From the Rodale book, Renewal: The Anti-Aging Revolution:
Very few individuals, if any, reach their potential maximum life span; they die instead prematurely of a wide variety of diseases--the vast majority being "free radical" diseases.
--Denham Harmon, M.D., Ph.D., who in 1954 first proposed the Free Radical Theory of aging
Honey, take a look at this. You might find it interesting."
Great moments in human history often begin inauspiciously. Such was the case in December 1945, when the wife of Denham Harmon handed him the latest issue of the
Ladies' Home Journal. It was opened to an article titled "Tomorrow You May Be Younger," written by William L. Laurence, science editor of the
New York Times. This article, heralding the work of a Russian gerontologist on an "anti-reticular cytotoxic serum," sparked Dr. Harmon's interest in finding an answer to the riddle of aging--a subject that scientists of the time knew absolutely nothing about.
For the next nine years, Dr. Harmon, a brilliant young organic chemist with a Ph.D. from the University of California, Berkeley, ruminated about the aging process. Because aging is such a universal phenomenon, he reasoned that it might have a single basic cause. But what could it be? The answer eluded him.
Though still obsessed with the question, he had to place it on the back burner while he completed medical school and an internship at Stanford University. Then one morning in November 1954, during a period in which he was simultaneously completing his residency in
internal medicine and doing research at Berkeley's Donner Laboratory, Dr. Harmon's quest ended. That day, while reading in his office, he had an "aha" experience that would revolutionize medical science: "(It) suddenly occurred to me that free radical reactions, however initiated, could be responsible for the progressive deterioration of biological systems."
Of course, sometimes even the best ideas are slow to be accepted. This one didn't exactly inspire words of praise--not at first, anyway. After thinking it over for a month, Dr. Harmon strolled the Berkeley campus, knocking on doors and presenting his newly formulated Free Radical Theory to his colleagues. To say that it was a hard sell would be an understatement. He might have had more success had he been hawking vacuum cleaners.
The scientists whom Dr. Harmon approached were singularly unimpressed. In fact, all but two flatly rejected his idea. One after another, they slammed the door in the face of the young upstart, who dared challenge the status quo with the preposterous notion that all degenerative disease--and the aging process itself--could be explained by the presence of free radicals.
Undaunted, Dr. Harmon pursued his theory. In subsequent years, he demonstrated how the effects of free radicals are reversed by nutrients known as antioxidants, how
antioxidants extend the life spans of laboratory animals, and how
antioxidants offer protection against heart disease, cancer, senile brain disease, and all other degenerative conditions associated with aging. Dr. Harmon proved that age-related immune deficiency is caused by free radicals and can be reversed by
In terms of scientific significance, Dr. Harmon's Free Radical Theory ranks with Galileo's invention of the telescope, Newton's discovery of gravity, and Einstein's theory of relativity. No breakthrough has had more profound implications for human health and longevity.
Now in his mid-eighties and still professionally active, Dr. Harmon deserves the Nobel Prize for his revolutionary work.
Free Radicals: Longevity's Most Formidable Foe
Dr. Harmon's Free Radical Theory has emerged as the best understood and most widely accepted explanation of the aging process. Having stood the test of time and countless research validations, it has become not just a damage theory but the damage theory. (You'll recall from chapter 1 that according to damage theories, cumulative cellular damage determines a person's age of death.) In fact, among doctors specializing in anti-aging medicine, Free Radical Theory has transcended mere theory status and is considered a biological fact of life.
Just what are these free radicals, anyway? Understanding where they come from, and why and how they do so much damage, requires a brief lesson in biochemistry.
Molecules are made up of atoms glued together by chemical bonds. Each bond consists of a pair of electrons. When a bond is broken, what's left are two molecular fragments, each of which contains one of the now unpaired electrons. These molecular fragments are highly charged and highly unstable, because they contain only one electron rather than two. These highly charged, highly unstable, highly reactive particles are what we know as free radicals.
Unfortunately for us humans, the biochemical saga of free radicals doesn't end there. Remember, each free radical contains one unpaired electron. And unpaired electrons, like unpaired humans, hate to be alone. They want a partner, and they're not above breaking up another bond to get what they want. Scientists call this process oxidation, and free radicals are masters at it. They're not particularly discriminating about where they get their new partners, either. They'll oxidize just about anything that gets in their way--punching holes in cell membranes, destroying key enzymes, and fracturing DNA.
