Antioxidants and Mortality
As seen on FOX News (February 28,2007)
Antioxidants are believed to reduce the risk of several diseases. However, in a previously published article, Bjelakovic and colleagues reported that antioxidant supplements (with the potential exception of selenium) had no effect on gastrointestinal cancer and were associated with an increase in all-cause mortality. In this issue of JAMA, the investigators report results of a systematic literature review to assess the effects of beta carotene, vitamins A and E, ascorbic acid (vitamin C), and selenium on allcause mortality among participants in primary and secondary disease prevention trials. The authors found that beta carotene, vitamin A, and vitamin E, taken singly or combined with other antioxidant supplements, were associated with increased allcause mortality.
Another case against taking isolated synthetically made vitamins.
Juice Plus+ provides whole food based nutrition from 17 different fruits, vegetables and grains.
An Apple A Day
The Role of Antioxidants in
the Endurance Athlete
David B. Phillips, M.D.
Much has been talked about in the sports and science
community about the adverse affects of prolonged and
strenuous exercise as it relates to the production of
free radicals in an athlete’s body. What are these by-
products of aerobic exercise and why are they
damaging to the human body? More importantly, what
role do antioxidants play in neutralizing these damaging
molecules and what can we as athletes do to facilitate
this protective process?
An Apple a Day
The ‘Radical’ Concept
Free radicals are highly reactive species produced
during various molecular processes in the human body.
While environmental factors such as pollution, radiation
and cigarette smoke can spawn free radicals, in this
article we will focus on those free radicals produced
during endurance exercise.
Free radicals are atoms or groups of atoms with an odd
or unpaired number of elections and can be formed
when oxygen interacts with certain molecules. Once
formed, these reactive radicals can start a chain
reaction, similar to a domino effect. In other words,
these compounds attack the nearest stable molecule,
“stealing” its electrons in order to gain stability. When
the “attacked” molecule loses its electron, it becomes
a free radical itself, beginning a chain reaction. Once
the process is started it can cascade, resulting in the
disruption of a living cell. Free radical damage not only
contributes to accelerated aging, it also causes
damage to immune cells. It’s not uncommon for
endurance athletes such as triathletes or marathoners
to have a higher incidence of colds and upper
respiratory infections after competition and intense
training. Free radical damage to cellular DNA plays a
significant role in the evolution of certain cancers,
heart disease and neurological disorders such as
Alzheimer’s disease.
Exercise and Oxidative Damage
Endurance exercise can increase oxygen utilization
from 10 to 20 times over the resting state and up to 100
to 200 times in working muscles. This greatly
increases the generation of free radicals via oxidative
metabolism in skeletal mitochondria. Fortunately, the
body has an elaborate antioxidant defense system that
utilizes dietary intake of antioxidant vitamins and
minerals as well as our body’s own enzyme systems to
decrease concentrations of the most harmful oxidants
in tissues. Regular endurance training has been shown
to enhance our internal antioxidant defense system,
these changes of which occur slowly over time and
appear to parallel other adaptations to exercise. When
free radical production exceeds the ability of
antioxidant enzymes and nutritionally obtained
antioxidants to neutralize them, oxidative stress
results. So, what can we as endurance athletes do to
minimize the damage caused by the inevitable overflow
of free radicals during training and competition?
Fruits and Vegetables:
The Power of the Pyramid!
A recent change in dietary intake of fruits and
vegetables by the USDA has placed a greater emphasis
on increasing our daily consumption from the previous
5-7 servings a day to 7-9 servings and up to 13 servings
or more for endurance athletes! Vitamins C, E, and beta
carotene are the primary vitamin antioxidants.
Previous research looking into the effects of
supplementing our diets with these isolated nutrients
has yielded equivocal results. Once thought to be
beneficial to cardiac health, isolated vitamin E
supplementation has now been questioned. Beta
carotene supplements have been shown to increase
lung cancer in smokers as well as contribute to
thickening of the lining of arteries.
Recent studies now point to the synergistic role of
numerous antioxidants obtained from the consumption
of whole foods such as fruits and vegetables.
Therefore, a diet rich in naturally occurring antioxidants
appears to outweigh the risks inherent to
supplementing one’s diet with isolated laboratory made
supplements. Furthermore, various key trace minerals
such as zinc, selenium and manganese found in
naturally occurring foods are needed for the proper
functioning of various endogenous antioxidant enzymes.
Training Right, Eating Right:
Final Thoughts
The endurance athlete faces a challenge of balancing
daily aerobic exercise with preventative measures that
minimize the damaging affects of oxidative stress.
Clearly, fruits and vegetables rich in antioxidants are
vital to this balance. Many of us may find it difficult to
consume the recommended amounts of fruits and
vegetables to achieve this balance. For those who are
unable to take in enough daily produce, cryoevaporated
fruits and vegetables in capsule form, such as Juice
Plus+, make it possible to supplement what we are not
able to consume when we visit the salad bar.
Antioxidant supplementation helps to bridge the gap
between what we eat on a daily basis (what we know
we should be eating!) and the optimal amount of
phytonutrients needed to combat the damaging effects
of oxidative stress.
As endurance athletes, it is important to be aware of
not only the benefits of aerobic exercise but the
potentially negative aspects training and racing can
have on our bodies and long term health. Finding a
healthy balance between training and proper nutrition
will go a long way in promoting longevity in any
endurance athletic activity.
For questions or further information related to oxidative
stress and nutrition, contact:
David B. Phillips, M.D.
(Dr. Phillips completed the 2005 Ironman World
Championships in Kona; he is a USAT All-American and
the 2004 USAT National Long Course Masters
Champion; he was ranked #1 USAT Southeast Masters
Division 2004 and was also an All-American swimmer at
Harvard University.)
FOR INFORMATION ON THE BENEFITS OF JUICE PLUS+
www.tri4juiceplus.com
REFERENCES
“Antioxidants: What are They and What Role Do
They Play in Physical Activity and Health?”
Priscilla M. Clarkson, Ph.D.
“The Role of Antioxidant Vitamins and Enzymes in
the Prevention of Exercise-induced Muscle
Damage,” Sports Medicine, 1996; 21: 213-38
“Antioxidants: Role of Supplementation to Prevent
Exercise-induced Oxidative Stress,” Medicine and
Science in Sports and Exercise, 25(2): 232-236,
1993, Feb.
“Oxidative Stress in Endurance Athletes,”
Triathlete Magazine, 256: 74-76, 2005, August.
(Excellent in-depth review of specific nutritional
antioxidants.)
