AVERY’S FAQ SERIES
Introduction
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As
incredible as it might sound, it's true: Antioxidant nutrients
can reduce your risk of developing more than eighty diseases,
including heart disease, arthritis, and cancer; and can help slow the aging process.
Why
are antioxidants so important? You probably know that people are
more likely to develop degenerative diseases as they age. These diseases are
caused by, or aggravated by, harmful chemical reactions that take place in the body.
The process is inevitable—in fact, these
same chemical reactions are what make
us age. However, the good news is that
these chemical reactions can be slowed, so these diseases are delayed for many, many years. For many people, the effects of these chemical
reactions can even be reversed,
enabling you to feel better and
healthier than you have in years. The miracle workers in this process are called antioxidant nutrients, and All About
Antioxidants explains how you
can use antioxidant nutrients to feel healthier.
Antioxidants can reduce
your likelihood of developing a multitude of
deadly diseases, such as cancer, heart
disease, and premature aging. Antioxidants
work by destroying harmful chemicals
in the body called "free radicals." These free radicals are the culprits in many diseases. Quite
simply, antioxidants neutralize
them. Knowing how to use specific antioxidants in the right combination can bolster your protection against free
radicals.
Although
antioxidant nutrients are in the news almost weekly now, I was the first scientist to describe them in consumer magazine articles about
my research in 1971. I didn't invent
or discover antioxidants, but I was
the first scientist to demonstrate antioxidant synergism—that is, that antioxidants work together—and that a practical combination of antioxidant nutrients could extend the
life spans of laboratory animals and prevent cancer. Today, we have numerous clinical studies that verify that this same protection applies to humans as
well. The history of research on
free radicals and antioxidants
actually goes back to 1954 with Denham Harman, M.D., Ph.D. Now, more than
forty years later, the evidence is
unequivocal. The "take-home
message" of this book is that you can immediately put these forty-plus years of research to your benefit now.
Do
you need antioxidants? Among the diseases linked to excess free
radicals are:
• Aging.
• Cancers.
• Coronary
heart disease.
• Autoimmune
diseases.
• Rheumatoid
arthritis.
• Alzheimer's
disease.
• Cataracts.
• Parkinson's
disease.
If
you are at risk for developing these diseases or have a family
history of any one of them antioxidant supplementation can give you an edge and help prevent, reduce the severity of, or delay the
appearance of these and many other
diseases. In fact, one study found
that the United States healthcare system could save $8.7 billion annually from
reduced hospitalizations if Americans consumed optimal levels of antioxidant vitamins C and E, plus beta-carotene. The five-year savings would exceed $45 billion. At a time when the American healthcare
system is nearly bankrupt, you would think that
people would start paying attention.
As
good as single antioxidants may be, one antioxidant alone cannot fully protect
you against the many different types of free radicals. However, a balanced team of antioxidant
nutrients very effectively helps protect against free-radical damage and thus
helps protect you from the different diseases associated with
free radicals. By the time you finish reading this book, you'll
have a good idea of which antioxidants you should be taking.
1.
The Basics of Antioxidants
What
exactly are antioxidants? What are free radicals? And how do they
affect your health? In this chapter, I answer many of these basic
questions. Generally speaking, antioxidants are good for your health,
and free radicals are bad. Although antioxidants are abundant
in fruits and vegetables, most people do not eat many of these foods and
therefore lack sufficient antioxidants. As a consequence, supplementing with antioxidant capsules or tablets becomes very important.
Q. What is an antioxidant?
A.
It might sound funny to hear that an "anti-something" is good for you. Quite
simply, an antioxidant is a substance that protects your body and other objects from a process
called oxidation.
The best
explanation is to think about why iron turns
rusty or butter becomes rancid. Oxygen, which is essential for life, is a very volatile and reactive element. It reacts with iron to form rust,
and it also reacts with the fats in
butter to oxidize them and to make
them rancid. A similar process occurs in
your body. As you get older, more oxidation occurs—in a sense, it makes your
body rusty. Anything that prevents or
slows the oxidation process is
called an antioxidant. Basically, an antioxidant protects other compounds against oxygen.
Your
body produces some antioxidants (called endogenous antioxidants),
but you must obtain others (exogenous antioxidants) from the diet. In fact, some
antioxidants, such as vitamins E and C, are absolutely essential for
life. The endogenous antioxidants are usually enzymes, coenzymes,
and sulfur-containing compounds, such as glutathione. The exogenous,
or dietary, antioxidants include vitamins such as vitamins C and E,
bioflavonoids, carotenoids, and several sulfur-containing
compounds.
Q. What is a free radical?
A.
Free radicals can be bad for your health. Quite simply, free radicals
are the bad guys that harm you, and antioxidants
are the good guys that protect you.
Want
a slightly more technical explanation? As you probably remember from your
science classes, the basic or smallest building blocks of chemical elements
are called atoms. An atom consists of a nucleus that contains
subatomic particles, such as protons and neutrons. Normally,
pairs of electrons orbit the nucleus, kind of like planets around
the sun. Molecules consist of groups atoms held together by the
actions of these pairs of electrons. Sometimes during chemical
reactions, an electron will be pulled away from the rest of the
molecule, creating a free radical. Essentially, a free radical
is an unpaired electron. Free radicals are highly
volatile and reactive, and they seek out another electron to make a new pair.
Free radicals cause damage when they pull electrons from normal
cells of the body.
Q, What qualifies a nutrient to be called an
antioxidant?
A. To be considered an
antioxidant, a substance must quench free
radicals by donating electrons, and a
little bit of the substance must go a long way. In other words, a few molecules of an antioxidant must protect many, many molecules.
Among the antioxidants
our bodies make are the enzymes catalase,
glutathione peroxidase, and superoxide
dismutase (SOD). However, these are not sufficient, and we must obtain others
from the diet. Some of the dietary
antioxidants include vitamin A and especially the related carotenoid family of
compounds, vitamin C, and vitamin E. Minerals are not by themselves antioxidants, but several minerals can become vital components of antioxidant enzymes
made by the body. These minerals include selenium,
which is needed to make the glutathione peroxidases; iron, which is
needed for catalase; and manganese, copper,
and zinc, which are needed for SOD.
Sulfur compounds, such as the sulfur-containing amino acids cysteine and
methionine, help the body produce the
most ubiquitous antioxidant within
cells, glutathione. Antioxidant coenzymes, such as NADH (nicotinamide adenine dinucleotide), coenzyme Q10, and alphalipoic acid, are made by the body and obtained through the diet.
Q. What do the endogenous antioxidants
do?
A.
The antioxidants your body makes have very specific roles. Many of
them are enzymes or coenzymes, which catalyze reactions in the
body. The most called-upon
endogenous antioxidant is glutathione, which is the primary antioxidant protector within
your body's cells. Glutathione is a small sulfur-containing
compound that teams up with selenium-containing enzymes called
glutathione peroxidases. Other heavy-duty
endogenous antioxidants are the
superoxide dismutases. One type of SOD contains the minerals copper and zinc, while another type contains the mineral manganese. SODs specifically
break up a harmful form of oxygen called superoxide
into hydrogen peroxide. While hydrogen peroxide
can damage cell components, it is not as destructive as superoxide. Another endogenous antioxidant called catalase contains the mineral
iron. Catalase breaks down hydrogen peroxide into water. The selenium-containing glutathione peroxidases can also convert hydrogen peroxide into water.
Q. What do the exogenous, or dietary, antioxidants
do?
A.
The exogenous antioxidant nutrients are broader in their
protective actions. For example, vitamin E resides in fat-containing body
components, such as cell membranes and lipoproteins (such as cholesterol),
and protects against many different types of oxidants. Vitamin C
is the most important antioxidant in the bloodstream. Vitamin E is
called a fat-soluble vitamin because it is compatible with fats, whereas
vitamin C is called a water-soluble vitamin because it is compatible
with water. Any of these individual antioxidants are beneficial
to health. But they offer greater benefits when taken as a group. This
is a key point I'll come back to over and over again in this book.
Q. How were the many health benefits of
antioxidant nutrients discovered?
A.
Vitamin E was once believed to be a vitamin without deficiency
symptoms. It was known to be a powerful natural antioxidant, but no
one could figure out how it worked in the body. It did not appear to
be involved in enzymatic reactions or to be incorporated
into structural components. This vitamin was a mystery that caused
many nutritionists to be skeptical that it was indeed essential for humans. Little
more was known about it, other than that it was required for the birth
of animals. Without vitamin E, laboratory animals would resorb the fetuses before
birth.
Thanks
to the research on antioxidants and their effects on aging and
cancer, scientists began looking at many of the nutrients
anew in terms of their antioxidant
activities. Studies of antioxidants' effects on the aging
process led to the discovery that antioxidant nutrients offered protection against
cancer. As an example, I presented my
research on antioxidant synergism and life extension of laboratory animals at the annual meeting of the Gerontological Society in 1970. Some scientists
felt that life expectancy was not
directly extended, but that it was
indirectly extended by preventing or delaying
diseases, such as cancer. This was an interesting concept and my later studies established that this was
indeed part of the explanation of the improved
life spans.
