The usefulness of very old animals

 kw: book reviews, nonfiction, aging, gerontology, longevity

This old fellow, assuming he isn't one of the patriarchs in Genesis, is probably half as old as the tortoise. Among terrestrial mammals, humans have the longest lives. Among all land animals, giant tortoises are probably the longest-lived. It is likely that "Darwin's tortoise" wasn't really brought back from the Galapagos Islands by Charles Darwin, to live to age 175 in a zoo. But it is known that these big tortoises can live at least 150 years, and possibly as long as 200.

No human (at least since the time of Moses) is known to have lived longer than 122 years, the known age of Jeanne Calment, who died in 1997. The second-longest, in the past few centuries anyway, seems to be a living woman currently aged 119. No (recent) man is known to have exceeded 113.

A side note on the great ages reported for Biblical patriarchs. The progression of ages tells a story, which may be more important than whether anyone actually lived 900+ years. What is commonly called "The Fall", the sin of Adam and Eve, is the first of four Falls. Here I'll focus on the longevity of the generations, the story within the story:

1. The first couple disobeyed God and were exiled from the orchards of Eden. Lifetimes went from "undetermined" (potentially endless) to mostly 900-969 years.
2. Cain killed his brother and fled from the presence of God. No lifetime of any of his descendants is recorded.
3. The earth became "filled with violence", motivating God to bring on the Flood, saving only one family. Noah was the last person to live more than 900 years (950). His son Shem lived 600 years, then 3 generations lived 433-464 years.
4. The tower of Babel ("to make ourselves a name") motivated God to confuse the languages. The next five generations lived 148-239 years, ending with Terah (the father of Abram), who lived to age 205.

Each Fall was followed by a reduction in life span by about half. Then Abram/Abraham lived 175 years, Isaac lived 180 years, and Jacob/Israel lived 147 years (his brother Ishmael lived 137 years). Thereafter, a few others including Moses lived to ages of 110 to 120, no more than that. In Psalm 90, composed shortly after God called Moses to return to Egypt, Moses, age 80, declared that the usual life span was 70, or as much as 80 years, "according to strength".

The progressive shortening of life span in Genesis drives home that disobedience to God leads to a shorter life.

Now to the book: Methuselah's Zoo: What Nature Can Teach Us About Living Longer, Healthier Lives, by Steven N. Austad. Dr. Austad is the first professor at his university (Alabama) to hold the Chair in Healthy Aging. His central theme is that nearly all our laboratory studies are of dismally short-lived animals: fruit flies (weeks to months) and mice (less than a year in the wild, less than 3 years in the lab) predominate; but we should be studying animals of exceptional longevity. At least some of them may have something to teach us about living long lives with good health.

Animals with short lives do have a little bit to teach. A mouse in the wild is most likely to wind up being eaten by an owl or a fox. It's well known that larger animals live longer, if only because there are fewer predators that can overcome them. But in a protected laboratory environment, a 3-year-old mouse is positively geriatric: thinning, graying hair; cataracts; feeble gait. Whatever aging is, mice do it fast, like everything else.

The book is full of stories of the unexpectedly long lives of certain animals. It opens with a bird called a fulmar. No firm conclusion is drawn about the longevity of fulmars, but we are introduced to one that might have been nearly as old as the ornithologist pictured with it in two photos taken 35 years apart. The bird outlived the scientist by a year or two, and may have lived 60 years or more. Fulmars are the size of seagulls. We have better information about other birds. A particular cockatoo lived to age 83.

Life in the slow lane can be longer. Tortoises are one example. I have a friend whose pet tortoise, about the size of a softball, was thirty years old the last time I saw him. Giant tortoises live longer, at least the aforementioned 150-175 years. Their heart rate is six beats per minute. Being exothermic (not self-heating like birds and mammals), they have low energy needs. It is said that we each get a potential 2-3 billion heartbeats; for humans that's from 60-90 years. For a giant tortoise, with a heart that beats at 1/10th the rate, maybe they can actually live 600-900 years!

I was intrigued by the animals that don't seem to get feebler with age. Old fulmars and old cockatoos don't have menopause in females (or E.D. in males). Neither do old tortoises. Other long-live mammals and birds do seem to end their lives with a number of years of infertility. I hope there is something useful to learn about genetic (or something else) differences between animals that age and animals that seem not to. It won't come easily or cheaply. Scientists study mice because they don't live long. It's at least 100 times as costly to study lifelong matters with naked mole rats that seem to live 50-100 times as long as field mice. Such studies would be multi-generation endeavors…multi-HUMAN-generation!

