When two or more atoms are linked together, molecules result.
The human body is composed of substances like proteins, fats and
DNA, which are basically just large molecules with dozens, hundreds or
thousands of atoms bonded together.
Human organisms maintain their structure and function by
reactions and chemical composition. All the chemical reactions needed to
sustain life are known as metabolism.
In order that a molecule is stable, it must contain the right
amount of electrons. If the molecule loses an electron when it isn't supposed
to, it is possible that it turns into a free radical.
Free radicals are unstable, electrically charged molecules in
the cells. They can react with other molecules (like DNA) and damage
them. Free radicals can
potentially alter the structure and function of several cells (Halliwell, 1996; Gutteridge &
Halliwell, 2000).
They can even form chain reactions, where the molecules they
damage also turn into free radicals.
When a molecule loses an electron, it turns into a free radical.
The antioxidant molecule donates an electron to the free radical,
effectively neutralizing it. As a result, the neutralization by the
antioxidants prevents the free radicals from causing harm.
Free radicals are constantly being formed during metabolism. Without
the existence of antioxidants, they would destroy the human bodies very fast.
Nonetheless, it is important to keep in mind that free radicals
also serve important functions that are essential for the functioning of the
human's organism.
For example, the body's immune cells use free radicals to kill
bacteria that try to infect the human body.
Organisms need a certain balance. They need
the right amount of free radicals, and the right amount of
antioxidants to keep them in check.
When this balance gets disrupted, the human body can be effected
negatively.
When the free radicals (pro-oxidants)
outnumber the antioxidants,
the result can be a state called oxidative stress. Compelling evidence has emerged that
oxidative stress makes a significant contribution to a lot of diseases.
During oxidative stress, important molecules in the body can
become severely damaged and sometimes even resulting in cell death. Oxidative stress is defined as “a
condition that is characterized by accumulation of (...) oxidative damage to
molecules that threaten the normal function of the cell or the organism” (Blomhoff, 2005).
Several stress factors and lifestyle habits are known to promote
excessive free radical formation and oxidative stress:
· Air pollution
· Cigarette smoke
· Alcohol intake
· Toxins
· High blood sugar levels
· Consuming large amounts of polyunsaturated fatty acids
· Radiation, including excessive sunbathing
· Infections by bacteria, fungi or viruses
· Excessive intake of iron, magnesium, copper, or zinc
· Too little oxygen in the body
· Too much oxygen
in the body
· Intense and prolonged exercise, which causes tissue
damage
· Excessive intake of antioxidants, such as vitamins C
and E
· Antioxidant deficiency
Prolonged oxidative stress leads to
increased risk of negative health outcomes, such as cardiovascular disease and
certain types of cancer. It is also thought to contribute to the aging process.
An antioxidant enzyme is “a
protein that limits oxidative stress“.
It is hypothesized that
antioxidants originating from foods may work as antioxidants in their own right
in vivo, as well as bring about beneficial health effects through other mechanisms,
including acting as inducers of mechanisms related to antioxidant defense, longevity,
cell maintenance and DNA repair.
Antioxidants Are Essential for Life and
Are Found in All Sorts of Foods.
There is a huge variety of different
antioxidants found in foods.
In addition to the well-known
antioxidants, vitamin C, vitamin E, and selenium, there are numerous other
antioxidants in dietary plants.
The best (and healthiest) strategy to
ensure adequate intake of antioxidants, is a diet rich in various vegetables
and fruit, along with other healthy dietary habits.
Spices, herbs and
supplements include the most antioxidant rich products, shown in a lot of
studies.
The antioxidant defense has components that prevent radical
formation, remove radicals before damage can occur, repair oxidative damage,
and eliminate damaged molecules.
Dietary plants rich in antioxidants
include the vegetables broccoli, Brussels sprouts, cabbage, kale, cauliflower,
carrots, onions, tomatoes, spinach and garlic. Nuts and seeds are among
the food categories that include the most antioxidant-rich food items.
Walnuts
contain massive amounts of antioxidants.
Pecans, chestnuts, peanuts,
pistachios, and sunflower seeds are very rich in total
antioxidants.
Hazelnuts, almonds, Brazil
nuts, macadamias, pine kernels, cashew nuts, flax seeds, poppy seeds, and
sesame seeds contain significant amounts of total antioxidants.
Most of the spices and
herbs have particularly high antioxidant contents.
We interpret the
elevated concentration of antioxidants observed in several dried herbs compared
to fresh samples, as a normal consequence of the drying process leaving most of
the antioxidants intact in the dried end product. This tendency is also seen in
some fruits and their dried counterparts. Thus, dried herbs and fruit are
potentially excellent sources of antioxidants. Like the content of any food component, antioxidant values
will differ for a wide array of reasons, such as growing conditions, seasonal
changes and genetically different cultivars, storage conditions and differences
in manufacturing procedures and processing. Differences in unprocessed and
processed plant food samples are also seen in our study where processed berry
products like jam and syrup have approximately half the antioxidant capacity of
fresh berries.
At the end of the day, the best way to ensure that you get the right amount of antioxidants, is to eat a real food based diet that includes plenty of healthy fruits and vegetables.
