mcanalley b.h. and vennum e. introduction to glyconutritionals (abridged). glycoscience &...

McAnalley B.H. and Vennum E. Introduction to Glyconutritionals (Abridged). GlycoScience & Nutrition 2000; 1(1) 1-5.

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Introduction to Glyconutritionals

Bill H. McAnalley, Ph.D. and Eileen Vennum, RAC


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Science and medicine have long tried to break the biocode by which the cells of the body

communicate with one another.


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The four major classes of biomolecules are proteins,

nucleic acids, lipids (fats) and carbohydrates. For many years, scientists focused on proteins as

the primary communication molecules.


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In the 1960s, research first began to appear on glycoproteins*, protein molecules bound with

carbohydrate molecules.

*“Glyco” means “sweet” and refers to sugars, or carbohydrates.


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Glycoprotein molecules coat the surface of every cell with a nucleus in the human body.


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Glycolipids, carbohydrate molecules bound with lipid (fat) molecules, are another kind of glycoform, or glycoconjugate,

found on cell surfaces


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We now know that nature uses the carbohydrates on cell

surface glycoconjugates as communication molecules.


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Scientists have identified eight sugars found on human cell surface glycoforms that are involved in

cellular recognition processes.*

* Murray RK. Glycoproteins. In Murray RK, et al. (eds): Harper’s Biochemistry. Stamford, Appleton and Lange; 2000:677.


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Just as four different shapes can be combined to make many

letters, the different carbohydrate molecules combine within our bodies to make many cellular

recognition “words”.


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The significance of these sugar components of glycoproteins is well illustrated by the different blood types.


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What raw materials does the body use to build the sugars to make

glycoforms?

The plants in our diet are the primary building blocks for the sugar portion

of these molecules.


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Enzymes are the tools the body uses to build the “glyco” portion

of glycoforms. Figure E illustrates the enzymes needed to

convert one form of sugar to another in the body.


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The conversion process requires time and energy.


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The effectiveness of the enzymatic conversion system to create the needed sugar molecules is not

absolute. Some individuals have inborn errors of metabolism. The conversion process also requires

specific vitamins at certain steps, and these vitamins may be missing.


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Until now, the fields of glycobiology and nutrition

have never been adequately investigated together.


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Although current nutrition textbooks stress the importance of

essential vitamins, minerals, proteins (amino acids) and fats in great detail, sugars are currently recognized only as a source of

energy.


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Of the required eight sugars named in Harper’s Biochemistry, only glucose and galactose are addressed

in the classic nutrition texts.


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Glyconutritionals are dietary supplements designed to provide substrates for the body to use in

building the “glyco” portion of glycoconjugates on cell surfaces.

Glyconutritionals are designed to make the necessary sugars available to cells

quicker and in greater quantity.


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A November 1998 review concluded that disorders in glycosylation are

much more common than originally thought. The author stated: “There is scant information on the availability

of mannose in food, but dietary mannose is probably insufficient to

supply all glycosylation.*

*Freeze HH. Disorders in protein glycosylation and potential therapy: tip of an iceberg? J.Pediatr. 1998;133:593-600


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We have only just begun to understand the biochemical

story written in the sweet language of life, but what an exciting language to learn!

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