What's more, free radicals are remarkably prolific. One free radical, unchecked, can cause new ones to form. These free radicals, in turn, give rise to many more. How does this happen?
Because it has so much energy, a free radical zips about until it bangs into a nearby molecule with a stable bond. The collision splits the stable molecule, releasing one of its two electrons. The free radical nabs the electron as a partner for its own unpaired electron, and the two form a stable bond. All this happens, quite literally, within nanoseconds.
The good news is that the free radical has stabilized itself. The bad news is that in doing so, it may have caused the formation of two more free radicals by breaking a stable bond, leaving the two atoms of the formerly stable molecule to share one unpaired electron. So begins a chain reaction that produces thousands of molecular fragments with unpaired electrons. And every one of these fragments is careening about, looking to swipe an electron from an unsuspecting stable molecule.
To get a clearer understanding of how free radicals multiply, imagine a football stadium filled to the brim with mousetraps, each mousetrap loaded with a Ping-Pong ball. If you drop one Ping-Pong ball into the stadium, it springs one mousetrap, causing it to fling its ball into the air. Then you have two loose Ping-Pong balls, which spring two more mousetraps. Within a matter of seconds, all of the mousetraps are sprung, and all of the balls are loose.
Now if all those mousetraps were stable molecules, and all those Ping-Pong balls were free radicals, you would have just witnessed a free radical free-for-all.
In their reckless quest for electrons, free radicals do a lot of structural damage to healthy cells. Injured cells can't function properly and may even die.
Most vulnerable to free radical attack is the cell membrane, which surrounds each cell and guards its jellylike interior. The cell membrane is a sophisticated, highly selective barrier whose all-important job is to guard access to the cell. It decides what gets in, what stays in, and what is expelled (forcibly, if need be). If cells were nightclubs, then cell membranes would be bouncers.
Inside each cell are many subcellular structures called organelles. Each organelle is wrapped in its own protective outer membrane and performs a highly specialized function. Mitochondria, for example, transform oxygen and food into energy, which the cell uses to carry out its tasks. Lysosomes scarf up and digest cellular garbage, which is then either recycled or jettisoned. The cell's nucleus is also an organelle. It houses DNA, the cell's genetic blueprint.
When a cell membrane or an organelle membrane is damaged by free radicals, it loses its protective properties. This puts the health of the entire cell at risk.
The cell membrane is a pushover for free radical attack because it is composed primarily of easily oxidized fatty acids. Like tiny but powerful bullets, highly charged free radical particles rip into the cell membrane, literally puncturing holes in it. A damaged cell membrane loses its selectivity. When this happens, transportation of nutrients, oxygen, and water into the cell and removal of waste products from the cell become compromised.
In much the same way, free radical damage to an organelle's membrane sabotages the organelle's function. When mitochondria are injured, for instance, these submicroscopic power plants can't produce the energy necessary to drive the cell's machinery. If damage to the mitochondrial membrane is extensive, the cell dies.
Free radicals can even bang their way through the protective membrane surrounding the nucleus, gaining access to the DNA molecules housed inside. If free radicals happen to break the DNA molecules in order to snatch electrons, the cell dies, or loses its ability to replicate, or replicates abnormally--a process known as mutation. Mutation can give rise to the collections of abnormal cells that we know as cancer.
But cancer isn't the only health problem for which free radicals are responsible. Cumulative free radical damage contributes to all sorts of organ- and tissue-specific diseases, including allergies, Alzheimer's disease, arthritis, atherosclerosis (hardening and clogging of the arteries), cancer, cataracts, infections, macular degeneration, multiple sclerosis, and Parkinson's disease. In fact, researchers now agree that most common ailments, including virtually all chronic degenerative diseases, are either caused directly by or are closely associated with free radical damage.
Immune Cells: Dedicated Defenders
Of all the cells in your body, immune cells are the most likely victims of free radical attack. Ironically, they put themselves at risk just by carrying out their assigned task.