Later,
scientists began studying the incidence of various diseases among
groups of people in relation to their intakes of dietary
antioxidant nutrients. When I studied the incidence of heart
disease in relation to intake of dietary vitamin E, I found that
the more vitamin E consumed and the longer that those
higher amounts were consumed, the more the incidence of heart disease
decreased. Gladys Block, Ph.D., of the University of California
conducted several studies in which she found that vitamin C and
carotenoids were associated with reduced risk of several cancers.
In 1993, Harvard researchers published studies showing that vitamin
E supplements taken for more than two years were associated
with reduced incidence of heart disease.
As
people began taking more antioxidant supplements, they reported
improvements in conditions ranging from menopause to
arthritis. These reports, coupled with the development of plausible theoretical
explanations, encouraged more scientists to investigate the
possible relationships. Eventually, scientists felt
sufficiently comfortable to study the relationship of antioxidants
and the incidence of Alzheimer's disease, cataracts, and other disorders.
Q. What are some of the most common antioxidant
nutrients?
A. The best known ones
are probably vitamins C and E.
Beta-carotene, lutein, and lycopene are part of the family of antioxidant
carotenoids, found in fruits and vegetables. Flavonoids, another group of antioxidant nutrients, are also found in fruits
and vegetables. Selenium, an
essential mineral, is necessary for
the body to produce glutathione peroxidase,
another antioxidant. Some antioxidants, such as coenzyme Q10 and alphalipoic acid, are found in foods and also produced by the body.
Q. Which is the best antioxidant?
A. When people start
debating which antioxidant is most important
or powerful, they are missing the idea that antioxidants work together in
concert. It is like arguing which
link in a chain is most important.
The chain is as strong as its weakest link. The same is true with antioxidants. There are reasons for this. Different antioxidants protect against
different types of free radicals in
different parts of cells and in different places in the body. In addition,
antioxidants help each other like
members of a sports team. This is
what I mean by antioxidant syner-gism—the
sum is greater than the parts.
Q. Would you explain more about antioxidant
synergism?
A.
I coined the term in the mid-1960s to explain what I was seeing in my
laboratory experiments, and it later became the focus of my
1970 and 1972 patent applications. Essentially, antioxidant synergism
is when the effects of combining antioxidants are greater than you
would expect from adding up the effects of all the antioxidants
individually. This
concept has become important in nutrition
to establish the teamwork effects of nutrients in general,
but especially of antioxidants. Antioxidants should not be
thought of as individual compounds. They should be thought of as complementary
players on a team, or in the way that individual instruments
form an orchestra. Doesn't a fifty-piece ensemble of various
woodwinds, brass, and strings sound better than a fifty-piece ensemble of snare
drums? Don't you think that a baseball team consisting of
various infielders, outfielders, pitchers, and catchers would be more
effective than another team of nine players, all of which are first-basemen standing around first base?
At
first, I could not adequately explain the antioxidant synergism that I was
observing, but some of the mechanisms were clarified with experiments.
Now they all seem to be understood. Dr. Denham Harman of the University of Nebraska had experimented with single compounds to see if they
had a protective effect. His first experiments were with sulfur compounds known to be protective against the effects of radiation on the body. In
1968, Dr. Harman demonstrated that a
diet consisting of 0.5 percent of vitamin E increased the life spans of mice by about 5 percent. Soon after, I reported
that synergistic combinations of
antioxidant nutrients were more
protective—with a 30-percent increase in average life span at lower and
practical dietary levels. Al Tappel, Ph.D.,
of the University of California at Davis confirmed the biological
synergism of the antioxidant nutrients used
in my laboratory animal studies. The reason for the synergism is that some
antioxidants are more effective against some free radicals, whereas other antioxidants are more
effective against other free
radicals. Synergism makes every link in the chain strong.
Q. Don't antioxidants also regenerate or recycle other antioxidants?
A.
That's correct. Lester Packer, Ph.D., of the University of California, Berkeley,
discovered that some antioxidants can
regenerate other antioxidants, and
this is another reason why they are synergistic. To explain a little more, after an antioxidant neutralizes a free radical, the antioxidant
becomes a weak free radical. Another
antioxidant can help regenerate this "used up" antioxidant.
For example, both alpha-lipoic acid and Pycnogenol can regenerate used vitamin C, which in turn, can regenerate used vitamin E. This means that alpha-lipoic acid and Pycnogenol extend the usefulness of vitamins C and E.
Q. In what foods are antioxidant nutrients
found?
A. A
varied diet containing at least five generous servings daily of fruits and vegetables
forms the foundation of an antioxidant-rich diet. There are thousands of antioxidant nutrients that occur in whole, unrefined foods that are not available in
supplements. Unfortunately, many of the antioxidant nutrients are removed during food processing. Vitamin E is stripped from vegetable oils in the
refining process and from whole
grains during their refinement into
white flour. Bioflavonoids taste bitter, so they are often removed from
refined foods. While a diet rich in fruits
and vegetables is the foundation, supplements are required to achieve the optimal levels of these antioxidant nutrients.
Carotenoids, another
family of antioxidants, are found in the
yellow, orange, and red fruits and vegetables,
and in some greens. Bioflavonoids are found
in most fruits, but particularly the blue and purple ones (such as grapes and blueberries). Vitamin C is found in citrus fruits, and bioflavonoids are found in the rinds (skins) of citrus.
Vitamin E is found in whole grains,
nuts, and vegetable oils. Selenium
is found in whole grains, garlic, and Brazil nuts—if there is enough selenium in the soils in which they are grown. So, even eating a
diet containing the correct foods doesn't guarantee that you will get optimal amounts
of selenium.
Q. Who discovered that free radicals caused
body damage?
A.
In 1954, Dr. Denham Harman was the first scientist to theorize
that the aging process was caused by free radicals. Until
then, free radicals were thought to exist only outside the body.
The only scientists that were familiar with free radicals were organic
chemists who utilized the production of free radicals to help
synthesize new compounds or make commercial processes for the production of complicated chemicals.
Harman
was very familiar with both free radicals and the human body. He was
a scientist experienced in radiation chemistry while at the Shell Development
Company and a physician at the Donner Laboratory of Medical Physics on the Berkeley
campus of the University of California. This unique combination gave him the
background to have the brilliant insight that free radicals
existed in the body and could cause damage.
The
discovery of biological free radicals and the damage they cause in
living systems is worthy of a Nobel
prize. This discovery has led to many advances in helping people
live better longer. By applying the knowledge stemming from Barman's research,
we have been able to delay many of the deleterious effects of
aging, reduce cancer and heart disease incidence, and relieve much suffering. This fact is
often overlooked as the tag given to Harman is
"the father of the free-radical theory of aging." Unfortunately, the
"aging" focus is too narrow and has obscured the broader implications
of Harman's research.
In
1968, Dr. Harman demonstrated that a diet consisting of 0.5 percent
of vitamin E increased the life spans of mice by about 5 percent. Soon after, I reported that synergistic combinations of antioxidant nutrients were more protective.
Q. How often do free radicals attack body
components?
A.
All the time! Bruce Ames, Ph.D., of the University of California at Berkeley estimates
that every single one of your body's cells (and you have trillions of them)
suffers about 10,000 free-radical "hits"
per day. Much of this damage is done to your deoxyribonucleic acid (DNA), or genetic material. One of the consequences is that the mutation rate increases. Elderly persons have nine
times the frequency of cell mutations as do infants. These mutations increase the risk
of cancer. In addition, cell membranes,
proteins, and fats are also being damaged
by free radicals. Over a typical seventy-year life span, the body generates an estimated seventeen tons of free
radicals. Your body needs to have its
antioxidant defenses optimized at all times.
Q. What kinds of damage do free radicals
cause?
A. Free radicals can
damage all types of substances and tissues
in the body. The easiest damage, and thus the most frequent, is to body fats. This is because fats are especially prone to oxidation. Scientists use
the term "lipid
peroxidation" to describe oxidized fats in the body. Lipid peroxidation sets off a chain reaction that will continue throughout the fatty material
until stopped by an antioxidant.
Free
radicals can damage the nucleic acid bases (adenine, thymine, guanine,
and cytosine), which together form DNA. This damage prevents
DNA from accurately replicating itself. Damaged, or mutated,
DNA leads to the replication of incorrect biological
information—such as cancer cells.
Free radicals can also
damage proteins, meaning that
some body components may not function efficiently. For example, free radicals
can damage the collagen proteins in skin, leading to tougher skin.
Damaged enzymes (which are proteins) will not work as efficiently
to drive biochemical reactions. Nor will the repaired enzymes
be able to repair as much free-radical damage, and a downward spiral causes
a snowballing effect leading to faster aging and possibly cancer.
Q. How can free radicals cause cancer?
A.
There are several ways free radicals can cause cancer. I'll
discuss them in more detail in Chapter 3, but here are some brief
explanations.
• Free
radicals can damage DNA, which causes mutations. Mutated cells
can develop into cancer.
• Free
radicals can activate so-called cancer genes, also known as oncogenes.
• Free radicals can
suppress the immune system, inactivating
the body's defense against cancer.
• Free
radicals can activate carcinogens or "precarcinogens" to
start the chemical reactions that
lead to cancer.
