Renewal Theory: A New View of Aging

The doctor of the future will give no medicine, but will interest his patients in the care of the human frame, in diet, and in the cause and prevention of disease.

--Thomas Edison

Would you please hold this and take my picture when I'm heading back?"

I handed my camera to my colleague Ellen, then slowly jogged away from our group and up the steep slope. This was the thrill of a lifetime. As I gained confidence, I picked up my pace, weaving past the dense clusters of tourists near the entrance and finally breaking free into the open area beyond. With each step, my excitement grew. I thought back on how Ellen and the others had humored my obsession for weeks: "Don't worry, Tim. You'll get your chance to jog on the Great Wall."

Ellen and I, along with eight others, were touring China as guests of the Chinese government--members of the first delegation of American physicians practicing Chinese Traditional Medicine who had ever been invited to visit the People's Republic. The red carpet had been rolled out for us as we traveled from one city to the next, touring hospitals and universities and clinics, observing firsthand how medical care was provided.

Just the day before, the entire faculty of the Shanghai College of Chinese Traditional Medicine attended my lecture on some acupuncture research I had done. Because I had learned acupuncture in the West, for years I wondered how my skills in this ancient healing art would compare with those of my Chinese peers. I was pleasantly surprised to discover that I had nothing to be ashamed of. I was practicing Chinese medicine the way doctors in China practice it, and I could discuss the finer points of traditional medical theory with ease. In fact, I had something to teach them, which is why they invited me to give that lecture. They had loved it, and now, still flush from that thrill, I thought the excitement would be impossible to top.

Earlier on our tour, I had had the opportunity to scrub in on an open-heart surgery performed only with acupuncture anesthesia. Incredibly, the patient smiled and chatted with me as the surgeons labored inside his chest.

But those emotional highs paled in comparison to this one. Ahead of me lay the Great Wall of China, winding its way across distant mountaintops before disappearing out of sight. It would continue 500 miles east to the Gulf of Chihli, part of the Yellow Sea. Behind me, it carved a 1,000-plus-mile swath westward to the gates of central Asia, deep in Gansu province.

In my lifetime, I had run across the Golden Gate Bridge, to the top of the Eiffel Tower, through the market at Marrakech, through the streets of Tokyo, London, Hong Kong, and Los Angeles. But none of that had prepared me for this.

The Journey of a Lifetime

As I raced along the great stone roadway, my thoughts drifted back 10 years to a night that literally changed my life. At the time, I was a resident physician at San Francisco General Hospital, and on that particular evening, I was on call. As I waited for the next emergency, I picked up a copy of The Yellow Emperor's Classic of Internal Medicine (Huang Ti Nei Ching Su Wen) and began reading through it. The book spoke directly to my feelings about the deficiencies of mainstream medicine. It described a system based on health and healing rather than pathology and disease, a system that restored balance and harmony to the body by using natural therapies rather than toxic drugs.

In my mind, Eastern and Western medicines had a lot to offer one another because they compensated for each other's shortcomings so well. Together they formed a much more perfect system of medicine. That night, I realized that I must learn Chinese medicine so I could offer my patients the best of both worlds.

All my years of preparation during medical school, my internship, and my residency hadn't prepared me for this fundamental shift in my philosophy of health and healing. Still, it came to me effortlessly, as though I could have been a Chinese doctor in a past life. My Chinese teachers presented their medicine as a richly symbolic and powerfully effective system developed to absolute sophistication more than 3,000 years ago. They viewed healing as the body's attempt to correct an imbalance of energy, and they were horrified by the Western practice of treating disease by poisoning the body with drugs. I embraced their teachings, as I, too, had become frustrated with the symptom-masking mentality of Western medicine.

I began prescribing nutritional remedies, herbs, and acupuncture to my patients, and I observed firsthand how these natural medicines stimulated the body to heal itself. Perhaps inevitably, my awe of the body's innate healing powers influenced my research in anti-aging medicine. I took for granted the validity of protecting the body from disease by naturally activating its own defense systems. To this day, I resist any anti-aging therapy that presents the body with unfamiliar chemicals or disturbs its natural balance.

As I ran, it occurred to me that the Great Wall stood as the symbolic destination of my journey into Chinese medicine, which had begun a decade before. My run there had in a way become a personal vindication from those short-sighted critics who had once asked me why I would throw away a bright future in medicine for what they viewed as quackery. Time saw fit to favor my vision and prove my detractors wrong.

