us that.  And so many of us may be walking around thinking that’s not true.  And I know I left that 502 thinking it’s not true – but I’m persuaded now.  But can you help us – this audience – appreciate that bit of good news – first question?  And then do we have any hints as to what is contributing to the potential good news here of the curve bending downward?

Albert Hofman: Thank you very much.  Yes, this was about five years ago that we first could observe in a big study – a cohort study – two sub-cohorts, namely from 1990 to 2000 and from 2000 to 2010.  The number of new cases – incidence– cases of Alzheimer’s disease and dementia.  And we observed in that one study over that period about a 20% decline.  I must say I think I presented it very cautiously, and I said but I am very happy to report that we about a month ago – it has not been published yet, so you’re the first, as an audience to hear this – we did now a combined analysis of five cohort studies, two in the U.S. and three in Europe.

And effectively it has the same – all these studies show, over the last 20, 25 years – there was a study that could look at 30 years – indeed show, per decade, about a 15% decline – perhaps some a 20% decline – something like that – in the incidence of Alzheimer’s disease and dementia.  So this is really, really very good news, because it must have something to do – and that comes to the question how did this happen – not because of treatment, because I’m afraid to say there is no treatment for Alzheimer’s disease.  We can have a bit of symptom relief, but treatment – no.  So this must have been a matter of preventing the disease.

And there are two, I think, big candidates for – discussed about this.  One is overall education, but I say this in a broad sense, along the lines that Dr. Berkman said – education changes for the better over a longer period – but also related to that, particularly indeed in the highest educated, there’s quite a bit of health differential (inaudible) in Alzheimer’s disease as well, so education is, according to one theory, the reason why we have this decline – increases in that.  Nobody is, I guess, here against education.  We – you know.

The second is treatment or prevention of cardiovascular disease and risk factors for heart disease and stroke.  Stroke in itself – so cerebrovascular stroke, ischemic stroke in particular, is one of the main, I would think, causes for dementia.  In repeated strokes, you will find a very, very high – if people live long enough – frequency of dementia and Alzheimer’s disease.  So if we prevent that and we do that not perfectly but reasonably well, by changing the risk factors – hypertension, high blood pressure, hypercholesterolemia – the statins have been wonderful in this context – perhaps that is, I think, in terms of my candidates – that’s the main reason why there has been a decline.

You see it also paralleled with the decline in heart disease – the heart disease decline.  If you think of why do we have this increase in life expectancy – and particularly in the second half or the latter – later, I should say perhaps – half of the 20th century – 1980, 1990 – it’s not infant mortality anymore.  In fact there is in fact even a bit of an increase of infant mortality in most of our countries.  But it is largely heart disease.  People get heart attacks but don’t die from it.  And so if that is the reason that you see this enormous – this decline – and therefore the increase in life expectancy, then that most likely is also a reason, I would think, that we have less dementia and Alzheimer’s disease.  There may be many other factors.  In fact, if you ask me what keeps you up, that is what I want to find out.  But these are the two big candidates for this.

Michelle Williams: So I have a little bit of a show and tell because, as I traveled around to my meetings the last two days, I picked up The Wall Street Journal.  And usually when I’m at school, I don’t get a chance to read the papers very thoroughly.  But when I’m traveling, there’s a lot of time in the airport, and I had four hours in Burbank waiting to get here yesterday, so I read this article very, very carefully.  And it was in the Business and Finance section of The Wall Street Journal.  And the front above the fold was drug makers not giving up on Alzheimer’s.  And I thought that the focus of this article was important and encouraging, and we’re all looking for a little bit of positive news.  And this is a question that I want to ask you both before I open it to the audience.  And it’s a positive frame, but the report here in this article is Pfizer – its recent trial is being closed because its results are not promising.

And what could be lost to the uninitiated reading this article is it’s really a bad time.  But what really is buried in this is, if you’re focusing on treating – this goes to what you said, Bert – treating a disease at its end state and you are thinking about it from a single protein correction for a complex disease, the outcome of failure in this case – in these types of early studies – are not surprising.  As a public health person, I took out of this several object lessons.  Going forward – and no one’s giving up here – Lilly is not giving up, Pfizer is not giving up, a lot of our biotech industry partners are not giving up – but if we were to have them in the audience to talk with them, how would we encourage them to take a handle of this challenge from a social determinants and etiologic public health perspective to accelerate how we get to solutions?  That’s my last simple question to you both before we open it up. (laughter)

Albert Hofman:  Thank you. Thank you.  I’ll leave it to Lisa. (laughter)

Lisa Berkman:  Really?  I was going to let you go first.