• Free
radicals can damage cell membranes and inactivate the sensory
mechanisms that limit
abnormal cell growth and reproduction.
By quenching free
radicals, antioxidant nutrients protect against these
undesirable activities.
Q. How do free radicals cause heart disease?
A. Free radicals damage
the particles that carry cholesterol in the
blood and, in a sense, turn "good" cholesterol "bad." This damage changes the cholesterol carrier in such a way that it enters into
the wall of the arteries and starts
the process that results in cholesterol
deposits. Free radicals can also turn on blood platelet cells, which can form abnormal clots and set the stage for a heart attack. Free
radicals can damage the lining of the
arteries, which can lead to cholesterol deposits forming. The process is
far more complicated than the old theories
about eating too much cholesterol or
fats. I'll discuss it more in the
next chapter.
Q. Can free radicals cause arthritis?
A.
They can certainly aggravate arthritic symptoms. Arthritis is
characterized by inflammation. Inflammation usually involves "superoxide
anion" free
radical. Arthritis can be treated by reducing inflammation with antioxidants,
including SOD. Several studies have shown that dietary antioxidants
reduce the severity of existing arthritis. One of the promising
antiinflammatory antioxidants is Pycnogenol, found in
French Maritime pine bark.
Q. How do free radicals cause cataracts?
A. Cataracts are caused
by free radicals reacting with the proteins
in the eye lens. The eye lens is normally
clear, so light can pass through it. Sunlight also includes ultraviolet rays,
which generate free radicals when they react with proteins in the lens. These free radicals, if not quenched by
antioxidants, damage the proteins in
the eye. The damaged proteins are not clear, but cloudy, forming a cataract. Thus, cataracts can be caused by over-exposure to
sunlight. High glucose (blood sugar) levels also generate free radicals and can damage the lens. Antioxidants prevent
this damage by terminating free
radicals. But because there are no blood vessels in the lens, the fluid around it has to contain sufficient antioxidants.
Q. Are any free-radical
reactions good for us?
A. As strange as it might sound, we
couldn't live without free radicals. The body uses free radicals to
destroy germs. In addition, free radicals are needed for
energy production. The problem is that most people are exposed to too
many free radicals, a situation called oxidative stress, and
this is not healthy. Antioxidant supplements help restore a
balance.
Q. Can we control the
production of free radicals in our bodies?
A. You can avoid things that either
increase your exposure to free radicals or increase your body's production
of free radicals. For example, tobacco smoke and smog increase
free radicals in the body. Sunlight and x-rays also increase
free-radical production. As the ozone layer in the atmosphere diminishes,
we are exposed to more ultraviolet energy from the sun. Fats
and sugars promote free radicals. Stress increases free-radical production. The
increase in oxygen consumption required during heavy exercise
increases free-radical formation. However, most of the body's
free radicals are produced as side reactions during the
normal utilization of oxygen to burn food to make energy. There are many things we can't control—you may not be able to move out of a polluted city but you can
compensate by increasing your intake
of antioxidants.
Q. Why didn't we hear about the benefits
of antioxidants until fairly recently?
A.
Until about ten to fifteen years ago, there weren't too many scientists
studying free radicals and antioxidants. When I began studying antioxidant
nutrients in 1959, there were fewer than a dozen or so American
scientists studying the role of antioxidant nutrients in aging, cancer, heart
disease, and health in general. Today thousands of scientists are
studying the benefits of antioxidant nutrients, and it's hard to go
through a typical day without reading or hearing something about
antioxidants.
This did not change
overnight. It took the hard work of several
scientists to inform the medical profession
of the benefits of antioxidant nutrients. Also, until recently, nutrition wasn't taken seriously by the medical profession. Dietary supplements were frowned
upon. Anything over the very low Recommended
Daily Allowance was considered risky, and anyone educating the public about the exciting research proving the health benefits of
supplements was called a "quack."
As
more and more evidence was published, it began making the news.
Doctors shifted their stance from "Don't take vitamin
pills because they may harm you" to "Take them if you want, but they are a waste of money." Now, a high percentage
of physicians take supplements and recommend them to their patients. At a 1995 meeting of
cardiologists, about 90 percent admitted taking vitamin E supplements, though only about 75 percent prescribed them for their patients.
Q. Are there some general, simple recommendations
for antioxidant supplements?
A.
Jeffrey Blumberg, Ph.D., chief of the antioxidant research laboratory at Tufts
University, helped found the Alliance for Aging Research to help disseminate exactly this type of information. At a
press conference, this nonprofit
research group noted that people
could live longer and be healthier if they took daily supplements of vitamins C and E and carotenoids. They recommended that
healthy people should take the following every day:
• 10CMOO
IU of vitamin E.
• 17,000-50,000
mg of carotenoids.
• 250-1,000
milligrams of vitamin C.
Dr. Blumberg reported
that "We have the confidence that these
things really do work." Later in this
book, I'll provide more comprehensive recommendations for antioxidant supplementation.
2.
Antioxidants
for a Healthy Heart
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The
common heart attack is due to coronary artery disease in which
lesions (deposits of cholesterol and other materials) narrow
the lumen (opening) of the arteries. The narrowing of arteries by deposits
is called atherosclerosis, and when it affects arteries feeding the heart, it's
called coronary heart disease. Since
there's a lot of cholesterol in these
deposits, many doctors assumed that cholesterol-rich foods would damage
blood-vessel walls. But there's more to the process—levels of free radicals and antioxidants influence your risk of heart disease.
Q. What is a heart attack?
A.
Having narrowed arteries (atherosclerosis), per se, does not cause
the common heart attack. The narrowed
arteries damage blood cells called platelets when the cells
are forced to squeeze by. Platelets are the blood cells
responsible for clotting, and squeezing and damaging them
facilitates the formation of blood clots. The clots can lodge in the narrowed arteries, completely shutting off the flow
of blood through that artery. This life-threatening condition is called
a coronary thrombosis—a blood clot in a coronary artery.
When
a blood clot shuts off the flow of blood in a coronary artery, the region of
the heart fed by the artery is starved of oxygen and nutrients. The result is the death of these cells, which is called an
infarct. This is the classic heart
attack called an acute myocardial (heart) infarction.
Q. What are some other common heart diseases?
A.
Another common form of heart disease is congestive heart failure, in
which the heart is too weak to pump efficiently. Usually, the heart itself has enlarged
as it has tried to compensate for the reduced output. Angina is
the pain experienced in the heart when there is not enough blood reaching all
parts of the heart during activity. Then there are disorders
of the heartbeat rate regularity—too irregular (arrhythmia), too fast
(tachycardia), or too slow (bradycardia) for an efficient pumping
action. Spasms can clamp an artery shut and cause a heart attack
even though there are no significant cholesterol deposits. High blood pressure
(hypertension) affects arteries and is a risk factor in various forms of heart
disease.
Q. How do cholesterol deposits form?
A.Cholesterol
is a fat and not soluble in blood (which is watery), so it
is carried in particles called lipoproteins. Two important lipoproteins
are low-density lipoprotein (LDL) and high-density lipoprotein
(HDL). The cholesterol carried by LDL is often called the "bad"
cholesterol. LDL carries cholesterol to the cells. The
cholesterol carried by HDL is often called the "good" cholesterol. HDL
carries cholesterol away from cells.
Cholesterol deposits seem to form only when LDL becomes damaged by oxidation.
It's then called oxidized LDL. Oxidized LDL can
infiltrate the artery lining and initiate a series of events that trap the
cholesterol in the oxidized LDL, attract white blood cells, and form a
deposit.
Q. How do antioxidant nutrients protect against cholesterol deposits?
A
LDL becomes oxidized only when the amount of antioxidants is insufficient to protect the
LDL against oxidation. Oxidized LDL is a
sign of very low antioxidant levels, because LDL is the medium that transports fat-soluble antioxidants through
the body. The prime antioxidant that protects LDL is vitamin E, although other antioxidants help by recycling vitamin E. Other antioxidants can also destroy
many of the free radicals before they reach LDL
to cause damage. The tendency to form oxidized LDL, and hence cholesterol deposits, depends on two
factors: the amount of LDL and the balance between
antioxidants and free radicals. Both are important, but the antioxidant /free
radical balance is the more important of the two.
Q. How do antioxidant nutrients protect against other causes of heart disease?
A.
While a lot of attention has been focused on cholesterol through
the years, the strongest dietary association with heart
disease is a deficiency of vitamin E. Cholesterol deposits
by themselves don't cause a heart attack.
They are a major contributing factor to
forming the blood clot (coronary thrombosis) that causes the heart attack (acute myocardial infarction). As long as the blood can squeeze by
the narrowing caused by the
cholesterol deposits in good volume, the heart will receive sufficient
oxygen and nutrients to keep the heart
tissue alive.
A
critical factor then is to maintain the proper "slipperiness"
of the blood cells and prevent a blood clot from forming in
the coronary arteries. Vitamin E, and especially Pycnogenol, have a protective anti-aggregation effect on blood
platelets, which are critical factors
in the blood clotting process. They are particularly effective against
the damage to platelets from stress and
smoking.
