Getting a Handle on Antioxidants (A color guide for selecting foods by specific antioxidant groups)

Getting a Handle on Antioxidants (A color guide for selecting foods by specific antioxidant groups)

By 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.

o Contamination by environmental conditions like pollution, radiation, cigarette smoke and herbicides

o Normal aging

o Poor diets that lack essential nutrients and phytochemicals

The result of this imbalance is cell and tissue damage that could lead to diseases like:

o Cancer

o Hypertension

o Diabetes

o Chronic inflammation

o 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:

o Superoxide dismutase

o Catalases

o Reductases

o Peroxidases

o 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.


* 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.

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

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