An Even Greater Wall

The Great Wall is an extraordinary sight to behold--a legendary testimonial to the power of protection. The largest manmade structure in the world, and the only one visible from the moon, the wall was built more than two millennia ago to defend the northern border of China against the marauding Huns. It rises 25 feet high and is wide enough to accommodate five horses abreast. In its heyday, it enabled the rapid transport of soldiers and supplies to wherever they were needed. These days, armies of tourists flock to marvel at its magnificence.

Continuing my run, I made my way up a very steep section of the wall to one of the garrison towers that are spaced at 200-yard intervals. Through a small window in the tower, I gazed out at the countryside, imagining myself as a Ch'in dynasty soldier dodging spears and arrows to defend my homeland. What was it like here 22 centuries ago, when the invading nomads from the north menaced the wall?

And then things took a surreal turn. I began to see some compelling parallels between the Great Wall and a cell wall, the tough outer membrane that surrounds every cell in the human body. The Great Wall protected China just as the cell membrane protects a cell.

Of course, the cell membrane is made not of stone but of fat (of all things!). But much like the Great Wall, the membrane serves as a barrier between the inside of the cell and would-be invaders. Swarming in and around the cell membrane are molecular soldiers called antioxidants. These molecules--which are either obtained directly from food or manufactured by the body--stand guard, ready to defend the cell against those enemy particles known as free radicals.

I began to envision the 25-foot-high wall that I was standing on as a giant cell membrane. Hordes of free radical Huns were aiming their spears and arrows in preparation for an attack, only to be turned back by the antioxidant soldiers (such as vitamins C and E, coenzyme Q₁₀ , and glutathione) stationed along the wall.

Now if this analogy seems a bit far-fetched, consider this: The total surface area protected by your cell membranes is far greater than the area protected by the Great Wall. And the membrane surrounding just one of your 100 trillion or so cells fends off more free radicals in a single day than all the spears and arrows hurled at the Great Wall since it was built.

The idea of maintaining a strong defense against potential damage, rather than allowing damage to occur and then trying to mop up the mess, made a lot of sense to me. I mulled it over as I ran back toward my group, feigning a dead-heat finish as Ellen snapped my picture. "You look a little dreamy," she said. "Are you okay?"

I just smiled.

What Is Renewal?

Even now, whenever I think of the Great Wall, it reminds me of the constant battle being waged within the human body at the cellular level. For me, the wall is a manifestation of the principles of Renewal.

Renewal is your body's master plan for rejuvenation. It consists of three very important functions that give your body the ability to maintain optimum health: protection, repair, and regeneration. Renewal prevents disease by protecting healthy cells and repairing damaged ones. When those options fail, Renewal replaces damaged or dead cells with new ones.

Like an automobile, the human body comes equipped with certain standard features. We each get our allotment of hair, teeth, lungs, and kidneys. We also get a healing system, the mission of which is to achieve and maintain optimum health. This system coordinates the resources that defend, repair, and restore the body. It provides the foundation for Renewal.

Why do we need such an elaborate healing system? In a word, damage. Damage threatens our survival. Any agent that harms the body undermines optimum health. And truth be told, damage can result from almost anything. The body even inflicts damage on itself, as it produces volatile free radicals in the course of carrying out routine tasks.

Fortunately, the body's healing system heads off much of the damage. Injured cells are constantly being repaired or replaced, although we're pretty much oblivious to it. Without this healing system, cells would rapidly succumb. Our life spans would be measured in days rather than decades.

Renewal, in other words, keeps us alive. Remarkably, it works even under the worst conditions, when it is unassisted, ignored, or hamstrung by bad habits. And with some support in the form of optimum diet, nutritional supplements, and regular exercise, Renewal can be your ticket to optimum health and maximum longevity.

The message here is that Renewal is under your control. You can facilitate it and extend your life span, or you can sabotage it and accelerate aging. What swings the pendulum one way or the other? The lifestyle choices that you make every day.

The Basic Ingredients

Prompt, efficient Renewal requires adequate supplies of six types of nutrients, along with a set of plans to coordinate them. When any of the nutrients runs low, Renewal slows. And when Renewal slows, the aging process speeds up.

Before we get into how Renewal works, let's take a closer look at each of its essential elements.

Amino acids. All enzymes are proteins, and all proteins consist of individual building blocks called amino acids . Other useful healing proteins, including antibodies and certain hormones, are synthesized from amino acids as well. To meet your daily protein requirement and give your body the amino acids it needs, without adding harmful fats to your diet, choose whole grains and beans over meats.

