| THE YOUTH PILL Scientists at the Brink of an Anti-Aging Revolution David Stipp New York: Current, 2010 | Rating: 5.0 High |
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| ISBN-13 978-1-61723-000-4 | ||||
| ISBN-10 1-61723-000-6 | 308pp. | HC | $26.95 | |
Nature sometimes figuratively holds up signs as if to jolt us into solving some riddle. Several cases in point germane to the subject of this book are described on pages 14 and 15. They are animal species which live an extraordinarily long time. There is a rule of thumb, for vertebrates, at least: the larger the animal, the longer it lives. But some species know how to break that rule.
"As E. Ray Lankester, an early authority on animal life spans, wrote in 1870, 'potential longevity appears to be very nearly practically unlimited.' A contemporary of Darwin (the two exchanged a number of letters), Lankester was particularly struck by evidence that many fish show no sign of deterioration with age, a mind-bending phenomenon that gerontologists now call 'negligible senescence.' In one notable case he cited, a 350-pound, 19-foot pike that was reportedly pulled from a German lake in 1497 bore a ring inscribed with the words 'I am the fish which was first of all put into this lake by the hands of the Governor of the Universe, Frederick the Second, the 5th of October 1230'—implying that it had inhabited the lake for 267 years after Swabia's King Frederick II released it." – Page 14 |
Longevity quotient is based on a rule of thumb for the maximum lifespan of any given species. Roughly, the larger the animal, the longer it lives. An animal's longevity quotient is defined as its maximum lifespan divided by the lifespan predicted by its average weight. It's currently known for about 580 species. So let's say mice live up to three years generally. A species of mouse that lives five years would have an unusually long life in mouse terms. Its LQ would be 1.8.
The author acknowledges that Lankester could have been the victim of deception. But he goes on to present reliable evidence for extreme age in several animal species. I summarize these in a table below.
| Sturgeon | 152 years |
| Ming the Clam (Icelandic quahog) | 405 years |
| Bowhead whale | 211 years |
There are other examples. In the plant kingdom, certain tree species are extremely durable. Stipp cites a bristlecone pine known as Methusalah in the Sierra Madre of California which has racked up over 4,800 annual rings. Indeed, Stipp expands on the story of animal longevity, delving into its biochemical basis, in Chapter 3: "Hagrid's Bat and the Saber-Toothed Sausage." (He gives good chapter title. And this chapter centers on Steve Austad, a scientist with as eclectic and adventurous a life as you'll find.1)
But I'm getting ahead of myself. The real story of this book is biochemical. In Chapter 2, Stipp covers the free radical theory of aging and the quest for powerful antioxidants to deal with radicals before they can damage cell structures extensively. As with many matters of human health, simply swallowing more antioxidants is not the answer.
"There's evidence that taking large doses of potent antioxidants can discombobulate intricate mechansisms in cells whose function is to counteract oxidative stress. The case for this distressing conclusion rests partly on the fact that, as strange as it may seem, free radicals serve as chemical messengers within cells as well as agents of destruction. Indeed, since the 1970s, scientists have discovered that radical messengers help regulate blood pressure, stimulate immune cells to attack infectious microbes, and switch on self-destruct programs in damaged cells that might otherwise form tumors." "And here's a very important related issue: When levels of free radicals within cells rise—which is thought to happen, for instance, when we exercise hard—they act as signals to boost SOD2 and other natural defenses against free radical damage. Thus, raining antioxidants down on cells may make them drop their overall guard against oxidative stress, leaving them open to damage that more than offsets the possible gain." – Page 47 |
While the free-radical theory of aging is far from discredited, it clearly needs elaboration if it is to reflect reality. Studies of animals with high LQ (longevity quotient) lend support to this. Africa's naked mole-rat has an LQ of around 5.3 and a relatively low level of natural antioxidants. Its longevity seems to arise from the fact that its cells are better at fending off the damage free radicals cause. (Other high-LQ animals, bats and birds especially, have mitochondria that "burn clean" — they produce fewer free radicals in the first place.)
Another complication is the controversial phenomenon labeled hormesis.
This rather unpleasant-sounding term denotes a biological process which is often a blessing. Substances which are harmful or fatal in high doses often stimulate aggressive counter-reactions when present in smaller amounts. To put it in other words, "What does not kill you makes you stronger."
"Hormesis was further linked to the weird and wacky in the 1950s, when earlier studies that had shown that low-level radiation could promote cellular growth via hormesis were twisted into plots for horror movies such as Them! and Godzilla, whose monsters supposedly grew gigantic after exposure to atomic bomb radiation. The rampaging protagonist in Attack of the 50 Foot Woman also apparently underwent radiation hormesis, as did a certain amount of her clothes, after encountering a large, radioactive alien. All of which goes to show once again that what doesn't kill you makes you a lot stronger, bigger, meaner, and, on occasion, more scantily clad." – Page 152 |
According to Stipp, the quest for means to "brake aging" involves not only compounds to prevent or reduce the damage caused by free radicals, but something that mimics the effect of caloric restriction (CR) — the only way known to extend lifespan. Scientists are looking at a class of proteins called "sirtuins" that seem to block or activate certain genes possessed by virtually all forms of life. Two of these are resveratrol, well known as a part of red wine, and an up-and-coming competitor called rapamycin (discovered on Easter Island, aka Rapa Nui.) Some others are rosiglitazone, metformin, and nordihydroguiaretic acid (NDGA). There are hints that aspirin and caffeine may have a little of this property.
It is a complicated subject, but Stipp explains it well, following a logical progression from radicals through inherited longevity to CR and the drugs that induce its effects. There are no definite breakthroughs to point to, but since 2000 the field of gerontology has become respectable, as measured by the interest of investors. One remarkable, and indicative, story is that of Sirtris Pharmaceuticals, which he covers in Chapter 11: "Sirtris, Master Voyager of the Vortex." Next comes his final chapter, "The George Burns Scenario." In it he sets forth and debunks the allegations of "apologists" — people who oppose anti-aging research. He counters their views with a hopeful and very sensible outlook, well supported by citations from writers like Robert N. Butler (The Longevity Revolution).
"Critics of this [anti-aging] quest, however, see little chance that anti-aging drugs would abet the scenario. They argue that the ability to brake aging may well engender a dangerous surfeit of needy oldsters gripped by greed and ennui. And these modern-day apologists have gotten quite heated up in recent years by signs that anti-aging breakthroughs aren't far off." – Pages 245-6 |
Such an apologist is Leon Kass, former chairman of the Bush administration's Council on Bioethics, who opined, "Let us resist the siren song of the conquest of aging and death . . . the finitude of human life is a blessing for every human individual, whether he knows it or not . . . The desire to prolong youthfulness is not only a childish desire to eat one's life and keep it; it is also an expression of a childish and narcissistic wish incompatible with a devotion to posterity."3
There are, of course, the usual endnotes and index. I recommend this report on the current state of gerontology research, and consider it a keeper for almost everyone.
To contact Chris Winter, send email to this address.