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Getting
A Handle On Antioxidants
(A Color Guide For Selecting Foods By Specific Antioxidant Groups)
Author: Dr. Paul Gross
Meet the
"New-trients"
Today’s consumers are witnessing a new era in how foods are
identified. New nutrients, not commonly understood for their health
benefits, seem to be popping up on our grocer's shelves every
day. Omega fatty acids, newly defined sources of dietary fiber,
and antioxidant phytochemicals are examples of healthful plant
elements that are creeping into public media reports and water-cooler
debates.
Laboratory
and preliminary human clinical studies are revealing anti-disease
properties of these "nutrients.” Extensive food and
medical research underway presently will eventually translate
the chemical properties into consumer understanding and terminology
that we’ll grasp and use in everyday conversation.
With such
potential significance to public health, the consumer education
process should begin now in a way that people, from teenagers
to grandparents, can readily understand antioxidants as easily
as we now understand calories, carbohydrates, fat percentage,
and vitamin C.
The scientific
and regulatory bodies for food labeling have a great challenge
ahead of them. There are thousands of plant food sources with
suspected health benefits with complicated chemical names that
are unfamiliar and can be intimidating. The challenge at hand
is to decipher this blizzard of names and to promote better nutrition
for our families and for ourselves.
Why Antioxidants?
The beneficial
antioxidant chemicals that we get from colorful plant foods represent
our best defense against threatening oxidants. While oxidative
stress is a normal part of cellular metabolism that occurs even
in healthy people, left unchecked, it can lead to damage that
accumulates with age.
Normally,
oxidative species or "free radicals" are neutralized
by antioxidant enzymes and food-derived antioxidants. However,
the following circumstances can cause an imbalanced oxidant-antioxidant
relationship that allows oxidative stress to go unopposed.
• Contamination
by environmental conditions like pollution, radiation, cigarette
smoke and herbicides
•
Normal aging
•
Poor diets that lack essential nutrients and phytochemicals The
result of this imbalance is cell and tissue damage that could
lead to diseases like:
•
Cancer
• Hypertension
• Diabetes
• Chronic inflammation
• Neuronal degeneration like Alzheimer’s disease
The Color
Code for Antioxidants
Over the past
five years, we have begun a valuable process for recognizing plant
food antioxidant qualities by groupings of color—The Color
Code, as written in two books entitled The Color Code and What
Color is Your Diet? (publication information below).
The following
is a summary of those color guides for antioxidants, and an example
of how we can begin to classify and categorize the different antioxidants
into the food color code.
Summary
of the Color Code
This is a
general scheme of example foods that can fit into each color class.
Keep in mind that there are no firm lines between the classes,
which allows for overlap.
1. Red –
tomato, pink grapefruit, watermelon
2. Blue/Red/Purple/Black (BRPB) – blueberry, cherry, prune,
blackberry
3. Orange/Yellow – carrot, pumpkin, orange, papaya
4. Green – broccoli, kale, spinach, pea
5. White – garlic, onion, cabbage, turnip
6. Brown/Gray – spices, nuts, seeds, endogenous sources
How to
Apply the Color Code
Here’s
a general breakdown of the color groups that have food chemicals
with antioxidant qualities:
1. Enzymes
(Brown/Gray)
A protein substance with a name ending in "ase", enzymes
stimulate biochemical reactions in living cells and help form
new compounds that, in this case, would serve antioxidant functions.
Members of this enzyme class of antioxidants include:
• Superoxide dismutase
• Catalases
• Reductases
• Peroxidases
• Transferases
2. Vitamins
(Brown/Gray)
Most consumers would already recognize the three main antioxidant
vitamins - A, C and E - that are derived from food and supplements
common to the public. Vitamins A and E are fat-soluble, providing
antioxidant protection in cell structures like the outer membrane
and inner nuclear organelles. Vitamin C dissolves readily in body
water compartments, so it is well distributed in the body. Of
particular note is the important role of vitamin C in protecting
vitamins A and E from damaging oxidative free radicals.
3. Phenolics
(BRPB)
With more than 8,000 individual chemicals that serve plants as
pigments, the phenolics (also called phenols or polyphenols) are
water-soluble acids that not only give plants colors, but also
differentiate scents, tastes, and bitterness. The large class
of phenolics (called flavonoids) is often mentioned in current
public media. Quercetin, kaempferol and peonidin are examples
of flavonoids that have been in the news recently.