Immune cells scavenge free radicals. If injured, immune cells are less able to do their job. In the short run, their impairment usually doesn't produce symptoms. Over time, persistent fatigue, recurrent infections, and allergies may be among the first signs of immune erosion.
If free radicals continue their attack on immune cells, and if the cells never get a chance to heal, the accumulated damage weakens the immune system even more. Eventually, this opens a potential Pandora's box of disorders caused by altered immune function. Free radical damage to an immune cell's protective outer membrane or DNA can be especially ominous.
Once damaged, an immune cell loses its ability to differentiate between good guys and bad guys. One of two scenarios, neither good, then unfolds. In the first, immune cells mistake friends for foes and begin attacking healthy tissues. This is known as an autoimmune disease, examples of which include lupus, multiple sclerosis, and rheumatoid arthritis. In the second scenario, immune cells mistake foes for friends. For example, they may fail to recognize cancer cells and, rather than annihilating them, ignore them and allow them to multiply.
The Link to Aging
Prolonged exposure to free radicals actually fast-forwards the aging process. One of the clearest manifestations of cumulative free radical damage is a phenomenon known as cross-linking.
Cross-linking affects protein, enzyme, DNA, and RNA molecules. A bit like handcuffing, it hampers the ability of its molecular hostages to perform their assigned tasks. In this way, cross-linking works to the detriment of the entire organism--especially if that organism happens to be your body. Because of cross-linking, the elastic, flexible tissue of youth gives way to the wrinkled skin, stiff joints, and hardened arteries of old age.
What's more, cross-linking worsens with age, as the cellular wear and tear of several decades accumulates and the body becomes less adept at scavenging free radicals. The result is the general, body-wide impairment of function that's synonymous with degenerative disease and aging.
In skin cells, the cross-linking of molecules causes the wrinkles characteristic of aging. In arterial cells, cross-linking reduces flexibility, which in turn raises blood pressure and puts extra strain on the heart as it pumps harder to maintain a continuous flow of blood. In the brain, cross-linking impedes message transmission between nerve cells--not good if you prefer crisp thinking and a rapid flow of ideas. Thought processes slow down, and memory and concentration problems are more likely.
For all of cross-linking's dirty work, its effects on DNA molecules may be most problematic. When these molecules are damaged, they compromise the cell's ability to correctly interpret its DNA-encoded genetic blueprint. This results in impaired DNA replication and protein assembly. The entire process of Renewal depends on cells being able to replicate themselves exactly. This is why the failure to protect a cell's genetic coding has particularly profound consequences.
Meet the Free Radical Formers
Since free radical damage fosters disease and shortens life, it stands to reason that we need to know not only where these rogues come from but also how to avoid them--or at least limit our exposure.
Unfortunately, free radicals are everywhere. They're in the foods we eat, the water we drink, the air we breathe. Even our bodies produce free radicals.
Our bodies are equipped to rein in and dispose of free radicals. The problem is that we usually have more of these troublemakers floating around than our bodies can manage. And that's when we run into problems.
Any combination of factors that produces excessive free radicals (or suboptimal scavenging) can ultimately cause mass destruction throughout the human body. This destruction has been linked to the development of disease and the acceleration of aging.
True, some sources of free radicals we can't control. But many we can. Here's a rundown of the primary offenders.
The Most Surprising Source
As you read this sentence, your body is generating humongous quantities of free radicals. And believe it or not, it's quite normal.
You see, these free radicals are a kind of cellular "exhaust"--a by-product of metabolism. They're produced as cells use oxygen to convert food into energy. The only way to avoid these free radicals would be to stop burning oxygen. But then your metabolism would shut down, too.
Because these free radicals are really your body's own doing, your body expects them and is designed to deal with them. It has highly efficient ways of grabbing and neutralizing these renegade particles before they can do harm. So your cells just keep on making them.
The Usual Suspects
The free radicals that occur naturally within your body should be no cause for concern. It's the excess free radicals, the ones that your body is not prepared to handle, that cause life-shortening damage. This extra load results from two key factors: an overabundance of toxins and a shortage of antioxidants (more on these later).
A complete list of all the external sources of free radicals would likely run on for pages. So here are a few of the more pernicious offenders.
