Introduction
My earlier book, How Not to Die, was not about living forever. It was not How to Not Die. Instead, it was how not to die prematurely, in pain after a long, chronic, disabling illness. The good news I shared is that we have tremendous power over our health destiny, in that the vast majority of premature death and disability is preventable with a healthy enough diet and lifestyle. How Not to Age has a similar premise. This book is not about immortality but rather how to age with grace and vitality rather than suffering from the ravages of infirmity and decrepitude. But why can’t we stop aging and go on forever?
“MAN WILL NEVER BE CONTENTED UNTIL HE CONQUERS DEATH.” —BERNARD STREHLER
From the Epic of Gilgamesh more than 4,000 years ago75 to the recent quincentennial of Ponce de León’s pursuit for the fountain of youth, humankind has yearned for the mythical elixir of life that would remedy the scourges of aging.76 And why not? It’s not like aging is some immutable constant in nature. Evolution has produced lifespans in animals that vary more than a millionfold, from mayflies whose adult lives may last only a few minutes to clams clocking in at over five hundred years.77 Just like the Wright brothers may have taken inspiration from birds, we can take inspiration from animals that age slowly, if at all.78
Why can’t we live forever? Some animals do, and I’m not talking about a two-hundred-year-old whale or even a thousand-year-old tree. There are actually species (with names like the immortal jellyfish) who apparently do not age and could technically go on forever.79 In a sense, humans are immortal, in that a few of our cells live on—the sperm or egg cells lucky enough to find each other. Each of our kids grows out of one of our cells, and that alone—I mean, the fact that a single cell can grow into a person—should make, in comparison, the notion of keeping our body going indefinitely seem biologically trivial. One little fertilized microscopic blob can turn into perhaps the most complex object in the known universe, the human brain, with its 100,000 miles80 of 86 billion neurons81 making 150 trillion connections.82 If that’s possible in biology, then what isn’t?
Still, there is much skepticism in the scientific community, where many believe aging is an irreversible process.83 “Anti-aging” is compared to “anti-gravity.”84 Vocal critics in the gerontology community have accused those suggesting the possibility of greatly extended human lifespans as being “contemptible … for duping the public” and claim that “anything past 130 [years of age] is ridiculous.”85 Such doubts are reliably countered by proponents who quote preeminent scientists of yore making similarly absolutist claims that did not age well.86 Nobel Prize–winning physicists spoke of the prospect of nuclear power as “talking moonshine,” a “completely unscientific Utopian dream, a childish bug-a-boo.”87 Lord Kelvin, considered one of the greatest scientists of his time, notoriously asserted, “Heavier-than-air flying machines are impossible,”88 doubling down on their impracticality in 1902, just one year before the first flight at Kitty Hawk.89
Already in the laboratory, genetic mutations can affect a tenfold increase in lifespan, at least in a species of tiny worm.90 In mice, dietary and genetic manipulation yields more like a 70 percent increase.91 Single tweaks, such as methionine restriction, incorporated into one of my Anti-Aging Eight (see here), can extend the average and maximum lifespans of rats by about 40 percent,92 which could translate to boosting human lifespan to an average of about 110, with the rare “centenarian” hitting 140 years of age.93 These results have yet to be replicated in people, but if we discovered interventions not only to slow aging but to actively repair the accumulated damage, the sky could be the limit.
Starry-eyed scientists in the field imagine that time could be effectively melted away, like that surrealist painting of drooping clocks,94 a “rejuvenation of your body leading ultimately to an endless summer of literally perpetual youth.”95 A “longevity escape velocity” is envisaged in which we would just have to live long enough for innovations to add more time than is passing, the tipping point at which each year we can add at least one extra year of life expectancy.96 This could theoretically enable humanity to have an essentially unlimited lifespan. Imagine dying the year before the critical juncture! I remain agnostic as to whether such a breakthrough is possible, but I hope this book will help regardless, whether you’re striving to live long enough to live forever97 or just trying to die young as old as possible.
FOUR BOOKS IN ONE
When I sat down to write (or rather stood up and started walking, typing at my treadmill desk), I needed to make a decision. What should I focus on? The more superficial signs of aging that everybody wants to know about, like wrinkles and graying hair, or the clinical aspects, like declining cognition? Or should I address how we might slow the aging process itself? I decided, as you can probably guess by the heft if you’re reading a printed copy old-school style, all of the above.
My inspiration for writing How Not to Age was a consensus document titled “Interventions to Slow Aging in Humans” that was compiled by the top researchers in anti-aging medicine, the likes of Drs. Fontana, Longo, Sinclair, and dozens of others—nearly everyone who’s anyone in the field. Brought together to identify the most promising strategies for developing drugs to combat aging, they identified a list of “essential pathways,” for example, the pharmacological inhibition of the hormone IGF-1 or drugs to block the enzyme mTOR. As I looked through the list, I realized: Every single one of these pathways could be regulated through diet. That became the opening section of this book.