Then there's cancer. We don't yet even know the cancer rate for elephants or whales. A bowhead whale, weighs more than 1,000 times as much as a human, and one might naively think they ought to get cancer 1,000 times as frequently. Nope. They live more than 200 years, but we know little more than that. There are a few genetic clues about the cancer-avoiding (not quite cancer-proofing) of huge animals, such has their possession of multiple copies of certain cancer-suppression genes, where humans have one copy only. But our ignorance is typically as colossal as their size.

Even more mysterious are small animals with extraordinary longevity, such as a one-ounce bat that lives 40+ years, or centuries-old mollusks no larger than a teacup. One concept dwelt on throughout the book is Longevity Quotient, LQ. If most one-ounce mammals live at most 3-4 years, and a one-ounce bat species can live 30-40 years, that is an LQ of 10. Humans have an LQ of about 4, although Jeanne Calment's 122-year life indicates an LQ of 5.5.

It is still not known whether there are two intermixed human populations, one with a typical longevity of about 85 years, and another that can make it routinely to 100. I have numerous ancestors who lived into their 90's, and an aunt who died last year at age 101. A friend of mine, who is 65 years old, is already older than everyone in his family tree that he knows about; his parents both lived about 60 years. Maybe there's a third population of shorter-lived humans.

Whatever our ultimate life span may be, recent trends in longevity seem to be based more on health span. Just keeping us from "untimely death" has been a triumph of public health measures including clean water systems, at least in some countries, and vaccination for many former scourges of humanity such as smallpox, measles, and polio. Most of the long-lived ancestors of mine that I mentioned above lived in the 16th, 17th, and 18th Centuries, when such public health measures weren't even dreamed of.

The author makes an important point about "life expectancy", which is different from longevity. Life expectancy is the average age that will be reached by a cohort of the population born at the same time. If infant and child mortality is high, even if some will reach ages greater than 100, the AVERAGE will be low. Population pyramids show this, in part:

A rectangular population pyramid like the one on the left shows that the death rate is low at all ages, until one reaches age 70, and then increases. A triangular distribution, or a "scooped triangle" such as the one on the right, shows a high death rate at all ages. The life expectancy for the US is about 78.5 (average of both sexes). One might initially guess that the life expectancy for DRC is below 30, but we must remember that each horizontal tier is a different cohort. This pyramid shows high death rate, but also high birth rate. The WHO figure for life expectancy of the DRC is 62. That is for the cohort in the bottom tier only, and it takes a lot of actuarial calculation to determine it. Regardless, the more triangular a population pyramid is, the lower the life expectancy. Both charts show a very few people living to 95 and beyond; fewer in DRC than in USA, of course. But there are some. The ultimate longevity in both countries is similar.

This just scratches the surface of a book full of information, well presented. Just finding out how long some animals can live is very time-consuming (decades to centuries!) and can be very costly. The author hopes we will soon begin to learn why some animals live so long. Will learning that help humans become bicentenarians (200+ age)? Perhaps. That makes it worth doing.

One small error I wish to correct. On page 186 it is stated that carbon-14 decays to carbon-12. No, it decays to nitrogen-14, by emitting a beta particle—a high-energy electron—which changes a neutron into a proton. The rest of the analysis in that chapter is correct.

Where are the Millenarians?

 kw: longevity, multiverse, musings

Among those who are so unwilling to die that they will try anything to circumvent the inevitable, I find a strange bunch who pin their hopes on the Multiverse.

The reasoning goes like this: the Multiverse has uncountable numbers of alternate universes that differ from the one we inhabit in numerous ways, from negligible to minor to rather major. They say (this is an approximate quote), "When someone in this universe is faced with death, so are many 'copies' in similar universes. Suppose you die in this universe, and so do many of your 'copies', but some of your 'copies' don't die in their universes. Can it be that your consciousness somehow traverses between universes, so that you find yourself in one of those where you didn't die? This can happen again and again. Therefore, nobody really dies, they just get a transfer to a place where they didn't die."

Let us consider for the moment that this supposition is true, and one may, just before (or during) dying, transfer to another universe where life goes on. If this can happen again and again, can it keep happening for a long, long time? If "nobody really dies," why is it that our universe doesn't seem to have anyone in it who has hung on for hundreds of years?

This couple recently celebrated their 81st anniversary. They are 98 and 102. Shouldn't there be someone out there celebrating anniversary #100, 200, or 1,000?

How is it that our universe isn't at the receiving end of lots of transfers? Further, if you get a transfer to the universe next door, what happens to the consciousness of your 'copy'?

Where are the thousand-year-old people?

What would you pay for ten more years?

kw: analysis, longevity, health

By taking one simple step, making one change, one intervention, most sedentary folks can add ten healthy years to their lives. I have several friends who are physicians. One of them who speaks at church conferences recently made a statement to those who are 50 and over. I checked on it with others, and they all agree with him. He said,

"If you are not already exercising daily, adding exercise to what you are doing every day will add, on average, ten years to your life."