The standard American diet. The standard American diet is a free radical fiasco just waiting to happen. It's liberally laced with high-fat, processed, preserved, pesticide-laden, chemically treated foods. It's chock-full of known free radical formers such as meat, butter, margarine, sugar, white flour, and alcohol. It emphasizes frying, browning, and other cooking methods that exponentially drive up the free radical count. Most significant of all, it's dangerously deficient in antioxidant-rich, free radicalfighting fruits and vegetables.
A high-fat diet. Consuming more than 10 percent of your calories from fat dramatically increases your body's free radical load. The reason: When bombarded by free radicals, fat molecules split apart easily. The weak bonds that hold together polyunsaturated fat molecules are especially sensitive to and readily broken by heat, light, or oxygen. The more fat you ingest, the more free radicals your body generates. This is why heart disease and cancer, two conditions associated with cumulative free radical damage, are most common in people who consume high-fat diets.
Trans-fats. Also known as funny-fats or ugly fats (because of what they do to the body), trans-fats are seething cauldrons of free radical activity. They're created by cooking at high heat and by hydrogenation (the process used to harden liquid vegetable oils). Most people get their trans-fats from the margarine they spread on their morning toast, the shortening in most baked goods, and the hydrogenated oil in processed and convenience foods (such as crackers, chips, and nuts). The average American ingests 100 pounds of trans-fats annually, a tremendous free radical load.
Chemicals. Some of the nastiest and most pervasive free radicals come from the vast and expanding array of toxic chemicals being released into the environment. Chlorination of water supplies spawns often dangerous levels of chloroform and trihalomethanes, both powerful free radical formers. The air is also saturated with free radical formers: oxides of sulfur and nitrogen, ozone (which is beneficial to humans only if it stays in the upper atmosphere), chlorine, aromatic hydrocarbons (such as benzene and toluene), formaldehyde, carbon monoxide, lead, asbestos, and tobacco smoke. The combustion of tobacco alone creates thousands of different free radicalgenerating chemicals. Even if you don't smoke, you may have a hard time escaping from secondhand smoke.
Pesticides. Pesticides are notorious free radical formers. They're also very soluble in fat. This means they're found in much larger quantities in foods of animal origin, which are naturally high in fat, than in foods of plant origin. Why? Well, an animal eats pesticide-sprayed feed every day over the course of its lifetime. The pesticide residues become concentrated in the animal's fatty tissues, the result of a vain attempt by the animal's body to remove the toxic substances. Then when you eat food from that animal--be it steak, chicken, milk, cheese, or butter--your body likewise tries to rid itself of the toxins by storing them in fatty tissues. Hidden away, the pesticide molecules eventually initiate free radical chain reactions. This phenomenon helps explain the epidemic of heart disease and cancer among meat-eaters.
Radiation. Ionizing radiation--including medical and dental x-rays, radon gas, and ultraviolet radiation from the sun--fractures stable molecules. In doing so, it creates free radicals. Cells are extremely sensitive to radiation, with the cell membranes and the chromosomes in the nuclei at highest risk for damage. And radiation doesn't have to be strong to do harm: Exposure so weak that it destroys only one molecule in 100 million can nevertheless trigger free radical chain reactions capable of killing an entire cell. And if radiation scores a direct hit on a cell's nucleus, the cell's DNA--the blueprint for cell replication--becomes damaged.
Sources of Free Radicals
Avoiding free radical formers may seem like an easy enough task. But the reality is, they're just about everywhere. The following list provides a mere sampling of substances and other factors that can cause a free radical overload. How many of these do you encounter every day?
Foods of animal origin
Foods that have been barbecued, broiled, fried, grilled, or otherwise cooked at high temperatures
Foods that have been browned or burned
Hydrogenated vegetable oils
Air pollutants such as asbestos, benzene, carbon monoxide,
chlorine, formaldehyde, ozone, tobacco smoke, and toluene
Chemical solvents such as cleaning products, glue, paints, and paint thinners
Over-the-counter and prescribed medications
Water pollutants such as chloroform and other trihalomethanes caused by chlorination
Medical and dental x-rays
The Story of Joe Six-Pack
Right about now, you might be thinking that the only way to avoid free radical exposure is to swear off eating, drinking, and even breathing for the rest of your life. Needless to say, the rest of your life would play out mighty quickly. There's no need to do anything so drastic. Remember, your goal is to keep a lid on free radical overload.
