Of course, the reason why aging is so intimidating isn't because it appears to sneak up on you like a first-rate mugger. In reality, aging is more like a savvy bank robber who's spent months casing the joint. Why the discrepancy? Because there are huge delays between the cause of the problem and the effects you actually see in your life. And that means you have to start building defenses in your thirties, forties, and fifties against attacks that may not occur until your sixties, seventies, and eighties.
Fortunately, science has finally figured out most of the spectacular biological processes that control aging. And by learning about such things as mitochondria, telomeres, sirtuin, nitric oxide, and the vagus nerve -- which you will do in this book -- you'll appreciate how to apply these remarkable discoveries to your own life. As we take you inside your own body, you'll learn about the shoelacelike chromosome that affects memory loss. You'll discover the body's cellular energy factories that play a role in damaging and preserving your arteries (and you thought it was all due to the buttered biscuits). You'll even figure out whether you're a good candidate for hormone therapy as you age and understand how your third eye controls your sleeping pattern (yes, we said third). Ultimately, by understanding the science behind your body, you'll slow your rate of aging -- to live long and strong. While science holds the keys, only you have the power to unlock your potential longevity.
After all, aging may be inevitable, but the rate of aging is certainly not.
Perhaps the best way to explain the dynamics of aging is to take a look at another complex system that's subjected to the same forces as your body: a city. Some cities remain beautiful and elegant in their old age (think of old but elegant European cities like London), while others that may not even be so old look worn down, beat up, and in need of an urban ICU. Every city experiences the ups and downs of aging; how well the city managers and residents adapt largely determines whether the city will age gracefully or end up on the wrong side of spray paint, riots, and urban decay (see Figure Intro 1).
Now, every city has its own genetic code, just as you have yours. For a city, genes are geography -- whether it's built on a river, or whether it's located in a hot or cold climate, or whether it lies directly in a prevalent hurricane path. The city's geography can't inherently change. But the city can adapt to that environment, with earthquake-proof construction, underground tunnels for walking in wintertime, or a ferry system for commuting. The adaptation the city makes to survive and to thrive is what's crucial to its vitality. The same goes for YOU.
Just because you've been dealt a genetic hand that predisposes you to heart disease or diabetes or needing pants as large as a parachute doesn't mean that you can't mitigate the effects of those genes. One of the major things we'll teach you is that while you can't change your genes, you can change whether they are turned on or off, or how you express them. Not every aggressive detrimental gene needs to be turned on, and not all of your sleepy protective genes have to remain dormant. Just like a city, you can compensate elegantly if you understand your options. After all, Rome is called the eternal city.