Complex carbohydrates. Complex carbohydrates supply the energy that powers a cell's chemical synthesis machinery. Unrefined grains and beans offer the highest quality complex carbs. Please, no sugars--not even natural sugars such as fructose, sucrose, and glucose. They just gum up the works, like fueling your car with kerosene instead of high-octane gasoline.

Essential fatty acids. These "fat vitamins" are irreplaceable in the process of Renewal. They serve as building blocks for cell membranes, as free radical scavengers and immune enhancers, and as anti-inflammatory compounds called prostaglandins. Seeds, beans, and vegetables contain modest amounts of essential fatty acids. But for an optimum intake, you need supplements, the best of which are flaxseed oil and borage oil . (You'll learn more about the essential fatty acids in chapter 8.)

Vitamins. These nutrients serve as catalysts for the astounding array of chemical reactions involved in Renewal. Certain vitamins--namely A, C, and E--also put in cameo appearances as antioxidants .

Minerals. Minerals play essential roles as cofactors for our enzyme systems. This means that they help enzymes perform certain tasks.

Phytochemicals. These recently discovered, multifaceted healing nutrients bridge the gap between basic nutrition and supernourishment. Research has already shown them to be key players in the prevention of heart disease, cancer, and other degenerative conditions. The various types of phytochemicals number in the thousands, although only a relative handful have been identified so far. What's more, they're found only in plant foods. Examples include the more than 600 carotenoids in orange and yellow vegetables, the quercetin and other flavonoids in citrus fruits, the protease inhibitors in soybean products, and the proanthocyanidins in grape seed extract.

Genetic program. To manage and coordinate the protection, repair, and regeneration of cells, your body's healing system needs, above all else, a set of plans. Your genetic program is the DNA double helix molecule. DNA controls everything a cell does by directing the manufacturing of thousands of different enzymes, each of which catalyzes one of the thousands of chemical reactions that keeps you alive.

A Cellular Affair

I never tire of thinking about the miracle of Renewal taking place in each one of the 100 trillion cells that make up the human body. In many respects, a cell is a lot like a miniature human body. It needs food. It generates energy. It eliminates waste. It reproduces. It has a definite life span. Your cells try very hard to stay healthy. And they desperately need your help.

To fully appreciate how Renewal works, you need a basic understanding of what goes on inside a cell. So join me as we take a brief tour of a typical cell to examine its most important components. Throughout the rest of the book, I'll be referring to the structures described here. (You may also want to refer to the illustration on page 13.)

Cell Membranes: A1 Protection

Perhaps the most important cellular structures are the membranes, the protective coverings located both inside and outside each cell. One membrane, called (appropriately enough) the cell membrane, forms the outer surface of the cell. Other membranes surround the organelles, smaller subcellular units that perform specialized functions. Examples of organelles include the mitochondria, which supply the cell's energy; lysosomes, which digest and expel cellular waste; and the nucleus, which houses DNA and chromosomes. You'll learn more about these structures a bit later in this chapter.

The membranes are highly selective two-way barriers that protect a cell and its organelles by functioning as combination security guards/ bouncers. Their primary job is to sift through the biochemical soup inside and outside the cell, deciding what gains entry and what gets booted out. Through their selectivity, the membranes control the internal environment not only of the cell as a whole but also of each of the organelles.

Since all of the membranes are made up primarily of fat molecules, optimum membrane health depends on optimum intake of the essential fatty acids. Throughout this book, I will repeatedly emphasize the importance of essential fatty acid supplements. I take them myself, because when undesirable chemical characters come a-knocking on my cells' doors, I want to be sure that my cells' bouncers--their membranes--turn them away. I also make sure that I get plenty of extra vitamin E and coenzyme Q₁₀, because these nutrients hang out in or near the membranes, protecting them from stray free radicals that might do damage.

Mitochondria: Essential for Energy

Mitochondria are teensy powerhouses that generate the energy necessary to drive all of the body's chemical and biological processes, including Renewal. Just as we depend on the local electric company to supply continuous energy to our homes, cells depend on their mitochondria to supply continuous energy for healing and repair.

In the mitochondria, the controlled burning of glucose (a sugar) in the presence of oxygen releases energy. The operative word here is "controlled": The energy must be generated in a smooth, gradual manner. Otherwise, the burning process produces excessive free radicals.

Controlled burning requires adequate supplies of several nutrients, including the B-complex vitamins, vitamin C, and coenzyme Q₁₀. Without enough of these nutrients, energy production, and with it the Renewal process, would fizzle faster than a wet firecracker on the Fourth of July.