PART I: SLOWING ELEVEN PATHWAYS OF AGING
The science of aging has been called “the most dynamic and provocative in modern biology.”98 An attempt to classify the theories of aging published more than thirty years ago identified more than three hundred such theories, and the number has only grown since then.99 In Part I, I identify the eleven most promising pathways for slowing the sands of time, ending each with practical proposals for targeting them naturally with diet and lifestyle changes. Part I is the nerdy section, and it contains critical concepts and terms that will be used throughout the book.
PART II: THE OPTIMAL ANTI-AGING REGIMEN
The odds of living to age one hundred have risen from approximately one in twenty million to as high as one in fifty.100 Why do some make it to their hundredth birthday but others don’t? It’s not just a matter of picking better parents. Studies following identical twins suggest that no more than 20 to 30 percent of the variance in lifespan is explained by gene inheritance.101 The media loves stories about hard-living centenarians who attribute their longevity to some combination of lard, vodka, and their favorite brand of cigarette, but how do centenarians and supercentenarians (those older than 110) really eat and live?
In Part II, I delve deep into the behaviors that those in the five longevity hot spot “blue zones” around the world share in common. In constructing the optimal anti-aging regimen, I explore the best and worst foods and beverages. Is red wine deserving of its symbolic status for longevity? What about coffee? I cover the “longevity vitamin” ergothioneine, the vegetarian’s Achilles’ heel, and the best exercise and sleep routine for the longest, healthiest life.
PART III: PRESERVING FUNCTION
Then, in Part III, I get to the nitty-gritty. What can you do to preserve your bones, bowels, and circulation? Your hair, hearing, and hormone balance? Your immune function and joint health? Your mind and your muscles? Your sex life and skin? Your teeth, your vision, and, finally, your dignity in death? There are chapters on each. Sneak peeks can be had at see.nf/trailer.
PART IV: DR. GREGER’S ANTI-AGING EIGHT
My Anti-Aging Eight is the final section of the book, an actionable checklist to complement the Daily Dozen I established in my earlier book How Not to Die. In addition to the wealth of recommendations throughout How Not to Age, this last part highlights specific foods, supplements, or behaviors that have the potential to offer some of the best opportunities to slow aging or improve longevity. My aim is to cover every possible angle for developing the optimal diet and lifestyle for the longest, healthiest lifespan based on the best available balance of evidence.
I. Slowing Eleven Pathways of Aging
INTRODUCTION
It has long been said that the best hope for a long life is to choose your parents wisely.102 Doesn’t longevity just run in the family? Siblings of centenarians, people who live to be at least one hundred, are certainly more likely to become centenarians themselves, and their parents are more likely to have lived to be at least ninety.103 On the other hand, the lifespans of spouses sometimes correlate as much as—or even more than—those of genetic relatives.104 Your partner may have as much of an impact as your parent. After all, we don’t only pass down genes. Perhaps Grandma’s healthy recipes or even a lifelong love of running runs in the family, too.
HOW IMPORTANT ARE YOUR GENES?
To tease out the role of genetics, researchers often turn to twin studies, comparing differences between identical twins and fraternal twins.105 Check out see.nf/genes to understand exactly how this ingenious method works to estimate heritability and what this and other methods have found. In short, only about 15 to 30 percent106 or less107 of our lifespan appears determined by our genes, which means how we live our lives may determine the bulk of our destiny.
To leverage the lifespan leeway we have beyond the relatively small genetic component, we must first understand the various aging pathways. The term “anti-aging” has been much abused in popular culture, attached to all manner of unproven products and procedures. The term should probably be reserved for things that can delay or reverse aging through the targeting of one or more of the established aging mechanisms.108 In a landmark paper cited more than 7,000 times in the biomedical literature,109 “The Hallmarks of Aging” identified nine common denominators of the aging process. I expound on them in see.nf/genes and address each one in this book.
There’s a Fly in My Aging Research!
There are numerous ways to try to unlock the mysteries of aging. You could study long-lived individuals like centenarians and supercentenarians (people who reached the age of 110), for instance, or particularly long-lived smokers to uncover the secrets to their resilience.110 Or, you could strike out in the opposite direction and study short-lived people, investigating tragic accelerated aging syndromes like progeria, where children age at eight to ten times the normal rate,111 wrinkling, balding, and then typically dying around age thirteen of a heart attack or stroke.112 Or, you could study long-lived animals. There’s a clam called the ocean quahog, whose heart can beat more than a billion times over its five-century lifespan.113
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