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Antioxidants
How do they work?
Antioxidants protect the cells, the tiny “building blocks” of information in
our bodies, in three ways:
· Binding with unstable atoms (free radicals)
· Transforming free radicals into “safe” compounds
· Repairing cell damage
Oxygen can create damaging by-products during normal cellular metabolism,
the process by which our bodies combine food and oxygen to create energy. These
by-products are unstable atoms called free radicals. Atoms consist of tiny materials
called electrons. In stable atoms, electrons come in pairs. Free radicals, however,
have one unpaired electron that is searching for a partner among existing electron
pairs in the body. If the free radical sucks a partner out of another molecule,
then that molecule becomes a free radical, and the cycle continues. Eventually,
a dangerous chain reaction rips through the body. If left unchecked, this chain
reaction may cause heart damage, cancer, cataracts, and a weak immune system.
Free radicals can also be created by cigarette smoke, ozone, pollution and radiation.
Antioxidants bind with free radicals before they can steal electrons from stable
atoms, Thus, antioxidants prevent free radical chain reactions before they can
cause damage.
Examples of antioxidants include:
· Vitamin C
· Vitamin E
· Beta-carotene (a form of vitamin A)
· Carotenoids (a group of pigments that add colour to fruits and vegetables)
· Selenium (a mineral)
· Gingko biloba
Benefits of antioxidants
Antioxidants are thought to help prevent:
· Cardiovascular disease
· Stroke
· Cancer
· Cataracts
· Macular degeneration
Some studies have suggested (but not proven) that diets high in carotenoids
reduce the risk of certain cancers. Also, vitamin C has been found to prevent
the formation of N-nitroso compounds, the cancer-causing substances from nitrates
and nitrites found in preserved meats and in some drinking water. It is also
possible that higher antioxidant levels slow or altogether prevent the development
of arterial blockages and the accumulation of plaque on arterial walls.
Sources of antioxidants:
Good sources of antioxidants include brightly coloured fruits and vegetables
such as:
· spinach
· carrots
· red bell peppers
· tomatoes
· sweet potatoes
· mangoes
· cantaloupe
Vitamin E can also be found in whole grains, nuts, seeds, fish and vegetable
oils, and apricots. Beta-carotene can be found in liver, egg yolk, milk and
butter.
Note that fruits and vegetables lose some of their antioxidant properties when
cooked or boiled. This is the reason your physical education teacher back in
school always told you to eat your fruits and vegetables raw.
Who can benefit from antioxidant supplements?
Research has yet to give a concrete answer to this question. Many researchers
claim that elderly people, frequent aspirin users, heavy drinkers, smokers,
and people with impaired immune systems may benefit from taking antioxidant
supplements daily. Opinions on the preventative powers of these supplements
vary. The American Heart Association, for example, does not recommend depending
on supplements for heart prevention until more conclusive research has been
completed. One reason for the caution is that no one has proven that antioxidants,
and not some other, yet-to-be-discovered substance found in fruits and vegetables,
are responsible for the health benefits of these foods.
Are antioxidants toxic in high amounts?
Possibly. Vitamins A and E are fat-soluble vitamins. Unlike the water-soluble
vitamins C and B, which dissolve in water and are discharged from the body through
urine, excess amounts of vitamin A and E are stored in the liver and other fatty
tissues. Any “excesses” stored in these areas are potentially toxic in very
high amounts.
How can I make sure I get enough antioxidants?
Make sure your diet is rich in fruits, vegetables (especially the brightly
coloured ones!) and whole grains. If you fall into one of the above-mentioned
groups that may be low in antioxidants, speak to your doctor. He or she can
help you determine whether or not you are a candidate for antioxidant supplements.
Antioxidants and athletes
It is important for athletes to note that exercise induces oxidization and
free radical creation. Currently, there is not enough conclusive evidence to
support mandatory antioxidant supplementation in athletes. However, anyone extremely
physically active should make sure their diets are rich in vitamin E—just in
case.
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