In
addition, the antioxidant nutrient Pycnogenol is a mild hypotensive
(an agent that lowers blood pressure), which helps maintain a normal blood pressure.
Pycnogenol also acts to maintain adequate nitric oxide levels so blood vessels can
relax. Recent studies have also linked
inflammation to heart disease.
Antioxidant nutrients, especially Pycnogenol, reduce inflammation.
Vitamin
E is important to the heart and arteries in more ways than protecting
LDL from oxidation. As an example, vitamin E is vital to
maintaining a healthy lining of the arteries. Tears in the lining
of arteries are another way in which deposits can form. Pycnogenol is a secondary factor in
every way that vitamin E helps—this is because Pycnogenol regenerates
vitamin C, which in turn, regenerates vitamin E. All of the antioxidants
together form one terrific team to prevent heart disease.
Q. Can antioxidant vitamins prevent heart
attacks?
A.
Yes, they can—especially vitamin E. A study by cardiologists at
Cambridge University found that daily supplements of 400 IU
or 800 IU of natural vitamin E reduced heart attacks by 77 percent. This was a
large scientific study involving 2,000 people over about five
years. In many respects, this single study was the major turning
point in making vitamin E acceptable to physicians.
Antioxidant
nutrients slow or reverse heart disease. A mixture of the
tocotrienol and tocopherol forms of vitamin E reversed the development of cholesterol deposits in
people. In another study, researchers
reported that vitamin E supplements, 100
IU or more daily, could slow the formation of cholesterol deposits.
Q. How do antioxidant nutrients protect us from stress?
A.When
your body is under stress, your body increases production of the
hormone adrenaline. Unfortunately, adrenaline activates the
blood platelets so that they have a greater tendency to clump together and form
a blood clot. While Pycnogenol can't make
your causes of stress go away, it can help keep your blood "slippery"
to reduce the chances of heart
attacks and strokes.
Studies
conducted in Germany by Peter Rohdewald, Ph.D., and confirmed by Dr.
Ronald Watson of the University of Arizona, Tucson, found that
Pycnogenol blocks the effect of adrenaline on blood platelets. Pycnogenol is
particularly effective against increased platelet aggregation
(stickiness and increased clotting tendency) caused by smoking.
Q. Does Pycnogenol work in the same way
that aspirin works to prevent heart attacks?
A. Not exactly. Aspirin
is widely prescribed by cardiologists to protect against heart attacks. The first studies showed that aspirin can
reduce the incidence of a second heart attack in heart patients. Later
studies showed that aspirin also reduces the risk of having a
first heart attack. So far, this sounds good, but, unfortunately,
many people develop serious problems with prolonged aspirin
use. They can
develop ulcerated linings of the gastrointestinal tract and an increased tendency to bleed. This can cause so much internal bleeding that it can cause
death. Some people have been known to develop this condition suddenly and without warning. While aspirin therapy has benefit for many people,
check with your doctor before taking
aspirin on a long-term basis. In the Pycnogenol studies, the researchers found that 100 mg of Pycnogenol achieved the same desired effect on blood
platelets in smokers as 500 mg of aspirin. Furthermore, due to Pycnogenol's
effects on the enzyme 5-lipoxyge-nase,
rather than on cyclooxygenase—the enzyme that aspirin inhibits—Pycnogenol did
not increase bleeding tendency as does aspirin.
Q. How do antioxidant nutrients protect the linings of arteries?
A.
One contributing factor in heart disease is damage to the lining
(endothelium) of the heart and arteries.
This damage can cause clots to form and allow cholesterol carriers
to enter the artery walls. Researchers at Loma Linda University, California, studied the protective effect of Pycnogenol using endothelial artery cells. They found that Pycnogenol reduced the damage to the endothelium caused by free radicals. They also noted that Pycnogenol increased the levels of other antioxidants in the cells due to its sparing and
regenerative effects. Other studies
have shown that vitamins C and E also
protect artery linings.
Q. How do antioxidant nutrients relax blood
vessels to help prevent high blood pressure?
A.
I'll give you a couple of examples. Pycnogenol has a mild hypotensive (blood pressure
lowering) effect that helps prevent high
blood pressure. There are two known reasons for this action. One mechanism
involves the optimization of nitric oxide production
in the blood vessels. Several researchers, including David Fitzpatrick, Ph.D., of the University of South Florida
and Lester Packer, Ph.D., of the University of California, Berkeley, have
studied this effect.
Nitric
oxide has recently aroused much interest among scientists, after having been
dismissed for decades
as not being an important compound in the body—merely a waste product or
inhaled air pollutant. Now, we understand
that it has far-reaching effects
throughout the body. Two enzyme systems control the production of nitric oxide.
One enzyme system produces nitric
oxide at a constant rate, while the
other is activated by stress. Some nitric oxide is always needed, but
too much can kill cells. Pycnogenol helps
regulate nitric oxide in the body at
optimal levels. It helps the body produce adequate levels of nitric
oxide for necessary functions, while
reducing the production of the enzyme that makes nitric oxide when too much nitric oxide is present. Dr. Fitzpatrick tested the effect of Pycnogenol on portions of the aorta and found that
it improved the production of nitric
oxide in the endothelium, which in turn had a relaxing effect on the aorta.
The
other reason for Pycnogenol's hypotensive effect is its effect on dietary fat.
In another study, researchers at the University of Maryland found that
antioxidants can counteract the deleterious action of a high-fat meal
on arteries. A high-fat meal prevents arteries from dilating
normally. The ability to widen when needed is critical,
especially in persons who have heart disease. In this study, healthy subjects ate a 900-calorie fast-food
meal of egg, sausage, muffin, and hash browns. The meal contained
50-percent saturated fat. The researchers measured the dilation
capacity of the brachial artery in one arm of each
volunteer before the meal and again two and four hours after the
meal. On the next day, the volunteers were given an identical meal,
but in addition, they received 1,000 mg of vitamin C and 800 IU of
vitamin E. This time, when the dilation capacities were measured,
they were near normal, almost as if they had not eaten the high-fat meal.
While
this vasorelaxation effect is important, Pycnogenol should not be
considered a hypotensive drug.
3.
Antioxidants
and Cancer Prevention
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Cancer is not a single
disease, but a group of many similar
diseases. There are about 100 different
types of cancer, and they all involve an abnormal behavior in some of the body's cells. Most cancers involve
tumors. In this chapter, I'll explain what cancer is, how free radicals are
involved in cancer, and how antioxidants protect against cancer.
Q. What exactly is cancer?
A«
To understand the nature of cancer, it helps to first understand
something about normal cell growth. Typically, the many cells of
your body grow and divide in an orderly fashion. Normal cells also
eventually die in a process called apoptosis, or cell suicide.
When cells lose the ability to control their
growth, they can divide quickly without any sense of
order. This results in excess tissue, called a tumor.
There
are two types of tumors, benign and malignant. Benign tumors are not
cancerous and do not spread. Only rarely, such as with benign
brain tumors, are they likely to kill a person. They can usually
be removed through surgery, and they do not usually recur. In
contrast, malignant tumors are cancerous—that is, they can infiltrate and
destroy nearby
tissues. Malignant cancer cells can also spread through the body and seed new tumors. Cancer cells seem to lose the ability to self-destruct—unless stopped,
they just keep reproducing.
Free
radicals are involved in cancers in a number of ways. They can mutate DNA, leading to
the creation of abnormal cells. Recent
research has found that cancerous tumors generate their own free radicals and promote still more mutations and abnormal
cells. This is why some tumors always seem to be
a step ahead of the treatment; they are changing rapidly.
Q. How does cancer happen?
A.
Cancer is not the result of one single thing going wrong. A cancer
forms through a series of steps. Simply having a mutated cell is
not enough to create
a cancer. The body has many safeguards to protect against aberrant cells. For
example, the immune system can come into play and destroy mutated cells before
they lead to cancer.
Free radicals seem to
encourage the formation of cancers at many
different stages. They can mutate, or permanently change, DNA so that it
conveys the wrong instructions to
cells—telling them to keep growing and not to stop. Normally, cells regulate their proliferation with their ability to sense
the population of neighboring cells. Free radicals can damage cell membranes and inactivate the sensory mechanisms in the membranes that limit cell growth
and reproduction. When cell sensors
become damaged, cell proliferation and growth become uncontrolled. In
addition, free radicals can suppress the immune system, inactivating the body's defense against cancer.
Based
on research, antioxidants can stop or slow each of the steps in
cancer development. Preliminary evidence suggests that antioxidants can also
reduce the chances of metastasis and boost
the immune system. Antioxidants may
have a role in apoptosis, which
helps eliminate mutated cells from the body. Although antioxidants seem to extend the life of normal cells, they
appear to help cancerous cells commit suicide. These findings point to the
fundamental regulatory roles of
antioxidants.
Q. How do antioxidants protect against cancer?
A.