Albert Hofman:  I think the big picture is that I think if we look in many years from now back and a full chapter of Alzheimer’s disease is written, it is a chapter largely with prevention.  I think that will be the case.  We will find ways to prevent it.  But there will be also a place probably for treatment at a certain stage.  In fact the 32 amyloid trials that failed failed – or because amyloid is not the thing – it is the consequence rather than the cause of dementia and Alzheimer’s disease.  It’s not impossible in fact.  Or it is because it is too late – you’re already there.  You have all these plaques and tangles in your head and there it is – you can’t do very much about it – or – and this is one of the things as well – the studies were simply too small.  If you see what – in heart disease – how the studies were, they are 10,000. 15,000, 20,000 people.  The studies typically in Alzheimer’s disease are 1,000, 1,500 – simply too small.  And it has been – this has been worked out quite well.  So I am not surprised about the failure, so to speak.

What is the way forward – also in terms of treatment?  Keep trying – probably earlier – and in combination with preventive activities.  I firmly think that the – for example, the vascular factors that I was talking about have an interaction – an interrelation with amyloid or tau or other proteins or NFL.  This is not what you think it is, although it is related – the neurofilament light, which is a very good marker for overall harm to the brain, and that is very strongly related – predictive of Alzheimer’s disease, it seems now, so – and that in relation – NFL particularly perhaps – in relation to these vascular factors – I think that’s the way forward.  That is what I would say to our big companies.  And indeed Pfizer may go out – although they don’t fully.  Others – other companies – really firmly are firmly committed to work in this still.  Yeah.

Michelle Williams:  That’s great.  Lisa?

Lisa Berkman:  So I would completely agree on the prevention front – that I think this is a public health moment, when medicine, once you have the disease, has a limited scope – like probably some role – but the biggest role is for us, as population scientists, to think about what we can do earlier – and I would just say probably much, much earlier.  So when we think about life course epidemiology – or if we ever believed education was causally related – it’s very likely that that happened in the first – you know, if not the first five years, the first 20 years, except for people here where it took 30 years – to do it – and still going.

But we’re talking about a life course of development of disease.  And treating things at the end is never going to be as good as thinking about, well, what could we have done in early childhood?  What could we have done in middle age, if we believe that social engagement of lifelong education had a role?  What could we do in old age, when people are symptomatic?  And I think our greatest gains are to think about the way early periods and be concentrating on theirs because those are the areas where we really have a chance at prevention.


That was a panel discussion with Dean Michelle Williams, Lisa Berkman, and Albert Hofman.


And there were some terrific audience questions that we didn’t have time to share—but we did want to share some insights around the common question of prevention.


Many people were wondering what can be done to prevent Alzheimer’s—and how late is too late?


Albert Hofman said physical activity is one key to prevention—that means being physically active early in life—and then maintaining physical activity late in life.

He said it’s never really too late to get active—although he admitted that once you reach your 80s there isn’t much more that can be done with regards to prevention.


People also asked about staying mentally active.

Lisa Berkman says it’s really a “use-it-or-lose-it” kind of phenomenon in some ways—that you need to constantly be using your brain and staying actively engaged both socially and cognitively.

But even in saying that she underscored the importance of physical activity—and maintaining heart health.


And this is obviously a fascinating subject that we could spend hours on, so if you are interested in learning more about the work of Berkman and Hofman, we’ll have some resources on our website, hsph.me/thisweekinhealth.


That’s all for this week’s episode.

A reminder if you’re a new listener, that you can always find new and old episodes of this podcast on iTunes, Soundcloud, and Stitcher.

February 8, 2018 — People are living longer than ever before—and that is raising new questions and challenges. In this week’s episode, we explore how public health researchers are grappling with issues surrounding aging and longevity. Lisa Berkman, Thomas D. Cabot Professor of Public Policy, Epidemiology, and Global Health and Population and Director of the Harvard Center for Population and Development Studies, will explain how demographic shifts will force us to rethink work and retirement. And Albert Hofman, Chair of the Department of Epidemiology and Stephen B. Kay Family Professor of Public Health and Clinical Epidemiology, explores how improved heart health may be behind an apparent decline in new cases of Alzheimer’s disease.

Learn more

The Aging Game (Harvard Public Health magazine)

Light in the Shadows (Harvard Public Health magazine)