Living Forever is Hard, part 2: Adult Longevity

by gwern3 min read9th Sep 201111 comments

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Aging
Personal Blog

Following Fight Aging's "A Primer on Compression of Morbidity" today to Fries's 2011 review article "Compression of Morbidity 1980–2011: A Focused Review of Paradigms and Progress" (Fries, incidentally, introduced the concept of "compression of morbidity" in 1980), I found some interesting details in it.

From section 3:

Mortality changes can be tracked with acceptable accuracy using the Vital Statistics of the United States or other sources [16]. Figure 2 summarizes the US data since 1900, which is generally similar to that of other developed nations. All measures of longevity increase monotonically for almost all years, providing periodic headlines and prophecies of impending crises. The real message, however, is that longevity gains from age 65 and above are quite slow and probably getting slower.

...Table 1 shows the average number of years of life remaining from 1900 to 2007 from various ages, combining both sexes and ethnic groups. From birth, life expectancy increased from 49.2 years (previously estimated at 47.3 years in these same sources) in 1900 to 77.9 in 2007, a gain of life expectancy of nearly 29 years and a prodigious accomplishment. The increase was largely due to declines in perinatal mortality and reduction in infectious diseases which affected mainly younger persons. Over this period, developed nations moved from an era of acute infectious disease to one dominated by chronic illness. As a result, life extension from age 65 was increased only 6 years over the entire 20th century; from age 75 gains were only 4.2 years, from age 85 only 2.3 years and from age 100 a single year. From age 65 over the most recent 20 years, the gain has been about a year [16].

Much confusion in longevity predictions comes from using projections of life expectancy at birth to estimate future population longevity [18]. For example, “If the pace of increase in life expectancy (from birth) for developed countries over the past two centuries continues through the 21st century, most babies born since 2000 will celebrate their 100th birthdays” [29]. Note from the 100-year line of Table 1 that life expectancies for centenarians would be projected to rise only one year in the 21st century, as in the 20th. Such attention-grabbing statements follow from projecting from birth rather than age 65, thus including infant and early life events to project “senior” aging, using data from women rather than both genders combined, cherry-picking the best data for each year, neglecting to compute effects of in-migration and out-migration, and others.
...Over the 107-year base period, the increase in life expectancy from birth over that from age 65 is approximately fourfold; over the 27-year base, it is less than twofold, documenting a flattening of the rate of increase in more recent periods (in the US). The “Point of Paradox” is the point at which the converging lines would cross. With the 107-year base, the Point of Paradox occurs in 2035 at an average age of 85.4.
...Since 1980 [1], we have performed similar calculations using data from many nations and many baseline periods and from different ages, with congruent results. The maximal average age ranges from 85 to about 93 years, with later base periods tending to be higher, and Japan and several other countries higher than the US We estimated the US maximum average life expectancy at 85 years in 1980, and now at 90 years. US White females currently project to 90.1 years. Thus, given generally stable trends, the maximal attainable mean life expectancy appears to be greater than 90 years and is almost certainly less than 100, far less than the 150 to 200 years still projected by some enthusiasts [29]

Related material is in Mike Darwin's ongoing series, "Interventive Gerontology":

  1. The Basics
  2. Diet,  Part 1
  3. Diet,  Part 2
  4. Diet,  Part 3

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[-][anonymous]10y 9

Two main criticisms (of the data/arguments provided in the linked Mike Darwin pages):

  1. Promotion of / dependence on Ancel Keys' Seven Countries study, when it is less than worthless (i.e., actively harmful). See, for example: "In his review Keys presented a perfect curvilinear correlation between the mortality from coronary heart disease and the consumption of fat in six countries, but his curve was based on a selection of countries that fit his hypothesis and it has not been confirmed in studies including many more countries (50)." "The seven countries were admittedly selected by Keys. Such selection may be helpful to illustrate an idea at a preliminary stage, but a proof of causality demands random data. In more recent studies, including many more countries, the association was weak, absent, or inverse (52)." (quotes and footnotes available at http://www.ravnskov.nu/myth4.htm)

  2. Darwin demonstrated a stark lack of understanding of the "traditional foods" movement (of which Cordain-leaning Paleo is just one variant, and of which I personally am not a fan). Much of what he said is outright false, inaccurate, or incomplete in ways that are important to pulling about the muddle of misinformation about nutrition. He should have just left his "Paleo" commentary out, since he clearly hasn't done the research to understand the claims.

The curious could look at Whole Health Source (http://wholehealthsource.blogspot.com/) especially with respect to the Kitavans, Masai, Tokelau, Inuit, and other traditional cultures with a wide spectrum of healthful diets, but all of it is good, The Perfect Health Diet (http://perfecthealthdiet.com/), and Archevore (http://www.archevore.com/get-started/) as starting points. There is a lot to read.

Or go the Quantified Self n=1 route: pick one of the three sites above, follow the advice for a month or three, and see how you feel, tracking as much as you can (mood/well-being, weight, sleep patterns, etc.) Like Max More, I am measurably improved on every health marker, as are a number of my friends and acquaintances.

Up-voted for the great links at the end about diet and nutrition as related to longevity. I've been looking for something exactly like that (a relatively scientific overview of nutrition as related to living as long as possible) for a long time.

Thanks!