Antioxidant nutrients protect against cancer in three ways: by destroying cancer-causing
free radicals, by boosting your body's
immune system so it can destroy
mutated cells before they become cancers,
and by reducing the tendency of cancer cells to adhere to other organs and glands. In addition, I believe that antioxidants inhibit several tumor
promoters and the activation of some pre-carcinogens into "true" carcinogens. This effect has
been demonstrated with antioxidants
called bioflavonoids and explains part of their protective actions against
cancers. Dr. David White of the University of
Nottingham in England has reported that Pycnogenol inhibits an enzyme (monooxygenase) from converting the prime pre-carcinogen in smoke,
benzo[a]pyrene, into its epoxide, which is a true carcinogen.
Don't
sweat the details. Population studies have shown that diets rich in
fruits and vegetables reduce the incidence of many cancers. Many scientists believe that the reason that fruits and
vegetables are so protective is that they are rich in antioxidants, especially vitamin C and bioflavonoids.
Q. How do antioxidant
nutrients boost immunity?
A. Several nutrients have been shown to
boost immunity, thus protecting us from all diseases and increasing
our body's ability to attack and kill cancer cells. Ranjit Chandra,
M.D., Adrianne Bendich, Ph.D., and Simin Meydani, D.V.M., Ph.D.,
have been pioneers in showing that nutritional supplements
stimulate the body's immune system.
Ronald Watson, Ph.D., of the University
of Arizona, Tucson, specializes in studying the immune system
and has conducted several studies with vitamin E and Pycnogenol and
the immune system. In one study, Dr. Watson and his
colleagues found that Pycnogenol boosted the levels of immune components called cytokines (formerly called
interleukins), specifically the IL-6
and IL-10 secreted by T-helper 2 cells. These cytokines decrease during HTV infection
and lead to progressive defects in T- and B-cell functions.
It so happens that the same cytokines are also important in the body's
resistance to cancer. Pycnogenol partially restored the decrease in IL-6 and IL-10
in laboratory animals that have a retro-virus very similar to HIV. In addition,
Pycnogenol greatly increased the activity
of a powerful type of immune cell
called the natural killer cell. David
Hughes, Ph.D., and his colleagues at the Institute of Food Research in England
have found that beta-carotene, found in carrots, increases the activity
of white blood cells called monocytes. Beta-carotene does this by
increasing the production of specific proteins on monocyte cell
surfaces so that the monocytes can better recognize cancer cells. Beta-carotene
also increases the production of tumor necrosis factor,
which is a cancer cell killer. Pycnogenol,
vitamin C, and other antioxidants also protect immune cells
from themselves. To explain, white blood cells release large numbers of free radicals when they are killing germs. Some of
these free radicals kill off white
blood cells. Antioxidants increase
the killing power of white blood
cells and, at the same time, protect them from excess free radicals.
Q.
How do antioxidants reduce the spread of cancer?
A.
Cancerous cells break off from tumors and travel through the body via the lymphatic
system. They seed new tumors in a process
called metastasis. Basically, the cancer cells stick to other tissues
and form new tumors. This process requires
molecules called cellular adhesion
molecules, such as ICAM-1 and
VCAM-1. Pycnogenol, quercetin, and other antioxidants reduce the activity of
these adhesion molecules, preventing the attachment of cancer cells.
Adhesion molecules are
also involved in inflammation, allergies, and atherosclerosis. By reducing their activity, antioxidants may protect against other diseases and disorders in yet another way. It
certainly explains why antioxidants
have been reported to ease allergic
symptoms.
Q. Is there evidence that antioxidant nutrients
actually reduce cancer incidence and death rate?
A.
Yes, there is. Many epidemiological studies show diets rich in fruits
and vegetables reduce the incidence of various cancers. Fruits and vegetables are rich in the antioxidant bioflavonoids, carotenoids,
and vitamin C. In addition, there are hundreds of laboratory animal studies, including my own, showing that antioxidants reduce the incidence of various cancers. As far as human clinical studies
go, there are a few. One joint United
States/China study found that
supplements of vitamin E, selenium, and beta-carotene reduced the risk of many
cancers, including lung cancer and stomach cancer, as well as increased life spans. A
well-controlled clinical study sponsored by the National Cancer
Institute and led by Larry Clark, Ph.D., of the University of
Arizona, Tucson, found that taking 200 meg of selenium daily
cut cancer incidence and cancer death rate in half, as well as
increased life spans. A 1998 Finnish double-blind, placebo-controlled
clinical study found that vitamin E supplements cut prostate cancer
incidence by 32 percent. These are just a few of the many
studies on the benefits of antioxidants.
4.
Staying Young With Antioxidants
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Every
living creature or plant grows old. As unpleasant as the thought
may be, it's a fact of life. Yet some people age far more gracefully than
others and look more youthful. This means that aging occurs at different rates, and
research on antioxidants indicates that the
rate of aging can be slowed. In this chapter, I explain how free radicals promote the aging process and how antioxidants can retard it.
Q. What happens to people as they age?
A.
Aging is the process that reduces the number of healthy cells in the body. With fewer
healthy cells, there is a higher percentage
of unhealthy cells. Different organs
seem to age at different rates in different
people. When the percentage of unhealthy cells in a particular person grows beyond a certain point,
the function of that organ is in jeopardy. In most people, the
heart gives out first; in others, it's the immune system or brain.
The
most striking factor in the aging process is the body's loss of youthful
"reserve" because of the decreasing
number of healthy cells in each organ. For
example, fasting blood glucose (blood sugar) levels remain fairly constant throughout life, but the glucose
tolerance measurement shows a less effective
response with aging. Glucose tolerance tests measure the reserve capacity of the endocrine system to respond
to the stress of an increased glucose load.
This same diminishment holds true for the recovery mechanisms of other systems. Simply stated, the aging process is the body's loss of
ability to respond to challenges or
stresses. The mass of healthy active
cells in each organ declines as a person ages, diminishing the organ's
ability to function normally.
Q. What causes this loss of reserve?
A.
By this point, you probably know the answer yourself: free radicals.
The cumulative effect of trillions of free-radical reactions is the
loss of cells. This damage occurs in a number of ways. For
example, free-radical damage
to the cell membranes can impair the cells' ability to transport
nutrients into the cell and waste products out. As a result, the cell will die.
Free
radicals also damage the cell's DNA, so that instead of
replicating a healthy cell, it produces a mutant cell that does not function
completely normally. Some of these cells may become cancerous, but most simply become less efficient with time. This
cellular inefficiency is a hallmark of aging.
The result of these and
many other types of free-radical reactions
is that the number of healthy, active
cells in the body decreases. This is analogous to the light bulbs in an old theater marquee that burn out one by one. For a while, the message can still
be read, but as the number of burned-out bulbs increases, eventually the message is not discernible. In the body, the cells in each organ decline, but
the organ still functions—up to a point.
Q. Can antioxidants help me live longer?
A.
The answer is yes—but the real idea is to live better as well as
longer. We should not want to just add years to our lives, but
also to add life to our years. In the laboratory animal experiments that I conducted,
my antioxidant-supplemented animals lived longer—about 30-percent longer average
life spans and 10-percent longer maximum life
spans. Furthermore, they weren't just
a bunch of old decrepit animals. They were healthier, looked younger, were more active, and had less disease.
The question then became, "Will
antioxidant nutrients do the same for
humans?"
Unfortunately,
we don't have double-blind, placebo-controlled clinical trials
performed over the entire life span of thousands of humans to prove
this—and we never will see such studies carried out. The expense
would be astronomical. We do, however, have other evidence.
As
the popularity of taking antioxidant supplements has increased, we
have witnessed a decline in chronic disability, heart disease death
rate, and, at long
last, cancer. At the same time, the average life span has increased. Although this evidence is indirect, it does support the idea that there has been
a positive effect on millions of people taking antioxidant supplements. Basically, if antioxidants
reduce your risk of cancer and heart
disease, they will inevitably extend your life expectancy.
There
have been many other studies, in addition to those I described earlier. A
number of years ago, I participated in a study with Linus Pauling, Ph.D., and Jim Enstrom, Ph.D., that examined
mortality among
health-conscious elderly Californians. This study
found that the death rate was lower for supplement users. Male supplement users had a 22-percent lower risk of death
and women had a 46-percent lower risk of death. Later, Enstrom and his colleagues reported that vitamin C supplements that provided over 250 mg per day reduced the mortality
rate in men by 35 percent, which translated
to a six-year increase in life expectancy.
One
recent study, reported in the Journal of the American Geriatrics Society, found
that centenarians—people aged 100 years or older—had substantially higher levels of
antioxidants and lower levels of free
radicals in their blood, compared with people between the ages of 70 and 99. They also ate relatively large quantities of antioxidant-rich fruits
and vegetables.
Q. Can antioxidant nutrients help prevent cataracts?
A. Yes, they can.
Cataracts, clouding of the lens of the eye, are associated with aging, with
exposure to sunlight, and with diabetes.
They are caused by free radicals oxidizing the protein that forms
lenses. A number of studies have found
correlations between high
antioxidant intake and reduced risk of cataracts. One
recent study reported that women who took vitamin C supplements—at
least 400IU daily for ten or more years—were less likely to develop cataracts.
Several antioxidants are of particular benefit to the eyes.