4. Carotenoids
(Orange/Yellow, Red)
A fat-soluble group of more than 600 individual chemicals, the
carotenoids (e.g., beta-carotene, lycopene, lutein and zeaxanthin
"zee-a-zan-thin") are especially powerful antioxidants.
Due to their chemical structure, they are an excellent source
of electrons that are aggressively sought by oxidative free radicals.
A carotenoid molecule donates electrons to a free radical, sacrificing
itself in antioxidant defense. Terpenes and xanthophylls are included
in this class.
5. Hormones
(Brown/Gray)
A growing field of medical research is identifying normal hormones
typically described with cell-to-cell messaging roles in the body
as having antioxidant functions. Presently only a few hormones
have this identified property such as melatonin, estradiol and
insulin, but future research will likely unravel similar functions
for the dozens of hormones known in human physiology.
6. Minerals
(All colors)
Minerals have elements that enable enzyme activity. Selenium,
zinc, manganese, magnesium and copper are minerals involved in
hundreds of antioxidant roles in the body.
7. Glutathione
(Brown/Gray)
Probably the human body’s single most important native antioxidant,
glutathione is a water-soluble molecule synthesized from food-derived
amino acids. It also depends on lipoic acid (below) for synthesis.
8. Lipid effectors
(Orange/Yellow)
Lipoic acid is perhaps the "perfect" antioxidant because
it is a small powerful molecule that dissolves readily both in
fatty layers of cells and in water – the only antioxidant
to do this. Other lipid oriented antioxidants include omega fatty
acids, tocopherols (like vitamin E), phytosterols, perillyl alcohol
and essential oils such as limonene.
9. Saponins,
steroids and stilbenes (Green, BRPB)
Related in this discussion only by their common first letter "s",
this group has established antioxidant functions and includes
some well-known chemicals such as resveratrol (a stilbene of red
wine and dark grapes), brassinosteroid (the growth regulator of
plants) and saponin (the waxy covering on plant leaves).
10. Sulfur-containing
chemicals (Green, White)
Including organosulfides, tri and diallyl sulfides and sulforaphane,
this group from plants like broccoli and cabbage has been shown
to have properties affecting antioxidant enzyme activity, inflammatory
mediators and tumor growth.
Proposing
an Antioxidant Nomenclature
Just as vitamins
have been given a nominal identity (Vitamin A, B, C…etc)
so too should we refer to antioxidants. This is a new system not
yet formally proposed to any regulatory authority or scientific
body. Classification of antioxidants must undergo the scrutiny,
revision and adoption by scientists, industry and government to
be acceptable for food label use in the public.
Here is the
proposed breakdown:
1. Antioxidant
C – carotenoids
2. Antioxidant E – enzymes
3. Antioxidant G – glutathione
4. Antioxidant H – hormones
5. Antioxidant L – lipid-associated chemicals
6. Antioxidant M – minerals
7. Antioxidant P – phenolics
8. Antioxidant S – saponins, steroids, stilbenes, sulfurs
9. Antioxidant V – vitamins
Over time,
the public must feel these proposed antioxidant classes are informative
and practical for understanding antioxidants and choosing preferred
foods. Time will tell, but this list gives us a simple working
structure to get a handle on naming antioxidants.
Reading
* Heber D. What Color Is Your Diet? HarperCollins, New York, 2001.
*
Joseph JA, Nadeau DA, Underwood A. The Color Code, Hyperion, New
York, 2002.
*
Lee J, Koo N, Min DB. Reactive oxygen species, aging, and antioxidative
nutraceuticals. Compreh. Rev. Food Sci. Food Safety 3:21-33, 2004.
Copyright 2006 Berry Health Inc.
| About
the Author: Dr. Paul Gross is a scientist and expert on
cardiovascular and brain physiology. A published researcher,
Gross recently completed a book on the Chinese wolfberry and
has begun another on antioxidant berries. Gross is founder
of Berry Health Inc, a developer of nutritional, berry-based
supplements. For more information, visit http://www.berrywiseonline.com |
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