To help you put this in perspective, allow me to share the story of Joe Six-Pack. Joe is a fairly typical American guy. On one particular Saturday morning, Joe wakes up a bit hungover as a result of getting a little too happy at happy hour the evening before. He drinks a glass or two of chlorinated tap water to rehydrate himself, then follows with a cup of coffee (cream and sugar added). His breakfast consists of fried eggs and toast with margarine.
After grabbing a quick shower and splashing on a palm-full of his favorite aftershave (containing alcohol, perfume, and other chemicals), Joe climbs in his car and heads for the beach. It's such a spectacular day that he rolls down all the windows and takes deep breaths of "fresh" air--which has already been contaminated with hefty doses of pollutants. At the beach, Joe buys a bag of chips and a cola at the snack bar, then chats with his buddies (both smokers) before falling asleep in the sun for a couple of hours.
Joe has already set himself up for free radical overload, and it isn't even lunch yet. If Joe maintains this lifestyle, he's headed for serious trouble. By age 60, Joe--a fairly typical American guy--will suffer a fairly typical massive coronary and undergo fairly typical coronary bypass surgery.
Antioxidants: Our Number One Ally
Joe can change many of his free radicalforming ways. And the sooner he does it, the better off he'll be. Because while he can't eradicate every last one of the free radicals in his body, he should make every effort to stay several steps ahead of them for as long as he can. This is the secret of longevity.
Lucky for Joe, he has a powerful weapon in the war on free radicals. Matching these molecular miscreants blow for blow are the body's built-in free radical defense systems. Without these systems, humans would be toast--our lives measured in minutes rather than decades.
The body relies on two particular defense systems to neutralize free radicals: the antioxidant nutrient system and the antioxidant enzyme system. The nutrients can be used as is, straight from the foods and supplements we consume. The enzymes must be synthesized, or manufactured by the body.
What makes the antioxidants so effective against free radicals is their willingness to give up their own electrons for the cause. The free radicals greedily accept the antioxidants' offer, like kids drooling over a piece of candy. Of course, once a free radical finds a partner for its unpaired electron, it immediately loses free radical status. It behaves itself and stays out of trouble from then on. And the best part is, the antioxidants are able to donate their electrons without generating free radicals themselves.
As evidence of the crucial role that antioxidants play in fending off free radicals and prolonging life, consider the findings of one of the earliest experiments conducted by Dr. Harmon. In this experiment, one group of rats ate standard rat chow, while another group ate rat chow fortified with antioxidants. The rats in the latter group lived 40 percent longer than the rats in the former. In human terms, this translates to about 40 extra years of life. As Dr. Harmon theorized, and as subsequent research has proven, the antioxidants protected the rats from free radical damage, thus extending their life spans.
But just as an abundance of antioxidants can add years to your life, a shortfall can take years away. Free radicals go unscavaged, continuing to roam your system and damage healthy cells. This is why it's so important to eat plenty of antioxidant-rich foods and take appropriate antioxidant supplements. The more antioxidants you have floating around your bloodstream and protecting your cells, the longer you can expect your life span to be.
Laying the Foundation for Renewal
The optimum longevity-promoting lifestyle, then, has two key components: First, it maximizes antioxidant intake from foods and supplements; and second, it minimizes factors that promote the formation of free radicals. We'll cover both of these components in more detail in later chapters. For now, here are the basics.
* Choose organic, pesticide-free, additive-free foods.
* Drink only purified water.
* Avoid exposure to volatile chemicals, including perfume, hair spray, glue, paint, gasoline, solvents, and smoke.
* Limit exposure to air pollution: Keep your windows closed when driving in heavy traffic, and stay off busy streets when exercising.
* When outdoors, limit the amount of time you spend in direct sunlight, especially at midday.
* Check your house for radon gas. (Hardware and home supply stores sell inexpensive testing kits.)
* Get medical and dental x-rays only when absolutely necessary.
* Take medications only when absolutely necessary. (Note: Always consult your doctor before you stop taking any medicine that he has prescribed.)
* Now that you've been formally introduced to both free radicals and antioxidants, let's explore their respective roles in the grander scheme of Renewal Theory.
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