The mitochondria also rely on certain nutrients to defend their membranes against the free radicals released during energy production. These protective nutrients include the antioxidant vitamins, A, C, and E; plus the antioxidant phytochemicals--flavonoids, carotenoids, and lycopene. In addition, cells make their own antioxidant enzymes, the most important of which is glutathione. Deficiencies of any of these nutrients can ultimately cause the mitochondria to misfire and lose power like an automobile with lousy spark plugs.

Lysosomes: Waste Disposal Specialists

In some respects, lysosomes are the most remarkable organelles, because they epitomize Renewal on a cellular level. These membrane-bound sacks contain powerful enzymes for digesting large organic molecules. Like teeny garbage disposal units, lysosomes engulf and digest cellular waste material, including proteins, sugars, fats, nucleic acids, pesticides, and food additives.

Lysosomes not only remove unwanted debris but they also help the body recycle its own building blocks by dismantling molecules into their component parts, which can then be reused. Enzymes, for instance, are protein molecules made up of chains of amino acids. Lysosomes can break down these molecules into their constituent amino acids, which are then returned to the body's amino acid pool--a kind of spare parts supply--to make another protein later. Lysosome-assisted cell Renewal is a large-scale operation: A typical human liver cell recycles half of its organic molecules weekly.

To function at top form, lysosomes, like mitochondria, require optimum amounts of all of the essential nutrients. Minerals such as zinc, selenium, and magnesium are especially important because they support a lysosome's digestive enzymes. Essential fatty acids keep the lysosome's protective membranes healthy. And platoons of antioxidants protect those membranes from attack by the toxins that the lysosome is supposed to contain. If a lysosome membrane ruptures, a caustic brew of digestive enzymes spills into the interior of the cell, wreaking havoc.

A diet replete with animal foods, additives, pesticides, pollutants, and other free radical formers is chock-full of the stuff that ends up as garbage in lysosomes. Eating this way places abnormal stresses on the cellular detoxification process and has been shown to shorten life.

Nucleus: The Center of the Action

The protection and repair functions of Renewal are particularly crucial to the nucleus. Located at the center of the cell, the nucleus contains DNA, your genetic blueprint. DNA serves two functions: It manufactures enzymes to help repair damaged cell structures, and it orchestrates replication to replace injured or worn-out cells.

A cell must contain intact, undamaged DNA in order to replicate without error. If the cell's antioxidant supply is depleted, unscavenged free radicals can fracture the DNA, causing faulty protein synthesis (which affects enzyme production) and/or inaccurate cell replication. This can lead either to cell death or to genetic mutation and uncontrolled cell division--the prelude to cancer. So you can see the importance of protecting your DNA with daily antioxidant supplements.

A Feast Fit for a Cell

As you can see, virtually every aspect of cellular function depends on the presence of key nutrients. When even one of these nutrients isn't available, the job performance of the cell's internal structures is compromised.

Unfortunately, the standard American diet, consisting of processed, pesticide-laced, devitalized foods, is not only criminally deficient in essential nutrients but also full of free radicals. It provides little nutritional support to cells and ultimately puts the kibosh on Renewal.

Admittedly, feasting with casual abandon on meat, dairy products, fried foods, fast foods, and convenience foods may feel satisfying in the short run. But in the long run, this practice will tick decades off your life.

On the other hand, following a low-fat, vegetarian diet and taking broad-spectrum, antioxidant supplements vastly improves your chances of living 100 years or longer. Not coincidentally, these are two of the three pillars of the Renewal Anti-Aging Program (the third being exercise). Sure, building your meals around fruits, veggies, grains, and beans may seem a little unappealing at first. But I'll wager that with time you'll come to love and crave these wholesome foods.

Your cells will appreciate your healthy food choices, too. After all, your cells are the final destination of everything that passes through your lips. And they have very definite preferences in terms of what you eat and drink. If only they could share with you their likes and dislikes, they would naturally guide you to an optimum diet.

In fact, let's suppose for a moment that you've invited five of your cells to your favorite restaurant for dinner. They scan the menu in search of something that suits their very particular appetites. The cells want a vegetarian meal because they crave the protective phytochemicals in produce and fear the free radicals in meat, which could blast their enzymes to smithereens. The meal has to be very low in fat, because an oxidized fat molecule--a free radical--could blow a hole in the cells' protective cell membranes. And the meal's ingredients must be organic, because a pesticide molecule or two could fracture the cells' DNA.