Vitamin C, of course, and also vitamin E have been associated
with a lower risk of cataracts. Lutein, related to beta-carotene,
may also reduce the risk of cataracts. Lutein is the only
carotenoid found near the lens. In addition, the lens is bathed in a fluid rich in glutathione. You can increase your body's
production of glutathione by taking vitamin C, alpha-lipoic acid, and N-acetylcysteine—all very good and important antioxidants.
Q. Can antioxidants really create more youthful
looking skin?
A.
They can help preserve your skin, reduce the aging of skin, and
maybe even reverse some damage. People with very weathered or wrinkled skin likely
either smoked for much of their lives or spent a lot of time outdoors. Smoking
is a major generator of free radicals throughout the
body—that's why it has been linked to so many types of cancer. Its most visible
effects, however, are probably on the skin. Similarly, exposure to
sunlight's ultraviolet rays generates large numbers of free radicals in the skin.
To
demonstrate the effect of free radicals, examine the skin on the
back of your hand by pulling it away from the hand. Let it
go and count the number of seconds it takes for the skin to spring back to place. Do the same test with people of different ages. In general, younger people will have more
elastic skin that quickly rebounds compared with older people. Now, do the same test with skin from a part of your body
that has not been as exposed to sunlight.
See the difference? The skin is of the same age all over your body, but it has aged more where exposed more to
sunlight.
To
minimize free radical damage to the skin, minimize your exposure to
the sun and don't smoke. To counter damage, take an antioxidant formula
and consider applying an antioxidant cream or lotion to your skin. Antioxidants
are absorbed and retained by the skin. Lester Packer, Ph.D., at the
University of California, Berkeley, has conducted a number
of experiments showing that skin antioxidants are quickly used up
under oxidative stress. Vitamins E and C and beta-carotene
reduce free-radical
damage to the skin. Packer has also demonstrated
that antioxidants in the skin work synergistically, which shouldn't be all that surprising because they work together every place else in the
body.
Q. Can antioxidant
nutrients help protect against sunburn?
A.
To a certain extent they can. Sunburn is inflammation caused by free radicals,
whose production was triggered by ultraviolet rays in sunlight. While antioxidants
are not a sunscreen or sunblock, per se, they do increase the skin's resistance
to free radicals and inflammation—and the skin's ability to repair damage.
In a number of studies, European researchers found that
supplementation with beta-carotene and the use of a topical
sunscreen was far more effective in reducing sunburn than the
use of a sunscreen alone. Other beneficial antioxidants include vitamins E and C and
flavonoids, particularly Pycnogenol. Taking
antioxidants internally, and applying
them topically, can give you inside-out protection against sunburn.
It's
not too late to take antioxidants—inside and outside—after a
sunburn either. They will help restore normal levels of antioxidants in the skin, and they should reduce inflammation and speed healing. Remember that excessive exposure to sunlight increases the risk of skin cancer, particularly
among fair-skinned people. It makes
no sense to tempt fate.
Q. Can antioxidant nutrients
improve fertility?
A. Yes, vitamin E,
vitamin C, selenium, alpha-lipoic acid, and
ferulic acid (an antioxidant found in Pycnogenol)
have each been shown to improve fertility.
Horse breeders swear by Pycnogenol and vitamin
C. Antioxidants in general improve sperm motility—that is, their ability to swim. Many urologists recommend that their infertile male patients
take antioxidants, as well as stop
smoking. A number of studies in men
have found that antioxidant supplementation
normalizes the appearance of sperm
and increases the likelihood of fertilizing their partner's eggs. In one study, 1,000 mg of vitamin C daily improved the sperm of men who smoked. Ami Amit, M.D., reported in the journal Fertility and
Sterility that he gave 200 IU of vitamin E
daily for three months to men with normal sperm counts but low
fertilization rates. The men's fertilization rate improved by 30 percent.
Q. Can antioxidants improve arthritis?
A.
Rheumatoid arthritis is an inflammatory disease. By now, you
understand that free radicals promote inflammation. While antioxidants are not a cure for arthritis, they can reduce the inflammation,
swelling, and pain associated with this condition. Vitamin E and selenium have individually and in combination reduced pain and swelling in
arthritis patients. In Israel, a
study found that 600IU of vitamin E
reduced the pain of arthritis in half of the patients, compared with only 4 percent of the patients receiving a placebo.
Arthritis
may also be aggravated by low levels of vitamin C. When people do
not obtain enough vitamin C, their blood vessels are more
likely to leak. Some of these blood cells can leak into joints, where they
stimulate an inflammatory reaction. Recently, French researchers
described two patients with scurvy (a severe deficiency of vitamin
C) whose symptoms included rheumatism. When they were given
high doses of vitamin C, their symptoms went away.
Q. Can antioxidants protect against Alzheimer's disease?
A. Yes, they can. Free
radicals are involved in Alzheimer's
disease, and antioxidants have been shown
to help. In a major study, published in the New England Journal
of Medicine, researchers found
that late-stage Alzheimer's disease patients who took
2,000 IU of vitamin E daily for just two years were able to delay for six to seven
months key symptoms of the disease. It has
not been proven, but I suspect that
taking more modest doses of vitamin
E (400 IU daily) much earlier in life will prevent or delay the onset of Alzheimer's disease.
Ishwarlal Jialal, M.D., of the
University of Texas Southwestern Medical
Center said, "Anyone with a family history of Alzheimer's disease
or heart disease would be foolish not to
take daily vitamin E supplements.
One
of the characteristics of Alzheimer's disease is the accumulation of
beta-amyloid protein, which literally chokes brain cells to death. In laboratory experiments, researchers at the Salk Institute of
Biological Sciences, San Diego, have
found that Pycnogenol prevented beta-amyloid from accumulating in brain
cells. I'm convinced that the best approach
is taking a broad selection of antioxidants. I'll describe such a program in the next chapter.
5.
How
to Use Antioxidants
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So
far we have discussed antioxidant nutrients and what they do. We have
put special emphasis on heart disease, cancer, and aging. This
should be adequate to understand that antioxidants can indeed improve your health and help you live better longer. Now, let's put what we know to practical use.
Q. Why should I take vitamin E?
A.
Vitamin E is the body's principal fat-soluble antioxidant. It's
also an essential nutrient. No other antioxidant can really fit
its shoes, so it is one of the most important antioxidants you can
take. It's particularly important because of the huge amount of fats
(particularly the polyunsaturated vegetable oils) people consume today
in the form of fried foods. Such fats are very prone to
oxidation, and they increase a person's requirements for vitamin E to prevent oxidation.
Of
all the antioxidants, the evidence supporting the use of vitamin E is by far the most
extensive. A recent study found that almost
half of cardiologists were taking
it. It comes close to being a "magic bullet"—a label given to
it that was once criticized.
Q. Is natural vitamin E better than synthetic?
A.
It certainly is. Vitamin E activity is shared by eight different
compounds—four of which are members of the tocopherol
family (alpha-, beta-, gamma-, and delta-tocopherol) and four of which are members of the tocotrienol family (alpha-, beta-,
gamma-, and delta-tocotrienol). The most common form of vitamin E found in American foods is gamma-toco-pherol, but this is because most of the oils
Americans consume are highly refined.
Biologically, the human body selects
for the natural d-alpha tocopherol form of vitamin E over all others, though other natural forms do play
important roles in health.
Synthetic
vitamin E, which is identified by the term "dl-alpha" is
not assimilated or retained as well as the natural form. For many
years, natural vitamin
E was rated about 36-percent more effective, on an equal-weight
basis, than synthetic vitamin E. Two recent studies have found
that it is actually twice as potent.
The
manufacturers of vitamin E supplements prefer to use the esterified forms of
alpha-toco-pherol, which are much more stable than the unes-terified
form. The stable esterified forms are the alpha-tocopheryl acetate and
alpha-tocopheryl suc-cinate. Esterified forms can be found
in both natural and synthetic vitamin E supplements.
Q. Can you explain a little more about tocotrienols?
A.
Tocotrienols are a family of four compounds that have weak vitamin E
activity. However, they may produce health benefits independent
of their vitamin E activity. For example, preliminary studies suggest
that tocotrienols can lower blood cholesterol and significantly
reduce the size of existing cholesterol deposits.
Q. How much vitamin E do I need?
A.
You certainly need more than the meager 8 IU or so found
typically in daily American diets. The current RDA is 15 IU
daily, and this is also far below the amount needed to reduce
the risk of heart disease. The Harvard studies found that
at least 200 IU daily for at least two years is needed to reduce the
risk of heart disease. Based on various studies, the optimal
amount seems to be 400 IU daily, though many people will benefit
from still higher dosages.
Q. What are the benefits of taking vitamin
C?
A.
Vitamin C has many health benefits, but recent research has shown
that large numbers of middle-class Americans do not obtain enough
of it. The late Nobel laureate Linus Pauling, Ph.D., recommended vitamin
C to reduce symptoms of the common cold. In analyzing almost two dozen studies
on vitamin C and colds, Harri Hemila, Ph.D., of the University of Helsinki,
Finland, found that 2 to 6 g daily reduced cold symptoms by about
one-third.
Pauling
also recommended that cancer patients take large amounts of
vitamin C—10 g or more daily. Abram Hoffer, M.D., Ph.D., found
that vitamin C decreased pain and increased life expectancy in cancer patients — but that a broader vitamin/ mineral program worked even better.