Edward Marks, “Life Expectancy” Doesn’t Measure How Long You’re Expected to Live

To complete the picture we need to estimate what age-specific death rates someone born in 1940 will face in the coming years. As I’ve written before, the mortality rate for any age decays exponentially, the rate of progress is relatively stable for any age, and we’ve made a lot more progress for younger ages than older ages. I’ve plotted the average yearly progress for each age below.

Before: I Don’t See Any Evidence That We’ll Live Hundreds of Years

The reality is actually worse than this makes it sound, because while the average progress across all ages is 2%, these gains are not evenly distributed. Most of them go to people younger than yourself. For instance, progress for a child in its first year is about 5% per year, whereas progress for an elderly person in their 100th year is about 0.1% per year. This means that the life curve isn’t so much flattening out or even shifting out but rectangularizing. More and more of the population will live healthily to an old age, but they’re not going to start living hundreds of years. At least not in our lifetimes.

...To know where these curves will go in the future, we take a look at the rate of change in the past. To do this we calculate the percentage change between each year, averaged across all ages. While it does vary a bit over time, it’s actually remarkably stable, which means smooth exponential decay. Each year the average chance of dying across all ages is about 2% lower than it was the year before. Just as importantly, while mortality rates have fallen dramatically, the percentage rate at which they are falling hasn’t changed much in the last 75 years. If anything, we’re making less progress each year as time goes on. While 2% per year might sound small, it’s not. A 2% decay per year leads a value to fall in half in about 34 years, and then to fall in half in the next 34 years after that, and so forth. But as I mentioned before this progress is not the same for all ages, with the chance of a 1-year-old dying falling in half roughly every 17 years, and the chance of a 70-year-old phone falling in half roughly every 53 years. Most of the gains we’ve made are in the first twenty years of life, with progress for older ages appearing to slow almost to a halt.

Deaths from the infections more than doubled from 1999 to 2007, to more than 17,000 a year from 7,000 a year, the Centers for Disease Control and Prevention reported. Of those who died, 83 percent were over age 65. Two thirds of the deaths were caused by a bacterium, Clostridium difficile, which people often contract in hospitals and nursing homes, particularly when they have been taking antibiotics. The bacteria have grown increasingly virulent and resistant to treatment in recent years.

But researchers were surprised to discover that the second leading cause of death from this type of illness was the norovirus. It causes a highly contagious infection, sometimes called winter vomiting illness, that can spread rapidly on cruise ships and in prisons, dormitories and hospitals. “I think there is perhaps a misperception that norovirus causes a mild illness,” said Aron Hall, an epidemiologist at the disease centers. “But this suggests a major problem that requires some attention.”

...Problems with C. difficile are not new: Health officials first began warning in 2004 that a more virulent and drug-resistant strain had emerged. It produces high amounts of two potent toxins that can wreak havoc in cells lining the intestine. But few people anticipated what gains the bacteria would make. Among hospitalized patients, cases rose to 336,000 in 2009 from 139,000 in 2000. Deaths from the infection seem to have leveled off in the past few years, but researchers say they are still far too high and should be dropping, as other hospital-related infections are. Estimates of cases occurring outside hospitals run as high as three million annually. Overall, C. difficile infections cost $1 billion a year, according to the disease centers. Two factors typically lead to the infection: taking antibiotics, which make the intestine vulnerable, followed by exposure to the bacteria or their spores in a hospital, clinic or nursing home that has not been properly disinfected. Spores can survive for weeks or maybe even months outside the body, and it takes bleach or other strong disinfectants to kill them. ...A quarter of the infections start in the hospital, and the rest occur in nursing home patients or people recently treated in doctors’ offices or clinics. Patients often carry the germs from one institution to another.

--"Gut Infections Are Growing More Lethal", NYT

[-][anonymous]10y -1

The ChronoPause links appear to be broken and/or the site is down. Is there any place to see cached versions of them, or have they been posted elsewhere? Perhaps re-posting them (if permission is given) to a LessWrong wiki area would be a good idea?

I have copies, of course, but I think it's a bit premature to start posting them - few sites have 99.999% uptime.

[-][anonymous]10y 0

It's been down for quite a while now though. And it's not just me. I agree that waiting is a good idea. But it's been at least 7 hours for me. Sites don't often experience 7 hours of downtime either. It was certainly worth asking if handy other copies existed and were easy to get to.

Your link says that the site is up, and indeed, it works for me.

(I hope this incident has been educational.)

[-][anonymous]10y 0

It has confirmed that asking for additional links was the right thing to do. It cost me nearly nothing to ask but would have allowed me to read the papers beginning a full day sooner had there been an existing alternate web archive of them. For such low cost (asking in a comment), the potential gain (getting to read the papers sooner rather than waiting almost a full day for the site to come back up) was certainly worth the ~3 seconds it took to ask the question.

And in the mean time wasted more than 3 seconds of my time and the time of all future readers who don't care about a day-long or less outage back in early 2012.

Thanks.

[-][anonymous]10y 0

This effect is too small to care about. When I come across such comments in other threads, I am able to quickly bypass them and the net effect is surely less than round off error from all other noisy inefficiencies. I'd say that by harping on my low threshold for asking, you've wasted more time (including your own) than just ignoring me in the first place.