JOURNAL OF APPLIED
NUTRITION, VOLUME 36, NUMBER 1, 1984 REPORT ASPARTAME:
METHANOL AND THE PUBLIC HEALTH
DR. WOODROW C. MONTE
ABSTRACT
Aspartame (L-aspartyl-L-phenylalanine methyl ester),
a new sweetener marketed under the trade name NutraSweet*,
releases into the human bloodstream one molecule of
methanol for each molecule of aspartame consumed.
This new methanol source is being added to foods
that have considerably reduced caloric content and,
thus, may be consumed in large amounts. Generally,
none of these foods could be considered dietary methanol
sources prior to addition of aspartame. When diet
sodas and soft drinks, sweetened with aspartame, are
used to replace fluid loss during exercise and physical
exertion in hot climates, the intake of methanol can
exceed 250 mg/day or 32 times the Environmental Protection
Agency's recommended limit of consumption for this
cumulative toxin.
There is extreme variation in the human response
to acute methanol poisoning, the lowest recorded lethal
oral dose being 100 mg/kg with one individual surviving
a dose over ninety times this level. Humans, due perhaps
to the loss of two enzymes during evolution, are more
sensitive to methanol than any laboratory animal;
even the monkey is not generally accepted as a suitable
animal model. There are no human or mammalian studies
to evaluate the possible mutagenic, teratogenic, or
carcinogenic effects of chronic administration of
methyl alcohol.
The average intake of methanol from natural sources
varies but limited data suggests an average intake
of considerably less than 10 mg/day8. Alcoholics may
average much more, with a potential range of between
0 and 600 mg/day, depending on the source and in some
cases the quality of their beverages.
Ethanol, the classic antidote for methanol toxicity,
is found in natural food sources of methanol at concentrations
5 to 500,000 times that of the toxin (Table 1). Ethanol
inhibits metabolism of methanol and allows the body
time for clearance of the toxin through the lungs
and kidneys.
The question asked is whether uncontrolled consumption
of this new sweetener might increase the methanol
intake of certain individuals to a point beyond which
our limited knowledge of acute and chronic human methanol
toxicity can be extrapolated to predict safety.