Upon further checking, I found that these are not ten years of poor quality; the final decline that we all must undergo if we are not taken suddenly by accident or illness will be delayed by ten years. Even more, it is likely that the early years of decline will be better also, effectively increasing our "health span" by more than ten years.

I once heard someone scoff, "Sure, I can exercise hours and hours for some added time. But will there be added non-exercising time?" That is, must you spend so much time in exercise that your time to enjoy other stuff is the same, just occurring later on? Let's investigate.

Consider the average fifty-year-old. If male, remaining life expectancy is 30 years, to age 80; if female, it is 33 years, to age 83. Adding exercise to gain ten years could yield either 90 or 93 total years. Ten years is 3,652.5 days, and with 16 waking hours per day, that comes to 58,440 waking hours. Let's use the figures for a male. Suppose that he must devote that whole 58,440 hours to exercise, spread over 40 years. How much is that? The simple calculation is this:

58,440 / (4×3,652.5) = 4 hr/d, or 1/4 of his waking hours.

This means that, if someone must add four daily hours of exercise, and must to keep it up for forty years to gain ten years of longevity, all the waking hours of the extra ten years will be spent exercising. He could take it easy instead, and it would be a wash. But how much is actually needed?

How much daily exercising time does my friend say is needed to get the ten-year bonus? Half an hour. That is, half an hour of doing something that increases heart rate, and leads to at least a "glow", if not becoming sweaty, by the end of the half hour. A half hour daily adds up to 7,305 hours spread over the forty years.

If it is legitimate to do so, we can put this figure into simple terms: Each year gained was "paid for" by 730.5 hours of exercise, or a half hour daily for four years. Four years of daily exercise gains an added year of healthy life.

Now, take care: This is not a linear relationship, so going for an hour instead of half an hour isn't going to give you twenty added years. It could add some, but I don't know how much. I remember Jack LaLanne, a fitness guru of the 1950's and '60's. His daily exercise routine was 4-5 hours of all kinds of exercise. He lived to age 96 years and 4 months. How long would he have lived without so much exercise? I don't know. But I do know that he enjoyed exercise, so it wasn't drudgery to him.

Exercise is drudgery to most of us who aren't already gym rats. But that half hour isn't too high a price to pay for the extra time it yields. This is the take-away message for someone fifty or so:

Break a sweat each day for four days, and gain a full day of life! Do so for the rest of your life, and you'll have lived an extra ten years.

Outliving myself

kw: longevity

If you have one clock, you know what time it is. If you have two or more, you are never sure. Prompted by a visit to the Social Security office, I ran their Life Expectancy Calculator, which uses only age and gender. It stated that, for my age cohort, I could expect to live to age 83.6, and when I am seventy, that will be pushed out to age 85.3. Fair enough. Then I got a wild hair…

I went to the Wharton How Long Will I Live page. The entry form has about forty questions. Their results are in the form of quartiles (they have a "Your Life Expectancy" value, but it is always very nearly the same as the median):

• First Quartile: 79.0
• Median: 86.9
• Third Quartile: 94.0

A third site of interest is the Living to 100 Life Expectancy Calculator. This site spreads a larger number of questions over several pages. It produced three items:

1. A calculated longevity, 90 in my case, with the note "You could live to 99."
2. A couple of pages of suggestions and how much each can impact life span. For example, I might add a year to my life by taking an aspirin a day (I currently take none).
3. Personalized recommendations by the doctor who runs the site, Dr. Perls. This came to about eight pages.

Finally, I went to one more web site, which turned out to be quite interesting: Peter Russell's Virtual Age Calculator. This has about twenty items, each a drag-bar. As you drag the bar, you see your virtual age and your expected longevity change. This makes it more tempting to cheat than usual! The upshot for me was that my virtual age is 48.6 (Funny, I don't look a day under 50), and my expected life span is 95.4. That sounds a bit optimistic. The biggest single factor is that my father is 89 and his grandparents lived into their late 80s and 90s. I suspect if I backed off a few years on that drag-bar (my mother lived only 81 years), the figures would change accordingly.

None of these asked the single most significant question that affects my life: Have you had or do you have cancer? I had colorectal cancer eleven years ago, lost 40 pounds during the period when I could not eat at all, and had half my colon removed. I suspect somebody somewhere has tables that would modify these four predictions, probably in the direction of about a decade downward!

So, what'll it be: 84, 87, 90 or 95? I won't expect more than another twenty years (85 total), but I'm basing my retirement planning on the 95 figure, just so I won't go broke. And I plan to get more of the fun stuff accomplished prior to age 75; it makes for fewer regrets. P.S. I suppose your local amateur shrink will tell you I'm in my third mid-life crisis, and I'd agree!