In
a study, Mark Levine, M.D., Ph.D., of the National Institutes of Health, found
that the first symptoms of vitamin C deprivation were fatigue and
irritability. In clinical practice, Hugh Riordan, M.D., of Wichita, Kansas, has
consistently found that large amounts of vitamin C supplements relieve
fatigue in patients.
Most
animals produce their own vitamin C. Humans and a handful of
other animals do not. But biochemically, they still seem to need
large amounts of it. For example, gorillas in the wild eat foods containing
about 4.5 g of vitamin C daily. Pauling thought that people need
at least 1 gram (1,000 mg) of vitamin C daily — he took 18 g daily
and lived to age 93. 1 think there are compelling reasons to take
several grams of vitamin C daily.
Q. What are carotenoids, and are they good
antioxidants?
Carotenoids
are antioxidants that do double duty as plant pigments. For
example, beta-carotene makes carrots orange, and lycopenes give tomatoes their
red color. Their colors enable them to absorb specific
frequencies of sunlight and prevent the formation
of light-induced free radicals.
About
forty to fifty carotenoids are found in the American diet, though only fourteen
are absorbed into the bloodstream. There are actually two classes of carotenoids: the
carotenes and the xanthophylls. Carotenes
are hydrocarbons, meaning that they contain only atoms of carbon and hydrogen, while the xanthophylls also contain oxygen.
Beta-carotene
has been the star of the carotenoid family. The body can split
a molecule of beta-carotene in half to form two molecules of vitamin A. Since
this is done only on an "as-needed" basis, beta-carotene
is considered a safe source of vitamin A. Then it was discovered that
beta-carotene was a very effective antioxidant, especially in protecting
against the reactive oxygen species called "singlet
oxygen." It also is vital to a healthy immune system.
In
recent years, other carotenoids have gained scientific respectability. Among these are
lutein and lycopene. If you eat a diet with
varied fruits and vegetables, you
probably get plenty of carotenoids. People
at risk of certain conditions may benefit from extra amounts of some. I'll discuss this shortly.
Q. If I get a lot of carotenoids, do I need vitamin
A too?
A.
Many people have been taught that vegetables, such as carrots,
are good sources of vitamin A. This is not completely true. There is no vitamin
A in carrots or any other vegetable. Fruits and vegetables can
contain lots of carotenoids, which our bodies can convert to
vitamin A, but "preformed" vitamin A is found only in animals.
Therefore, if you are a strict vegetarian, you may have
trouble getting optimal amounts of vitamin A.
Many people will do
better with preformed vitamin A in their
diets. Vitamin A, of course, is an essential nutrient. Older persons and
diabetics may have lower efficiencies in converting carotenoids into vitamin A. Therefore, it is a good practice
to get some vitamin A in the diet,
as well as ample carotenoids.
Q. What is lycopene?
A.»
Lycopene is one of the more important dietary carotenoids. The
richest source of it is tomato sauces (more so than raw
tomatoes); there is also some in watermelon and guava. One
study found that men who ate ten or more lycopene-rich tomato
meals weekly had a 45-percent reduced risk of developing prostate
cancer. Diets rich in lycopene are also associated with a
reduced risk of pancreatic and cervical cancers. Recently, a European-based study
reported that diets high in lycopene have
been associated with a 48-percent
reduction in heart attacks compared with diets low in lycopene.
Q. What are lutein and zeaxanthin?
A.
Like lycopene and beta-carotene, lutein is a very important
carotenoid, and zeaxanthin, another carotenoid, is often
associated with it. Lutein is found in many leafy green vegetables, alfalfa, marigold
petals, and egg yolks. Zeaxanthin is found in corn. The body may be
able to convert some lutein into zeaxanthin.
Lutein
and zeaxanthin are essential for vision. They form the macula lutea,
which, because of its yellow color, filters out harmful blue light. People with
macular degeneration are often deficient in lutein and zeaxanthin and have only a thin,
ineffective deposit of lutein and zeaxanthin
in the eye. Because the macula is responsible
for both "fine" and "central" vision, macular
degeneration can lead to serious visual
impairment and blindness.
Recent
research indicates that lutein might also protect against heart
disease and cancer. Because lutein is fat soluble, it is transported
by the low-density
lipoprotein (LDL) form of cholesterol. At least
one study indicates that lutein protects vitamin E from oxidation in LDL. It may also contribute to the health of the immune system.
Q. What are bioflavonoids?
A.
The term bioflavonoids, or flavonoids, covers thousands of
nutritional substances that have a common basic structure.
Nearly all are found in plants, which means they are also common in fruits and vegetables. The structure of flavonoid compounds makes them easy to donate electrons to other molecules, and thus they are usually
excellent antioxidants. Although flavonoids have many similarities, they have differences, which lead to
their varied biochemical activities.
Like
carotenoids, flavonoids serve as plant pigments that filter out
harmful wavelengths of light. Some common bioflavonoids include quercetin, rutin,
hesperidin, genistein, diadzein, and those found in many herbs.
Herbalists have been successfully using bioflavonoid-rich plant extracts for centuries to treat various illnesses. Flavonoids were discovered
in 1936 by Nobel laureate Albert Szent-Gyorgyi,
M.D., Ph.D. He found that flavonoids prevented capillary permeability, or fragility, which resulted in easy bruising and edema. Szent-Gyorgyi initially
called flavonoids "vitamin P" (for the permeability factor). Later,
most scientists dropped the vitamin P name,
though flavonoids do have vitaminlike functions.
Q. What is Pycnogenol?
A.
Pycnogenol is derived from the bark of French Maritime pine trees,
and much of the product consists of a subgroup of antioxidant flavonoids called proanthocyanidins. Pycnogenol also consists of
substances chemists call
"organic acids," which are also powerful antioxidants. All together, Pycnogenol consists of about forty or so compounds. It is a good
example of synergistic antioxidants.
Lester Packer, Ph.D., has found that
the key flavonoids in Pycnogenol are not as powerful individually as the
total sum of antioxidants naturally found in Pycnogenol.
Q. What is coenzyme Q10?
A. Coenzyme Q10,
or CoQ10, is a vitamin-like substance
made by the body and also found in foods, such as organ meats. Its primary function is in helping to convert food to energy. Secondary to this,
it is a powerful antioxidant. These
two functions do overlap. It is
beneficial to people with various types of heart failure. CoQ10
increases the energy output of
hearts, making them stronger. Unlike drugs, it does this naturally. Some
cardiologists recommend as much as 300 to
400 mg of CoQ10 daily to treat heart failure, though most people do not need this much. Some recent
research indicates that it may also help prevent the recurrence of
breast cancer.
Q. You've mentioned alpha-lipoic acid
— can you explain more about it?
A. Like CoQ10,
alpha-lipoic acid plays key roles in converting
food to energy. German physicians have used
it for years to treat diabetic polyneuropathy, a severe nerve disorder. It can also lower and stabilize blood sugar levels, making it important for diabetics
and people prone to diabetes.
Alpha-lipoic acid is
also a very powerful antioxidant. The body
converts some alpha-lipoic acid into
dihydrolipoic acid, an even more powerful antioxidant (which, unlike
alpha-lipoic acid, is not sold as a
supplement). In addition, alpha-lipoic acid can help regenerate numerous other antioxidants, including vitamin C, vitamin E, and glutathione.
High
blood sugar levels generate large numbers of free radicals. These
free radicals account, in part, for the complications of
diabetes. Alpha-lipoic helps in two ways, by lowering blood sugar
levels a little and by quenching free radicals.
Q. What is NADH?
A.
NADH stands for nicotinamide adenine dinu-cleotide. This is a complex
compound built around vitamin B3 (niacinamide,
nicotinamide). Like CoQ10 and alpha-lipoic acid, NADH
plays a key role in converting food to energy. (These
substances are not interchangeable—they function in different places during energy-producing chemical reactions.) Similar
to CoQ10 and alpha-lipoic acid, NADH is also a powerful antioxidant.
Jorg
Birkmayer, M.D., Ph.D., director of the Birkmayer Institute for
Parkinson's Therapy, Vienna, has been a leader in the
clinical use of NADH. He has found it helpful in many patients with
Parkinson's disease, Alzheimer's disease, depression, and chronic
fatigue. In one small study of Alzheimer's disease patients,
Birkmayer found that 10 mg of NADH daily before breakfast for eight
to twelve weeks resulted in striking improvements. The
Alzheimer's disease patients' average scores
on cognitive and function tests improved by 50 percent.
Joseph Bellanti, M.D.,
director of Georgetown University's
International Immunology Center, Washington,
D.C., recently reported that nineteen of twenty-six patients with chronic
fatigue syndrome improved after
taking NADH supplements. Eight of the
patients benefited from significant relief of symptoms.
Q. What is glutathione?
A.
Glutathione is the antioxidant workhorse within the body's cells.
This powerful antioxidant is a sulfur-containing tripeptide formed in
the body from
three amino acids: cysteine (a sulfur-containing
amino acid), glutamic acid, and glycine. Glutathione assists in keeping the immune system healthy, neutralizing
intracellular free radicals, and detoxifying
many harmful chemicals. Glutathione serves as a substrate, or chemical
foundation, for many enzymes, such as the selenium-containing glutathione
peroxidases that reduce free radical reactions.
