jgpo@iwu1c.UUCP (John, KA9MNK) (01/21/84)
Sorry if this is a duplicate. I spent an hour entering the original and I
think postnews ate it. Now I get to type it all over again. [Mumble, grumble,
curse]
Since I amplified some of Chris Scussel's comments regarding Aspartame, a few
people have sent me mail requesting additional information regarding
phenylketonuria (PKU) and its relationship to the active ingredient in
Equal and NutraSweet. Since a couple of people were concerned about having
PKU and not knowing it, I decided to post this to the net, instead of replying
by mail, as PKU apparently is not well known to the general public and the
phenylalanine warning on Aspartame-containing products seems to be causing
undue concern.
SOURCE: The Merck "Manual of Diagnosis and Therapy," Twelfth Edition,
Merck Sharp & Dohme Research Laboratories, 1972
PKU is an "inborn error of metabolism characterized by elevation of blood
phenylalanine frequently associated with mental retardation." [Merck, p. 1111]
PKU is transmitted by a recessive gene and is caused by a deficiency of the
liver enzyme which breaks down phenylalanine. It occurs in 7 out of every
100,000 births in the USA, and is considerably less common among Blacks and
Ashkenazi Jews.
"During the first few weeks of life, there may be unusual irritability,
epileptic seizures, and vomiting. About one-fourth of these children show
generalized infantile eczema and another fourth have dry skin. Many have a
'mousy' smell as a result of phenylacetic acid in the urine and sweat.
Though there are many exceptions, phenylketonurics tend to have blue eyes,
blond hair, and fair skin." [Merck, p. 1111]
About two-thirds of children with PKU will show moderate to severe mental
retardation.
Diagnosis of PKU is by blood test and urinalysis. "In most states, all
newborn infants are tested for PKU to detect the condition before
significant [central nervous system] damage occurs. When the diagnosis
is confirmed, dietary treatment is started, so that mental retardation is
lessened or even prevented." [Merck, p.924]
"Phenylketonuric infants maintained on good treatment from the first few
weeks of life will usually achieve an I.Q. of about 95. Those started
on treatment at a later age will show poorer mental development. The
treatment can usually be discontinued after age 5 yr with no ill effects.
There appears to be little value in starting treatment in retarded
children aged 3 yr or more." [Merck, p. 1114]
"Elevations of serum phenylalanine can be controlled effectively by reducing,
but *not* [Merck's emphasis] eliminating this amino acid in the diet."
[Merck, p. 1115] Milk (very high in phenylalanine) is replaced by a
preparation such as "Lofenalac" and solid foods are evaluated by a system
of "phenylalanine equivalents." One equivalent equals 15 mg phenylalanine.
"For instance, 16 tablespoons of applesauce contains phenylalanine 15 mg,
or 1 equivalent. One medium baked potato contains phenylalanine 120 mg,
or 8 equivalents." [Merck, p. 1115] The child is monitored by weekly
or monthly blood tests, and the amount of phenylalanine equivalents in the
diet is modified to maintain the child's serum phenylalanine at normal
levels.
As can be seen, PKU is a disorder present at birth and sufficiently severe
that its presence going undetected is extremely unlikely. Also, judging
from the phenylalanine levels found in ordinary foods, it is my opinion
that the amounts of phenylalanine ingested through the consumption of
reasonable quantities of Aspartame-containing products are insufficient to
overwhelm the (normal) body's ability to break down this amino acid.
This item has been submitted for the general information of the net
readership and should not be construed as medical advice. If you have any
questions or concerns regarding PKU, Aspartame, or anything else of a
medical nature, please consult a physician. I have no connection, whatsoever,
with G. D. Searle or any soft drink or beverage manufacturer or distributor.
The opinions expressed are entirely my own and are not necessarily those of
my employer, AT&T Bell Laboratories.
Keep well,
John Opalko
AT&T Bell Laboratories, Naperville, IL
{whatever}!ihnp4!iwu1c!jgpo