Once everyone has ordered, the cells engage you in a rather enlightening conversation about your nutrition habits. Cell #1, a liver cell, speaks up first: "I appreciate it when you take your supplements. They give me an upper hand on those free radicals, and they make cleaning the toxins from your blood so much easier. By the way, I'd love to get some N-acetylcysteine supplements. I need them to make more glutathione, my main defense against free radicals. The more glutathione I have, the safer and healthier I am."

"For me, more ginkgo, choline, and B vitamins, please," chimes in Cell #2, a zippy and communicative nerve cell. "These supplements help me make more neurotransmitters so I can do a better job of helping you think. And that acetyl-L-carnitine supplement you tried last month . . . excellent! That stuff helped me produce more energy, and it made my membranes more resistant to free radical damage. You could cut out the alcohol, though. The glass of wine you had yesterday really knocked my socks off. I was out for a couple of hours. And two of my sisters died from it! Alcohol really hurts us cells. Mr. Fancy Liver there can handle it--he just clones more cells. But when we nerve cells are knocked off . . Hey, that's it!"

Cell #3, a kidney cell, also has a request to make: "Would you mind sticking with purified water? Hey, I have a job to do. It's tough enough without you drinking tap water. That stuff is swimming with toxic chemicals, and they make me sick."

"And while we're on the subject," adds Cell #4, a pancreas cell, "I've had about all the sugar I can handle. You've really been pouring it into your system lately, and you don't have to. I can make all the sugar you need if you just feed me whole grains."

Cell #5, an immune cell, throws in its two cents' worth: "We lymphocytes need fewer animal fats and more essential fatty acids to strengthen our membranes so we can protect you better. A virus almost nailed me last week because I had a weak spot in my outer membrane. We'd like more flaxseed oil and borage oil. And skip the margarine and other hydrogenated oils, okay?"

Renewal at Work

If your cells seem a bit hypersensitive about how you feed them . . . well, they have to be. For them, getting the right nutrients is a matter of life or death. An optimum diet fuels Renewal.

Renewal goes on constantly, just trying to keep up with everyday cellular wear and tear. But sometimes the process kicks into overdrive, as the result of illness or injury. The presence of physical symptoms is a clear message that cells are sustaining damage. Whether the cause of the symptom is an acute, minor ailment (such as a headache or cold) or a chronic degenerative disease (such as arthritis or osteoporosis), Renewal attempts to make the necessary repairs.

Of course, some of the most serious conditions--including heart disease, stroke, and cancer, the ones I call silent killers--develop without obvious symptoms to alert us that the body's healing system has been activated. Nevertheless, Renewal is at work, trying to patch up or replace sick cells. And perhaps more than ever, it needs our support.

When damage occurs on the outside of the body, we can observe the miracle of Renewal as it unfolds. I had the chance to do so a number of years ago, when my mother suffered a mishap. While out for her daily run--a pretty remarkable habit for a woman who was in her seventies at the time--Mom tripped on a bump in the sidewalk, landing flat on her face. Ouch! Her nose was fractured, and her forehead and cheeks were scraped and bruised. She was able to get back on her feet with a helping hand from a Good Samaritan. When Mom reported to a nearby emergency room to get patched up, the doctor on duty told her that she would need at least a month to recover. That doctor didn't figure on Renewal!

Mom had been following the Renewal Anti-Aging Program for several years by then, and her body was revved up for rapid repair. Even I couldn't believe how quickly she healed. The third day after her fall, her scabs were coming off. A couple days after that, the bruising was virtually gone. Mom recovered completely within about half the amount of time expected for someone her age. The Renewal Program--a combination of diet, supplements, and exercise--had paved the way for rapid healing.

Incidentally, this mishap didn't slow my mother one bit. She's now in her eighties and healthy as a horse. She still follows the Renewal Program, jogging every other day (though she pays a bit more attention to the contours of the sidewalk) and lifting weights on her "off" days. She's on track for maximum life span--120 healthy, vital years.

An Extraordinary Process

You now know that in order to extend your life span, you must thwart cellular damage while supercharging your healing system. Accomplishing this requires the three separate but complementary components of Renewal: protection, repair, and regeneration. Each of these components must function optimally. If one falters, the entire Renewal process becomes impaired.

Let's examine the progression of cellular Renewal--from damage through protection, repair, and regeneration--in greater detail.

When Damage Is Done

Since the preceding chapter covered free radicals, I'll assume that you already know more about cellular damage than you bargained for. To summarize, your cells are under a virtually constant state of siege, getting kicked around by free radicals on a more or less nonstop basis. In fact, free radicals are responsible for most cellular damage--the kind of damage that shortens lives and kills people before their time.