Glutathione
plays a key position in the antioxidant cycle, as it can
regenerate most other antioxidants, but not NADH. Glutathione levels
can be increased with several nutritional
supplements, including selenium, N-acetyl
cysteine, cysteine, and alpha-lipoic
acid.
Q. What is NAC?
A.
NAC, technically known as N-acetylcysteine, is another important antioxidant.
It works chiefly by increasing the body's production of glutathione. A study
by Italian researchers found that NAC supplements greatly reduced
symptoms of the flu. Other researchers are investigating
NAC as a cancer-preventing compound. It is similar to the sulfur-containing
amino acid cysteine, but better absorbed and more efficient.
Q. What would be a basic antioxidant protection
plan?
A.
Fruits and vegetables are the richest sources of antioxidants. Therefore, the foundation
of any antioxidant-boosting dietary plan
would be to eat a variety of fruits and vegetables—a total of five to nine servings daily. Next, I would recommend a good multivitamin/multimineral support for basic nutrition. To this foundation, add the following:
•
200-400 IU of natural vitamin E.
• 250-1,000
mg of vitamin C.
• 50-100
meg of selenium.
If
your multivitamin/multimineral supplement contains these amounts,
you're off to a great start.
Q. What is a more comprehensive antioxidant
program?
A. Again, start with a
diet containing five to nine servings of
fruits and vegetables and a good multivitamin/multimineral
supplement. To this, add the following antioxidants. You may be able to find most of these in a high-potency multivitamin or antioxidant formula. Strive for the dosages listed
below, but a little less or a little
more would be fine.
• 400-800
IU of vitamin E.
• 500-4,000
mg of vitamin C.
• 100-200
meg of selenium.
• 15-25
mg of mixed carotenoids.
• 8,000-12,000
IU of vitamin A.
• 30-120
mg of CoQ10.
• 25-100
mg of Pycnogenol.
• 25-100
mg of alpha-lipoic acid.
On
top of that, if you're inclined and can afford it, consider the
following optional antioxidants:
• 5-10 mg of NADH.
• 300-600
mg NAC.
• 5
mg of lycopene.
• 5
mg of lutein (along with some zeaxanthin).
• 50-100 mg of grape seed
extract.
Q. Are all of these antioxidant nutrients safe?
A.
Yes, they are. All of these substances are found in traditional
diets, though many are removed, through food processing, from the modern
Western diet.
Bear
in mind that everything can be toxic at some level—including
oxygen and water. The amounts discussed as being optimal are far
below the levels that could cause adverse effects. However, it must be pointed out that
selenium and vitamin A do have toxic limits
that you should be aware of. Here are some
upper limits.
• Selenium—Do
not exceed 600 meg daily.
• Vitamin
A—Do not exceed 25,000 IU daily.
• Vitamin
C—25 g and above may cause loose stools.
• Carotenoids—Take
no more than 25 mg daily, if you are a heavy smoker or heavy
drinker.
You
may exceed these upper limits for short periods of time under
the direction of your physician.
Q. What's the future of antioxidant research?
A.
Thousands of articles on antioxidants now appear each year in
scientific and medical journals. This is in stark contrast
to twenty or thirty years ago, when very little research was being
conducted on free
radicals and antioxidants. Researchers are currently focusing on the most basic details of how they work—that
is, molecular biology. This is about as "hard"
as science gets. The evidence so far is that free radicals damage genes and activate "bad"
genes, whereas antioxidants protect
genes and activate "good"
genes. Because genes contain the biological instructions for how our
bodies work, this research demonstrates that
free radicals and antioxidants function
at the core of our existence. All trends point to future research being positive and confirming the many health
benefits of antioxidants.
Conclusion
|
|
Free
radicals and antioxidants are among the most important discoveries
of the past 100 years. One can hurt you, and the other can protect you.
In
the years since Dr. Denham Harman first proposed that free radicals
fuel the aging process, researchers have documented their role
in more than
eighty diseases. All of the major diseases confronting people today—heart disease, cancer, Alzheimer's disease, and arthritis—are caused by or aggravated by free radicals.
The
beauty of natural antioxidants is that they neutralize free radicals.
In doing so, they can slow down and often reverse free radical
damage—and reduce your risk of disease. And while many individual
antioxidants, such as vitamins E and C, can have remarkable and rapid
benefits, antioxidants generally work best as a group. This
is because they are clearly synergistic.
As
we move into the twenty-first century, antioxidant research is on the
upswing. Thousands of studies on antioxidants are published in scientific and
medical journals each year. Antioxidant supplements, which concentrate many of
the antioxidants found in foods, are safe and relatively inexpensive,
compared to the pain and cost of treating disease. It only makes sense to eat
an antioxidant-rich diet and to fortify your diet with additional antioxidants.
The
take-home message of this book is simple: Antioxidants can help you
live better, longer—to add life to your years, as well as
years to your life.
Glossary
Antioxidant.
A nutrient that protects body components against undesirable
chemical reactions.
Bioflavonoids.
A class of antioxidant compounds produced by plants.
Carotenoids.
A family of antioxidant nutrients produced by plants. Some carotenoids can be
converted
into vitamin A in the body.
Coenzyme.
A cofactor that combines with an enzyme and helps the enzyme
function.
Electron. A negatively
charged elementary particle of atoms and
molecules.
Enzyme. A biological
catalyst that promotes a biochemical
reaction.
Free
radical. A molecule with an unpaired electron that can damage the body's cells.
Free radicals promote aging and diseases.
In
vitro. Referring to laboratory experiments performed in laboratory
glassware.
Lipid.
A chemical term referring to fats and oils.
Lipoprotein.
A particle that is made of fats (lipids) and proteins. Lipoproteins
carry cholesterol and fat-soluble vitamins throughout the
bloodstream.
Nitric
oxide. A simple molecule consisting of nitrogen and oxygen. Nitric oxide is a free
radical.
Oxidation.
The reaction of a compound with oxygen, or whenever a molecule
loses an electron during a chemical reaction.
Oxidative
stress. The situation when there is a serious imbalance in the ratio of free radicals to
antioxidants. Too many free radicals and too
few antioxidants lead to oxidative stress.
Platelets.
Small blood cells involved in forming blood clots.
References
Clark
LC, et al., "Effects of selenium supplementation
for cancer prevention in patients with carcinoma of the skin: A
randomized controlled trial," JAMA 276(24) (Dec 25,1996):
1957-1963.
Enstrom JE,
"Vitamin supplement use and mortality:
Study that found no relationship is challenged," Am. ]. Publ. Health 84(6)
(June 1994): 1034-1038.
Enstrom
JE, Kanim LE, and Klein MA, "Vitamin C intake and mortality among
a sample of the United States population," Epidemiology 3(3)
(May 1992): 194-202.
Enstrom
JE and Pauling L, "Mortality among health-conscious elderly
Californians," Proc. Natl. Acad. Sci. 79(19) (Oct 1982):
6023-6027.
Gey KF, "Inverse
correlation between plasma vitamin E and mortality from ischemic heart disease
in cross-cultural
epidemiology," Am. J. din. Nutr. 53(S) (Jan 1991):
326S-334S.
Harman D, "Free
radical theory of aging: effect of free radical reaction inhibitors on the
mortality rate of male LAP mice/' /. Gerontology 23(4)
(Oct 1968): 476-482.
Packer
L, "Interactions among antioxidants in health and disease: vitamin
E and its rediox cycle," Proc. Soc. Exp. Biol. Med. 200(2) (June 1992):
271-276.
Passwater RA,
"Slowing the Aging Process," 23rd Annual Mtg. Gerontol. Soc., Toronto
(Oct 21-24, 1970). Also Gerontology 10(3) 28 (1970).
Passwater
RA. Supernutrition:
Megavitamin Revolution. New York: Dial Press, 1975.
Passwater
RA. Supernutrition
for Healthy Hearts. New York: Dial Press, 1977.
Passwater
RA, "Vitamin E reduces heart disease incidence," Prevention 28(7)
(1976): 66-72.
Rimm
EB, et al., "Vitamin E consumption and the risk of coronary heart disease in
men," N. Engl. J. Med. 328(20) (May 20,1993):
1450-1456.
Stampfer
MJ, et al., "Vitamin E consumption and the risk of coronary
disease in women," N. Engl. J. Med. 328(20) (May 20,1993):
1444-1449.
Tomeo
AC, et al., "Antioxidant effects of toco-trienols in patients with hyperlipidemia
and carotid stenosis," Lipids 30(12)
(Dec 1995): 1179-1183.
Suggested Readings
Challem
J. All
About Vitamins. Garden City Park, NY: Avery Publishing
Group, 1998.
Lieberman S. The Real Vitamin and Mineral Book. Garden
City Park, NY: Avery Publishing Group, 1997.
Passwater
RA. Beta-Carotene
and Other Carotenoids. New Canaan, CT: Keats, 1996.
Passwater
RA. Lipoic
Acid: The Metabolic Antioxidant. New Canaan, CT: Keats,
1995.