*NutraSweet is a trademark of
G.D. Searle & Co.
Director of the Food Science and Nutrition Laboratory
Arizona State University Tempe, Arizona 85287
ASPARTAME
Aspartame (L-aspartyl-L-phenylalanine methyl ester)
has recently been approved as a sweetener for liquid
carbonated beverages. It has had wide acceptance as
an additive in many dry food applications after Food
and drug Administration approval on July 24, 1981.
The Food and Drug Administration, Dr. Richard Wurtman
and myself have received well over a thousand written
complaints relative to aspartame consumption. By far,
the most numerous of these include dizziness, visual
impairment, disorientation, ear buzzing, high SGOT,
tunnel vision, loss of equilibrium, severe muscle
aches, numbing of extremities, pancreatitis, episodes
of high blood pressure, retinal hemorrhaging, menstrual
flow changes, and depression. The validity of these
complaints has yet to be scientifically evaluated.
However, a thorough knowledge of just what makes this
new sweetener stand apart from other nutritional substances
might aid physicians in making dietary recommendations
for their patients.
Aspartame (NutraSweet)* is a small molecule made
up of three components: Phenylalanine, aspartic acid,
and methanol (wood alcohol)47. When digested, these
components are released into the bloodstream.
Phenylalanine and aspartic acid are both amino acids
which are found in natural proteins, and under normal
circumstances are beneficial, if not essential, for
health. Proteins are complex molecules which contain
many chemically bonded amino acids. it takes several
enzymes to break these bonds and liberate the amino
acids. This is a slow process and the amino acids
area released gradually into the bloodstream. The
quaternary structure of protein also slows the digestion
of these amino acids: the amino acids in the center
of the protein molecule aren't released until the
outer layers of amino acids on the surface have been
swept away. This natural time release process saves
the body form large numbers of any one of the 21 amino
acids being released into the bloodstream at any one
time.
Aspartame requires the breaking of only two bonds
for absorptioin. This happens very quickly with the
potential to raise component blood levels rapidly.
The methyl ester bond of phenylalanine is the first
to cleave due to its susceptibility to pancreatic
enzymes. This is highly unusual; the methyl esters
associated with pectin for instance are completely
impervious to all human digestive enzymes.