A typical cell is hit by approximately 20 billion free radicals per day. By way of comparison, envision an army of 200,000 Hun archers staging an attack on the Great Wall of China. Assuming that each archer has 100 arrows, the amount of damage this army would inflict upon the 1,500-mile stretch of wall would equal roughly one-thousandth of the amount of damage that free radicals inflict upon every cell in your body every day. Viewed another way, each archer would need to shoot 100,000 arrows to match one cell's daily dose of free radical hits.

Amazingly, your cells can withstand this type of punishment, as long as your antioxidant guard is up. Antioxidants neutralize free radicals, preventing them from doing harm. This is why consuming generous amounts of antioxidants from foods and supplements is so important.

When your antioxidant intake falls below par, free radicals gain the upper hand. A few billion hits here, a few billion hits there, and pretty soon you're dealing with major cellular damage. This cumulative damage robs cells of their ability to replicate themselves. It drives the aging process and eventually leads to death.

Protection: The Best Policy

To be sure, free radicals are a persistent, provocative lot. But just as surely, we are not at their mercy. Nature has provided us with a complex and awesome array of weaponry with which to defend ourselves and our cells. Let's take a closer look at these potent protectors.

Antioxidant nutrients. The workhorses of the body's healing system, the antioxidant nutrients fall into one of two subcategories: essential nutrients and phytochemicals. The antioxidant essential nutrients are those that we absolutely must have in order to stay alive. They include the following:

* Vitamins A, C, and E--the nutrients most people think of when they hear the word "antioxidants"

* The antioxidant minerals copper, selenium, and zinc, which support free radicalscavenging enzymes

* Certain essential fatty acids and amino acids that double as antioxidants (in addition to their other responsibilities)

* Coenzyme Q₁₀, a vitamin-like antioxidant that scavenges free radicals and boosts the immune system

Unlike the antioxidant essential nutrients, antioxidant phytochemicals are not considered necessary for survival. But these plant-derived compounds are just as essential if you want to protect yourself from degenerative disease and achieve the very best health. (We'll discuss these "supernutrients" in more detail in chapter 25.)

In chapter 2, we discussed how antioxidant nutrients donate electrons to free radicals in order to neutralize them. In addition, these nutrients safeguard one another against oxidation (the process by which free radicals snatch electrons from healthy cells) via multiple, overlapping backup systems. For example, beta-carotene recycles vitamins A and E--and even other carotenoids--by replacing their lost electrons so they can rejoin the free radical fray.

In my practice, I evaluate a patient's antioxidant nutrient status using a blood test called an antioxidant profile. This test measures levels of all of the antioxidant essential nutrients as well as several of the antioxidant phytochemicals.

Antioxidant enzymes. The human body has learned that it can't depend entirely on foods for an uninterrupted supply of antioxidants. So cells have developed the ability to produce their own protectants, a trio of special antioxidant enzymes with exotic-sounding names: glutathione peroxidase, superoxide dismutase, and catalase. These "homemade" antioxidants are manufactured by every cell in your body. They work hand-in-hand with antioxidants from your diet, lying in wait to ambush free radicals wherever they might appear.

By far, the most important of the antioxidant enzymes is glutathione, the primary free radical scavenger for a cell's various membranes, including the mitochondrial membranes. The mitochondria, you'll recall, generate a cell's energy supply through the controlled burning of glucose. This process releases high concentrations of free radicals, which proceed to pound the mitochondria's protective membranes.

Since glutathione performs such an important function--if a cell loses its energy supply, it can't do its job--maintaining an optimum level of the enzyme is considered a powerful anti-aging strategy. In fact, glutathione status is closely correlated with vulnerability to life-shortening health problems. The lower a person's glutathione level, the higher his risk for heart disease, cancer, autoimmune disease, and all other degenerative conditions. The opposite is also true: A high glutathione level offers greater protection from illness and increased longevity.

A simple laboratory test called an oxidative stress profile can tell you whether your glutathione level is low and your free radical count is high (excess free radicals deplete glutathione). If so, you can significantly increase your body's glutathione production by taking a supplement that contains the enzyme as well as the enzyme's precursors, N-acetylcysteine and lipoic acid.

The immune system. Your body can also rid itself of free radicals via its immune system, whose cells dispatch the varmint particles in two ways. First, cells called T lymphocytes and macrophages identify, surround, engulf, and digest free radicalforming invaders such as viruses, bacteria, allergens, and pollutants. (This process is known as phagocytosis.) Second, other immune system cells, called B lymphocytes, manufacture antibodies that hunt down the undesirable invaders and zap them before they cause trouble.

Repair: A Cellular Tool Kit

When antioxidants and the immune system fail to protect a cell against damage, the body resorts to its next line of defense: repair. The job can range in magnitude from fixing minor dings in the cell's outer membrane to replacing oxidized strands of DNA in the nucleus.

Before we get into the nitty-gritty of the cellular repair process, allow me to share a short history lesson. In April 1906, San Francisco was shaken to the ground by a devastating earthquake. No amount of precautions could have protected the city from the devastation that ensued. Anything that managed to withstand the temblor was largely consumed by the fires that followed. But the citizens of this marvelous city completely rebuilt it in just a few short years.

Some 150 years earlier, an even more devastating earthquake hit Lisbon, the capital city of Portugal. In six minutes, the city was reduced to rubble. Its harbor dried up momentarily, then flooded when a 55-foot wall of water rushed back in. Fires broke out, and landslides were triggered by aftershocks. By nightfall, 60,000 people had lost their lives. Yet Lisbon rose from its own ashes and these days sports a bustling economy.

By now you may be wondering what any of this has to do with cellular repair. Well, think of your cells as microscopic San Franciscos and Lisbons. For them, the kind of damage that free radicals cause closely resembles that of an earthquake--except it's more severe, and it never stops.

Every single cell in your body sustains 20 billion free radical hits of varying severity every single day of your life. In each instance, repair must occur rapidly and efficiently so the cell's operations can proceed unhindered. You can see why the process never stops.

For Renewal to be effective, the rate of repair must keep up with the rate of damage. Once damage outpaces repair, the aging process accelerates and disease develops. The slower the rate of cellular repair, the faster the rate of aging, and vice versa.

The components of a cell that are most vulnerable to free radical damage are its proteins (especially the enzymes that catalyze essential chemical reactions), its fatty acids (primarily those in the cell's membranes), and its DNA (housed in the cell's nucleus). Fixing damaged enzymes is no big deal. Nor is patching holes in the cell's membranes. Both jobs are simply a matter of synthesizing replacement protein or lipid (fat) molecules, which is done from the genetic program in the cell's DNA. So repairing enzymes and membranes, while important, is more or less an I-can-do-it-blindfolded-with-both-hands-tied-behind-my-back affair.

Not so with repairing DNA. Damage to DNA presents a much greater threat to a cell, because its genetic program is in danger. Without an intact genetic program, a cell cannot do its assigned job, repair itself, or replicate itself accurately. Damaged DNA, also known as mutated DNA, is like a damaged floppy disk: The message that's encoded within it comes out scrambled. Failure to repair damaged DNA translates into accelerated aging.

DNA consists of very long chains of pairs of nucleic acids, which are attached to a "backbone" of sugars and phosphates (creating the familiar double helix configuration). Think of the paired nucleic acids as representing letters of the alphabet. Together, they form words that are your genetic code. When the paired nucleic acids are damaged by free radicals, the long chains that make up the DNA are actually fractured, and the words become unintelligible.

Because preserving DNA is so critical to human survival, nature has not left it to chance. Of all of the mind-boggling tasks that the body can perform, I think DNA repair tops the list. It requires a wondrous combination of craftiness and versatility.

Each cell continuously monitors its own DNA for "coding errors"--that is, free radical damage. When such an error is detected, a team of highly specialized DNA repair enzymes (more than 50 have been identified so far) goes to work.

First, an enzyme called DNA nuclease identifies and snips out the damaged DNA segment, which may include several pairs of nucleic acids. Then another enzyme, DNA polymerase, inserts a replacement segment, restoring the correct sequence of nucleic acids. Finally, a third enzyme, DNA ligase, seals any remaining gaps in the DNA chain.

The DNA repair process is kind of like replacing a link in a broken necklace, but it happens much faster. If you could shrink yourself down and watch it, you'd think it was a magic trick.

I can't help but be fascinated by this process--by the free radical "earthquakes" that decimate DNA molecules and the enzymatic construction crews that rebuild them. Why, the mere notion that the human body could repair any molecule, much less a large, complex DNA molecule, was unheard of when I was a medical student.

The process isn't perfect, however. After all, each of your DNA molecules takes about 10,000 free radical hits each day. The DNA repair enzymes do their best to keep up, working nonstop to patch up the damage. But hits come so fast and furious that the repair crew can't help but allow a small amount of damage to slide by unchecked.

A small amount of damage here and there presents no serious problem. But over the course of a lifetime, the damage that the repair enzymes miss begins to pile up. Damaged DNA can still replicate, but it bestows its coding errors on its offspring. Then these new cells malfunction, too.

This always reminds me of that classic I Love Lucy episode in which Lucy and Ethel get jobs on the production line in a candy factory. At first, they keep pace just fine. Then the conveyor belt speeds up, and the chocolates glide past faster than the women can pick them up and pack them. They stuff the candy in their mouths, in their clothes--and still they can't catch up. Sure, it makes for hilarious television. But when it happens on a cellular level, the results aren't quite so amusing.

There is a direct relationship between the rate of cumulative damage to DNA and the rate of aging. In fact, species that live longer than humans--turtles, for example--accumulate damage more slowly than we do. The current standard model for aging--the most comprehensive theory to date--asserts that cumulative damage to DNA renders cells unable to replicate correctly, which gradually erodes cellular function and precipitates degenerative disease. What's more, damaged DNA cannot accurately produce the enzymes that drive thousands of chemical reactions throughout the body, which further accelerates aging.

The aging process, then, works something like this: A shortage of antioxidants gives free radicals the upper hand. They assault DNA in such rapid-fire fashion that enzymatic repair crews can't quite keep up. Unrepaired DNA damage accumulates, impairing cell replication and enzyme production--both of which are regulated by DNA. The end result: cellular degeneration.

If DNA repair mechanisms were to fail completely, we'd be in big trouble. In fact, this is what happens to people who have a dermatological disorder called xeroderma pigmentosum. Their skin cells have lost the genetic program to manufacture repair enzymes. As a result, the cells cannot patch up the DNA damage caused by the sun's ultraviolet radiation. (Ultraviolet radiation produces free radicals that are indistinguishable from those produced in the body.) People who have xeroderma pigmentosum invariably experience accelerated skin aging as well as skin cancer.

Because the failure of DNA repair has such catastrophic consequences, you want to do what you can to keep the repair mechanisms in tip-top shape. Above all else, this means maximizing levels of antioxidants while minimizing levels of free radicals. Antioxidants protect DNA molecules against free radical damage. And the fewer free radicals around, the less damage they'll cause in the first place.

This is where the Renewal Anti-Aging Program can help. The program not only provides for optimum antioxidant intake but also reduces free radical exposure. By following the program, you'll ultimately have millions fewer DNA lesions per cell than a person of the same age who does not follow the program.

Regeneration: Nature's Most Amazing Feat

When a cell suffers so much damage that it's beyond repair, it dies. At this point, Renewal offers one final option: regeneration. Your body replaces the dead cell with an exact replica. Since cells are dividing all of the time anyway, this presents no great challenge--provided that cumulative DNA damage is minimal and necessary nutrient building blocks are available.

As I wrote this book, I had a tough time coming up with a story to illustrate Renewal through cell replication. Then fate intervened.

This time, the story involves Emma, my seven-year-old daughter. One day, Emma's preschool teacher burst into my office, visibly upset. "Emma smashed her finger in the door at school," she told me. "Do you think she needs stitches?"

I ran out to the teacher's car, where my daughter was waiting. After the longest 10-second hug ever, Emma carefully unwrapped the loose cloth bandage around her left index finger and bravely held it out for me to see. Her fingertip was just about severed, the bone crushed, the nail nowhere to be found. "Yes, she needs stitches," I said, understating the problem with as much calm as I could muster under the circumstances.

Fortunately, my friend and neighbor, John Canova, M.D., was in his office a few blocks away. For two hours, I held Emma's "good" hand while Dr. John carefully cleaned and anesthetized the injured finger and stitched the severed portion back on--deftly, painstakingly, with superb surgical expertise. I know it hurt a lot, but Emma was a real trouper.

Six weeks later, Emma produced her injured finger for inspection, proudly holding it up beside her other index finger for comparison. "Emma," I said, "you sure did a good job of healing that finger." Except for the nail, which hadn't yet grown back, both fingers appeared identical! Anyone who had seen the "before picture" of Emma's injury would have been amazed at how well her finger healed.

Emma's experience is an ideal example of how cell replication works--though with not so much drama on a day-to-day basis. Your body constantly replaces damaged and worn-out cells in every organ and tissue (with the exception of nerve cells, which can be repaired but not replaced). And this process goes on inside you literally every moment of your life.

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In summary, Renewal Theory describes your body's healing system: how it protects your cells from damage, repairs injured cells, and regenerates irreparable cells. The rest of this book will show you how to incorporate Renewal Theory into your everyday life so you can achieve your maximum life span.